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Electrical and Electronics Engineering publications abstract of: 06-2011 sorted by title, page: 0
» “Top Secret Rosies” [The Good, the Bad, and the Ugly: Engineering FACTS]
Abstract:
Before the invention of electronic computers, “computer” was a job description, not a machine. There were a number of areas where large-scale, repetitive calculations were needed, including actuarial tables for the insurance industry and gunnery tables for the military. Despite the tradition of mathematics-based careers being male dominated and the male-oriented nature of the industries using such computers, women were prominent in the field.
Autors: Geselowitz, M.;
Appeared in: IEEE Women in Engineering Magazine
Publication date: Jun 2011, volume: 5, issue:1, pages: 20 - 21
Publisher: IEEE
 
» 1× N Multimode Interference Beam Splitter Design Techniques for On-Chip Optical Interconnections
Abstract:
We derive an analytical relation for the maximum number of output channels for high-performance multimode interference (MMI)-based 1 × N optical beam splitters for a given MMI width. Using eigenvalue-expansion-based simulation results, we validate the analytical relation. Experimental data from MMIs fabricated on silicon nanomembrane also confirm the effectiveness of the design methodology for on-chip optical beam splitter designs.
Autors: Hosseini, A.;Kwong, D. N.;Zhang, Y.;Subbaraman, H.;Xu, X.;Chen, R. T.;
Appeared in: IEEE Journal of Selected Topics in Quantum Electronics
Publication date: Jun 2011, volume: 17, issue:3, pages: 510 - 515
Publisher: IEEE
 
» 1.3 μm, 50 Gbit/s electroabsorption modulators integrated with DFB laser for beyond 100G parallel LAN applications
Abstract:
A 1.3 μm, 50 Gbit/s electroabsorption modulator integrated with a DFB laser for future parallel LAN, the total data rate of which is over 100 Gbit/s, is developed. Very clear eye openings after 40 km transmission under 50 Gbit/s operation on singlemode fibre are demonstrated for eight wavelengths with discrete packages for the first time.
Autors: Fujisawa, T.;Takahata, K.;Kobayashi, W.;Tadokoro, T.;Fujiwara, N.;Kanazawa, S.;Kano, F.;
Appeared in: Electronics Letters
Publication date: Jun 2011, volume: 47, issue:12, pages: 708 - 710
Publisher: IEEE
 
» 1.8 V Low-Transient-Energy Adaptive Program-Voltage Generator Based on Boost Converter for 3D-Integrated NAND Flash SSD
Abstract:
In this paper we present an adaptive program-voltage generator for 3D-integrated solid state drives (SSDs) based on a boost converter. The converter consists of a spiral inductor, a high-voltage MOS circuit, and an adaptive-frequency and duty-cycle (AFD) controller. The spiral inductor requires an area of only 5 5 mm in an interposer. The high-voltage MOS circuit employs a mature NAND flash process. The AFD controller, implemented in a conventional low-voltage MOS process, dynamically optimizes clock frequencies and duty cycles at different values of output voltage, . The power consumption, rising time, and circuit area of the program-voltage generator are 88%, 73%, and 85% less than those of a program-voltage generator with a conventional charge pump, respectively. The total power consumption of each NAND flash memory is reduced by 68%. We also present the design methodology of the high-voltage MOS circuit of the boost converter with a conventional NAND flash process, in which charge-pump-based program-voltage generators are implemented.
Autors: Ishida, K.;Yasufuku, T.;Miyamoto, S.;Nakai, H.;Takamiya, M.;Sakurai, T.;Takeuchi, K.;
Appeared in: IEEE Journal of Solid-State Circuits
Publication date: Jun 2011, volume: 46, issue:6, pages: 1478 - 1487
Publisher: IEEE
 
» 10 MeV electrons irradiation effects in variously doped n-GaN
Abstract:
We studied 10 MeV electron irradiation effects in a group of n-GaN films grown by standard metalorganic chemical vapor deposition (MOCVD) and by epitaxial lateral overgrowth (ELOG) techniques. The samples were either undoped or Si-doped, so that the shallow donor concentrations ranged from 1014 cm-3 to 3 × 1018 cm-3. It was found that electron irradiation led to the compensation of n-type conductivity and that the carrier removal rate substantially increased with an increase in the starting donor concentration. For the MOCVD samples, it was observed that the main compensating defect introduced by electrons was a 0.15 eV electron trap detected by admittance spectroscopy. Once the Fermi level crossed the level of these traps two other centers with activation energies of 0.2 and 1 eV were found to contribute to the compensation, so that after high doses, the Fermi level in moderately doped samples was pinned near Ec -1 eV. In ELOG samples the 0.15 eV electron traps were not detected. Instead only the 0.2 and 1 eV traps were introduced by irradiation. The carrier removal rate in the ELOG n-GaN was found to be measurably lower than for MOCVD samples with a similar doping level. The results are compared to previously published data and possible models of compensation are discussed.
Autors: Polyakov, A. Y.;Lee, In-Hwan;Smirnov, N. B.;Govorkov, A. V.;Kozhukhova, E. A.;Kolin, N. G.;Korulin, A. V.;Boiko, V. M.;Pearton, S. J.;
Appeared in: Journal of Applied Physics
Publication date: Jun 2011, volume: 109, issue:12, pages: 123703 - 123703-8
Publisher: IEEE
 
» 10th Electron Technology ELTE 2010 and 34th International Microelectronics and Packaging IMAPS/CPMT Poland Joint Conference - Guest Editorial
Abstract:
Andrzej, Dziedzic
Autors: Source: Microelectronics Reliability, Volume 51, Issue 7, July 2011, Pages 1157-1158
Appeared in: Microelectronics Reliability
Publication date: Jun 2011
Publisher: Elsevier B.V.
 
» 12 space shuttle missions that weren't
Abstract:
the U.S. space shuttle fleet is set for retirement following the launch of Atlantis, scheduled for mid-July. In all, the fleet will have flown 135 missions, the first in 1981, but there were many more on the drawing board. With scrubbed missions that included daring rescues, in-orbit satellite snatches, and dangerous explosives, you can see why some of these didn't make the cut. But just imagine if they had.
Autors: Oberg, J.;
Appeared in: IEEE Spectrum
Publication date: Jun 2011, volume: 48, issue:6, pages: 13 - 13
Publisher: IEEE
 
» 21st-Century Data Miners Meet 19th-Century Electrical Cables
Abstract:
Researchers can repurpose even extremely raw historical data for use in prediction.
Autors: Rudin, Cynthia;Passonneau, Rebecca J.;Radeva, Axinia;Ierome, Steve;Isaac, Delfina F.;
Appeared in: Computer
Publication date: Jun 2011, volume: 44, issue:6, pages: 103 - 105
Publisher: IEEE
 
» 235 GHz Amplifier Using 150 nm InP HBT High Power Density Transistor
Abstract:
In this letter, a four-stage 235 GHz heterojunction bipolar transistor (HBT) amplifier is reported. Each stage uses a single-emitter 0.15 InP HBT with collector current density of 25 , maximum frequency of oscillation greater than 500 GHz, and a cutoff frequency of 320 GHz. The MMIC amplifier is realized in inverted microstrip topology. The amplifier demonstrates measured small signal gain of 12.7 dB and output power of 2.6 mW with a power gain of 9.4 dB. This corresponds to transistor output power density of 5.7 at 235 GHz. This is the highest HBT transistor output power density published to date at frequencies above 170 GHz, which indicates high power InP HBT power amplifiers should be viable with on-chip power combining.
Autors: Radisic, V.;Scott, D.;Wang, S.;Cavus, A.;Gutierrez-Aitken, A.;Deal, W. R.;
Appeared in: IEEE Microwave and Wireless Components Letters
Publication date: Jun 2011, volume: 21, issue:6, pages: 335 - 337
Publisher: IEEE
 
» 245-GHz InAlN/GaN HEMTs With Oxygen Plasma Treatment
Abstract:
We report lattice-matched high-electron mobility transistors on a SiC substrate with a record current gain cutoff frequency . The key to this performance is the use of an oxygen plasma treatment to form a thin oxide layer on the InAlN barrier and to reduce the gate leakage current by more than two orders of magnitude. In addition, the RF transconductance collapse is reduced in the -treated devices, which results in a significant improvement in the . In a transistor with a gate length of 30 nm, an of 245 GHz is achieved, the highest value ever reported in GaN-based field-effect transistors.
Autors: Lee, D. S.;Chung, J. W.;Wang, H.;Gao, X.;Guo, S.;Fay, P.;Palacios, T.;
Appeared in: IEEE Electron Device Letters
Publication date: Jun 2011, volume: 32, issue:6, pages: 755 - 757
Publisher: IEEE
 
» 2D analytical calculation of the electric field in lightly doped Schottky barrier double-gate MOSFETs and estimation of the tunneling/thermionic current
Abstract:
 Highlights: ? An analytical approach to calculate the electric field in SB-DG-MOSFETs was presented. ? It is valid for subthreshold region and does not introduce any fitting parameters, all parameters depend on geometry and boundary conditions. ? An approach to calculate the tunneling and thermionic current in SB-DG-MOSFETs was presented. ? The approach shows a good agreement with the simulation results down to 65nm channel lengths in the subthreshold region. ? The model presented here is able to predict the current well for several barrier heights and geometries.

Autors: In this paper we present a new approach to calculate the channel electric field within a Schottky barrier Double-Gate MOSFET (SB-DG-MOSFET) in subthreshold region by solving Poissons equation. The Poisson equation is solved two dimensionally in an an
Appeared in: Solid-State Electronics
Publication date: Jun 2011
Publisher: Elsevier B.V.
 
