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Electrical and Electronics Engineering publications abstract of: 07-2014 sorted by title, page: 0
» 'New' solutions of Class-E power amplifier with finite dc feed inductor at any duty ratio
Abstract:
'New' Class-E solutions are proposed by varying three different design parameters which are introduced in the voltage and current equations in order to extend the Class-E 'design space', of which the 'new' solutions can apply to optimal and suboptimal operation. The design procedure of suboptimal Class-E power amplifier (PA) is analysed in details and then a suboptimal Class-E PA based on GaN HEMT CGH40010F is designed to prove the correctness of the 'new' solutions. The measured maximum output power of 39.6 dB, power-added-efficiency of 74.7% and drain efficiency of 78.9% were obtained at 2.6 GHz with a 28 dBm input power. These measurement results show that a similar or better level of efficiency and output power that are reported for optimal Class-E PAs at lower frequencies using the same transistor, and the presented 'new' solutions extend the 'design space' of Class-E PA. This paper give engineers more degrees of freedom to design Class-E PA.
Autors: Du, X.;Nan, J.;Chen, W.;Shao, Z.;
Appeared in: IET Circuits, Devices & Systems
Publication date: Jul 2014, volume: 8, issue:4, pages: 311 - 321
Publisher: IEEE
 
» 0.3–4.3 GHz Frequency-Accurate Fractional- Frequency Synthesizer With Integrated VCO and Nested Mixed-Radix Digital - Modulator-Based Divider Controller
Abstract:
If the modulus of the digital delta-sigma modulator (DΔΣM) in a fractional- frequency synthesizer is a power of two, then the output frequency is constrained to be a rational multiple of the phase detector frequency , where the denominator of the rational multiplier is a power of two. If the required output frequency is not related to in this way, one is forced to approximate the ratio by using a small programmable modulus DΔΣM or a very large power-of-two modulus. Both of these solutions involve additional hardware. Furthermore, the programmable modulus solution can suffer from spurs, while the large power of two lacks accuracy. This paper presents a new solution, based on mixed-radix algebra, where the required ratio is formed by combining two different moduli. The programmable modulus solves the accuracy problem, while the large power-of-two modulus minimizes the spur content. In addition, the phase detector can be clocked at high speed. This paper explains the theoretical foundations of the method, elaborates a design methodology, and presents measured results for an 0.18 µm SiGe BiCMOS prototype.
Autors: Kennedy, M.P.;Mo, H.;Fitzgibbon, B.;Harney, A.;Shanan, H.;Keaveney, M.;
Appeared in: IEEE Journal of Solid-State Circuits
Publication date: Jul 2014, volume: 49, issue:7, pages: 1595 - 1605
Publisher: IEEE
 
» 15 Gb/s index-coupled distributed-feedback lasers based on 1.3 μm InGaAs quantum dots
Abstract:
The static properties and large-signal modulation capabilities of directly modulated p-doped quantum-dot distributed-feedback lasers are presented. Based on pure index gratings the devices exhibit a side-mode-suppression ratio of 58 dB and optical output powers up to 34 mW. Assisted by a broad gain spectrum, which is typical for quantum-dot material, emission wavelengths from 1290 nm to 1310 nm are covered by the transversal and longitudinal single-mode lasers fabricated from the same single wafer. Thus, these lasers are ideal devices for on-chip wavelength division multiplexing within the original-band according to the IEEE802.3ba standard. 10 Gb/s data transmission across 30 km of single mode fiber is demonstrated. The maximum error-free data rate is found to be 15 Gb/s.
Autors: Stubenrauch, M.;Stracke, G.;Arsenijevic, D.;Strittmatter, A.;Bimberg, D.;
Appeared in: Applied Physics Letters
Publication date: Jul 2014, volume: 105, issue:1, pages: 011103 - 011103-4
Publisher: IEEE
 
» 2-D Non-Isolated Pixel 6/8 Modulation Code
Abstract:
In this paper, we introduce a 2-D non-isolated pixel modulation code to mitigate the problem of 2-D inter-symbol interference, the major obstacle of holographic data storage systems. The proposed modulation code does not allow a pixel to be isolated from its adjacent bits. We compare the bit error rate (BER) performance between the proposed and the conventional 6/8 balanced modulation codes. The proposed code shows better BER performance than that of the conventional 6/8 balanced code in a poor channel environment, such as large blur and misalignments.
Autors: Kim, B.;Lee, J.;
Appeared in: IEEE Transactions on Magnetics
Publication date: Jul 2014, volume: 50, issue:7, pages: 1 - 4
Publisher: IEEE
 
» 2014 MTT-S Graduate Student Fellowship Awards [Education News]
Abstract:
Autors: Crupi, G.;Kaul, R.;Li, C.;Brazil, T.;Gupta, R.;
Appeared in: IEEE Microwave Magazine
Publication date: Jul 2014, volume: 15, issue:5, pages: 118 - 121
Publisher: IEEE
 
» 21.5-to-33.4 GHz Voltage-Controlled Oscillator Using NMOS Switched Inductors in CMOS
Abstract:
To demonstrate the applicability of NMOS switched variable inductors in the millimeter wave frequencies, a 21.5 to 33.4 GHz wide tuning range LC voltage-controlled oscillator (LC-VCO) with frequency tunable output buffers that uses variable inductors is reported. The measured phase noise at 10 MHz offset of VCO fabricated in a 65 nm bulk CMOS process varies from to dBc/Hz. The oscillator core consumes 4 or 6 mA from a 1.2 V power supply. These correspond to a record 43.3% tuning range. ranges from to dBc/Hz. With tunable output buffers, the measured signal output power is above dBm across the entire frequencies.
Autors: Zhang, J.;Sharma, N.;O, K.K.;
Appeared in: IEEE Microwave and Wireless Components Letters
Publication date: Jul 2014, volume: 24, issue:7, pages: 478 - 480
Publisher: IEEE
 
» 3-10 GHz ultra wideband front-end transceiver in 0.13 μm complementary metal oxide semiconductor for low-power biomedical radar
Abstract:
A new integrated low-power, low-complexity ultra wideband (UWB) transceiver front-end in standard 130 nm complementary metal oxide semiconductor technology which can be used in UWB radar biomedical sensing applications is proposed in this study. The transceiver comprises of a full UWB band transmitter, an on-chip diplexer and a full UWB band receiver front-end. The transmitter generates Gaussian-pulse-modulated and rectangular-pulse-modulated signals at different carrier frequencies within the designated UWB by using a digitally controlled oscillator. The transmitter consumes an average power of 8 mW at a 10 MHz pulse rate. The on-chip diplexer has a 1 dB insertion loss and an isolation of -30 dB. Its switch is co-designed with the receiver's input matching network to optimise the power matching while achieving good noise performance. The receiver low noise amplifier has a 3-10 GHz input matching bandwidth with a power gain of 16 dB. The overall receiver front-end consumes an average power of 12 mW. The core area of the transceiver circuit is 500 μm by 1100 μm. The experiments show that the proposed radar transceiver can successfully detect a human respiration pattern within 50 cm. This novel design using a DCO-type UWB transceiver integrated with an on-chip diplexer demonstrates the use of the low power UWB radar detection in biomedical applications.
Autors: Wang, X.;Dinh, A.;Teng, D.;
Appeared in: IET Circuits, Devices & Systems
Publication date: Jul 2014, volume: 8, issue:4, pages: 272 - 279
Publisher: IEEE
 
» 3-D Holographic Data Storage Circuit Design
Abstract:
In this paper, we propose a 3-D holographic data storage circuit design. According to optical principle, holographic data storage and processing circuit are designed to record the holographic image and achieve 3-D holographic display. The circuit performs the rotation, mirror, and shift operation of holographic image and calibrates the stereo panoramic imaging system. In the system, multirate operating is adopted to achieve holographic image resizing. Simultaneously, holographic image calibration is performed to acheive smooth panoramic stereo image. After designing, the system provides fantasy 3-D holographic images that attract human attention.
Autors: Fan, Y.;Lu, C.;Syu, D.;Chen, S.;Shie, Y.;
Appeared in: IEEE Transactions on Magnetics
Publication date: Jul 2014, volume: 50, issue:7, pages: 1 - 5
Publisher: IEEE
 
» 3-D Image and Storage Applications
Abstract:
Autostereoscopic display with glass-free, wide viewing zone, and reality is recognized as future trend. In order to acquire 3-D content for multiview autostereoscopic images, we use the data obtained from 3-D laser scanner and 3-D cam-box for 3-D modeling. The advantage of 3-D cam-box is quick scanning to achieve a 3-D model, and the advantage of 3-D laser scanner is high resolution. In order to make the 3-D image contents quickly, the simulation-based image production process has been proposed for mass production of high quality 3-D image contents. The data storage capacity of multiview image will be multiple of regular 2-D image. The 3-D floating systems can be made by using either aspheric lens or Fresnel lens. For applications, we hope the aspheric lens with high producing cost will be replaced by Fresnel lens. We setup measurement methods to evaluate the optimization results of the 3-D floating image system. Some phenomena caused by lens distortion, such as illumination loss, crosstalk, and optimum viewing distance can degrade the quality of stereoscopic effect. Therefore, reducing lens distortion of optical system is a major problem of interest in 3-D floating image display systems.
Autors: Huang, D.;Jeng, T.;Hsiao, F.;Hong, C.;Chen, Y.;Chen, C.;
Appeared in: IEEE Transactions on Magnetics
Publication date: Jul 2014, volume: 50, issue:7, pages: 1 - 7
Publisher: IEEE
 
» 3-D Vertical Dual-Layer Oxide Memristive Devices
Abstract:
Dual-layer resistive switching memory devices with WOx switching layer formed at the sidewall of the horizontal electrodes have been fabricated and characterized. The devices exhibit well-characterized analog switching characteristics and small mismatch in electrical characteristics for devices formed at the two layers. The 3-D vertical device structure allows higher storage density and larger connectivity for neuromorphic computing applications. We show that the vertical devices exhibit potentiation and depression characteristics similar to planar devices, and can be programmed independently with no crosstalk between the layers.
Autors: Gaba, S.;Sheridan, P.;Du, C.;Lu, W.;
Appeared in: IEEE Transactions on Electron Devices
Publication date: Jul 2014, volume: 61, issue:7, pages: 2581 - 2583
Publisher: IEEE
 
» 3D imaging using narrowband bistatic MIMO radar
Abstract:
A new method for three-dimensional (3D) imaging via a narrowband bistatic multiple-input??multiple-output (MIMO) radar with two uniform rectangular arrays is presented. After matched filtering and phase compensation, the method utilises the 2D cross-range images measured by the transmit and receive arrays to reconstruct the 3D image of the target. Compared with the 3D wideband monostatic MIMO imaging, lower hardware cost can be achieved since the narrowband waveforms are employed. In addition, the range alignment in wideband imaging can be avoided for the poor range resolution of the narrowband waveforms.
Autors: Yang, J.;Su, W.;Gu, H.;
Appeared in: Electronics Letters
Publication date: Jul 2014, volume: 50, issue:15, pages: 1090 - 1092
Publisher: IEEE
 
» 3GPP LTE Random Access Channel Self-Optimization
Abstract:
This paper addresses self-optimization of the random access channel (RACH) in the Third-Generation Partnership Project (3GPP) Long-Term Evolution (LTE). Ensuring satisfactory random access (RA) performance in terms of access delay (AD) is crucial for reducing the delays associated with initial access and handovers. The feasibility of self-optimization is investigated by means of simulations, where the coupling between several parameters and the RACH performance in terms of AD is provided. We present two candidate feedback control algorithms that automatically adjust key RACH parameters to meet specified AD targets.
Autors: Amirijoo, M.;Gunnarsson, F.;Andren, F.;
Appeared in: IEEE Transactions on Vehicular Technology
Publication date: Jul 2014, volume: 63, issue:6, pages: 2784 - 2793
Publisher: IEEE
 
» 40 Gbit/s pulsed RZ-BPSK transmission with a 40 GHz self-pulsated distributed feedback laser diode Mach??Zehnder intensity modulator link
Abstract:
A self-starting pulsed encoding of a Mach?? Zehnder intensity modulator (MZM) is demonstrated to generate a 40 Gbit??s return-to-zero binary phase-shiftedkeying (RZ-BPSK) data stream by using the optoelectronic feedback loop. By driving the MZM with an optoelectronic oscillator, both the electrical clock and the optical pulse train at 40 GHz can be extracted to deliver and trigger the synthesizer-free 40 Gbit??s RZ-BPSK data. The pulsed RZ carrier with a pulsewidth of 10.5 ps provides a jitter as low as 150 fs and an extinction ratio as high as 7.8 dB, which is particularly suitable for the RZ-BPSK transmission at 40 Gbit??s. The back-to-back transmitted synthesizerfree 40 Gbit??s RZ-BPSK data with a pattern length of 223 - 1 reveals a receiving power sensitivity of ??16.3 dBm at the requested bit error rate of 10??9 by setting the DC bias of the BPSK demodulator at 3.76 V. After 25 km single-mode-fiber transmission, the RZ-BPSK data indicates a power penalty of 4 dB when compared with the back-to-back case.
Autors: Chi, Y.-C.;Wang, H.-Y.;Cheng, C.-H.;Lin, G.-R.;
Appeared in: IEEE/OSA Journal of Optical Communications and Networking
Publication date: Jul 2014, volume: 6, issue:7, pages: 610 - 618
Publisher: IEEE
 
» 802 LAN/MAN Standards: High Quality and Market Relevant
Abstract:
This column provides an overview of the 802 LAN/MAN Standards Committee over the past 34 years and postulates reasons for its success.
Autors: Nikolich, Paul;
Appeared in: Computer
Publication date: Jul 2014, volume: 47, issue:7, pages: 93 - 95
Publisher: IEEE
 
» 88- A 1-MHz Stray-Insensitive CMOS Current-Mode Interface IC for Differential Capacitive Sensors
Abstract:
The paper describes an innovative technique to implement a low-power high-speed CMOS interface circuit for differential capacitive sensors. The proposed approach comprises a capacitance to current converter providing current-summing and current-differencing capability. It also exploits an autotuning feedback loop to control the common-mode current, thereby ensuring virtually the same maximum sensitivity and measure accuracy irrespectively of the input parasitic capacitance. Therefore, the main limitation of all previous current-mode techniques is nearly eliminated. Besides, as an additional distinctive aspect, the proposed solution is suitable for both linear- and hyperbolic-type capacitive sensors. To validate the idea an interface circuit was designed in a 65-nm CMOS technology powered from a 2.5-V supply and dissipating 88- A standby current. Measurements show that relative capacitive sensor variations up to fF ( of the nominal value) even in presence of a large parasitic capacitance of 2.5 pF are detected in less than 1 s with a sensitivity of about 5 nA/fF and with an relative error lower than , without requiring digital calibration.
Autors: Scotti, G.;Pennisi, S.;Monsurro, P.;Trifiletti, A.;
Appeared in: IEEE Transactions on Circuits and Systems I: Regular Papers
Publication date: Jul 2014, volume: 61, issue:7, pages: 1905 - 1916
Publisher: IEEE
 
» -Channel Oversampled Graph Filter Banks
Abstract:
This paper proposes -channel oversampled filter banks for graph signals. The filter set satisfies the perfect reconstruction condition. A method of designing oversampled graph filter banks is presented that allows us to design filters with arbitrary parameters, unlike the conventional critically sampled graph filter banks. The oversampled graph Laplacian matrix is also introduced with a discussion of the entire redundancy of the oversampled graph signal processing system. The practical performance of the proposed filter banks is validated through graph signal denoising experiments.
Autors: Tanaka, Y.;Sakiyama, A.;
Appeared in: IEEE Transactions on Signal Processing
Publication date: Jul 2014, volume: 62, issue:14, pages: 3578 - 3590
Publisher: IEEE
 
» In-Situ Silver Nanoparticle Formation on Surface-Modified Polyetherimide Films
Abstract:
This paper extends the scope of a novel process previously reported by the group for the hydrolysis and subsequent metallization of polyimide substrates to encompass polyetherimide. Silver nanoparticles are grown in-situ by chemical reduction of silver ions implanted in the substrate. Factors affecting the level of hydrolysis are investigated, with temperature of the hydrolyzing solution found to be the key factor. The presence of silver nanoparticles is also confirmed by X-ray diffraction.
Autors: Watson, D.E.;Ng, J.H.;Aasmundtveit, K.E.;Desmulliez, M.P.Y.;
Appeared in: IEEE Transactions on Nanotechnology
Publication date: Jul 2014, volume: 13, issue:4, pages: 736 - 742
Publisher: IEEE
 
» SymbexNet: Testing Network Protocol Implementations with Symbolic Execution and Rule-Based Specifications
Abstract:
Implementations of network protocols, such as DNS, DHCP and Zeroconf, are prone to flaws, security vulnerabilities and interoperability issues caused by developer mistakes and ambiguous requirements in protocol specifications. Detecting such problems is not easy because (i) many bugs manifest themselves only after prolonged operation; (ii) reasoning about semantic errors requires a machine-readable specification; and (iii) the state space of complex protocol implementations is large. This article presents a novel approach that combines symbolic execution and rule-based specifications to detect various types of flaws in network protocol implementations. The core idea behind our approach is to (1) automatically generate high-coverage test input packets for a network protocol implementation using single- and multi-packet exchange symbolic execution (targeting stateless and stateful protocols, respectively) and then (2) use these packets to detect potential violations of manual rules derived from the protocol specification, and check the interoperability of different implementations of the same network protocol. We present a system based on these techniques, SymbexNet, and evaluate it on multiple implementations of two network protocols: Zeroconf, a service discovery protocol, and DHCP, a network configuration protocol. SymbexNet is able to discover non-trivial bugs as well as interoperability problems, most of which have been confirmed by the developers.
Autors: Song, J.;Cadar, C.;Pietzuch, P.;
Appeared in: IEEE Transactions on Software Engineering
Publication date: Jul 2014, volume: 40, issue:7, pages: 695 - 709
Publisher: IEEE
 
» A 0.039 mm Inverter-Based 1.82 mW 68.6 dB-SNDR 10 MHz-BW CT- -ADC in 65 nm CMOS Using Power- and Area-Efficient Design Techniques
Abstract:
We present design techniques for the realization of compact, low-power CT- -ADCs in ultra-deep-submicron CMOS: A resonant single-opamp third-order integrator with loss compensation, an inverter-based opamp with digitally assisted biasing and common mode control, a pseudo-differential modulator topology with quasi-1.5-bit quantization, a jitter-noise-reduction DAC with NRZ pulse shape, a mismatch-tolerant IIR quantizer, linearized single-ended FIR-DACs with passive DT compensation, and a rail-to-rail dynamic latched comparator. A highly compact 41.4 fJ/conv.-step, 77 dB-SFDR, 1.1 V ADC has been implemented to prove these concepts. The entire active analog circuitry in this minimalistic third-order modulator consists of only ten CMOS inverters.
Autors: Zeller, S.;Muenker, C.;Weigel, R.;Ussmueller, T.;
Appeared in: IEEE Journal of Solid-State Circuits
Publication date: Jul 2014, volume: 49, issue:7, pages: 1548 - 1560
Publisher: IEEE
 
» A 0.14- 1.4-mW 59.4-dB-SFDR 2.4-GHz ZigBee/WPAN Receiver Exploiting a “Split-LNTA + 50% LO” Topology in 65-nm CMOS
Abstract:
Pub DtlA compact low-power 2.4-GHz ZigBee/wireless personal area network receiver is reported. It optimizes passive pre-gain with an inverter-based split low-noise transconductance amplifier (split-LNTA) to avoid the RF balun and its associated insertion loss, while enabling isolated in-phase (I)/quadrature (Q) passive mixing. The latter essentially saves power as a 50%-duty-cycle local oscillator (50% LO) can be generated more efficiently than its 25% counterpart. Specifically, a 2.4-GHz LC voltage-controlled oscillator (VCO) followed by an input-impedance-boosted Type-II RC-CR network produces the desired 50% four-phase LO with optimized power, I/Q accuracy, and phase noise. We also analytically compare the proposed “split-LNTA 50% LO” architecture with the existing “single-LNTA 25% LO,” identifying their distinct features under current- and voltage-mode operations. The receiver fabricated in 65-nm CMOS exhibits 32-dB voltage gain, 8.8-dB noise figure (NF) and out-band input-referred third-order intercept point that correspond to 59.4-dB spurious-free dynamic range. The VCO measures phase noise at 3.5-MHz offset. The achieved power (1.4 mW) and area (0.14 ) efficiencies are favorably comparable with the state-of-the-art.
Autors: Lin, Z.;Mak, P.-I.;Martins, R.P.;
Appeared in: IEEE Transactions on Microwave Theory and Techniques
Publication date: Jul 2014, volume: 62, issue:7, pages: 1525 - 1534
Publisher: IEEE
 
» A 0.54 THz Signal Generator in 40 nm Bulk CMOS With 22 GHz Tuning Range and Integrated Planar Antenna
Abstract:
This work presents the design and measurements of a 0.54 THz signal generator implemented in a 40 nm bulk CMOS technology. An LC-VCO operating at 180 GHz is connected to a nonlinear buffer, which is designed to generate the wanted third harmonic at 540 GHz. The third harmonic is coupled via a transformer to the output. The developed techniques are implemented on two different chips: one with a probe pad for on-wafer measurements and one with an on-chip planar dipole. The measured peak output power using a WR-1.5 probe is 31 dBm at 543 GHz, for 16.8 mW of dc power consumption. By changing value of the parasitic I-MOS varactors of the LC-VCO (“parasitic tuning”), the output frequency can be tuned from 561.5 to 539.6 GHz, resulting in a 21.9 GHz tuning range, which is the highest reported so far for CMOS THz oscillators. The 3-dB output bandwidth is 5.5 GHz. The 540 GHz signal generator with on-chip antenna is used for THz imaging without the use of substrate or focusing lenses, demonstrating some of the capabilities of CMOS for low-cost, mass-produced THz imagers.
Autors: Steyaert, W.;Reynaert, P.;
Appeared in: IEEE Journal of Solid-State Circuits
Publication date: Jul 2014, volume: 49, issue:7, pages: 1617 - 1626
Publisher: IEEE
 
» A 10–67 GHz 1.44 mW 20.7 dB Gain VGA-Embedded Downconversion Mixer With 40 dB Variable Gain Range
Abstract:
A high gain low power variable gain downconversion mixer is presented here. In a conventional mixer, its conversion gain is limited by the load impedance due to limited voltage supply. In addition, accurate conversion gain control is challenging due to DC-offset and various parasitic effects.
Autors: Boon, C.C.;Yi, X.;
Appeared in: IEEE Microwave and Wireless Components Letters
Publication date: Jul 2014, volume: 24, issue:7, pages: 466 - 468
Publisher: IEEE
 
» A 120 GHz Fully Integrated 10 Gb/s Short-Range Star-QAM Wireless Transmitter With On-Chip Bondwire Antenna in 45 nm Low Power CMOS
Abstract:
In this paper, a fully integrated -band transmitter with on-chip dipole bondwire antenna implemented in 45 nm low-power CMOS is presented. The purpose of this 120 GHz wireless connector is to provide a high-speed short-range wireless communication link. On-chip frequency generation, insensitive to VCO pulling, is integrated together with a direct carrier quadrature vector modulator, ASK modulator, four-stage differential transformer-coupled power amplifier, and bondwire antenna. A -bit PRBS generator, capable of generating three parallel bit streams at a clock frequency of 8 GHz, is integrated on the same chip for measurement purposes. The transmitter is capable of efficiently generating BPSK, QPSK, and Star-QAM modulation formats. Data transmission over a distance up to 1 m is achieved for data rates as high as 2 Gb/s. For shorter distances, data rates up to 10 Gb/s are measured.
Autors: Deferm, N.;Reynaert, P.;
Appeared in: IEEE Journal of Solid-State Circuits
Publication date: Jul 2014, volume: 49, issue:7, pages: 1606 - 1616
Publisher: IEEE
 
» A 128-Stage Analog Accumulator for CMOS TDI Image Sensor
Abstract:
The impacts of parasitic phenomenon on the performance of the analog accumulator in CMOS TDI image sensor are analyzed in this paper, and a modified accumulator with decoupling capacitor to combat the parasitic phenomenon is also proposed. A 128-stage modified accumulator is designed and simulated. A prototype 1024 128 CMOS TDI image sensor with the 128-stage modified accumulator is fabricated in 0.18- m one-poly four-metal 1.8 V/3.3 V CMOS technology. With a line rate of 3875 lines/s, at 128 stages the measured sensitivity and SNR improvement of the fabricated sensor are 617.1 V/lux•s and 16.6 dB respectively. The simulation and experiment results have proved the effectiveness of the decoupling capacitor when combating the parasitic phenomenon in the analog accumulator. The proposed modified accumulator is suitable for application in CMOS TDI image sensor with high stages.
Autors: Nie, K.;Yao, S.;Xu, J.;Gao, J.;Xia, Y.;
Appeared in: IEEE Transactions on Circuits and Systems I: Regular Papers
Publication date: Jul 2014, volume: 61, issue:7, pages: 1952 - 1961
Publisher: IEEE
 
» A 19 dBm, 15 Gbaud, 9 bit SOI CMOS Power-DAC Cell for High-Order QAM W-Band Transmitters
Abstract:
A mm-wave I-Q power-DAC is reported at -band. The circuit, which is fabricated in a 45 nm SOI CMOS technology, employs a series-stacked Gilbert-cell output stage with gate finger geometry segmentation to directly modulate a 85–95 GHz carrier. The Gilbert-cell provides phase inversion and 7 bits for ASK envelope modulation, each of which can be switched at speeds up to 15 Gb/s. A ninth bit turns the entire DAC cell on and off at 15 Gb/s, as needed to create an arbitrary 15 Gbaud QAM constellation in a symmetrical 4×4 I–Q power-DAC transmitter array, with free-space power combining and antenna-level segmentation. The measured output power and PAE of the I or Q DAC cells are 19 dBm and 8.9%, respectively. Three effective bits of amplitude resolution and one phase bit are estimated from the small-signal S-parameter measurements in the 80–95 GHz range. The envelope amplitude resolution reduces to only two effective bits under saturated output power operation. The OOK bit provides over 45 dB of measured attenuation and dynamic range, relative to the peak output power.
Autors: Shopov, S.;Balteanu, A.;Voinigescu, S.P.;
Appeared in: IEEE Journal of Solid-State Circuits
Publication date: Jul 2014, volume: 49, issue:7, pages: 1653 - 1664
Publisher: IEEE
 
» A 2.56 Gb/s Soft RS (255, 239) Decoder Chip for Optical Communication Systems
Abstract:
Due to high transmission rate requirement for optical communication systems, the growing uncertainty of received signals results in the limited transmission distance. In this paper, a decision-confined soft RS decoder chip is proposed to enhance the error correcting performance with area-efficient architectures. Instead of generating numerous possible candidate codewords and determining the most likely one as output codeword, our approach produces only one codeword by confining the degree of error location polynomial. Therefore, hardware complexity is significantly reduced by eliminating decision making unit. Moreover, an iteration-reduced RiBM algorithm is provided to enlarge the coding gain by using more least reliable positions (LRPs) in the limited operation latency. According to simulation results, our proposed soft RS (255, 239; 8) decoder with 5 LRPs outperforms 0.4 dB at codeword error rate (CER) as compared to hard RS decoders. Implemented in standard CMOS 90 nm technology, the soft decoder chip can achieve 2.56 Gb/s throughput with similar complexity as a hard decoder. It can fit well for 10–40 Gb/s with 16 RS decoders in optical fiber systems and 2.5 Gb/s GPON applications.
Autors: Lin, Y.-M.;Hsu, C.-H.;Chang, H.-C.;Lee, C.-Y.;
Appeared in: IEEE Transactions on Circuits and Systems I: Regular Papers
Publication date: Jul 2014, volume: 61, issue:7, pages: 2110 - 2118
Publisher: IEEE
 