» 2nd European Conference on Human Centred Design for Intelligent Transport Systems
Abstract:
On-board Traffic Information and Control Systems (TICS) or In-vehicle Information Systems (IVIS) for drivers are becoming more and more common these days. While driving, these systems provide information about the status of the vehicle, the optimal route, traffic jams, etc. Despite the usefulness of such systems, one could be concerned about the potential distraction and the additional cognitive load these systems impose on the driver, leading to an increased risk of accidents. Proper design of the Human- Machine-Interface (HMI) is unequivocally a key factor in balancing the demands for increasing functionality with the already existing physical and mental load of the driver.
Autors: Krems, J.F.;
Appeared in: IET Intelligent Transport Systems
Publication date: Jun 2011, volume: 5, issue:2, pages: 101 - 102
Publisher: IEEE
 
» 3-Cell Network MIMO Architectures with Sectorization and Fractional Frequency Reuse
Abstract:
In this paper, we present a 3-cell network multiple-input multiple-output (MIMO) architecture with fractional frequency frequency (FFR) and a novel tri-sector frequency partition scheme. One fundamental question to apply the network MIMO technique in such a high interference environment is: how many base stations should be coordinated together to provide sufficient performance? We will demonstrate that the FFR-based 3-cell network MIMO architecture with the proposed tri-sector frequency partition can not only effectively overcome the inter-group interference, but can avoid executing the complex multi-base-station joint processing for a huge number of cluster of cells at all locations. It will be shown that the proposed 3-cell network MIMO with the rearranged tri-sector frequency partition strategy can outperform the 7-cell network MIMO with omni-directional antennas. Various sector antenna architectures and the method for determining the inner region of the FFR cell planning are also discussed and analyzed on top of the network MIMO system. We hope that this study can provide important insights into the design of the network MIMO systems from the perspectives of architecture and deployment.
Autors: Li-Chun Wang;Chu-Jung Yeh;
Appeared in: IEEE Journal on Selected Areas in Communications
Publication date: Jun 2011, volume: 29, issue:6, pages: 1185 - 1199
Publisher: IEEE
 
» 30-nm Tunnel FET With Improved Performance and Reduced Ambipolar Current
Abstract:
This paper presents the optimization of double-gate silicon (Si) tunnel field-effect transistors (TFETs). It shows that, for the heterodielectric structure, the ION current is boosted by correctly positioning the source with respect to the gate edge. The second booster used in this paper is the Si thickness that is tuned in order to maximize the ION current. The effects that lead to the performance increase are explained on a physical basis. We also demonstrate that the ambipolar character of the TFET is completely inhibited by using only one spacer of 30-nm length to separate the drain and the gate.
Autors: Anghel, C.;Hraziia;Gupta, A.;Amara, A.;Vladimirescu, A.;
Appeared in: IEEE Transactions on Electron Devices
Publication date: Jun 2011, volume: 58, issue:6, pages: 1649 - 1654
Publisher: IEEE
 
» 3D Shape Reconstruction of Loop Objects in X-Ray Protein Crystallography
Abstract:
Knowledge of the shape of crystals can benefit data collection in X-ray crystallography. A preliminary step is the determination of the loop object, i.e., the shape of the loop holding the crystal. Based on the standard set-up of experimental X-ray stations for protein crystallography, the paper reviews a reconstruction method merely requiring 2D object contours and presents a dedicated novel algorithm. Properties of the object surface (e.g., texture) and depth information do not have to be considered. The complexity of the reconstruction task is significantly reduced by slicing the 3D object into parallel 2D cross-sections. The shape of each cross-section is determined using support lines forming polygons. The slicing technique allows the reconstruction of concave surfaces perpendicular to the direction of projection. In spite of the low computational complexity, the reconstruction method is resilient to noisy object projections caused by imperfections in the image-processing system extracting the contours. The algorithm developed here has been successfully applied to the reconstruction of shapes of loop objects in X-ray crystallography.
Autors: Strutz, T.;
Appeared in: IEEE/ACM Transactions on Computational Biology and Bioinformatics
Publication date: Jun 2011, volume: 8, issue:3, pages: 797 - 807
Publisher: IEEE
 
» 3D Stress-Strain Model of the Nb Sn Wire
Abstract:
The performance of multifilament wires is highly strain-sensitive. Since the strain in each individual filament rather than the overall strain on the wire influences the superconducting properties, it is very important to build a relationship between the internal strain in each filament and external loads. In this study, a 3D model is developed to address the relationship. It is found that the geometry of the cross-section of the filaments plays an important role in the relationship between the stress and strain.
Autors: Chen, J.;Han, K.;Kalu, P. N.;
Appeared in: IEEE Transactions on Applied Superconductivity
Publication date: Jun 2011, volume: 21, issue:3, pages: 2509 - 2512
Publisher: IEEE
 
» 5 technologies that will shape the web
Abstract:
It was 1997-eons ago, in internet years??and the Web was only beginning to take off. People used dial-up modems to get online, and Netscape Navigator was the browser of choice. Google was still a research project of two Stanford students, and Facebook-well, Mark Zuckerberg was a 13-year-old having his Star Wars-themed bar mitzvah. Flash forward to 2011. The Web has since reinvented itself time and again: when businesses embraced it in the late 1990s, when Google dominated search in the early 2000s, when user-generated content became prominent in the mid-2000s. Today the Web is going through another reinvention, morphing into a place where our social interactions are ever more important. And the main force behind this phenomenon is, of course, Facebook, led by Zuckerberg, now a 27-year-old billionaire.
Autors: Ackerman, E.;Guizzo, E.;
Appeared in: IEEE Spectrum
Publication date: Jun 2011, volume: 48, issue:6, pages: 40 - 45
Publisher: IEEE
 
» 60 GHz reflection-type phase shifter using 0.13μm CMOS body-floating switches
Abstract:
A two-bit reflection-type phase shifter (RTPS) is fabricated using 0.13 μm CMOS process for 60 GHz operation. The reflective loads in the RTPS are designed to achieve minimal loss with use of shunt switches and body-floating resistors. The measurement shows an average insertion loss of 6.4 dB for four phase states with the worst case loss of 7.7 dB at 60 GHz.
Autors: Choi, S.H.;Lee, Y.M.;Kim, M.;
Appeared in: Electronics Letters
Publication date: Jun 2011, volume: 47, issue:12, pages: 701 - 703
Publisher: IEEE
 
» 7.4 Gb/s 6.8 mW Source Synchronous Receiver in 65 nm CMOS
Abstract:
A high-frequency jitter tolerant receiver in 65 nm CMOS is presented. Jitter tolerance is improved by tracking correlated jitter using a pulsed clock forwarded from the transmitter side. The clock receiver comprises two injection locked oscillators to frequency-multiply, deskew, and adjust jitter tracking bandwidth. Different data rates and latency mismatch between the clock and data paths are accommodated by a jitter tracking bandwidth that is controllable up to 300 MHz. Each receiver consumes 0.92 pJ/bit operating at 7.4 Gb/s and has a jitter tolerance of 1.5 UI at 200 MHz.
Autors: Hossain, M.;Chan Carusone, A.;
Appeared in: IEEE Journal of Solid-State Circuits
Publication date: Jun 2011, volume: 46, issue:6, pages: 1337 - 1348
Publisher: IEEE
 
» L10 FePt based exchange coupled composite bit patterned films
Abstract:
We demonstrate a 2.5-fold coercivity reduction in FePt based exchange coupled composite bit patterned media (ECC-BPM) by coupling a lower anisotropy Co/Pd–Co/Ni-multilayer system to the top of a high anisotropy FePt L10 film. Furthermore the tight switching field distribution (SFD) of the lower anisotropy system reduces the SFD of the ECC-BPM composite system compared to a single layer FePt film. The relative amount of switching field and SFD reduction in these ECC-BPM arrays agree with corresponding micromagnetic simulations.
Autors: McCallum, A. T.;Krone, P.;Springer, F.;Brombacher, C.;Albrecht, M.;Dobisz, E.;Grobis, M.;Weller, D.;Hellwig, O.;
Appeared in: Applied Physics Letters
Publication date: Jun 2011, volume: 98, issue:24, pages: 242503 - 242503-3
Publisher: IEEE
 
» SmNiO3/NdNiO3 thin film multilayers
Abstract:
Rare earth nickelates RENiO3 (RE=rare earth), which attract interest due to their sharp metal-insulator phase transition, are instable in bulk form due to the necessity of an important oxygen pressure to stabilize Ni in its 3+ state of oxidation. Here, we report the stabilization of RE nickelates in [(SmNiO3)t/(NdNiO3)t]n thin film multilayers, t being the thickness of layers alternated n times. Both bilayers and multilayers have been deposited by metal-organic chemical vapor deposition. The multilayer structure and the presence of the metastable phases SmNiO3 and NdNiO3 are evidenced from by x-ray and Raman scattering. Electric measurements of a bilayer structure further support the structural quality of the embedded RE nickelate layers.
Autors: Girardot, C.;Pignard, S.;Weiss, F.;Kreisel, J.;
Appeared in: Applied Physics Letters
Publication date: Jun 2011, volume: 98, issue:24, pages: 241903 - 241903-3
Publisher: IEEE
 
» p-type conduction induced by N-doping in α-Fe2O3
Abstract:
A p-type N-doped α-Fe2O3 was developed by magnetron sputtering of a Fe2O3 target in a plasma containing N2 and Ar followed by postannealing. Photoelectrochemical measurement under visible light irradiation (>410 nm) showed that NFe2O3 exhibits a typical cathodic photocurrent originated from the p-type conduction. X-ray photoemission spectroscopy indicated that the atomic N incorporated substitutionally at O sites was responsible for the p-type conduction. The concentration of acceptors was very close to that for Zn-doped Fe2O3, a typical p-type α-Fe2O3. This finding would stimulate further research on p-type Fe2O3 for solar fuel generation, etc.
Autors: Morikawa, Takeshi;Kitazumi, Kousuke;Takahashi, Naoko;Arai, Takeo;Kajino, Tsutomu;
Appeared in: Applied Physics Letters
Publication date: Jun 2011, volume: 98, issue:24, pages: 242108 - 242108-3
Publisher: IEEE
 
» -QAM Constellation Formats for DMT Over 1-mm Core Diameter Plastic Optical Fiber
Abstract:
The family of quadrature amplitude modulation (QAM) constellations in combination with discrete multitone modulation is employed to maximize the throughput of 1-mm core diameter plastic optical fibers. Using this scheme together with a bit and power loading algorithm, a bit-rate improvement of 12% is achieved compared with using only -QAM scheme. A bit rate of 5.6 Gb/s is demonstrated over 50 m of 1-mm core diameter graded-index plastic optical fiber (POF).Pub _bookmark Command="[Quick Mark]"
Autors: Visani, D.;Okonkwo, C. M.;Shi, Y.;Yang, H.;van den Boom, H. P. A.;Tartarini, G.;Tangdiongga, E.;Koonen, A. M. J. T.;
Appeared in: IEEE Photonics Technology Letters
Publication date: Jun 2011, volume: 23, issue:12, pages: 768 - 770
Publisher: IEEE
 