» A 246 GHz Hetero-Integrated Frequency Source in InP-on-BiCMOS Technology
Abstract:
A 246 GHz source in InP-on-BiCMOS technology is presented. It consists of a voltage controlled oscillator (VCO) in BiCMOS technology and a frequency tripler in transferred-substrate InP-HBT technology, which is integrated on top of the BiCMOS MMIC in a wafer-level bonding process. The VCO operates at 82 GHz with 6 dBm output power and the combined circuit delivers at 246 GHz, with a phase noise of at 2 MHz offset. To the knowledge of the authors, this is the first hetero-integrated signal source in this frequency range reported so far. The results illustrate the potential of the hetero integrated process for sub-mm-wave frequencies.
Autors: Hossain, M.;Kraemer, T.;Ostermay, I.;Jensen, T.;Janke, B.;Borokhovych, Y.;Lisker, M.;Glisic, S.;Elkhouly, M.;Borngraeber, J.;Tillack, B.;Meliani, C.;Krueger, O.;Krozer, V.;Heinrich, W.;
Appeared in: IEEE Microwave and Wireless Components Letters
Publication date: Jul 2014, volume: 24, issue:7, pages: 469 - 471
Publisher: IEEE
 
» A 26–28-Gb/s Full-Rate Clock and Data Recovery Circuit With Embedded Equalizer in 65-nm CMOS
Abstract:
This paper presents a power and area efficient approach to embed a continuous-time linear equalizer (CTLE) within a clock and data recovery (CDR) circuit implemented in 65-nm CMOS. The merged equalizer/CDR circuit achieves full-rate operation up to 28 Gb/s while drawing 104 mA from a 1-V supply and occupying 0.33 mm . Current-mode-logic (CML) circuits with shunt peaking loads using customized differential pair layout are used to maximize circuit bandwidth. To minimize the area penalty, differential stacked spiral inductors (DSSIs) are employed extensively. A novel and practical methodology is introduced for designing DSSIs based on single-layer inductors provided in foundry process design kits (PDK). The DSSI design increases the inductance density by over 3 times and the self-resonance frequency by 20% compared to standard single-layer inductors in the PDK. The measured BER of the recovered data by the CDR is less than at 27 Gb/s for 400 mV pseudo-random binary sequence (PRBS) as input data. The measured rms jitter of the recovered clock and data are 1.0 and 2.6 ps, respectively. The CDR is able to lock to inputs ranging from 26 to 28 Gb/s with PRBS pattern. Measurement results show that with the equalizer enabled, the CDR can recover a 26-Gb/s PRBS data with after a channel with 9-dB loss at 13 GHz.
Autors: Sun, L.;Pan, Q.;Wang, K.-C.;Yue, C.P.;
Appeared in: IEEE Transactions on Circuits and Systems I: Regular Papers
Publication date: Jul 2014, volume: 61, issue:7, pages: 2139 - 2149
Publisher: IEEE
 
» A 4.1-mW 3.5-GS/s 6-Bit Time-Interleaved ADC in 40-nm CMOS
Abstract:
This brief presents an improved timing scheme for a 4 interleaved 6-bit pipelined binary search (PLBS) analog-to-digital converter (ADC). The individual channel consists of a calibrated fully dynamic PLBS architecture with a 1-bit folding front-end. This work enhances the ADC conversion rate up to 3.5 GS/s, for 4.1-mW power consumption. The peak spurious-free dynamic range and signal-to-noise-plus-distortion ratio (SNDR) are 44.1 and 31.2 dB, respectively, measured for low input frequency. With near-Nyquist input frequency, the SNDR drops to 29.5 dB, yielding an energy-per-conversion step of 48 fJ. The prototype has been fabricated in a 40-nm low-power digital CMOS process. The ADC active area is .
Autors: Spagnolo, A.;Verbruggen, B.;Wambacq, P.;D'Amico, S.;
Appeared in: IEEE Transactions on Circuits and Systems II: Express Briefs
Publication date: Jul 2014, volume: 61, issue:7, pages: 466 - 470
Publisher: IEEE
 
» A 60 GHz Low Phase Variation Variable Gain Amplifier in 65 nm CMOS
Abstract:
This letter presents a 57–66 GHz low phase variation variable gain amplifier (VGA) in standard RF 65 nm CMOS process with a chip area of 0.25 mm . The phase compensation is achieved by using the different trends of phase between current-steering and splitting-cascade topologies. This VGA achieves the phase variation lower than 7 with 33 dB gain control range (GCR). The 3 dB bandwidth is from 50 to 70 GHz with 21 dB peak gain.
Autors: Siao, D.-S.;Kao, J.-C.;Wang, H.;
Appeared in: IEEE Microwave and Wireless Components Letters
Publication date: Jul 2014, volume: 24, issue:7, pages: 457 - 459
Publisher: IEEE
 
» A 700- V Junction-Isolated Triple RESURF LDMOS With N-Type Top Layer
Abstract:
A junction-isolated triple RESURF (JITR) LDMOS with high breakdown voltage (BV) and low specific on-resistance ( ) is proposed in this letter. Compared with the conventional triple RESURF (CTR) LDMOS, the new structure features a highly doped n-type top (N-top) layer at the surface of N-well, providing a low on-resistance surface conduction path in the on-state. The experimental result demonstrates that low and high BV of above 730 V are achieved by the JITR LDMOS. of the JITR LDMOS is about 15%–24.3% lower than that of the CTR LDMOS. The JITR LDMOS with horizontal N-toplayer and P-buried layer resembles a super junction (SJ) LDMOS. Compared with the reported SJ LDMOS, the SJ layer of JITR LDMOS is formed in the longitudinal direction instead of the width direction, and the proposed JITR LDMOS exhibits almost the highest BV and high power figure of merit (FOM, defined as BV ) in comparison to the published SJ LDMOS.
Autors: Qiao, M.;Li, Y.;Zhou, X.;Li, Z.;Zhang, B.;
Appeared in: IEEE Electron Device Letters
Publication date: Jul 2014, volume: 35, issue:7, pages: 774 - 776
Publisher: IEEE
 
» A -band High LO-to-RF Isolation Triple Cascode Mixer With Wide IF Bandwidth
Abstract:
A -band triple cascode down conversion mixer using a 0.15- pseudomorphic high-electron mobility transistor process is proposed in this paper. Due to the utilization of modified bias topology, resistive mixing core, and IF low-pass filter, this circuit has a very wide IF bandwidth. Moreover, the triple cascode structure is used in this mixer for high local oscillator (LO)-to-RF isolation and compact chip area. The measured results illustrate that the mixer achieves 9–13-dB upper sideband conversion loss with dc-to-26-GHz IF bandwidth, and the LO-to-IF, LO-to-RF, and RF-to-IF isolation are 38, 42, and 40 dB, respectively with 5-dBm LO power at 86 GHz. When the LO power is 7 dBm at 96 GHz, the upper sideband conversion loss is 10–14 dB with dc-to-24-GHz IF bandwidth, and LO-to-IF, LO-to-RF, and RF-to-IF isolation are 29, 41.5, and 45 dB, respectively. The power consumption is 24 mW and chip area is 1 .
Autors: Kao, J.-C.;Lin, K.-Y.;Chiong, C.-C.;Peng, C.-Y.;Wang, H.;
Appeared in: IEEE Transactions on Microwave Theory and Techniques
Publication date: Jul 2014, volume: 62, issue:7, pages: 1506 - 1514
Publisher: IEEE
 
» A Brief History of Metal-Clad Switchgear [History]
Abstract:
Metal-clad switchgear has been a workhorse of medium-voltage distribution systems, both industrial and utility, for nearly 80 years. While changes in this equipment have not been nearly as frequent as in some other types of equipment, such as variable-frequency electronic drives, during that period, there were many developments in the design and application of metal-clad switchgear. However, since it has a normal service life of 40 years or so, rapid change in equipment design is not demanded by the users.
Autors: Bridger, B.;Brusso, B.;
Appeared in: IEEE Industry Applications Magazine
Publication date: Jul 2014, volume: 20, issue:4, pages: 7 - 81
Publisher: IEEE
 
» A Broadband Model Over 1–220 GHz for GSG Pad Structures in RF CMOS
Abstract:
A broadband model for ground-signal-ground (GSG) pad structures in RF CMOS is presented. The inductive parasitics of the S- and G-pads are considered. Fringe capacitors are introduced to capture the nonideal capacitive parasitics of the S-pad. A method to analytically extract the model parameters is proposed. The model renders excellent agreement with the measured and simulated data over 1–220 GHz, for a GSG pad structure manufactured in TSMC 90-nm RF CMOS technology.
Autors: Liu, J.;Yu, Z.;Sun, L.;
Appeared in: IEEE Electron Device Letters
Publication date: Jul 2014, volume: 35, issue:7, pages: 696 - 698
Publisher: IEEE
 
» A brush-shaped air plasma jet operated in glow discharge mode at atmospheric pressure
Abstract:
Using ambient air as working gas, a direct-current plasma jet is developed to generate a brush-shaped plasma plume with fairly large volume. Although a direct-current power supply is used, the discharge shows a pulsed characteristic. Based on the voltage-current curve and fast photography, the brush-shaped plume, like the gliding arc plasma, is in fact a temporal superposition of a moving discharge filament in an arched shape. During it moves away from the nozzle, the discharge evolves from a low-current arc into a normal glow in one discharge cycle. The emission profile is explained qualitatively based on the dynamics of the plasma brush.
Autors: Li, Xuechen;Bao, Wenting;Jia, Pengying;Di, Cong;
Appeared in: Journal of Applied Physics
Publication date: Jul 2014, volume: 116, issue:2, pages: 023302 - 023302-6
Publisher: IEEE
 
» A CAD-Based Tool for Calculating Power Deposition on Tokamak Plasma-Facing Components
Abstract:
The SMARDDA software library is used to model plasma interaction with complex engineered surfaces. A simple flux-tube model of power deposition necessitates the following of magnetic fieldlines until they intersect the geometry taken from a computer aided design (CAD) database. Application is made to: 1) models of ITER tokamak limiter geometry and 2) MAST-U tokamak divertor designs, illustrating the accuracy and effectiveness of SMARDDA, even in the presence of significant nonaxisymmetric ripple field. SMARDDA's ability to exchange data with CAD databases and its speed of execution also gives it the potential for use directly in the design of tokamak plasma-facing components.
Autors: Arter, W.;Riccardo, V.;Fishpool, G.;
Appeared in: IEEE Transactions on Plasma Science
Publication date: Jul 2014, volume: 42, issue:7, pages: 1932 - 1942
Publisher: IEEE
 
» A Charge-Trapping Model for the Fast Component of Positive Bias Temperature Instability (PBTI) in High- Gate-Stacks
Abstract:
We propose a physical model for the fast component ( s) of the positive bias temperature instability (PBTI) process in SiOx/HfO2 gate-stacks. The model is based on the electron-phonon interaction governing the trapping/emission of injected electrons at the preexisting defects in the dielectric stack. The model successfully reproduces the experimental time dependences of the shift on both stress voltage and temperature. Simulations allow the extraction of the physical characteristics of the defects contributing to PBTI, which are found to match those assisting the leakage current in these stacks (i.e., oxygen vacancies).
Autors: Vandelli, L.;Larcher, L.;Veksler, D.;Padovani, A.;Bersuker, G.;Matthews, K.;
Appeared in: IEEE Transactions on Electron Devices
Publication date: Jul 2014, volume: 61, issue:7, pages: 2287 - 2293
Publisher: IEEE
 
» A Circular Polarization Selective Surface Implemented on a Flexible Substrate
Abstract:
A new technique to realize a circular polarization selective surface (CPSS) implemented with Pierrot cells is proposed. This technique uses a folded flexible substrate, which enables the implementation of the 3D Pierrot cells on a single metal layer defined with precision printed circuit board techniques, without the need for metallized via holes. A left-hand CPSS is designed to illustrate the benefits of the proposed approach. For the fabricated prototype, the measured characteristics at normal incidence are in good agreement with simulations results obtained with HFSS. It is shown that compared to other Pierrot cell designs presented in the literature, this new approach simplifies the fabrication process while giving similar performance.
Autors: Lopez, I.;Laurin, J.-J.;
Appeared in: IEEE Transactions on Antennas and Propagation
Publication date: Jul 2014, volume: 62, issue:7, pages: 3847 - 3852
Publisher: IEEE
 
» A Circularly Polarized Multiple Radiating Mode Microstrip Antenna for Satellite Receive Applications
Abstract:
A beam peak and null steering multiple radiating mode based microstrip patch antenna is presented for satellite receive applications operating at L1 Global Positioning System (GPS) band. Two collocated microstrip patch antennas were designed to produce and radiating modes. These orthogonal and circularly polarized radiation patterns were combined enabling full hemispherical steering of a single beam peak and null. Using theoretical analysis and full-wave simulation, the multimode aperture was designed to operate over a 25 MHz bandwidth centered at 1.575 GHz, which covers the L1 GPS band. Impedance and radiation pattern measurements of the passive antenna aperture were in close agreement with the simulated data. Next, this antenna was integrated with an active feed network allowing full hemispherical control over the beam null position and limited beam peak scan in increments. Using a simple calibration scheme, the measured beam peak and null elevation angles were programmed to within of the intended value based on simulation. Azimuthal positions were consistently offset by from the simulated value, which could be resolved in the board layout by phase matching the transmission lines and test point locations. The antenna maintained high total efficiency 68% and low axial ratio 3 dB over all steering angles.
Autors: Labadie, N.R.;Sharma, S.K.;Rebeiz, G.M.;
Appeared in: IEEE Transactions on Antennas and Propagation
Publication date: Jul 2014, volume: 62, issue:7, pages: 3490 - 3500
Publisher: IEEE
 
» A Class of Fast Exact Bayesian Filters in Dynamical Models With Jumps
Abstract:
We address the statistical filtering problem in dynamical models with jumps. When a particular application is adequately modeled by linear and Gaussian probability density functions with jumps, a usual method consists in approximating the optimal Bayesian estimate [in the sense of the minimum mean square error (MMSE)] in a linear and Gaussian jump Markov state space system (JMSS). Practical solutions include algorithms based on numerical approximations or on sequential Monte Carlo (SMC) methods. In this paper, we propose a class of alternative methods which consists in building statistical models which, locally, similarly model the problem of interest, but in which the computation of the MMSE estimate can be be computed exactly (without numerical nor SMC approximations) and at a computational cost which is linear in the number of observations.
Autors: Petetin, Y.;Desbouvries, F.;
Appeared in: IEEE Transactions on Signal Processing
Publication date: Jul 2014, volume: 62, issue:14, pages: 3643 - 3653
Publisher: IEEE
 
» A Class of Stable Square-Root Nonlinear Information Filters
Abstract:
Information filters can process nonlinear systems with uncertain prior knowledge, and the particular square-root form of adaptive filters can improve numerical stability. Based on a square-root decomposition of information matrix and an extra positive definite matrix, the unscented transform and the cubature rule are applied to the information filtering architecture for nonlinear estimation. A class of stable square-root nonlinear information filters is then proposed in this technical note. In addition, the boundedness of their estimation errors is also proven. Results from simulations of filtering a chaotic map demonstrate that the proposed square-root nonlinear filters can improve numerical stability, and has better filtering performance than other information filters.
Autors: Wang, S.;Feng, J.;Tse, C.K.;
Appeared in: IEEE Transactions on Automatic Control
Publication date: Jul 2014, volume: 59, issue:7, pages: 1893 - 1898
Publisher: IEEE
 
» A Closed-Loop Brain–Computer Interface Triggering an Active Ankle–Foot Orthosis for Inducing Cortical Neural Plasticity
Abstract:
In this paper, we present a brain–computer interface (BCI) driven motorized ankle–foot orthosis (BCI-MAFO), intended for stroke rehabilitation, and we demonstrate its efficacy in inducing cortical neuroplasticity in healthy subjects with a short intervention procedure (∼15 min). This system detects imaginary dorsiflexion movements within a short latency from scalp EEG through the analysis of movement-related cortical potentials (MRCPs). A manifold-based method, called locality preserving projection, detected the motor imagery online with a true positive rate of 73.0 ± 10.3%. Each detection triggered the MAFO to elicit a passive dorsiflexion. In nine healthy subjects, the size of the motor-evoked potential (MEP) elicited by transcranial magnetic stimulation increased significantly immediately following and 30 min after the cessation of this BCI-MAFO intervention for ∼15 min ( and , respectively), indicating neural plasticity. In four subjects, the size of the short latency stretch reflex component did not change following the intervention, suggesting that the site of the induced plasticity was cortical. All but one subject also performed two control conditions where they either imagined only or where the MAFO was randomly triggered. Both of these control conditions resulted in no significant changes in MEP size ( and ). The proposed system provides a fast and effective approach for inducing cortical plasticity through BCI and has potential in motor function rehabilitation following stroke.
Autors: Xu, R.;Jiang, N.;Mrachacz-Kersting, N.;Lin, C.;Asin Prieto, G.;Moreno, J.C.;Pons, J.L.;Dremstrup, K.;Farina, D.;
Appeared in: IEEE Transactions on Biomedical Engineering
Publication date: Jul 2014, volume: 61, issue:7, pages: 2092 - 2101
Publisher: IEEE
 
» A Closing Circle: Back to Authoring
Abstract:
Since the turn of this century, we have seen striking developments in multimedia technologies that let communication means flourish, through which people now can easily share their interests, opinions, visions, prejudices, hopes, fears, fetishes, the here and now, their inner state in measurement, or simply glimpses of the richness or boredom of their everyday lives. These technologies have revolutionized people's lives by altering the ways they learn, investigate, negotiate, and argument in public and private as well as how they meet, date, and befriend. In this reflective piece, Frank Nack argues that, for the development of multimedia technologies, social media research should focus on the interaction and communication basics of the different media and how they can be added into representations that actually help to improve human communication in digital environments.
Autors: Nack, Frank;
Appeared in: IEEE Multimedia
Publication date: Jul 2014, volume: 21, issue:3, pages: 4 - 6
Publisher: IEEE
 
» A Cloud-Storage RFID Location Tracking System
Abstract:
This paper presents a cloud-storage location tracking system designed and implemented with radio frequency identification (RFID) technology, wireless sensor network (WSN) technology, and a location tracking algorithm (LTA), based on cloud computing technology. This system used the signal attenuation model (SAM) in a nonopen space, received signal strength indicator (RSSI), link quality indicator (LQI), and cloud localization algorithm (CLA) for object tracking. The cloud-storage RFID location tracking system using a network node communication technique provided real-time localization and tracking for object recognition and collected the object information from sensors. The software as a service (SaaS) model was used for cloud computing to enhance user convenience. The personal homepage program (PHP) and cascading style sheets (CSS) language technologies were used for the user interface of the system. The SAM and reference tag information were used to reduce localization errors in the nonopen space. The cloud-storage RFID location tracking system achieved significant improvements in both high localization accuracy and low hardware costs.
Autors: Lai, Y.;Cheng, J.;
Appeared in: IEEE Transactions on Magnetics
Publication date: Jul 2014, volume: 50, issue:7, pages: 1 - 4
Publisher: IEEE
 
» A Combination of Concentrator Photovoltaics and Water Cooling System to Improve Solar Energy Utilization
Abstract:
In this paper, concentrator photovoltaics (CPVs) were used to integrate the extraction of light energy and thermal energy. The water cooling system that is proposed in this paper provides effective cooling by circulating cold water to remove heat in the photovoltaics. The experimental results were subsequently analyzed and compared with the power generation efficiency of the examined photovoltaics. The use of a water-circulation cooling system improves the power capacity of the photovoltaics by 2%–15% and enhances the power generation efficiency of the photovoltaics by 2.29%–3.37%. Through the combined application of photovoltaic and thermal technologies, the total energy of the overall system can be improved by 37%–59% even after accounting for the energy consumption of the cooling system. As a result, environmental protection, energy savings, and an increase in the efficiency of sunlight utilization can be achieved. Finally, a neural network was used to optimize this increase in efficiency.
Autors: Kuo, M.;Lo, W.;
Appeared in: IEEE Transactions on Industry Applications
Publication date: Jul 2014, volume: 50, issue:4, pages: 2818 - 2827
Publisher: IEEE
 
» A combined capacitance-voltage and hard x-ray photoelectron spectroscopy characterisation of metal/Al2O3/In0.53Ga0.47As capacitor structures
Abstract:
Capacitance-Voltage (C-V) characterization and hard x-ray photoelectron spectroscopy (HAXPES) measurements have been used to study metal/Al2O3/In0.53Ga0.47As capacitor structures with high (Ni) and low (Al) work function metals. The HAXPES measurements observe a band bending occurring prior to metal deposition, which is attributed to a combination of fixed oxide charges and interface states of donor-type. Following metal deposition, the Fermi level positions at the Al2O3/In0.53Ga0.47As interface move towards the expected direction as observed from HAXPES measurements. The In0.53Ga0.47As surface Fermi level positions determined from both the C-V analysis at zero gate bias and HAXPES measurements are in reasonable agreement. The results are consistent with the presence of electrically active interface states at the Al2O3/In0.53Ga0.47As interface and suggest an interface state density increasing towards the In0.53Ga0.47As valence band edge.
Autors: Lin, Jun;Walsh, Lee;Hughes, Greg;Woicik, Joseph C.;Povey, Ian M.;O'Regan, Terrance P.;Hurley, Paul K.;
Appeared in: Journal of Applied Physics
Publication date: Jul 2014, volume: 116, issue:2, pages: 024104 - 024104-8
Publisher: IEEE
 
» A Compact and Low-Cost Optical Pickup Head-Based Optical Microscope
Abstract:
An optical pickup head (OPH) is a compact and low-cost but of high-precision optical system. In the past, it has been used for much scientific research besides optical disc storage, in particular, for the length-related measurements. In this paper, we propose a compact and low-cost OPH-based optical microscope (OM). A CMOS sensor disassembled from the web camera is fixed below the fold mirror of the OPH. The revised structure is simple and low cost but without permanently altering the original structure of the OPH. The user can choose operation modes of either the OPH or OM by a simple switching. We estimated that the optical magnification of the OM is 15.5X. The experimentally measured resolution of the OM is m for the visible light, and it achieved diffraction limit for narrow-band light source. From the results of optical simulation, the main factor deteriorating the resolution is chromatic aberration. Astigmatic aberration is not important. Some plant cells investigation results using the microscope are also demonstrated in this paper.
Autors: Lee, Y.;Chao, S.;
Appeared in: IEEE Transactions on Magnetics
Publication date: Jul 2014, volume: 50, issue:7, pages: 1 - 4
Publisher: IEEE
 
» A Compact Gysel Power Divider With Unequal Power-Dividing Ratio Using One Resistor
Abstract:
A novel compact Gysel power divider is proposed and investigated in this paper. The proposed power divider consists of two transmission lines, a pair of coupled lines, and only one grounded resistor for unequal power-dividing ratio. Comparing to the conventional Gysel power divider, the new power divider saves its space by eliminating the 180 electrical length transmission line and reduces complicity by using one grounded resistor. The flexibility in choosing the value of the resistor provides favorable freedom in circuit realization. In addition, analytic design formulas of the proposed power divider, for both equal and unequal ratio cases, are given. For the equal radio case, two grounded resistors are required. Two prototype power dividers are simulated, fabricated, and measured. Both prototypes operate at 2 GHz, but with different power divisions, one for power division ratio and the other for . There are good correlation between the measured results and those of the theoretically designed, justifying the circuit configuration and the design theory.
Autors: Wang, X.;Wu, K.-L.;Yin, W.-Y.;
Appeared in: IEEE Transactions on Microwave Theory and Techniques
Publication date: Jul 2014, volume: 62, issue:7, pages: 1480 - 1486
Publisher: IEEE
 
» A Compact Wideband Slot-Loop Hybrid Antenna With a Monopole Feed
Abstract:
This communication presents a compact monopole-fed slot-loop hybrid antenna for wideband wireless communications. The wideband characteristic is achieved by coupling three different resonant modes of the proposed slot-loop hybrid antenna, namely, a loop mode for the lower band, a slot mode for the middle band and a monopole mode for the higher band. The proposed antenna is built and tested to verify the design strategy. The measured impedance bandwidth ranges from 1.82 GHz to 5.68 GHz (102.9%) with stable performance, including bi-directional radiation pattern, vertical polarization and gain. The proposed slot-loop hybrid antenna also shows the merits of compact dimension, low cross-polarization and low cost.
Autors: Pan, G.;Li, Y.;Zhang, Z.;Feng, Z.;
Appeared in: IEEE Transactions on Antennas and Propagation
Publication date: Jul 2014, volume: 62, issue:7, pages: 3864 - 3868
Publisher: IEEE
 
» A compact, diode laser based excitation system for microscopy of NV centers
Abstract:
We demonstrate that a recently introduced family of direct-emitting green laser diodes is a simple yet efficient light source for excitation of NV centers in diamond. Thanks to their fast (sub-ns) response time, these sources are suitable for a broad variety of measurements, including pulsed optically detected magnetic resonance (ODMR) and fluorescence lifetime imaging. This feature, together with a drastically simplified design, is a significant advantage over the traditional excitation system comprising an Nd: YAG laser switched by an acousto-optic modulator. We introduce a simple design for such a compact laser system and experimentally verify that it enables simultaneous lifetime and ODMR measurements on NV centers. In particular, we find that the NV charge state remains stable in spite of the short excitation wavelength of the new source.
Autors: Oeckinghaus, Thomas;Stohr, Rainer;Kolesov, Roman;Tisler, Julia;Reinhard, Friedemann;Wrachtrup, Jorg;
Appeared in: Review of Scientific Instruments
Publication date: Jul 2014, volume: 85, issue:7, pages: 073101 - 073101-4
Publisher: IEEE
 
» A Continuous Analytical Model for 2-DEG Charge Density in AlGaN/GaN HEMTs Valid for All Bias Voltages
Abstract:
An analytical model for 2 Dimensional Electron Gas (2-DEG) charge density in AlGaN/GaN High Electron Mobility Transistors is developed considering electron charge in the AlGaN barrier layer. Simplified Fermi-Dirac statistics are used to calculate the electron charge density in the AlGaN barrier. This model is valid for the entire range of operation from subthreshold to practical forward biases. The results from the model show an excellent match with simulation results from a numerical self-consistent Poisson-Schrodinger solver. The model correctly predicts the saturation of 2-DEG charge density at higher gate biases.
Autors: Karumuri, N.;Turuvekere, S.;DasGupta, N.;DasGupta, A.;
Appeared in: IEEE Transactions on Electron Devices
Publication date: Jul 2014, volume: 61, issue:7, pages: 2343 - 2349
Publisher: IEEE
 