» Scaling and Anisotropies in Co-Doped Ba-122 Thin Films
Abstract:
We have successfully grown epitaxial, supercon-ducting films of (Ba-122)with . The films grow without observable correlated defects parallel to the c-axis, as confirmed by TEM. This is also reflected in the absence of a c-axis peak in . In contrast to cuprate high- superconductors such as or even , the pnictides show a rather low anisotropic behavior in their behavior as well as in their upper critical fields, . As a multiband superconductor, Ba-122 exhibits a temperature dependent electronic mass anisotropy.
Autors: Hanisch, J.;Iida, K.;Haindl, S.;Kurth, F.;Kauffmann, A.;Kidszun, M.;Thersleff, T.;Freudenberger, J.;Schultz, L.;Holzapfel, B.;
Appeared in: IEEE Transactions on Applied Superconductivity
Publication date: Jun 2011, volume: 21, issue:3, pages: 2887 - 2890
Publisher: IEEE
 
» Superconductors With Addition of Other Diborides and SiC
Abstract:
The discovery of superconductivity at 39 K in has been catching the attention of scientists due to the possibility of applying the material in magnets and electronic devices operating with cryocoolers (temperatures around 20 K). In the present work, a methodology to optimize the critical current densities of this material is described. bulk samples were prepared and analyzed with the addition of other diborides with the same C32 hexagonal structure as ( , , , and ) and with simultaneous addition of SiC. Microstructural characterization, performed using SEM+EDS and XRD, was extremely important to determine the distribution and compositional characterization of the superconducting phase. Magnetic superconducting characterization using SQUID was performed to determine the best material addition. As a result we could analyze the behavior of each addition on the current transport capacity, including an analysis of the magnetic flux pinning mechanisms.
Autors: Da Silva, L. B. S.;Rodrigues, D.;Serrano, G. D.;Metzner, V. C. V.;Malachevsky, M. T.;Serquis, A.;
Appeared in: IEEE Transactions on Applied Superconductivity
Publication date: Jun 2011, volume: 21, issue:3, pages: 2639 - 2642
Publisher: IEEE
 
» A 0.13- 1-GS/s CMOS Discrete-Time FFT Processor for Ultra-Wideband OFDM Wireless Receivers
Abstract:
A discrete-time (DT) fast Fourier transform (FFT) processor is presented as an architectural approach to Fourier transform processing multigigahertz of spectral bandwidth. The processor is considered with the specific application of demodulating orthogonal frequency-division multiplexing (OFDM) modulation. The processor enables increased receiver linearity beyond that which is typically limited by the signal-to-noise-and-distortion ratio of high sample rate ADCs by performing OFDM demodulation in the DT domain. The circuit design of the prototype DT-FFT processor is presented and measurement results from the CMOS 0.13- test chip are shown. Results show that the processor demodulates OFDM at 1 GS/s with an accuracy better than 2.8% error vector magnitude while drawing 25 mW from a 1.2-V power supply. The processor demonstrates a measured dynamic range of 49 dB, a 13-dB improvement over that of a 6-bit quantization limited all-digital FFT processor and ADC pair. The DT-FFT is also shown to better tolerate large blocking signals with an 8-dB dynamic range improvement. The DT-FFT core area is .
Autors: Lehne, M.;Raman, S.;
Appeared in: IEEE Transactions on Microwave Theory and Techniques
Publication date: Jun 2011, volume: 59, issue:6, pages: 1639 - 1650
Publisher: IEEE
 
» A 0.18?m CMOS ring VCO for clock and data recovery applications
Abstract:
In this paper, a 3.125GHz four stage voltage controlled ring oscillator is presented. The oscillator has been designed in a 0.18?m CMOS process with a 1.8V supply. Behavioral simulations predict an 18% tuning range for the oscillator, with -91dBc/Hz phase noise at 1MHz offset. Its power consumption has been simulated to be as low as 15.3mW and the variation of its DC level of oscillation is 20mV, which corresponds to 1.3% of its mean value. While consuming less area than an LC VCO, the proposed oscillator design achieves a more stable and reliable operation point.
Autors: C., Sánchez-Azqueta , S., Celma , F., Aznar
Appeared in: Microelectronics Reliability
Publication date: Jun 2011
Publisher: Elsevier B.V.
 
» A 0.6-V 0.33-mW 5.5-GHz Receiver Front-End Using Resonator Coupling Technique
Abstract:
In this study, a low-power and low-voltage 5.5-GHz receiver front-end circuit is designed using a resonator coupling technique. An on-chip transformer combined with the parasitic capacitances from a low-noise amplifier (LNA), a mixer, and the transformer itself comprises two coupled resonators of the resonator coupling network (RCN). The RCN functions as a balun, and couples energy from the LNA to the mixer. Under the critical coupling condition, the RCN gives a maximal current gain at resonance frequencies, equivalent to the same level by an ideal transformer. The analysis shows that the current gain is quite tolerable to the coupling coefficient variation, an advantageous feature for on-chip transformer design. The technique is verified by the receiver front-end in 0.18- CMOS technology. The RCN possess a current gain as high as 12 dB at 5.5 GHz. The measured input return loss, conversion gain, and third-order intermodulation intercept point of the entire circuit are 16 dB, 17.4 dB, and 1.5 dBm, respectively. The noise figure is 7.8 dB at the IF frequency of 1 MHz. The power consumption is only 0.33 mW from a 0.6-V supply. The required local oscillator power is only 9.5 dBm. This receiver front-end successfully demonstrates the resonator coupling technique.
Autors: Li, C.-H.;Liu, Y.-L.;Kuo, C.-N.;
Appeared in: IEEE Transactions on Microwave Theory and Techniques
Publication date: Jun 2011, volume: 59, issue:6, pages: 1629 - 1638
Publisher: IEEE
 
» A 1.2-V Piecewise Curvature-Corrected Bandgap Reference in 0.5 m CMOS Process
Abstract:
A 1.2-V piecewise curvature-corrected CMOS bandgap reference (BGR) is proposed. It features in utilizing piecewise nonlinear curvature-corrected current and rail-to-rail operational amplifier to a conventional first-order current-mode BGR. The corrected current is zero, exponential with temperature and proportional to the squared temperature in the lower, middle and higher temperature range (TR). The rail-to-rail operational amplifier biased by a current proportional to absolute temperature (PTAT) helps to provide negative feedback for the proposed BGR. Measured results indicate that the proposed BGR achieves temperature coefficient (TC) of 8.9 ppm/ C in the TR of 40 C–110 C without trimming, power supply rejection (PSR) of 58 dB and line regulation of 2.4 mV/V in the supply range of 1.2–3.2 V. It is fabricated in CSMC 0.5- m mixed-signal CMOS process with power consumption of 48 W and effective chip area of 0.1 mm .
Autors: Li, J.-H.;Zhang, X.-B.;Yu, M.-Y.;
Appeared in: IEEE Transactions on Very Large Scale Integration Systems
Publication date: Jun 2011, volume: 19, issue:6, pages: 1118 - 1122
Publisher: IEEE
 
» A 10-bit 100-MS/s 4.5-mW Pipelined ADC With a Time-Sharing Technique
Abstract:
A 10-bit pipelined ADC employs both opamp-and time-sharing techniques to reduce the power consumption and silicon area. The proposed ADC needs only one opamp to complete the 10-bit conversion. This ADC has been fabricated in a 90-nm digital CMOS technology and occupies only 0.058 . It operates at 100 MS/s and achieves an SNDR of 55.0 dB while the power consumption is 4.5 mW from a 1.0-V supply.
Autors: Huang, Y.-C.;Lee, T.-C.;
Appeared in: IEEE Transactions on Circuits and Systems I: Regular Papers
Publication date: Jun 2011, volume: 58, issue:6, pages: 1157 - 1166
Publisher: IEEE
 
» A 10-bit, 40-MS/s, 1.21 mW Pipelined SAR ADC Using Single-Ended 1.5-bit/cycle Conversion Technique
Abstract:
This paper presents an area efficient 10-bit, 40 MS/s SAR ADC. The design strategy to minimize the circuit area adopts the pipelined architecture. The 10-bit SAR ADC is divided into 4-bit (first stage) and 6-bit (second stage) SAR ADC. The two-stage pipelined structure achieves a reduction of the number of capacitors, which is the dominant source of the circuit area of SAR ADCs. To avoid the comparator offset issue, the proposed single-ended 1.5 bit/cycle algorithm is used in the first stage. The single-ended scheme reduces the conversion cycle while maintaining sufficient tolerance of the comparator offset. The second stage uses a pseudo C-2C architecture that is useful for minimizing the load capacitance of the residue amplifier and minimizing the circuit area. Fabricated in 65-nm CMOS with an active area of 0.06 mm , it achieves a peak SNDR of 55.1 dB and a peak SFDR of 71.5 dB at 40 MS/s sampling rate. The power consumption is 1.21 mW.
Autors: Furuta, M.;Nozawa, M.;Itakura, T.;
Appeared in: IEEE Journal of Solid-State Circuits
Publication date: Jun 2011, volume: 46, issue:6, pages: 1360 - 1370
Publisher: IEEE
 
» A 10-MHz Green-Mode Automatic Reconfigurable Switching Converter for DVS-Enabled VLSI Systems
Abstract:
A power-efficient, high-frequency, automatic reconfigurable switching converter is presented in this paper for DVS-enabled VLSI systems. Tailored to the system-level power management, the proposed cross-layered green-mode (GM) operation scheme adaptively configures the converter into three operation structures to achieve a seamless step-up/down voltage conversion with minimized power loss. In addition, an adaptive power transistor sizing (APTS) scheme is incorporated to further improve efficiency on the transistor level. To enable high-frequency operation in all power regulation conditions, an -assisted single-bound hysteresis controller (SBHC) is also proposed in this work. Meanwhile, in order to suppress output spectrum variations induced by the hysteresis controller, an adaptive frequency compensator (AFC) is employed. The proposed converter was fabricated with IBM 130-nm CMOS process, with a total chip area of 1 mm . Its output voltage can be seamlessly regulated from 0.9 to 2.2 V, with a maximum load power of 400 mW. The input voltage is designed at 1.5 V, but is variable at any level between 0.9 and 1.8 V. The switching frequency of the converter is regulated at 10 MHz in all three operation modes, with 3% deviation. Experimental results show a 26.7- s/V down-tracking and 93.3- s/V up-tracking speed for dynamic voltage scaling (DVS) reference tracking. Line regulation is maintained below 0.8% throughout the full input voltage range, with a lowest value of 0.17%. The power efficiency stays above 80% over the entire 400-mW power range, with a peak value of 92.1% at 1.2-V output and 250-mW load power.
Autors: Zheng, C.;Ma, D.;
Appeared in: IEEE Journal of Solid-State Circuits
Publication date: Jun 2011, volume: 46, issue:6, pages: 1464 - 1477
Publisher: IEEE
 