» A Continuous-Time Ripple Reduction Technique for Spinning-Current Hall Sensors
Abstract:
This paper presents a new ripple-reduction technique for spinning-current Hall sensors, which obviates the need for low-pass filtering to suppress the ripple caused by up-modulated sensor offset. A continuous-time ripple-free output is achieved by the use of three ripple reduction loops (RRLs), which continuously sense the offset ripple and then use this information to drive a feedback loop that cancels sensor offset before amplification. Since no low-pass filter is involved, the bandwidth of the resulting system can be much higher than the spinning frequency. Moreover, since the front-end no longer has to process sensor offset, the requirements on its dynamic range can be significantly relaxed. A prototype system consisting of a Hall sensor readout system realized in a 0.18 CMOS process was combined with three off-chip RRLs realized with off-chip electronics. At a spinning frequency of 1 kHz, the RRLs reduce the offset ripple by more than 40 dB to about 10 , while also achieving low offset (25 ) and wide bandwidth (over 100 kHz).
Autors: Jiang, J.;Kindt, W.J.;Makinwa, K.A.A.;
Appeared in: IEEE Journal of Solid-State Circuits
Publication date: Jul 2014, volume: 49, issue:7, pages: 1525 - 1534
Publisher: IEEE
 
» A Convenient Vision-Based System for Automatic Detection of Parking Spaces in Indoor Parking Lots Using Wide-Angle Cameras
Abstract:
A convenient indoor vision-based parking lot system using wide-angle fisheye-lens or catadioptric cameras is proposed, which is easy to set up by a user with no technical background. Easiness in the system setup mainly comes from the use of a new camera model that can be calibrated using only one space line without knowing its position and direction, as well as from the allowance of convenient changes in detected parking space boundaries. After camera calibration based on the new camera model is completed, parking space boundary lines are automatically extracted from input wide-angle images by a modified Hough transform with a new cell accumulation scheme, which can generate more accurate equal-width curves using the geometric relations of line positions and directions. In addition, the user may easily add or remove the boundary lines by single clicks on images, and parking spaces can be segmented out by region growing with the use of the boundary lines. Finally, vacant parking spaces can be detected by a background subtraction scheme. A real vision-based parking lot has been established and relevant experiments conducted. Good experimental results show the correctness, feasibility, and robustness of the proposed methods.
Autors: Shih, S.;Tsai, W.;
Appeared in: IEEE Transactions on Vehicular Technology
Publication date: Jul 2014, volume: 63, issue:6, pages: 2521 - 2532
Publisher: IEEE
 
» A Cost-Effective Sideslip Estimation Method Using Velocity Measurements From Two GPS Receivers
Abstract:
This paper demonstrates that the vehicle sideslip can be estimated through the kinematic relationship of velocity measurements from two low-cost GPS receivers. To compensate for the low update rate of low-cost GPS receivers, acceleration/angular rate measurements from an inertial measurement unit (IMU) are merged with the GPS measurements using an extended Kalman filter (EKF). Two technical challenges were addressed: 1) unsynchronized updates of the two GPS receivers and 2) significant delays in GPS velocity measurement. A stochastic observability analysis reveals that the proposed method guarantees the observability when a vehicle has nonzero yaw rates. Experimental verification shows that the vehicle sideslip is estimated regardless of surface friction levels under several maneuvers.
Autors: Yoon, J.;Peng, H.;
Appeared in: IEEE Transactions on Vehicular Technology
Publication date: Jul 2014, volume: 63, issue:6, pages: 2589 - 2599
Publisher: IEEE
 
» A Cross-Layer Rethink on the Sensing-Throughput Tradeoff for Cognitive Radio Networks
Abstract:
This letter investigates the sensing-throughput tradeoff problem in cognitive radio networks from a cross-layer perspective, jointly considering the impact of imperfect spectrum sensing and access contention. Furthermore, the optimized solution to this tradeoff is formulated via taking the interference probability, rather than the detection probability, as the optimization constraint. Compared with the results obtained only from the physical layer, the proposed solutions can improve the secondary throughput significantly.
Autors: Zhang, S.;Zhao, H.;Wang, S.;Wei, J.;
Appeared in: IEEE Communications Letters
Publication date: Jul 2014, volume: 18, issue:7, pages: 1226 - 1229
Publisher: IEEE
 
» A Current-Mode, Low Out-of-Band Noise LTE Transmitter With a Class-A/B Power Mixer
Abstract:
A complete SAW-less transmitter meeting LTE requirements is presented. High power efficiency and low out-of-band noise are obtained exploiting fully current operation of an analog baseband followed by a class-A/B power mixer. Out-of-band emissions are limited by filtering noise and DAC replicas right before the signal up-conversion through a current-mode Biquad feeding directly the power-mixer. The transmitter, implemented in 55 nm CMOS technology, shows 158 dBc/Hz RX-band noise emission at 30 MHz offset for LTE10, while consuming 96 and 34 mW from the single 1.8 V power supply at 4 and 10 dBm output power, respectively. ACLR is always below 42 dBc up to 4 dBm for both LTE10 and LTE20.
Autors: Codega, N.;Rossi, P.;Pirola, A.;Liscidini, A.;Castello, R.;
Appeared in: IEEE Journal of Solid-State Circuits
Publication date: Jul 2014, volume: 49, issue:7, pages: 1627 - 1638
Publisher: IEEE
 
» A Data Rate and Concurrency Balanced Approach for Broadcast in Wireless Mesh Networks
Abstract:
In this paper, we address the problem of joint power control and scheduling for minimizing broadcast delay in wireless mesh networks. Given a set of mesh routers and a routing tree, we aim to assign power for relay nodes and compute an optimal transmission schedule such that the total delay for a packet broadcast from the root to all the routers is minimized. We consider rate adaptation in our scheme. This is a difficult issue. High power enables high data rate but causes high interference, whereas low power allows more concurrent transmissions at the expense of data rate. We study the tradeoff between data rate and concurrency and propose a balanced method. We introduce a metric called standard deviation of average remaining broadcast time to determine the priority of the two parameters. When this metric is greater than a threshold, the nodes will take the data-rate-first approach to increase the data rate; otherwise, the concurrency-first approach will be used to increase the number of concurrent transmissions. Theoretical analysis is given to show the upper and lower bounds of this metric. Simulations have demonstrated that our proposed method can reduce the broadcast delay significantly as compared with existing methods.
Autors: Chang, Y.;Liu, Q.;Jia, X.;
Appeared in: IEEE Transactions on Wireless Communications
Publication date: Jul 2014, volume: 13, issue:7, pages: 3556 - 3566
Publisher: IEEE
 
» A detailed experimental study on the benefits of electrically grounding glass mounted global positioning system antennas to the vehicle roof
Abstract:
The placement of global positioning system (GPS) patch antennas on vehicles is important as its location directly affects navigation system performance. GPS antennas mounted on the front glass window has been adopted by several vehicle manufacturers around the world. In this work, we present a detailed experimental study on the effect of antenna mounting parameters as well as shorting it to the roof of the vehicle on its performance characteristics. Specifically, we investigate the effect of the glass tilt angle, the distance of the antenna from the rooftop of the vehicle in addition to grounding it to the rooftop versus not-grounding to the rooftop of a vehicular platform.
Autors: Aloi, D.N.;Steffes, A.;Ghafari, E.;Sharawi, M.S.;
Appeared in: IET Microwaves, Antennas & Propagation
Publication date: Jul 2014, volume: 8, issue:10, pages: 782 - 793
Publisher: IEEE
 
» A Digital Timing Mismatch Calibration Technique in Time-Interleaved ADCs
Abstract:
A digital calibration scheme is proposed to minimize the timing mismatch in time-interleaved analog-to-digital converters (TIADCs). First, the scheme is to subtract the outputs from adjacent channel ADCs and to utilize the expectations of the absolute value of the subtracted results to represent the actual sampling time interval. The timing mismatch is recognized by comparing these expectations. The obtained information is fed back to adjust variable delay buffers, thus reducing the timing mismatch. The application of this scheme to a 12-bit 1.6 GS/s four-channel TIADC is demonstrated. Simulation results show that with an input signal whose bandwidth is limited to the Nyquist frequency, the proposed timing mismatch calibration scheme is effective and capable of reducing the mismatch to the minimum. Compared with traditional calibration schemes, the proposed scheme is more feasible to implement and consumes less power and chip area.
Autors: Li, J.;Wu, S.;Liu, Y.;Ning, N.;Yu, Q.;
Appeared in: IEEE Transactions on Circuits and Systems II: Express Briefs
Publication date: Jul 2014, volume: 61, issue:7, pages: 486 - 490
Publisher: IEEE
 
» A Direct Approach to Computing Spatially Averaged Outage Probability
Abstract:
This letter describes a direct method for computing the spatially averaged outage probability of a network with interferers located according to a point process and signals subject to fading. Unlike most common approaches, it does not require transforms such as a Laplace transform. Examples show how to directly obtain the outage probability in the presence of Rayleigh fading in networks whose interferers are drawn from binomial and Poisson point processes defined over arbitrary regions. We furthermore show that, by extending the arbitrary region to the entire plane, the result for Poisson point processes converges to the same expression found by Baccelli et al.
Autors: Valenti, M.C.;Torrieri, D.;Talarico, S.;
Appeared in: IEEE Communications Letters
Publication date: Jul 2014, volume: 18, issue:7, pages: 1103 - 1106
Publisher: IEEE
 
» A discussion on open access [The President's Page]
Abstract:
The July President Page is hosting an article by Gianluca Setti on Open Access. Open Access is a hot topic among researchers, editors, and research funding institutions, and has reached the legislation level in several countries. It is also crucial for IEEE, an institution that receives most of its revenues from IPs related to archival publications. It is then a pleasure and, I think, a good service to ComSoc members to introduce Gianluca and his paper.
Autors: Benedetto, S.;Setti, G.;
Appeared in: IEEE Communications Magazine
Publication date: Jul 2014, volume: 52, issue:7, pages: 6 - 9
Publisher: IEEE
 
» A Divergence-Free Meshless Method Based on the Vector Basis Function for Transient Electromagnetic Analysis
Abstract:
Although meshless methods, in particularly those with scalar radial basis functions (RBFs), have been applied effectively to solve electromagnetic problems, their solutions may not be always divergence free in source-free regions, resulting in possibly large errors. In this paper, a new vector RBF based meshless method, which is divergence free, is proposed for solving transient electromagnetic problems. Its divergence properties are investigated and compared with those of scalar RBFs; and they are further verified with numerical examples that present good accuracy.
Autors: Yang, S.;Chen, Z.;Yu, Y.;Ponomarenko, S.;
Appeared in: IEEE Transactions on Microwave Theory and Techniques
Publication date: Jul 2014, volume: 62, issue:7, pages: 1409 - 1416
Publisher: IEEE
 
» A DoF-Based Link Layer Model for Multi-Hop MIMO Networks
Abstract:
The rapid advances of MIMO to date have mainly stayed at the physical layer. Such fruits have not fully benefited MIMO research at the network layer mainly due to the computational complexity associated with the matrix-based model that MIMO involves. Recently, there have been some efforts to simplify link layer model for MIMO so as to facilitate research at the upper layers. These models only require simple numeric computations on MIMO’s degrees-of-freedom (DoFs) to characterize spatial multiplexing (SM) and interference cancellation (IC). Thus, these models are much simpler than the original matrix-based model from the communications world. However, achievable DoF regions of these DoF-based models are not analyzed. In this paper, we re-visit this important problem of MIMO modeling. Based on accounting of how DoFs are consumed for SM and IC, we develop a tractable link layer model for multi-hop MIMO networks. We show that under common assumptions of DoF-based models and additional assumption of no dependency cycle, this model includes all the feasible solutions by the matrix-based model under SM and IC for any network topology. This work offers an important building block for theoretical research on multi-hop MIMO networks.
Autors: Shi, Y.;Liu, J.;Jiang, C.;Gao, C.;Hou, Y.T.;
Appeared in: IEEE Transactions on Mobile Computing
Publication date: Jul 2014, volume: 13, issue:7, pages: 1395 - 1408
Publisher: IEEE
 
» A Dual Price-Based Congestion Control Mechanism for Optical Burst Switching Networks
Abstract:
A dual price-based congestion control (DPCC) mechanism for optical burst switching (OBS) networks is proposed in this paper, which can achieve an optimal rate-reliability tradeoff by allocating proper network traffic and resources based on the idea of network utility maximization (NUM). The DPCC uses the congestion and reliability prices and feedback information to dynamically adjust the users’ data sending rate and the end-to-end data transmission reliability in an OBS network. The performance of DPCC is evaluated and analyzed through simulations. Results verify that DPCC works very well in terms of its convergence and optimality. Moreover, compared with TCP, DPCC can achieve a maximum network utility, a parameter which can be used to reflect the overall user satisfaction degree in a network. DPCC is scalable due to its distributed nature.
Autors: Zhang, T.;Dai, W.;Wu, G.;Li, X.;Chen, J.;Qiao, C.;
Appeared in: Journal of Lightwave Technology
Publication date: Jul 2014, volume: 32, issue:14, pages: 2492 - 2501
Publisher: IEEE
 