» A 10.2 Mbps Pulse Harmonic Modulation Based Transceiver for Implantable Medical Devices
Abstract:
A low power wireless transceiver has been presented for near-field data transmission across inductive telemetry links, which operates based on pulse harmonic modulation (PHM). This PHM transceiver uses on-off keying (OOK) of a pattern of pulses to suppress inter-symbol interference (ISI), and its characteristics are suitable for low-power high-bandwidth telemetry in implantable neuroprosthetic devices. To transmit each bit across a pair of high-Q LC-tank circuits, the PHM transmitter generates a string of narrow pulses with specific amplitudes and timing. Each pulse generates a decaying oscillation at the harmonic frequency that the receiver LC-tank is tuned at, which is then superimposed with other oscillations across the receiver at the same frequency, to minimize the ISI. This allows for reaching high data rates without reducing the inductive link quality factor (to extend its bandwidth), which significantly improves the range and selectivity of the link. The PHM receiver architecture is based on non-coherent energy detection with programmable bandwidth and adjustable gain. The PHM transceiver was fabricated in a 0.5- m standard CMOS process, occupying 1.8 mm . The transceiver achieved a measured 10.2 Mbps data rate with a bit error rate (BER) of at 1 cm distance using planar implant sized (1 cm ) figure-8 coils. The PHM transmitter power consumption was 345 pJ/bit and 8.85 pJ/bit at 1 cm and zero link distances, respectively. The receiver dissipates 3 mW at 3.3 V supply voltage.
Autors: Inanlou, F.;Kiani, M.;Ghovanloo, M.;
Appeared in: IEEE Journal of Solid-State Circuits
Publication date: Jun 2011, volume: 46, issue:6, pages: 1296 - 1306
Publisher: IEEE
 
» A 100 pJ/bit, (32,8) CMOS Analog Low-Density Parity-Check Decoder Based on Margin Propagation
Abstract:
One of the key factors underlying the popularity of low-density parity-check (LDPC) code is its iterative decoding algorithm which is amenable to efficient analog and digital implementation. However, different applications of LDPC codes (e.g. wireless sensor networks) impose different sets of constraints which include speed, bit error rates (BER) and energy efficiency. Our previous work reported an algorithmic framework for designing margin propagation (MP) based LDPC decoders where the BER performance can be traded off with its energy efficiency. In this paper we present an analog current-mode implementation of an MP-based (32,8) LDPC decoder. The implementation uses only addition, subtraction and threshold operations and hence is independent of transistor biasing. Measured results from prototypes fabricated in a 0.5 m CMOS process verify the functionality of a (32,8) LDPC decoder and demonstrate the trade-off capability which is realized by adapting a system hyper-parameter. When configured as a min-sum LDPC decoder, the proposed implementation demonstrates superior BER performance compared to the state-of-the-art analog min-sum decoder at SNR greater than 3.5 dB. We show that an optimal configuration of the same MP-based decoder can also deliver up to 3 dB improvement in BER compared to the benchmark min-sum LDPC decoder.
Autors: Gu, M.;Chakrabartty, S.;
Appeared in: IEEE Journal of Solid-State Circuits
Publication date: Jun 2011, volume: 46, issue:6, pages: 1433 - 1442
Publisher: IEEE
 
» A 14 b 23 MS/s 48 mW Resetting ADC
Abstract:
High-resolution, moderate-speed, calibration-free analog-to-digital converters (ADCs) are becoming increasingly difficult to design in low-voltage nanometer-scale CMOS processes. We propose an ADC architecture based on a resetting modulator that achieves high resolution, despite poor component matching and poor analog transistor performance. A prototype design pipelines a second-order resetting modulator and a 10 b cyclic ADC. The device achieves 14 b resolution and samples as a Nyquist converter at 23 MS/s. This calibration-free ADC achieves no missing codes, 87 dB SFDR and 11.7 b ENOB. The ADC is fabricated in 0.18 m CMOS and occupies a core area of 0.5 mm . It consumes 48 mW from a 2 V supply.
Autors: Lee, C. C.;Flynn, M. P.;
Appeared in: IEEE Transactions on Circuits and Systems I: Regular Papers
Publication date: Jun 2011, volume: 58, issue:6, pages: 1167 - 1177
Publisher: IEEE
 
» A 14 bit 200 MS/s DAC With SFDR 78 dBc, IM3 83 dBc and NSD 163 dBm/Hz Across the Whole Nyquist Band Enabled by Dynamic-Mismatch Mapping
Abstract:
This paper presents a 14 bit 200 MS/s current-steering DAC with a novel digital calibration technique called dynamic-mismatch mapping (DMM). By optimizing the switching sequence of current cells to reduce the dynamic integral nonlinearity in an domain, the DMM technique digitally calibrates all mismatch errors so that both the DAC static and dynamic performance can be significantly improved in a wide frequency range. Compared to traditional current source calibration techniques and static-mismatch mapping, DMM can reduce the distortion caused by both amplitude and timing mismatch errors. Compared to dynamic element matching, DMM does not increase the noise floor since the distortion is reduced, not randomized. The DMM DAC was implemented in a 0.14 CMOS technology and achieves a state-of-the-art performance of , and in the whole 100 MHz Nyquist band.
Autors: Tang, Y.;Briaire, J.;Doris, K.;van Veldhoven, R.;van Beek, P. C. W.;Hegt, H. J. A.;van Roermund, A. H. M.;
Appeared in: IEEE Journal of Solid-State Circuits
Publication date: Jun 2011, volume: 46, issue:6, pages: 1371 - 1381
Publisher: IEEE
 
» A 24-GHz Modular Transmit Phased Array
Abstract:
This paper presents a 24-GHz modular transmit phased array based on the extended-resonance technique. The extended-resonance technique, capable of obviating the need for separate power divider and phase shifters, is utilized along with heterodyne mixing in the proposed phased array. Heterodyne mixing allows phase shifting to be performed at lower frequencies. A modular approach is exploited to realize a scalable phased-array design. The design complexity associated with large phased arrays can be significantly reduced by using this approach. Moreover, a modified extended-resonance circuit topology to enhance the scan range is proposed. As a proof-of-principle, the 24-GHz transmit phased array is fabricated and the measurement results are presented.
Autors: Ehyaie, D.;Mortazawi, A.;
Appeared in: IEEE Transactions on Microwave Theory and Techniques
Publication date: Jun 2011, volume: 59, issue:6, pages: 1665 - 1672
Publisher: IEEE
 
» A 2 2 MIMO DVB-T2 System: Design, New Channel Estimation Scheme and Measurements With Polarization Diversity
Abstract:
The increasing interest in MIMO (Multiple-Input Multiple-Output) systems has given rise to a prolific research activity in recent years. Both theoretical and practical issues have been studied. However, so far few MIMO testbeds or prototypes have been built for DVB-T or future standards. In this paper, a novel 2 × 2 MIMO testbed specifically designed for evaluating the performances of a DVB-T2 MIMO system is presented. The description of signal processing is detailed including a new scheme to estimate the MIMO channel matrix. Finally, measurement results with different polarization schemes are presented for typical scenarios, obtaining higher capacity in LoS situations using polarization diversity.
Autors: Gomez-Calero, C.;Cuellar Navarrete, L.;de Haro, L.;Martinez, R.;
Appeared in: IEEE Transactions on Broadcasting
Publication date: Jun 2011, volume: 57, issue:2, pages: 195 - 203
Publisher: IEEE
 
» A 3-D Smith Chart Based on the Riemann Sphere for Active and Passive Microwave Circuits
Abstract:
This letter proposes a spherical 3-D Smith Chart suitable for representing both active and passive microwave circuits. Using the mathematical concept of the Riemann sphere, the extended reflection coefficient plane is transformed into the surface of the unit sphere. Since the proposed Smith Chart compiles the whole complex plane, all possible loads are included. A simple graphic tool is thus obtained that successfully unifies active and passive circuits. In addition, lossy lines with complex characteristic impedances can also be represented. The letter presents the 3-D Smith Chart, provides its main governing equations, and also enumerates its more important properties.
Autors: Muller, A. A.;Soto, P.;Dascalu, D.;Neculoiu, D.;Boria, V. E.;
Appeared in: IEEE Microwave and Wireless Components Letters
Publication date: Jun 2011, volume: 21, issue:6, pages: 286 - 288
Publisher: IEEE
 
» A 3.6 s Latency Asynchronous Frame-Free Event-Driven Dynamic-Vision-Sensor
Abstract:
This paper presents a 128 128 dynamic vision sensor. Each pixel detects temporal changes in the local illumination. A minimum illumination temporal contrast of 10% can be detected. A compact preamplification stage has been introduced that allows to improve the minimum detectable contrast over previous designs, while at the same time reducing the pixel area by 1/3. The pixel responds to illumination changes in less than 3.6 . The ability of the sensor to capture very fast moving objects, rotating at 10 K revolutions per second, has been verified experimentally. A frame-based sensor capable to achieve this, would require at least 100 K frames per second.
Autors: Lenero-Bardallo, J. A.;Serrano-Gotarredona, T.;Linares-Barranco, B.;
Appeared in: IEEE Journal of Solid-State Circuits
Publication date: Jun 2011, volume: 46, issue:6, pages: 1443 - 1455
Publisher: IEEE
 
» A 3.6 s Latency Asynchronous Frame-Free Event-Driven Dynamic-Vision-Sensor
Abstract:
This paper presents a 128 × 128 dynamic vision sensor. Each pixel detects temporal changes in the local illumination. A minimum illumination temporal contrast of 10% can be detected. A compact preamplification stage has been introduced that allows to improve the minimum detectable contrast over previous designs, while at the same time reducing the pixel area by 1/3. The pixel responds to illumination changes in less than 3.6 μs. The ability of the sensor to capture very fast moving objects, rotating at 10 K revolutions per second, has been verified experimentally. A frame-based sensor capable to achieve this, would require at least 100 K frames per second.
Autors: Leñero-Bardallo, J.A.;Serrano-Gotarredona, T.;Linares-Barranco, B.;
Appeared in: IEEE Journal of Solid-State Circuits
Publication date: Jun 2011, volume: 46, issue:6, pages: 1443 - 1455
Publisher: IEEE
 
» A 32 x 32 element row-column addressed capacitive micromachined ultrasonic transducer
Abstract:
This paper presents characterization and initial imaging results of a 32 x 32 element two-dimensional capacitive micromachined ultrasonic transducer array. The devices are fabricated using a wafer bonding process in which both the insulation layer and the membrane are user-deposited silicon nitride. The transducers use a row-column addressing scheme to simplify the fabrication process and beamformer. By adjusting the number of rows and columns that are biased, the effective aperture of the transducer can be adjusted. This is significant because it permits imaging in the near-field of the transducer without the use of a lens. The effect on the transmit beam profile is demonstrated. The transducer has a center frequency of 5.9 MHz and a relative bandwidth of 110%. Images of horizontal and vertical wires are taken to demonstrate image resolution. A three-dimensional image of four pin heads is also demonstrated.
Autors: Logan, A.S.;Wong, L.L.P.;Chen, A.I.H.;Yeow, J.T.W.;
Appeared in: IEEE Transactions on Ultrasonics, Ferroelectrics and Frequency Control
Publication date: Jun 2011, volume: 58, issue:6, pages: 1266 - 1271
Publisher: IEEE
 
» A 3T Gain Cell Embedded DRAM Utilizing Preferential Boosting for High Density and Low Power On-Die Caches
Abstract:
Circuit techniques for enabling a sub-0.9 V logic-compatible embedded DRAM (eDRAM) are presented. A boosted 3T gain cell utilizes Read Word-line (RWL) preferential boosting to increase read margin and improve data retention time. Read speed is enhanced with a hybrid current/voltage sense amplifier that allows the Read Bit-line (RBL) to remain close to VDD. A regulated bit-line write scheme for driving the Write Bit-line (WBL) is equipped with a steady-state storage node voltage monitor to overcome the data ‘1’ write disturbance problem of the PMOS gain cell without introducing another boosted supply for the Write Word-line (WWL) over-drive. An adaptive and die-to-die adjustable read reference bias generator is proposed to cope with PVT variations. Monte Carlo simulations compare the 6-sigma read and write performance of proposed eDRAM against conventional designs. Measurement results from a 64 kb eDRAM test chip implemented in a 65 nm low-leakage CMOS process show a 1.25 ms data retention time with a 2 ns random cycle time at 0.9 V, 85 , and a 91.3 per Mb static power dissipation at 1.0 V, 85 .
Autors: Chun, K. C.;Jain, P.;Lee, J. H.;Kim, C. H.;
Appeared in: IEEE Journal of Solid-State Circuits
Publication date: Jun 2011, volume: 46, issue:6, pages: 1495 - 1505
Publisher: IEEE
 
» A 5 Gb/s Automatic Within-Pair Skew Compensator for Differential Data in 0.13 CMOS
Abstract:
This paper presents an automatic within-pair skew compensator for high-speed differential data transmission. A wide-bandwidth data delay line is proposed to provide adjustable delay for data signals. Also presented is an on-chip within-pair skew detection circuit to detect skew between the differential data signals for automatic close-loop skew compensation. A within-pair skew compensator prototype for 5 Gb/s data was fabricated in 0.13 CMOS. Measurement results show that the within-pair skew compensator can automatically compensate for within-pair skew of 200 ps ( 1 unit interval). It consumes 20.4 mW from 1.2 V supply and occupies 0.015 die area.
Autors: Zheng, Y.;Liu, J.;
Appeared in: IEEE Transactions on Circuits and Systems I: Regular Papers
Publication date: Jun 2011, volume: 58, issue:6, pages: 1191 - 1202
Publisher: IEEE
 
» A 59–66 GHz Highly Stable Millimeter Wave Amplifier in 130 nm CMOS Technology
Abstract:
The design and fabrication of four-stage cascaded mm-wave low noise amplifiers (LNAs) in a 130 nm CMOS technology are presented. The simultaneous high stability factor and low noise figure are obtained using proper inductors in both gate and source of the transistor. Measured gain of 14.7 dB with a 7 GHz bandwidth has been achieved. The larger inductors are realized with microstrip lines to improve the performance of the LNA and minimize the circuit size.
Autors: Fahimnia, M.;Mohammad-Taheri, M.;Wang, Y.;Yu, M.;Safavi-Naeini, S.;
Appeared in: IEEE Microwave and Wireless Components Letters
Publication date: Jun 2011, volume: 21, issue:6, pages: 320 - 322
Publisher: IEEE
 
» A 60 GHz Broadband Stacked FET Power Amplifier Using 130 nm Metamorphic HEMTs
Abstract:
A V-band monolithic microwave integrated circuit power amplifier (PA) using metamorphic high electron mobility transistors (mHEMTs) is developed using a stacked-FET structure. Design methodology to optimize the series power combining power amplifiers at millimeter-waves is also presented. The fabricated PA using triple-stacked 130 nm mHEMTs shows a gain of 16 dB and a saturated output power of 20 dBm with a power added efficiency of 19% at 59 GHz. The 3 dB output power bandwidth is as wide as 15 GHz.
Autors: Kim, Y.;Koh, Y.;Kim, J.;Lee, S.;Jeong, J.;Seo, K.;Kwon, Y.;
Appeared in: IEEE Microwave and Wireless Components Letters
Publication date: Jun 2011, volume: 21, issue:6, pages: 323 - 325
Publisher: IEEE
 
» A 60 pW g C Continuous Wavelet Transform Circuit for Portable EEG Systems
Abstract:
This paper presents a low power, low voltage and low frequency bandpass filter implementation of a continuous wavelet transform (CWT) for use with physiological signals in the electroencephalogram (EEG) range (1–150 V, 1–70 Hz bandwidth). Experimental results are presented for a 1 V, 7th order g C filter based CWT with filter center frequencies ranging from 1 to 64 Hz.
Autors: Casson, A. J.;Rodriguez-Villegas, E.;
Appeared in: IEEE Journal of Solid-State Circuits
Publication date: Jun 2011, volume: 46, issue:6, pages: 1406 - 1415
Publisher: IEEE
 
» A 60 pW g C Continuous Wavelet Transform Circuit for Portable EEG Systems
Abstract:
This paper presents a low power, low voltage and low frequency bandpass filter implementation of a continuous wavelet transform (CWT) for use with physiological signals in the electroencephalogram (EEG) range (1-150 μV, 1-70 Hz bandwidth). Experimental results are presented for a 1 V, 7th order gmC filter based CWT with filter center frequencies ranging from 1 to 64 Hz. Low power and low frequency operation is achieved by biasing the transconductor transistors at low current levels in the deep weak inversion region. The resulting increased mismatch and reduced bandwidth are compensated for at the topology level. The filter has a 43 dB dynamic range and a 60 pW power consumption. This power consumption is three orders of magnitude lower than existing CWT implementations and assessed via a suitable figure of merit the performance is better than all considered bandpass filters. The improvement in the state-of-the-art originates from the close integration of the application requirements, CWT theory, bandpass filter design theory, and low transconductance transconductor design. These topics are described in detail.
Autors: Casson, A.J.;Rodriguez-Villegas, E.;
Appeared in: IEEE Journal of Solid-State Circuits
Publication date: Jun 2011, volume: 46, issue:6, pages: 1406 - 1415
Publisher: IEEE
 
» A 92 GHz Bandwidth Distributed Amplifier in a 45 nm SOI CMOS Technology
Abstract:
A low-power cascode distributed amplifier is demonstrated in a 45 nm silicon-on-insulator (SOI) CMOS process. The amplifier achieves a 3 dB bandwidth of 92 GHz. The peak gain is 9 dB with a gain-ripple of less 1.5 dB over the 3 dB bandwidth. The group-delay variation is under over the 3 dB bandwidth. The amplifier consumes 73.5 mW from a 1.2 V supply and results in a gain-bandwidth efficiency figure of merit of 3.53 GHz/mW. The chip occupies an area of 0.45 including the pads.
Autors: Kim, J.;Buckwalter, J. F.;
Appeared in: IEEE Microwave and Wireless Components Letters
Publication date: Jun 2011, volume: 21, issue:6, pages: 329 - 331
Publisher: IEEE
 
» A -Band Injection-Locked Frequency Divider With Inductive Feedback for a Locking Range Enhancement
Abstract:
An injection-locked frequency divider (ILFD) with an inductive feedback for enhanced locking range has been developed in a commercial 0.13 Si RFCMOS technology and compared with a conventional ILFD. The proposed ILFD showed a significant improvement in the locking range over the conventional ILFD, operating at a frequency range of 43.60–48.95 GHz. The dc power consumption of the ILFD was 0.58 mW with a supply voltage of 1.2 V for the divider core.
Autors: Seo, H.;Seo, S.;Jeon, S.;Rieh, J.-S.;
Appeared in: IEEE Microwave and Wireless Components Letters
Publication date: Jun 2011, volume: 21, issue:6, pages: 317 - 319
Publisher: IEEE
 
» A Ball Grid Array Package With a Microstrip Grid Array Antenna for a Single-Chip 60-GHz Receiver
Abstract:
This paper presents the design of a ball grid array package and more importantly describes the integration of a microstrip grid array antenna in the package in a low temperature cofired ceramic (LTCC) technology for a single-chip 60-GHz receiver. The grid array package has a small volume of 13.5 8 1.265 mm and can house a 60-GHz receiver die of current size. The package samples were fabricated and measured. The package part demonstrates low insertion loss dB and excellent matching with return loss dB below 5 GHz; while the antenna part achieves good matching ( dB), high efficiency , and directional patterns with the main beam in the boresight direction from 57 to 64 GHz as well as high gain with the peak value of 14.5 dBi at 60 GHz.
Autors: Sun, M.;Zhang, Y. P.;Liu, D.;Chua, K. M.;Wai, L. L.;
Appeared in: IEEE Transactions on Antennas and Propagation
Publication date: Jun 2011, volume: 59, issue:6, pages: 2134 - 2140
Publisher: IEEE
 
» A Beacon of Light
Abstract:
Oligonucleotide-Templated nanoclusters (NCs) consisting of a few atoms of silver (DNA/Ag NCs) have been made into a new molecular probe that lights up upon target DNA binding, termed a NanoCluster Beacon (NCB). We discovered that the interactions between silver NCs and a proximal, guanine-rich DNA strand can lead to tremendous red fluorescence enhancement [1].
Autors: Hsin-Chih Yeh;Sharma, J.;Han, J.J.;Martinez, J.S.;Werner, J.H.;
Appeared in: IEEE Nanotechnology Magazine
Publication date: Jun 2011, volume: 5, issue:2, pages: 28 - 33
Publisher: IEEE
 
» A bi-phase enabled serial acquisition system for remote processing of digitized ECG
Abstract:
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Autors:

Graphical abstract

 Graphical abstract: ECG signal acquisition from remote patients for diagnosis and clinical decision making has been one of thrust areas of engineering and scientific research from long time. Several communication media hav
Appeared in: Computers & Electrical Engineering
Publication date: Jun 2011
Publisher: Elsevier B.V.
 