» A Filtering ΔΣ ADC for LTE and Beyond
Abstract:
This paper presents a filtering ADC for the LTE communication standard, where a second-order Delta–Sigma modulator (DSM) is incorporated into the third-order Chebychev channel-select filter (CSF) of the radio receiver. The CSF introduces an additional third-order suppression of both thermal and quantization DSM noise, while the CSF transfer function is maintained. A design method for the filtering ADC accounting for unavoidable DSM-DAC delays is developed and experimentally demonstrated. The 65 nm CMOS prototype is clocked at 576/288 MHz with an 18.5/9.0 MHz LTE bandwidth, has an in-band gain of 26 dB, an SNDR of 56.4/58.1 dB, an input-referred noise of 5 nV/ , and an out-of-band (half-duplex) IIP3 of 20/12 dBV rms , with a power consumption of 7.9/5.4 mW and an overall state-of-the art performance.
Autors: Andersson, M.;Anderson, M.;Sundstrom, L.;Mattisson, S.;Andreani, P.;
Appeared in: IEEE Journal of Solid-State Circuits
Publication date: Jul 2014, volume: 49, issue:7, pages: 1535 - 1547
Publisher: IEEE
 
» A Fine-Grain Variation-Aware Dynamic -Hopping AVFS Architecture on a 32 nm GALS MPSoC
Abstract:
In order to optimize global energy efficiency in the context of dynamic process, voltage and temperature variations in advanced nodes, a fine-grain adaptive voltage and frequency scaling architecture is proposed for multiprocessor systems-on-chip (MPSoC), where each processing element is an independent voltage–frequency island. This architecture has been implemented on a 32 nm globally asynchronous locally-synchronous MPSoC. It shows up to 18.2% energy gains thanks to local adaptability compared with a global dynamic voltage and frequency scaling approach using 25% timing margins between slow and nominal process, by reducing margins to 60 ps of the real process. These gains are obtained for a total area overhead of 10% including local frequency/voltage actuators, sensors, and digital controller.
Autors: Miro-Panades, I.;Beigne, E.;Thonnart, Y.;Alacoque, L.;Vivet, P.;Lesecq, S.;Puschini, D.;Molnos, A.;Thabet, F.;Tain, B.;Ben Chehida, K.;Engels, S.;Wilson, R.;Fuin, D.;
Appeared in: IEEE Journal of Solid-State Circuits
Publication date: Jul 2014, volume: 49, issue:7, pages: 1475 - 1486
Publisher: IEEE
 
» A finite element study of balloon expandable stent for plaque and arterial wall vulnerability assessment
Abstract:
The stresses induced within plaque tissues and arterial layers during stent expansion inside an atherosclerotic artery can be exceeded from the yield stresses of those tissues and, consequently, lead to plaque or arterial layer rupture. The distribution and magnitude of the stresses in each component involved in stenting might be clearly different for different plaque types and different arterial layers. In this study, a nonlinear finite element simulation was employed to investigate the effect of plaque composition (calcified, cellular, and hypocellular) on the stresses induced in the arterial layers (intima, media, and adventitia) during implantation of a balloon expandable coronary stent into a stenosed artery. The atherosclerotic artery was assumed to consist of a plaque and normal/healthy arterial tissues on its outer side. The results indicated a significant influence of plaque types on the maximum stresses induced within the plaque wall and arterial layers during stenting but not when computing maximum stress on the stent. The stress on the stiffest calcified plaque wall was in the fracture level (2.38 MPa), whereas cellular and hypocellular plaques remain stable owing to less stress on their walls. Regardless of plaque types, the highest von Mises stresses were observed on the stiffest intima layer, whereas the lowest stresses were seen to be located in less stiff media layer. The computed stresses on the intima layer were found to be high enough to initiate a rupture in this stiff layer. These findings suggest a higher risk of arterial vascular injury for the intima layer, while a lower risk of arterial injury for the media and adventitia layers.
Autors: Karimi, Alireza;Navidbakhsh, Mahdi;Razaghi, Reza;
Appeared in: Journal of Applied Physics
Publication date: Jul 2014, volume: 116, issue:4, pages: 044701 - 044701-8
Publisher: IEEE
 
» A Flexible Pinhole Camera Model for Coherent Nonuniform Sampling
Abstract:
The flexible pinhole camera (FPC) allows flexible modulation of the sampling rate over the field of view. The FPC is defined by a viewpoint and a map specifying the sampling locations on the image plane. The map is constructed from known regions of interest with interactive and automatic approaches. The FPC provides inexpensive 3D projection that allows rendering complex datasets quickly, in feed-forward fashion, by projection followed by rasterization. The FPC supports many types of data, including image, height field, geometry, and volume data. The resulting image is a coherent nonuniform sampling (CoNUS) of the dataset that matches the local variation of the dataset's importance. CoNUS images have been successfully implemented for remote visualization, focus-plus-context visualization, and acceleration of expensive rendering effects such as surface geometric detail and specular reflection. A video explaining and demonstrating the FPC is at http://youtu.be/kvFe5XjOPNM.
Autors: Popescu, Voicu;Benes, Bedrich;Rosen, Paul;Cui, Jian;Wang, Lili;
Appeared in: IEEE Computer Graphics and Applications
Publication date: Jul 2014, volume: 34, issue:4, pages: 30 - 41
Publisher: IEEE
 
» A Folded Reflectarray Antenna With a Planar SIW Slot Array Antenna as the Primary Source
Abstract:
An integrated design of a planar source-fed folded reflectarray antenna (FRA) with low profile is proposed to achieve high gain for Q-band millimeter wave high data rate wireless communication applications. A planar substrate integrated waveguide (SIW) slot array antenna is adopted as the primary source to illuminate the proposed FRA. Considerations of the off-focus loss and the asymmetry - and -plane beamwidths loss of the planar source are thoroughly investigated to improve the aperture efficiency of the reflectarray antenna. A prototype is implemented and the experimental results are in good agreement with the predictions, which exhibit a measured less than 10 dB over the frequency band of 41.6–44 GHz, a maximum boresight gain of 31.9 dBi at 44 GHz with the aperture efficiency of 49% and a 3 dB gain drop bandwidth of 41.8–44.9 GHz. By integrating with the planar feed, the proposed folded reflectarray antenna benefits from its low-profile, low cost, and the ability of coplanar integration with millimeter wave planar circuits while maintaining the good performance in terms of gain and efficiency.
Autors: Jiang, M.;Hong, W.;Zhang, Y.;Yu, S.;Zhou, H.;
Appeared in: IEEE Transactions on Antennas and Propagation
Publication date: Jul 2014, volume: 62, issue:7, pages: 3575 - 3583
Publisher: IEEE
 
» A Four-Channel, 36 V, 780 kHz Piezo Driver Chip for Structural Health Monitoring
Abstract:
This paper describes a four-channel piezo driver chip for use in active structural health monitoring. Each channel can drive a piezoelectric transducer with a continuous-wave signal of 36 V and 780 kHz. The waveform is synthesized using filtered pulse-width modulation (PWM), where the pulse transition times are precomputed through a least-square optimization problem. A calibration technique is introduced to achieve subnanosecond timing accuracy and 40.5 dB signal distortion. A 13 mm proof-of-concept IC was fabricated in a 0.25 m BCD process and evaluated within an application test bed.
Autors: Guo, Y.;Aquino, C.;Zhang, D.;Murmann, B.;
Appeared in: IEEE Journal of Solid-State Circuits
Publication date: Jul 2014, volume: 49, issue:7, pages: 1506 - 1513
Publisher: IEEE
 
» A Frequency Reconfigurable Transmitter Antenna With Autonomous Switching Capabilities
Abstract:
Frequency reconfigurable antennas have many benefits that can be used to improve the performance of wireless systems. Then again, many existing multiband systems cannot use a frequency reconfigurable antenna because of the additional control signals required to operate the antenna. In this communication, an autonomous frequency reconfigurable antenna topology that does not require these control signals from the radio is presented. To control the antenna, a power splitter and bandpass filter is used to pass a portion of the RF power driving the antenna in a particular band to voltage-doubling circuitry. This voltage-doubler circuit is then used to convert the RF signal into a DC output control voltage which then in turn controls the reconfigurable features of the antenna. By setting the bandpass filter to one of the reconfigurable frequencies, RF power can then be used to reconfigure the antenna in a specific band while not reconfiguring in other bands. This flexibility makes this design very useful for existing and future cost effective wireless systems.
Autors: Hinsz, L.;Braaten, B.D.;
Appeared in: IEEE Transactions on Antennas and Propagation
Publication date: Jul 2014, volume: 62, issue:7, pages: 3809 - 3813
Publisher: IEEE
 
» A frequency-domain three-stage algorithm for active deception jamming against synthetic aperture radar
Abstract:
Efficient generation of jamming signal is an important but intractable issue in active deception jamming against synthetic aperture radar. Considerations must be given to both the computational complexity and the focus depth of the false scatterers of a deception template. However, existing methods cannot meet both demands mentioned above when generating jamming signal of an extended false scene or scattered false targets. In this study, a frequency-domain three-stage algorithm (FDTSA) is proposed. In theory, the jammer system is deliberately reformatted in the two-dimensional frequency domain. Accordingly, the implementation of the FDTSA can be effectively accelerated by fast Fourier transform and by separating the modulation process of a repeat jammer into three stages: the offline stage, the initialisation stage and the real-time modulation stage. Theoretical analyses and simulation results indicate that the FDTSA can get rid of severe focus deterioration of the false scatterers and reasonable computational load is required.
Autors: Liu, Y.;Wang, W.;Pan, X.;Dai, D.;Feng, D.;
Appeared in: IET Radar, Sonar & Navigation
Publication date: Jul 2014, volume: 8, issue:6, pages: 639 - 646
Publisher: IEEE
 
» A Fully-Integrated 40–222 GHz InP HBT Distributed Amplifier
Abstract:
This letter presents an ultra-wideband distributed amplifier (DA) implemented in a 250 nm InP HBT technology. Four cascode gain cells are distributed along the input and output microstrip lines to achieve wideband operation. Each cascode cell employs inductive peaking at the output to further enhance the bandwidth and to align the phase delay between the input and output lines. All dc bias components are fully integrated on-chip. The DA exhibits a measured gain of 10 dB with a 3 dB bandwidth extending from 40 to 222 GHz. The maximum output power was measured to be 6.0, 9.2, and 8.5 dBm at 60, 77, and 134 GHz, respectively, which allows the DA to also be used as a medium-power amplifier. To the authors' best knowledge, the DA achieves the highest 3 dB bandwidth of 182 GHz reported thus far, while showing low dc power consumption (105 mW) compared to other state-of-the-art DAs.
Autors: Yoon, S.;Lee, I.;Urteaga, M.;Kim, M.;Jeon, S.;
Appeared in: IEEE Microwave and Wireless Components Letters
Publication date: Jul 2014, volume: 24, issue:7, pages: 460 - 462
Publisher: IEEE
 
» A Generalization of the Scattering Transformation for Conic Systems
Abstract:
A generalized version of the scattering transformation is introduced which allows for rendering of the input-output characteristics of a nonlinear conic system into an arbitrary prescribed conic sector. The transformation is consequently applied to the problem of stabilization of conic systems interconnections. The stability is achieved by rendering the input-output characteristics of the subsystems into complementary cones such that the graph separation stability condition is satisfied. In the presence of communication delays, the scattering-based technique for stabilization of feedback interconnections is generalized to the case of arbitrary conic subsystems.
Autors: Polushin, I.G.;
Appeared in: IEEE Transactions on Automatic Control
Publication date: Jul 2014, volume: 59, issue:7, pages: 1989 - 1995
Publisher: IEEE
 
» A Generalized Nash Equilibrium Approach for Robust Cognitive Radio Networks via Generalized Variational Inequalities
Abstract:
Resource sharing between primary users (PUs) and secondary users (SUs) in cognitive radio (CR) networks is built on strict interference limitations. However, such limitations may be easily violated by SUs using imperfect SU-to-PU channel state information (CSI). In this paper, we propose a robust decentralized CR network design by explicitly taking into account imperfect SU-to-PU CSI from a game theoretical perspective. We formulate the CR network design as a generalized Nash equilibrium problem (GNEP), where the SUs compete with each other over the resources made available by the PUs, who are protected by the robust aggregate interference constraints. We establish a framework-based generalized variational inequality (GVI) theory to analyze the formulated robust GNEP. It is shown that the solution to the robust GNEP can be obtained by solving a GVI, which can be addressed by a distributed pricing mechanism in the CR network, where the SUs play a priced NEP with given prices and the PUs are in charge of setting prices. Then, we propose distributed algorithms, along with their convergence properties, for the SUs to solve the priced NEP and for the PUs to update prices, respectively. We also provide an efficient method to compute the optimal transmit strategy of each SU via convex optimization.
Autors: Wang, J.;Peng, M.;Jin, S.;Zhao, C.;
Appeared in: IEEE Transactions on Wireless Communications
Publication date: Jul 2014, volume: 13, issue:7, pages: 3701 - 3714
Publisher: IEEE
 
» A Geometrical Approach to Duality Transformations for Tellegen Media
Abstract:
Duality transformations are of key importance in the study of Tellegen (i.e., achiral and nonreciprocal biisotropic) media: they often can reduce electromagnetic problems with both Tellegen media and simple isotropic media (SIMs), to simpler problems just with SIMs. Here, we generalize known results and derive the most general classes of Tellegen media that can be reduced, under the same duality transformation, to SIMs. Furthermore, it is shown that a family of isorefractive Tellegen media can be completely mapped onto the Riemann sphere where duality transformations are conformal mappings. Depending on their geometrical action in the Riemann sphere the duality transformations are then classified as: 1) generalized rotations; 2) Lorentz boosts; or 3) Galilean boosts. Applications include a wide range of structures containing Tellegen media: from (open and closed) waveguides to photonic crystals.
Autors: Prudencio, F.R.;Matos, S.A.;Paiva, C.R.;
Appeared in: IEEE Transactions on Microwave Theory and Techniques
Publication date: Jul 2014, volume: 62, issue:7, pages: 1417 - 1428
Publisher: IEEE
 