» A Boltzmann-weighted hopping model of charge transport in organic semicrystalline films
Abstract:
We present a model of charge transport in polycrystalline electronic films, which considers details of the microscopic scale while simultaneously allowing realistically sized films to be simulated. We discuss the approximations and assumptions made by the model, and rationalize its application to thin films of directionally crystallized poly(3-hexylthiophene). In conjunction with experimental data, we use the model to characterize the effects of defects in these films. Our findings support the hypothesis that it is the directional crystallization of these films, rather than their defects, which causes anisotropic mobilities.
Autors: Kwiatkowski, Joe J.;Jimison, Leslie H.;Salleo, Alberto;Spakowitz, Andrew J.;
Appeared in: Journal of Applied Physics
Publication date: Jun 2011, volume: 109, issue:11, pages: 113720 - 113720-6
Publisher: IEEE
 
» A Brief History of Multiprocessors and EDA
Abstract:
The Last Byte takes a brief look at the recent history of multiprocessor design and EDA to see where the community stands today. Turning sophisticated systems into commodity items has presented its share of problems, but innovation continues to thrive, nonetheless, and offers considerable promise for validation and testing solutions.
Autors: Shukla, Sandeep;Mishra, Prabhat;Zilic, Zeljko;
Appeared in: IEEE Design & Test of Computers
Publication date: Jun 2011, volume: 28, issue:3, pages: 96 - 96
Publisher: IEEE
 
» A brief survey of radio access network backhaul evolution: part I
Abstract:
As radio access networks (RAN) are evolving, the accompanying backhaul technologies are also being adapted constantly to meet the required cost-performance curve. The evolution in the RAN backhaul is being triggered by the adoption of Ethernet as the physical interface and the proven advantages of IP in simplifying the network layer. This article attempts to survey some of the prevalent and upcoming backhaul technology trends based on the aforementioned evolution within RAN. Wherever possible, a critical analysis of a particular technology trend for its technical and commercial feasibility is also presented.
Autors: Raza, H.;
Appeared in: IEEE Communications Magazine
Publication date: Jun 2011, volume: 49, issue:6, pages: 164 - 171
Publisher: IEEE
 
» A Broadband 900-GHz Silicon Micromachined Two-Anode Frequency Tripler
Abstract:
The design, fabrication, and measurement are presented for a 900-GHz frequency tripler with silicon micromachined blocks made using deep reactive ion etching. The broadband design results in more than 60 between 877.5–922.5 GHz and the peak output power of 85.3 in the frequency response, all measured at room temperature. In power sweep measurement, the tripler delivers the maximum power of 109.3 at 909 GHz. This is the first demonstration of a frequency tripler using silicon micromachining at these frequencies and suggests that this technology is a viable option for receiver arrays in the terahertz frequency range.
Autors: Li, Y.;Mehdi, I.;Maestrini, A.;Lin, R. H.;Papapolymerou, J.;
Appeared in: IEEE Transactions on Microwave Theory and Techniques
Publication date: Jun 2011, volume: 59, issue:6, pages: 1673 - 1681
Publisher: IEEE
 
» A Calderón-Preconditioned Single Source Combined Field Integral Equation for Analyzing Scattering From Homogeneous Penetrable Objects
Abstract:
A new regularized single source equation for analyzing scattering from homogeneous penetrable objects is presented. The proposed equation is a linear combination of a Calderón-preconditioned single source electric field integral equation and a single source magnetic field integral equation. The equation is immune to low-frequency and dense-mesh breakdown, and free from spurious resonances. Unlike dual source formulations, this equation involves operator products that cannot be discretized using standard procedures for discretizing standalone electric, magnetic, and combined field operators. Instead, the single source equation proposed here is discretized using a recently developed technique that achieves a well-conditioned mapping from div- to curl-conforming function spaces, thereby fully respecting the space mapping properties of the operators involved, and guaranteeing accuracy and stability. Numerical results show that the proposed equation and discretization technique give rise to rapidly convergent solutions. They also validate the equation's resonant free character.
Autors: Valdes, F.;Andriulli, F. P.;Bagci, H.;Michielssen, E.;
Appeared in: IEEE Transactions on Antennas and Propagation
Publication date: Jun 2011, volume: 59, issue:6, pages: 2315 - 2328
Publisher: IEEE
 
» A cDNA Microarray Gene Expression Data Classifier for Clinical Diagnostics Based on Graph Theory
Abstract:
Despite great advances in discovering cancer molecular profiles, the proper application of microarray technology to routine clinical diagnostics is still a challenge. Current practices in the classification of microarrays' data show two main limitations: the reliability of the training data sets used to build the classifiers, and the classifiers' performances, especially when the sample to be classified does not belong to any of the available classes. In this case, state-of-the-art algorithms usually produce a high rate of false positives that, in real diagnostic applications, are unacceptable. To address this problem, this paper presents a new cDNA microarray data classification algorithm based on graph theory and is able to overcome most of the limitations of known classification methodologies. The classifier works by analyzing gene expression data organized in an innovative data structure based on graphs, where vertices correspond to genes and edges to gene expression relationships. To demonstrate the novelty of the proposed approach, the authors present an experimental performance comparison between the proposed classifier and several state-of-the-art classification algorithms.
Autors: Benso, A.;Di Carlo, S.;Politano, G.;
Appeared in: IEEE/ACM Transactions on Computational Biology and Bioinformatics
Publication date: Jun 2011, volume: 8, issue:3, pages: 577 - 591
Publisher: IEEE
 
» A Charge-Domain Auto- and Cross-Correlation Based Data Synchronization Scheme With Power- and Area-Efficient PLL for Impulse Radio UWB Receiver
Abstract:
A 1.2 V 100 Mb/s 2.93 mW discrete-time charge-domain impulse radio ultra-wideband (IR-UWB) receiver is developed in 65 nm CMOS. In the charge-domain, the template of the correlator is represented by capacitance and the correlation is implemented by charge addition instead of voltage multiplication and voltage integration. Power consumption of the charge-domain receiver is minimized by a novel auto- and cross-correlation based synchronization scheme. To reduce the power consumption and the chip area of the PLL clock generator for the receiver, a dual charge-pump PLL is proposed to scale up the capacitance of the loop filter without extra charge-pump current. The developed UWB receiver with the area- and power-efficient PLL achieves the energy consumption of 29.3 pJ/bit with the 62.5-ps timing step for data synchronization.
Autors: Liu, L.;Sakurai, T.;Takamiya, M.;
Appeared in: IEEE Journal of Solid-State Circuits
Publication date: Jun 2011, volume: 46, issue:6, pages: 1349 - 1359
Publisher: IEEE
 
» A cluster-based routing protocol for wireless sensor networks with nonuniform node distribution
Abstract:
 Abstract: Due to the nonuniform node distribution, the energy consumption among nodes are more imbalanced in cluster-based wireless sensor networks. Based on this problem, in this paper, a cluster-based routing protocol for wireless sensor networks with nonuniform node distribution is proposed, which includes an energy-aware clustering algorithm EADC and a cluster-based routing algorithm. EADC uses competition range to construct clusters of even sizes. At the same time, the routing algorithm increases forwarding tasks of the nodes in scarcely covered areas by forcing cluster heads to choose nodes with higher energy and fewer member nodes as their next hops, and finally, achieves...
Autors: Jiguo, Yu , Yingying, Qi , Guanghui, Wang , Xin, Gu
Appeared in: AEU - International Journal of Electronics and Communications
Publication date: Jun 2011
Publisher: Elsevier B.V.
 
» A Cluster-Validity Index Combining an Overlap Measure and a Separation Measure Based on Fuzzy-Aggregation Operators
Abstract:
Since a clustering algorithm can produce as many partitions as desired, one needs to assess their quality in order to select the partition that most represents the structure in the data, if there is any. This is the rationale for the cluster-validity (CV) problem and indices. This paper presents a CV index that helps to find the optimal number of clusters of data from partitions generated by a fuzzy-clustering algorithm, such as the fuzzy c-means (FCM) or its derivatives. Given a fuzzy partition, this new index uses a measure of multiple cluster overlap and a separation measure for each data point, both based on an aggregation operation of membership degrees. Experimental results on artificial and benchmark datasets are given to demonstrate the performance of the proposed index, as compared with traditional and recent indices.
Autors: Le Capitaine, H.;Frelicot, C.;
Appeared in: IEEE Transactions on Fuzzy Systems
Publication date: Jun 2011, volume: 19, issue:3, pages: 580 - 588
Publisher: IEEE
 
» A CMOS 4.35-mW +22-dBm IIP3 Continuously Tunable Channel Select Filter for WLAN/WiMAX Receivers
Abstract:
A low-power high linearity CMOS G -C channel select filter for WLAN/WiMAX receivers in 90-nm CMOS technology is presented. To reduce power consumption a biquad cell with simple architecture is used. A simple but efficient technique is also proposed to improve the linearity of the filter without increasing its power consumption. Coarse and fine tuning techniques are used to tune the cutoff frequency of the sixth-order Butterworth low-pass filter from 8.1 MHz to 13.5 MHz suitable for WLAN and WiMAX applications. The measurement results show an in-band IIP3 of 22 dBm, an HD3 better than 40 dB at 470 mV input signal amplitude, and an input referred noise of 75 nV/ Hz at a power consumption of 4.35 mW from a 1-V supply. The differential filter occupies a chip area of 0.239 mm excluding pads.
Autors: Savadi Oskooei, M.;Masoumi, N.;Kamarei, M.;Sjoland, H.;
Appeared in: IEEE Journal of Solid-State Circuits
Publication date: Jun 2011, volume: 46, issue:6, pages: 1382 - 1391
Publisher: IEEE
 
» A Community Knowledge Base for IT Security
Abstract:
Does every organization need to reinvent the wheel when it comes to IT security? Not if the IT community can develop a formal knowledge base for sharing and applying IT security management knowledge.
Autors: Fenz, Stefan;Parkin, Simon;Moorsel, Aad van;
Appeared in: IT Professional
Publication date: Jun 2011, volume: 13, issue:3, pages: 24 - 30
Publisher: IEEE
 
» A compact digital time differential perturbed angular correlation-spectrometer using field programmable gate arrays and various timestamp algorithms
Abstract:
A user-friendly fully digital time differential perturbed angular correlation (TDPAC)-spectrometer with six detectors and fast digitizers using field programmable gate arrays (FPGA) is described and performance data are given. The new spectrometer has an online data analysis feature, a compact size, and a time resolution such as conventional analog spectrometers. Its calculation intensive part was implemented inside the digitizer. This gives the possibility to change parameters (energy windows, constant fraction trigger delay) and see their influence immediately in the γ-γ correlation diagrams. Tests were performed which showed that the time resolution using a 60Co source with energy window set at 1.17 MeV and 1.33 MeV is 265 ps with LaBr3(Ce) scintillators and 254 ps with BaF2 scintillators. A true constant fraction algorithm turned out to be slightly better than the constant fraction of amplitude method. The spectrometer performance was tested with a TDPAC measurement using a 44Ti in rutile source and a positron lifetime measurement using 22Na. The maximum possible data rate of the spectrometer is 1.1 × 106 γ quanta per detector and second.
Autors: Jager, Markus;Iwig, Kornelius;Butz, Tilman;
Appeared in: Review of Scientific Instruments
Publication date: Jun 2011, volume: 82, issue:6, pages: 065105 - 065105-9
Publisher: IEEE
 
» A Comparative Study on Control Algorithm for Active Front-End Rectifier of Large Motor Drives Under Unbalanced Input
Abstract:
This paper investigates unbalance compensating control algorithms for the active front-end rectifier employed in high-power motor drive systems. The generic voltage-source-converter topology of the three-level neutral-point clamped rectifier is selected for the comparative study. Three different control algorithms have been formulated based on the symmetrical components and synchronous frames under generalized unbalanced operating conditions. Control algorithms have been investigated with respect to major design factors in large drive systems: fault ride-through capability, harmonic distortions, and efficiency. The control algorithm having zero amplitude of negative-sequence input current shows the most optimized and cost-effective performance regarding the fault ride-through capability and efficiency aspects. The control algorithm nullifying the oscillating components of the instantaneous active power generates the least harmonic distortions. A combination of these two control algorithms depending on system requirements and operating modes provides improved performance factors of fault ride-through capability, low harmonic distortions, and efficiency under generalized unbalanced operating conditions.
Autors: Suh, Y.;Go, Y.;Rho, D.;
Appeared in: IEEE Transactions on Industry Applications
Publication date: Jun 2011, volume: 47, issue:3, pages: 1419 - 1431
Publisher: IEEE
 
» A Comparative Study on Uplink Sum Capacity with Co-Located and Distributed Antennas
Abstract:
It has been long believed that the distributed antenna system (DAS) has great potentials for capacity improvement compared to the traditional cellular system with co-located base-station antennas. Intuitively, the distributed characteristic of antennas provides a much more efficient utilization of spatial resources. It, however, also significantly complicates the channel modeling and system analysis. Despite an increasing amount of academic attention and industrial interest, how to characterize the capacity advantages of the DAS in the multiuser scenario remains largely unknown. In this paper, we present a comparative study on the uplink ergodic sum capacity with multiple base-station antennas either co-located or uniformly distributed within a given area. We demonstrate that under the same consumption of transmission power, enormous gains can be achieved by the distributed antenna layout thanks to (1) reduced minimum access distance of each user; and (2) enhanced channel fluctuations which provide a significant boost to the sum capacity when the channel state information is available at both the transmitter and the receiver sides. We further apply the analysis to a cellular system with full cooperation among base stations. The comparison verifies that the DAS yields a much higher sum capacity, and capacity gains increase with the number of base-station antennas per cell.
Autors: Lin Dai;
Appeared in: IEEE Journal on Selected Areas in Communications
Publication date: Jun 2011, volume: 29, issue:6, pages: 1200 - 1213
Publisher: IEEE
 
» A Comparison of Control and Modulation Schemes for Medium-Voltage Drives: Emerging Predictive Control Concepts Versus PWM-Based Schemes
Abstract:
Control and modulation schemes for ac electrical drives synthesize switched three-phase voltage waveforms that control the electrical machine. Particularly in medium-voltage applications, the aim is to minimize both the switching losses in the inverter and the harmonic distortions of the stator currents and the torque. For a given modulation scheme, lower switching losses usually imply higher distortion factors and vice versa. This tradeoff can be described by a hyperbolic function, as shown in this paper for pulsewidth modulation (PWM). A number of predictive control concepts are rapidly emerging. Their characteristic hyperbolic tradeoff functions are derived, compared with each other, and benchmarked with respect to PWM and offline optimized pulse patterns (OPPs). It is shown that predictive schemes with long prediction horizons shift the performance tradeoff curve toward the origin, thus lowering both the switching losses and the harmonic distortions. As a result, at steady-state operating conditions, these predictive schemes achieve a performance similar to OPPs, while providing a superior dynamic performance during transients.
Autors: Geyer, T.;
Appeared in: IEEE Transactions on Industry Applications
Publication date: Jun 2011, volume: 47, issue:3, pages: 1380 - 1389
Publisher: IEEE
 
» A comparison of harvest index estimation methods of winter wheat based on field measurements of biophysical and spectral data
Abstract:
 Highlights: ? Nitrogen (N) fertilizer had a great effect on the harvest index (HI) of winter wheat. ? The fraction of water transpired after anthesis of winter wheat was not sensitive to the N deficiency. ? The relation between HI and the fraction of aboveground biomass accumulation after anthesis was uncertain. ? The ratio of the mean NDVI after anthesis to that of the pre-anthesis period was valuable in HI estimation. ? It gave a good accuracy in HI estimation of winter wheat just using the canopy NDVI data after anthesis.

Autors: Crop harvest index (HI) is a key parameter in grain yield simulation from indirect biomass estimates and varies with crop growth conditions. How to access the HI still remains an issue to be addressed. Several HI estimation techniques for wheat have
Appeared in: Biosystems Engineering
Publication date: Jun 2011
Publisher: Elsevier B.V.
 
» A Comparison of Recent Elevation Change Estimates of the Devon Ice Cap as Measured by the ICESat and EnviSAT Satellite Altimeters
Abstract:
We have used surface elevation measurements acquired by the Ice, Cloud,and land Elevation Satellite Geoscience Laser Altimeter System (GLAS) and EnviSAT Radar Altimeter 2 (RA-2) satellite altimeters to assess the elevation change of the 13 700-km2 Devon Ice Cap (DIC) in Arctic Canada between 2002 and 2008. We present algorithms for the retrieval of elevation change rates over ice caps using data acquired from these satellites. A comparison of GLAS elevation data to those acquired by the RA-2 shows reasonable agreement between the two instruments; the root mean square elevation change difference was 56 cm, and the correlation coefficient between the two data sets was 0.68. Using only RA-2 elevation measurements, which are spatially and temporally more continuous, we determined the elevation change rate of the areas of the DIC where the surface geometry allows the RA-2 retracker to maintain lock. This includes most of the DIC, excluding large parts of the eastern half of the ice cap. The elevation change rate was found to be insignificant given a statistical estimate of the measurement error (-0.09 ± 0.29 m/a). We also present an assessment of the regional variations of the DIC elevation change, including a significant -0.71 ± 0.49 m/a elevation change rate of the 1980-km2 western arm. Furthermore, we present evidence of a localized 2-m drop in the surface elevation of the South Croker Bay Glacier during summer 2007. This drop is apparent within both satellite data sets, and we interpret this signal to reflect a sudden speedup of the glacier.
Autors: Rinne, E.;Shepherd, A.;Muir, A.;Wingham, D.;
Appeared in: IEEE Transactions on Geoscience and Remote Sensing
Publication date: Jun 2011, volume: 49, issue:6, pages: 1902 - 1910
Publisher: IEEE
 
» A Comprehensive LER-Aware TDDB Lifetime Model for Advanced Cu Interconnects
Abstract:
A time-dependent dielectric breakdown (TDDB) lifetime model predicting the impact of line-edge roughness (LER) on Cu interconnect reliability is proposed. The structure, validity, and accuracy of the model are evaluated and discussed. The model is applied to an interconnect scaling scenario that includes conventional patterning and spacer-defined patterning of nanometer-scale Cu wires. LER-aware TDDB lifetime predictions are obtained from the model, and consequent recommendations on how to improve the TDDB lifetime of future interconnects are derived.
Autors: Stucchi, M.;Roussel, P. J.;Tokei, Z.;Demuynck, S.;Groeseneken, G.;
Appeared in: IEEE Transactions on Device and Materials Reliability
Publication date: Jun 2011, volume: 11, issue:2, pages: 278 - 289
Publisher: IEEE
 
» A Comprehensive Statistical Model for Cell Signaling
Abstract:
Protein signaling networks play a central role in transcriptional regulation and the etiology of many diseases. Statistical methods, particularly Bayesian networks, have been widely used to model cell signaling, mostly for model organisms and with focus on uncovering connectivity rather than inferring aberrations. Extensions to mammalian systems have not yielded compelling results, due likely to greatly increased complexity and limited proteomic measurements in vivo. In this study, we propose a comprehensive statistical model that is anchored to a predefined core topology, has a limited complexity due to parameter sharing and uses micorarray data of mRNA transcripts as the only observable components of signaling. Specifically, we account for cell heterogeneity and a multilevel process, representing signaling as a Bayesian network at the cell level, modeling measurements as ensemble averages at the tissue level, and incorporating patient-to-patient differences at the population level. Motivated by the goal of identifying individual protein abnormalities as potential therapeutical targets, we applied our method to the RAS-RAF network using a breast cancer study with 118 patients. We demonstrated rigorous statistical inference, established reproducibility through simulations and the ability to recover receptor status from available microarray data.
Autors: Yoruk, E.;Ochs, M.F.;Geman, D.;Younes, L.;
Appeared in: IEEE/ACM Transactions on Computational Biology and Bioinformatics
Publication date: Jun 2011, volume: 8, issue:3, pages: 592 - 606
Publisher: IEEE
 
» A Comprehensive Study of High- Island-Gate Varactors (IGVs) for CMOS Millimeter-Wave Applications
Abstract:
This paper presents a comprehensive study on the high- island-gate varactor (IGV), which includes a comparison with the conventional multifinger varactors (MFVs) and analyses on the effect of structural variations on the varactor performance. The study shows that the IGV exhibits smaller and larger factor compared to the MFV, while its capacitance tuning ratio is smaller. The effect of the dimension variation and shape of the gate island, as well as the gate thickness, is substantial and the observed trends can be exploited for IGV optimization. This work indicates that the IGV is a highly promising option for millimeter-wave applications.
Autors: Oh, Y.;Rieh, J.-S.;
Appeared in: IEEE Transactions on Microwave Theory and Techniques
Publication date: Jun 2011, volume: 59, issue:6, pages: 1520 - 1528
Publisher: IEEE
 