» A Global Maximum Error Controller-Based Method for Linearization Point Selection in Trajectory Piecewise-Linear Model Order Reduction
Abstract:
We propose a new linearization point selection method based on a global maximum error controller for the trajectory piecewise-linear (TPWL) model order reduction (MOR). This method is based on a simple fact that the simulation cost of the TPWL model is very low, and selects the state at which the responses of the current TPWL model and the full nonlinear model have the maximum difference as a new linearization point. Numerical results show that the proposed method can generate the TPWL model of smaller size and higher accuracy, and can easily be extended to generate the TPWL model for multiple training inputs.
Autors: Liu, Y.;Yuan, W.;Chang, H.;
Appeared in: IEEE Transactions on Computer-Aided Design of Integrated Circuits and Systems
Publication date: Jul 2014, volume: 33, issue:7, pages: 1100 - 1104
Publisher: IEEE
 
» A Grid-Level High-Power BTB (Back-To-Back) System Using Modular Multilevel Cascade Converters WithoutCommon DC-Link Capacitor
Abstract:
This paper provides an intensive discussion on analysis, simulation, and experiment of a back-to-back (BTB) systemunifying two modular multilevel cascade converters based on double-star chopper cells (MMCCs-DSCCs). Each of the twoDSCCs connected back-to-back consists of multiple cascaded chopper cells and a center-tapped inductor per leg. Lowvoltage steps bring significant reductions in harmonic voltage and current to the BTB system. Neither dc-link capacitornor voltage sensor is required for regulating the dc-link voltage and controlling the dc-link current. A three-phase200-V, 10-kW, 50-Hz downscaled BTB system with phase-shifted PWM is designed, constructed, and tested to verify itsoperating principles and performance. Analytical, simulated, and experimental results agree well with each other insteady and transient states. Experimental waveforms confirm the effectiveness of a self-starting/restartingprocedure.
Autors: Sekiguchi, K.;Khamphakdi, P.;Hagiwara, M.;Akagi, H.;
Appeared in: IEEE Transactions on Industry Applications
Publication date: Jul 2014, volume: 50, issue:4, pages: 2648 - 2659
Publisher: IEEE
 
» A Handover Mechanism Considering the Abstracted R-Factor
Abstract:
The user-perceived performance of voice services can be improved if the handover (HO) criterion is designed to consider the mean opinion score (MOS). However, this involves several problems, such as the measurement difficulty of the MOS, the detection difficulty of the MOS degradation factors, and the requirement of cross-layer design. To solve these problems, we propose an abstracted R-factor-based HO mechanism. The HO trigger used for this mechanism is derived by the optimization problem that considers the abstracted R-factor as the objective function. We first verify that the optimal HO trigger values exist for maximizing the R-factor by simulation. The derived HO trigger is similar to the optimal value extracted via simulation. The derived HO trigger is characterized by the linearization coefficients of the R-factor, the minimum required signal quality, the HO interruption time, and the variance of the average signal-to-interference-plus-noise ratio (SINR). These parameters can be easily obtained in the network. Therefore, the complexity of user equipment (UE) caused by the proposed HO mechanism is lower than that caused by the HO mechanisms that directly use the R-factor.
Autors: Lee, H.;Kim, J.;
Appeared in: IEEE Transactions on Vehicular Technology
Publication date: Jul 2014, volume: 63, issue:6, pages: 2687 - 2696
Publisher: IEEE
 
» A High-Frequency Accelerometer Based on Distributed Bragg Reflector Fiber Laser
Abstract:
We propose an optical accelerometer based on distributed Bragg reflector (DBR) fiber laser sensor. The transducer's vibration reduces the birefringence of the preloaded fiber laser and consequently changes the beat frequency of the two orthogonally polarized lasing modes, thus the frequency can be used to retrieve the acceleration information. The DBR probe is a segment of bare erbium fiber, which has a very high natural frequency of vibration. Experimental results show that sensitivity of 4.810 MHz/g with a dynamic range of 0.01g–5g (where g m/s is the gravity of the earth) and natural frequency of kHz can be obtained with this sensing system.
Autors: Yu, K.;Lai, C.;Wu, C.;Zhao, Y.;Lu, C.;Tam, H.;
Appeared in: IEEE Photonics Technology Letters
Publication date: Jul 2014, volume: 26, issue:14, pages: 1418 - 1421
Publisher: IEEE
 
» A high-frequency electron paramagnetic resonance spectrometer for multi-dimensional, multi-frequency, and multi-phase pulsed measurements
Abstract:
We describe instrumentation for a high-frequency electron paramagnetic resonance (EPR) and pulsed electron-electron double resonance (PELDOR) spectroscopy. The instrumentation is operated in the frequency range of 107−120 GHz and 215−240 GHz and in the magnetic field range of 0−12.1 T. The spectrometer consisting of a high-frequency high-power solid-state source, a quasioptical system, a phase-sensitive detection system, a cryogenic-free superconducting magnet, and a 4He cryostat enables multi-frequency continuous-wave EPR spectroscopy as well as pulsed EPR measurements with a few hundred nanosecond pulses. Here we discuss the details of the design and the pulsed EPR sensitivity of the instrumentation. We also present performance of the instrumentation in unique experiments including PELDOR spectroscopy to probe correlations in an insulating electronic spin system and application of dynamical decoupling techniques to extend spin coherence of electron spins in an insulating solid-state system.
Autors: Cho, F.H.;Stepanov, V.;Takahashi, S.;
Appeared in: Review of Scientific Instruments
Publication date: Jul 2014, volume: 85, issue:7, pages: 075110 - 075110-7
Publisher: IEEE
 
» A High-Linearity Capacitance-to-Digital Converter Suppressing Charge Errors From Bottom-Plate Switches
Abstract:
A high-precision capacitance-to-digital converter (CDC) that is configurable to interface with unipolar or push-pull-type capacitive sensors is presented in this paper. In the conventional switched-capacitor CDC, it is well known that clock feedthroughs and charge injections from top-plate switches can be eliminated by a bottom-plate sampling scheme. However, those charge errors from the bottom-plate switches depend on the digital output and the varying value of the sensing capacitor itself. They will thus affect the overall CDC linearity. When the varying range of the sensing capacitor is wide, the nonlinearity becomes more pronounced. This paper proposes new switching and calibration schemes to reduce these non-idealities. A prototype of a second order CDC employing the proposed techniques in a 0.18 m CMOS process achieves a 53.2 aF RMS resolution with a 1 ms conversion time. The proposed calibration technique improves the linearity of the CDC from 9.3 bits to 12.3 bits and from 10.1 bits to 13.3 bits in the unipolar and push-pull-type sensing modes, respectively, with a sensing capacitance varying from 0.5 to 3.5 pF. The CDC is also demonstrated with a real-life pressure sensor.
Autors: Li, B.;Sun, L.;Ko, C.-T.;Wong, A.K.-Y.;Pun, K.-P.;
Appeared in: IEEE Transactions on Circuits and Systems I: Regular Papers
Publication date: Jul 2014, volume: 61, issue:7, pages: 1928 - 1941
Publisher: IEEE
 
» A High-Speed Power Detector for -Band Communication
Abstract:
A -band power detector (PD) consisting of a four-way power divider and four identical active PD units is proposed, where four individual PD units are derived by the input signals having the same amplitude, but a 90 phase difference. The outputs of the PD units are combined, to suppress the first, second, and third harmonics due to phase cancellation. Consequently, the ripple at the output is minimized. The proposed PD is designed and manufactured in a 0.25- InP DHBT technology, which is characterized by on-chip measurements with both a sinusoidal signal and a binary amplitude shift-keying modulated signal at a data rate up to 13 Gb/s over different carrier frequencies from 100 to 150 GHz. Measured bit error rate for a pseudorandom binary sequence is less than at the carrier frequency of 120 GHz, and less than at the carrier frequency of 150 GHz. In addition, the proposed PD achieves state-of-the-art power/energy efficiency, which exhibits the lowest energy per bit of 1.1 pJ/bit. Total dc power consumption of the PD is 15 mW.
Autors: Bao, M.;Chen, J.;Kozhuharov, R.;Zirath, H.;
Appeared in: IEEE Transactions on Microwave Theory and Techniques
Publication date: Jul 2014, volume: 62, issue:7, pages: 1515 - 1524
Publisher: IEEE
 
» A Highly Reliable 2-Bits/Cell Split-Gate Flash Memory Cell With a New Program-Disturbs Immune Array Configuration
Abstract:
A highly reliable 2-bits/cell split-gate flash memory cell in a novel program-disturbs immune array architecture is fabricated and demonstrated. Using a novel metal interconnect technique, a new virtual-ground array architecture is realized to greatly improve program disturbs as compared with conventional and-type configuration. A fully self-aligned process with shallow trench isolation in cell array is also proposed for the first time to fabricate this word-line shared split-gate structure without any lithomisalignment issue. Moreover, the negative charge trap in select gate (SG) oxide during conventional poly-to-poly Fowler-Nordheim tunneling erase operation is found as an important contribution to the cycling degradation for cells with thin SG oxide, and a negative control gate bias erase scheme is then presented to enhance the endurance reliability in this paper. A 250-°C baking experiment (before and after cycling) is performed to explore this cell's data retention characteristics, proving the free of extrinsic and intrinsic defect. Erase and program characteristics are comparable with conventional split-gate cell as well.
Autors: Fang, L.;Gu, J.;Zhang, B.;Kong, W.;Zou, S.;
Appeared in: IEEE Transactions on Electron Devices
Publication date: Jul 2014, volume: 61, issue:7, pages: 2350 - 2356
Publisher: IEEE
 
» A Horizontally Polarized Rectangular Stepped Slot Antenna for Ultra Wide Bandwidth With Boresight Radiation Patterns
Abstract:
In this paper, a horizontally polarized UWB antenna is proposed. The UWB nature of the antenna is achieved using a stepped impedance microstrip feed line to excite the stepped slot configuration. The dB experimental impedance bandwidth acquired from VNA is 10 GHz (from 3.2 GHz to 13.2 GHz) which is 122% at the center frequency of 8.2 GHz. Symmetric feeding of the slot ensures good polarization characteristics and uniform radiation patterns throughout the operating band. The measured co to cross polarization ratio in boresight direction is around 15 dBi over most of the frequencies while the average peak gain is around 5 dBi. With the help of parametric studies, the choice of the antenna dimensions is justified. Finally, a modified design with band-notch characteristics to suppress interference from 5 GHz WLAN systems is presented. The simulated and measured results are in good agreement.
Autors: Kumar, R.;Khokle, R.K.;Ram Krishna, R.V.S.;
Appeared in: IEEE Transactions on Antennas and Propagation
Publication date: Jul 2014, volume: 62, issue:7, pages: 3501 - 3510
Publisher: IEEE
 
» A Hybrid Approach for Fast and Accurate Trace Signal Selection for Post-Silicon Debug
Abstract:
A major challenge in post-silicon debug is the lack of observability to the internal signals of a chip. Trace buffer technology provides one venue to address this challenge by online tracing of a few selected state elements. Due to the limited bandwidth of the trace buffer, only a few state elements can be selected for tracing. Recent research has focused on automated trace signal selection problem to maximize restoration of the untraced state elements using the few traced signals. Existing techniques can be categorized into high quality but slow simulation-based techniques and lower quality but much faster metric-based techniques. This paper presents a new trace signal selection technique which has comparable or better quality than simulation-based while it has a fast runtime, comparable to the metric-based techniques.
Autors: Li, M.;Davoodi, A.;
Appeared in: IEEE Transactions on Computer-Aided Design of Integrated Circuits and Systems
Publication date: Jul 2014, volume: 33, issue:7, pages: 1081 - 1094
Publisher: IEEE
 
» A Hybrid Intelligent Model for Deterministic and Quantile Regression Approach for Probabilistic Wind Power Forecasting
Abstract:
With rapid increase in wind power penetration into the power grid, wind power forecasting is becoming increasingly important to power system operators and electricity market participants. The majority of the wind forecasting tools available in the literature provide deterministic prediction, but given the variability and uncertainty of wind, such predictions limit the use of the existing tools for decision-making under uncertain conditions. As a result, probabilistic forecasting, which provides information on uncertainty associated with wind power forecasting, is gaining increased attention. This paper presents a novel hybrid intelligent algorithm for deterministic wind power forecasting that utilizes a combination of wavelet transform (WT) and fuzzy ARTMAP (FA) network, which is optimized by using firefly (FF) optimization algorithm. In addition, support vector machine (SVM) classifier is used to minimize the wind power forecast error obtained from WT+FA+FF. The paper also presents a probabilistic wind power forecasting algorithm using quantile regression method. It uses the wind power forecast results obtained from the proposed hybrid deterministic WT+FA+FF+SVM model to evaluate the probabilistic forecasting performance. The performance of the proposed forecasting model is assessed utilizing wind power data from the Cedar Creek wind farm in Colorado.
Autors: Haque, A.U.;Nehrir, M.H.;Mandal, P.;
Appeared in: IEEE Transactions on Power Systems
Publication date: Jul 2014, volume: 29, issue:4, pages: 1663 - 1672
Publisher: IEEE
 
» A Hybrid Model for Improved Hysteresis Loss Prediction in Electrical Machines
Abstract:
This paper presents a model for calculating the hysteresis loss in electrical machines. The model can achieve accurate and computationally efficient hysteresis loss calculations by utilizing both analytical equations and the Energetic hysteresis model. The model results are experimentally verified by comparing to a series of minor hysteresis loop measurements. The hybrid model is then implemented to calculate the core losses in a switched reluctance machine using finite-element simulation. The results show that precise machine core loss prediction requires having a model that is capable of calculating the hysteresis losses under a variety of minor hysteresis loops.
Autors: Ibrahim, M.;Pillay, P.;
Appeared in: IEEE Transactions on Industry Applications
Publication date: Jul 2014, volume: 50, issue:4, pages: 2503 - 2511
Publisher: IEEE
 
» A linear model approach for ultrasonic inverse problems with attenuation and dispersion
Abstract:
Ultrasonic inverse problems such as spike train deconvolution, synthetic aperture focusing, or tomography attempt to reconstruct spatial properties of an object (discontinuities, delaminations, flaws, etc.) from noisy and incomplete measurements. They require an accurate description of the data acquisition process. Dealing with frequency-dependent attenuation and dispersion is therefore crucial because both phenomena modify the wave shape as the travel distance increases. In an inversion context, this paper proposes to exploit a linear model of ultrasonic data taking into account attenuation and dispersion. The propagation distance is discretized to build a finite set of radiation impulse responses. Attenuation is modeled with a frequency power law and then dispersion is computed to yield physically consistent responses. Using experimental data acquired from attenuative materials, this model outperforms the standard attenuation-free model and other models of the literature. Because of model linearity, robust estimation methods can be implemented. When matched filtering is employed for single echo detection, the model that we propose yields precise estimation of the attenuation coefficient and of the sound velocity. A thickness estimation problem is also addressed through spike deconvolution, for which the proposed model also achieves accurate results.
Autors: Carcreff, E.;Bourguignon, S.;Idier, J.;Simon, L.;
Appeared in: IEEE Transactions on Ultrasonics, Ferroelectrics and Frequency Control
Publication date: Jul 2014, volume: 61, issue:7, pages: 1191 - 1203
Publisher: IEEE
 
» A Low Overhead Quasi-Delay-Insensitive (QDI) Asynchronous Data Path Synthesis Based on Microcell-Interleaving Genetic Algorithm (MIGA)
Abstract:
In this paper, we propose a design approach to mitigate the hardware overhead of the data completion detection circuit in quasi-delay-insensitive (QDI) asynchronous-logic circuits. In this proposed design approach, three novelties are highlighted. Firstly, a novel microcell-interleaving approach is proposed to reduce the number of completion detection (CD) circuits while retaining the required QDI attribute. Secondly, we analyze the performance of the QDI circuits based on the proposed microcell-interleaving approach graphically in terms of power dissipation, transistor count and delay, and evaluate/determine the upper and lower boundaries of these performance profiles. Thirdly, we propose a microcell-interleaving genetic algorithm (MIGA) to stochastically optimize the proposed microcell-interleaving approach on power dissipation, transistor count, and delay. To validate the proposed design approach, a complete performance profile of ISCAS-85 C499 circuit is investigated on the basis of differential cascode voltage switch logic (DCVSL) and dynamic strong indicating (DSI) microcells. We demonstrate the efficiency of the proposed design approach by benchmarking against the competing DCVSL, null convention logic and DSI designs on five ISCAS-85 circuits. Specifically, the proposed designs, on average, are better in power dissipation, better in area, and better in a composite metric of , and reasonably slower for the lowest power dissipation points. We further demonstrate the practicality of the proposed design approach by implementing an 8-tap 16-bit asynchronous QDI finite impulse response filter. Finally,- we demonstrate the and improved efficiency of the proposed MIGA over the greedy algorithm and dynamic programming, respectively.
Autors: Zhou, R.;Chong, K.;Gwee, B.;Chang, J.S.;
Appeared in: IEEE Transactions on Computer-Aided Design of Integrated Circuits and Systems
Publication date: Jul 2014, volume: 33, issue:7, pages: 989 - 1002
Publisher: IEEE
 
» A Low-Complexity Algorithm for Neighbor Discovery in Wireless Networks
Abstract:
We study a neighbor discovery problem in wireless networks for which each node wishes to identify the so-called neighboring nodes within a single-hop communication. This problem can be optimally addressed using maximum a posteriori (MAP) estimation, but its implementation is notoriously difficult in practice. In this letter, we present a low-complexity algorithm consisting of two stages: 1) we solve such problem using LASSO estimator that is a convex relaxation of MAP estimator to encourage a sparse solution; and 2) we find a desired binary vector (e.g., indicator of neighbor nodes) by taking a “hard-decision” with threshold, carefully chosen by exploiting fading statistics. Finally, we provide some numerical results to confirm that the proposed algorithm performs quite well.
Autors: Hong, S.;Kim, J.;
Appeared in: IEEE Communications Letters
Publication date: Jul 2014, volume: 18, issue:7, pages: 1119 - 1122
Publisher: IEEE
 
» A Machine Vision-Based Maturity Prediction System for Sorting of Harvested Mangoes
Abstract:
Seasonal fruits, like mango (Mangifera Indica L.), are harvested from gardens or farms in batches; the mangoes present in each batch are not uniformly matured, therefore, sorting of mangoes into different groups is necessary for transporting them into different locations. With this background, this paper proposes a machine vision-based system for classification of mangoes by predicting maturity level, and aimed to replace manual sorting system. The prediction of maturity level has been performed from the video signal collected by the Charge Coupled Device (CCD) camera placed on the top of the conveyer belt carrying mangoes. Extracted image frames from the video signal have been corrected and processed to extract various features, which were found to be more relevant for the prediction of maturity level. Recursive feature elimination technique in combination with support vector machine (SVM)-based classifier has been employed to identify the most relevant features among the initially chosen 27 features. Finally, the optimum set of reduced number of features have been obtained and used for classification of the mangoes into four different classes according to the maturity level. For classification, an ensemble of seven binary SVM classifiers has been combined in error correcting output code, and the minimum hamming distance-based rule has been applied in decision making phase. For the experimental study, the mangoes of five different varieties were collected from three different locations and in three different batches. The obtained experimental result found to provide an average classification accuracy up to 96%.
Autors: Nandi, C.S.;Tudu, B.;Koley, C.;
Appeared in: IEEE Transactions on Instrumentation and Measurement
Publication date: Jul 2014, volume: 63, issue:7, pages: 1722 - 1730
Publisher: IEEE
 
» A magnetically shielded room with ultra low residual field and gradient
Abstract:
A versatile and portable magnetically shielded room with a field of (700 ± 200) pT within a central volume of 1 m × 1 m × 1 m and a field gradient less than 300 pT/m, achieved without any external field stabilization or compensation, is described. This performance represents more than a hundredfold improvement of the state of the art for a two-layer magnetic shield and provides an environment suitable for a next generation of precision experiments in fundamental physics at low energies; in particular, searches for electric dipole moments of fundamental systems and tests of Lorentz-invariance based on spin-precession experiments. Studies of the residual fields and their sources enable improved design of future ultra-low gradient environments and experimental apparatus. This has implications for developments of magnetometry beyond the femto-Tesla scale in, for example, biomagnetism, geosciences, and security applications and in general low-field nuclear magnetic resonance (NMR) measurements.
Autors: Altarev, I.;Babcock, E.;Beck, D.;Burghoff, M.;Chesnevskaya, S.;Chupp, T.;Degenkolb, S.;Fan, I.;Fierlinger, P.;Frei, A.;Gutsmiedl, E.;Knappe-Gruneberg, S.;Kuchler, F.;Lauer, T.;Link, P.;Lins, T.;Marino, M.;McAndrew, J.;Niessen, B.;Paul, S.;Petzoldt, G
Appeared in: Review of Scientific Instruments
Publication date: Jul 2014, volume: 85, issue:7, pages: 075106 - 075106-8
Publisher: IEEE
 
» A Mammoth Move: Relocating the 50th Street Substation [History]
Abstract:
THE PRESENT GRAND CENTRAL Terminal on 42nd Street in midtown Manhattan, New York City, opened in 1913. A recent article in this column described in detail the electrification of the terminal to eliminate the need for steam locomotives in its operation (see Figure 1).
Autors: Blalock, T.;
Appeared in: IEEE Power and Energy Magazine
Publication date: Jul 2014, volume: 12, issue:4, pages: 80 - 87
Publisher: IEEE
 
» A Method to Extend Orthogonal Latin Square Codes
Abstract:
Error correction codes (ECCs) are commonly used to protect memories from errors. As multibit errors become more frequent, single error correction codes are not enough and more advanced ECCs are needed. The use of advanced ECCs in memories is, however, limited by their decoding complexity. In this context, one-step majority logic decodable (OS-MLD) codes are an interesting option as the decoding is simple and can be implemented with low delay. Orthogonal Latin squares (OLS) codes are OS-MLD and have been recently considered to protect caches and memories. The main advantage of OLS codes is that they provide a wide range of choices for the block size and the error correction capabilities. In this brief, a method to extend OLS codes is presented. The proposed method enables the extension of the data block size that can be protected with a given number of parity bits thus reducing the overhead. The extended codes are also OS-MLD and have a similar decoding complexity to that of the original OLS codes. The proposed codes have been implemented to evaluate the circuit area and delay needed for different block sizes.
Autors: Reviriego, P.;Pontarelli, S.;Sanchez-Macian, A.;Maestro, J.A.;
Appeared in: IEEE Transactions on Very Large Scale Integration Systems
Publication date: Jul 2014, volume: 22, issue:7, pages: 1635 - 1639
Publisher: IEEE
 
» A Minmax Extremum-Seeking Controller Design Technique
Abstract:
This paper considers the solution of a minmax optimization problem using adaptive extremum seeking control. It is assumed that the equations describing the dynamics of the nonlinear system and the cost function to be minimized are unknown and that the objective function is measured. The appropriate selection of the minimizing and the maximizing inputs is also assumed to be known a priori. The proposed extremum-seeking control technique uses a time-varying estimation of the unknown gradients that minimizes the impact of the choice of dither signal on the performance of the extremum seeking control system. Two examples are used to illustrate the effectiveness of the proposed technique.
Autors: Guay, M.;Dochain, D.;
Appeared in: IEEE Transactions on Automatic Control
Publication date: Jul 2014, volume: 59, issue:7, pages: 1874 - 1886
Publisher: IEEE
 
» A Modified Belief Propagation Polar Decoder
Abstract:
In this paper, a modified belief propagation (BP) polar decoder is proposed. Unlike the orignal BP polar decoders, a check node is added to each node of the proposed decoder. In the BP decoding, the propagated messages of the nodes are modified by multiplying the messages from the check nodes, so as to enhance the reliability of these propagated messages. Numerical results show that the proposed decoder achieves better performance than that of the original BP decoders, only at cost of some additional multiplications, which indicates its effectiveness.
Autors: Zhang, Y.;Liu, A.;Pan, X.;Ye, Z.;Gong, C.;
Appeared in: IEEE Communications Letters
Publication date: Jul 2014, volume: 18, issue:7, pages: 1091 - 1094
Publisher: IEEE
 
» A Monolithic, 500 °C Operational Amplifier in 4H-SiC Bipolar Technology
Abstract:
A monolithic bipolar operational amplifier (opamp) fabricated in 4H-SiC technology is presented. The opamp has been used in an inverting negative feedback amplifier configuration. Wide temperature operation of the amplifier is demonstrated from 25 °C to 500 °C. The measured closed loop gain is around 40 dB for all temperatures whereas the 3 dB bandwidth increases from 270 kHz at 25 °C to 410 kHz at 500 °C. The opamp achieves 1.46 V/ s slew rate and 0.25% total harmonic distortion. This is the first report on high temperature operation of a fully integrated SiC bipolar opamp which demonstrates the feasibility of this technology for high temperature analog integrated circuits.
Autors: Hedayati, R.;Lanni, L.;Rodriguez, S.;Malm, B.G.;Rusu, A.;Zetterling, C.;
Appeared in: IEEE Electron Device Letters
Publication date: Jul 2014, volume: 35, issue:7, pages: 693 - 695
Publisher: IEEE
 
» A Multi-Disciplinary Course Portfolio on Computer Applications in Power Systems
Abstract:
As a response to the new requirements posed by the shift towards Smartgrids, there have been many initiatives worldwide to develop and update power engineering education curricula. This paper reports efforts to develop courses with the purpose to cross the gap between the disciplines of power engineering and information communication technology at KTH—the Royal Institute of Technology in Sweden. The course portfolio is engineered to complement several master programs offered by the university, and the intended audience are students and practitioners both with and without the power engineering background. This paper primarily focuses on details of a keystone course, Computer Applications in Power Systems, and its connection with the other courses in the portfolio. To prove the popularity and relevance of the reported course portfolio, increasingly positive feedback from students, recognition from industry partners, and accomplishments in terms of meeting several strategic goals in education set by the IEEE Power & Energy Society are also reported by this paper.
Autors: Nordstrom, L.;Zhu, K.;Wu, Y.;
Appeared in: IEEE Transactions on Power Systems
Publication date: Jul 2014, volume: 29, issue:4, pages: 1919 - 1927
Publisher: IEEE
 
» A Multi-Objective Collaborative Planning Strategy for Integrated Power Distribution and Electric Vehicle Charging Systems
Abstract:
An elaborately designed integrated power distribution and electric vehicle (EV) charging system will not only reduce the investment and operation cost of the system concerned, but also promote the popularization of environmentally friendly EVs. In this context, a multi-objective collaborative planning strategy is presented to deal with the optimal planning issue in integrated power distribution and EV charging systems. In the developed model, the overall annual cost of investment and energy losses is minimized simultaneously with the maximization of the annual traffic flow captured by fast charging stations (FCSs). Additionally, the user equilibrium based traffic assignment model (UETAM) is integrated to address the maximal traffic flow capturing problem. Subsequently, a decomposition based multi-objective evolutionary algorithm (MOEA/D) is employed to seek the non-dominated solutions, i.e., the Pareto frontier. Finally, collaborative planning results of two coupled distribution and transportation systems are presented to illustrate the performance of the proposed model and solution method.
Autors: Yao, W.;Zhao, J.;Wen, F.;Dong, Z.;Xue, Y.;Xu, Y.;Meng, K.;
Appeared in: IEEE Transactions on Power Systems
Publication date: Jul 2014, volume: 29, issue:4, pages: 1811 - 1821
Publisher: IEEE
 

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