» A Compressed Sensing Approach for Array Diagnosis From a Small Set of Near-Field Measurements
Abstract:
A technique for array diagnosis using a small number of measured data acquired by a near-field system is proposed. The technique, inspired by some recent results in the field of compressed sensing, requires the preliminary measurement of a failure-free reference array. The linear system relating the difference between the field measured using the reference array and the field radiated by the array under test, and the difference between the coefficients of the reference and of the AUT array, is solved using a proper regularization procedure. Numerical examples confirm that the technique gives satisfactory results in terms of failure detection with a reduction in the number of data of two orders of magnitudes compared to standard back-propagation technique and of one order of magnitude compared to the number of elements of the array, provided that the number of fault elements is small. This result is relevant in practical applications, since the high cost of large array diagnosis in near-field facilities is mainly caused by the time required for the data acquisition. Accordingly, the technique is particularly suitable for routine testing of arrays.
Autors: Migliore, M. D.;
Appeared in: IEEE Transactions on Antennas and Propagation
Publication date: Jun 2011, volume: 59, issue:6, pages: 2127 - 2133
Publisher: IEEE
 
» A Computational Market for Distributed Control of Urban Road Traffic Systems
Abstract:
In the last decade, economic approaches based on computational markets have been proposed as a paradigm for the design and control of complex sociotechnical systems, such as urban road traffic systems. The control problem of an urban road traffic system can be modeled as a distributed resource-allocation problem to apply market-based techniques as solution methods. In this paper, we design a competitive computational market, where driver agents trade the use of the capacity inside the intersections with intersection manager agents. We show how the market dynamics influence the drivers' behavior, leading to a more efficient use of the urban road traffic system, in terms of lower average travel times and less congestion.
Autors: Vasirani, M.;Ossowski, S.;
Appeared in: IEEE Transactions on Intelligent Transportation Systems
Publication date: Jun 2011, volume: 12, issue:2, pages: 313 - 321
Publisher: IEEE
 
» A Conceptual Model for Multi-Temporal Landscape Monitoring in an Object-Based Environment
Abstract:
Remote sensing plays a critical role in contemporary monitoring programs, but our strategies for processing these data using automated procedures are not always reliable. In particular, the task of separating real from spurious changes remains problematic, especially in an object-based environment where differential errors in classification quality, spatial registration, scene illumination, resolution, and object delineation have forced some operators to adopt labor-intensive visual-interpretation strategies, or employ manual interaction on an object-by-object basis. In this paper, we present an updated summary of our new disturbance-inventory approach to land-cover monitoring that combines object-based classification and change-detection strategies with boundary-conditioning routines designed to maximize the spatial and thematic integrity of the finished products. With this approach, the final maps are only altered in regions of confirmed change, and spurious gaps, slivers, stretches, and encroachments are avoided. The approach constitutes an innovative, efficient, and transparent framework that can handle all the basic landscape dynamics, including feature appearance, disappearance, succession, expansion, and shrinkage, without the need for manual editing.
Autors: Linke, J.;McDermid, G.J.;
Appeared in: IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing
Publication date: Jun 2011, volume: 4, issue:2, pages: 265 - 271
Publisher: IEEE
 
» A Construction of Systematic MDS Codes With Minimum Repair Bandwidth
Abstract:
In a distributed storage system based on erasure coding, an important problem is the repair problem: If a node storing a coded piece fails, in order to maintain the same level of reliability, we need to create a new encoded piece and store it at a new node. This paper presents a construction of systematic -MDS codes for that achieves the minimum repair bandwidth when repairing from nodes.
Autors: Wu, Y.;
Appeared in: IEEE Transactions on Information Theory
Publication date: Jun 2011, volume: 57, issue:6, pages: 3738 - 3741
Publisher: IEEE
 
» A continuous semi-empiric transfer characteristics model for surrounding gate undoped polysilicon nanowire MOSFETs
Abstract:
 Highlights: ? A continuous semi-empiric Lambert function-based compact model is proposed for the transfer characteristics of Poly-Si NW MOSFETs. ? It consists of a single analytically differentiable equation with only four parameters. ? Its adequacy is ascertained by comparing measured characteristics of experimental devices to model play-backs calculated using extracted parameters.

Autors: A new continuous semi-empiric compact model for the current transfer characteristics of surrounding gate undoped polycrystalline silicon (Poly-Si) nanowire (NW) MOSFETs is proposed. The model consists of a single equation based on the Lambert functio
Appeared in: Solid-State Electronics
Publication date: Jun 2011
Publisher: Elsevier B.V.
 
» A continuous-wave optical parametric oscillator around 5-μm wavelength for high-resolution spectroscopy
Abstract:
We present a continuous-wave optical parametric oscillator (OPO) capable of high resolution spectroscopy at wavelengths between 4.8 μm and 5.4 μm. It is based on periodically poled lithium niobate (PPLN) and is singly resonant for the signal radiation around 1.35 μm. Because of the strong absorption of PPLN at wavelengths longer than 4.5 μm, the OPO threshold rises to the scale of several watts, while it produces idler powers of more than 1 mW and offers continuous tuning over 15 GHz. A supersonic jet spectrometer is used in combination with the OPO to perform measurements of the transient linear molecule Si2C3 at 1968.2 cm-1. Fifty rovibrational transition frequencies of the ν3 antisymmetric stretching mode have been determined with an accuracy on the order of 10-4 cm-1, and molecular parameters for the ground and the v3 = 1 state have been determined most precisely.
Autors: Krieg, J.;Klemann, A.;Gottbehut, I.;Thorwirth, S.;Giesen, T. F.;Schlemmer, S.;
Appeared in: Review of Scientific Instruments
Publication date: Jun 2011, volume: 82, issue:6, pages: 063105 - 063105-8
Publisher: IEEE
 
» A Control-Theoretic Approach to Distributed Optimal Configuration of 802.11 WLANs
Abstract:
The optimal configuration of the contention parameters of a WLAN depends on the network conditions in terms of number of stations and the traffic they generate. Following this observation, a considerable effort in the literature has been devoted to the design of distributed algorithms that optimally configure the WLAN parameters based on current conditions. In this paper, we propose a novel algorithm that, in contrast to previous proposals which are mostly based on heuristics, is sustained by mathematical foundations from multivariable control theory. A key advantage of the algorithm over existing approaches is that it is compliant with the 802.11 standard and can be implemented with current wireless cards without introducing any changes into the hardware or firmware. We study the performance of our proposal by means of theoretical analysis, simulations, and a real implementation. Results show that the algorithm substantially outperforms previous approaches in terms of throughput and delay.
Autors: Patras, Paul;Banchs, Albert;Serrano, Pablo;Azcorra, Arturo;
Appeared in: IEEE Transactions on Mobile Computing
Publication date: Jun 2011, volume: 10, issue:6, pages: 897 - 910
Publisher: IEEE
 
» A Controlled Experiment for Program Comprehension through Trace Visualization
Abstract:
Software maintenance activities require a sufficient level of understanding of the software at hand that unfortunately is not always readily available. Execution trace visualization is a common approach in gaining this understanding, and among our own efforts in this context is Extravis, a tool for the visualization of large traces. While many such tools have been evaluated through case studies, there have been no quantitative evaluations to the present day. This paper reports on the first controlled experiment to quantitatively measure the added value of trace visualization for program comprehension. We designed eight typical tasks aimed at gaining an understanding of a representative subject system, and measured how a control group (using the Eclipse IDE) and an experimental group (using both Eclipse and Extravis) performed these tasks in terms of time spent and solution correctness. The results are statistically significant in both regards, showing a 22 percent decrease in time requirements and a 43 percent increase in correctness for the group using trace visualization.
Autors: Cornelissen, Bas;Zaidman, Andy;van Deursen, Arie;
Appeared in: IEEE Transactions on Software Engineering
Publication date: Jun 2011, volume: 37, issue:3, pages: 341 - 355
Publisher: IEEE
 
» A Converter-Based Starting Method and Speed Control of Doubly Fed Induction Machine With Centrifugal Loads
Abstract:
The adjustable-speed drive is attractive for pump, compressor, and other centrifugal load applications due to its flexibility and high operating efficiency, compared with the conventional constant-speed drive system. This paper has developed a converter-based starting method for a doubly fed induction machine (DFIM) with centrifugal loads by constant volts/hertz control, instead of using the additional starting resistors or autotransformer. A grid synchronization scheme is then developed to complete the transition from motor starting to vector-controlled speed regulation in the high-speed region. Therefore, the machine can successfully operate in the full speed range by combining constant volts/hertz control and vector control. Since the centrifugal load torque reduces quickly with speed (square relationship), the partially rated converter may provide enough torque at low speeds. Two starting alternatives can be used according to different turns ratios between the machine stator and rotor windings. The proposed control scheme can be simply implemented with a one-quadrant partially rated power converter. The voltage and current ratings of the converter are carefully designed considering the centrifugal load characteristic and the operating speed range. Some important application issues such as “soft grid connection” and rotor position estimation are also discussed. The proposed control scheme has been validated by simulation and experimentally verified through a DSP-controlled 30-kW DFIM system by starting from the rotor side. The drive system can successfully run in the full speed range with the proposed control method and control sequences.
Autors: Yuan, X.;Chai, J.;Li, Y.;
Appeared in: IEEE Transactions on Industry Applications
Publication date: Jun 2011, volume: 47, issue:3, pages: 1409 - 1418
Publisher: IEEE
 
» A convex optimization approach to robust iterative learning control for linear systems with time-varying parametric uncertainties?
Abstract:
In this paper, we present a new robust iterative learning control (ILC) design for a class of linear systems in the presence of time-varying parametric uncertainties and additive input/output disturbances. The system model is described by the Markov matrix as an affine function of parametric uncertainties. The robust ILC design is formulated as a min-max problem using a quadratic performance criterion subject to constraints of the control input update. Then, we propose a novel methodology to find a suboptimal solution of the min-max optimization problem. First, we derive an upper bound of the worst-case performance. As a result, the min-max...
Autors: Dinh Hoa, Nguyen , David, Banjerdpongchai
Appeared in: Automatica
Publication date: Jun 2011
Publisher: Elsevier B.V.
 
» A Coordinated Control Method to Smooth Wind Power Fluctuations of a PMSG-Based WECS
Abstract:
This paper presents an output power smoothing method by a simple coordinated control of DC-link voltage and pitch angle of a wind energy conversion system (WECS) with a permanent magnet synchronous generator (PMSG). The WECS adopts an AC-DC-AC converter system with voltage-source converters (VSC). The DC-link voltage command is determined according to output power fluctuations of the PMSG. The output power fluctuationsin low- and high-frequency domains are smoothed by the pitch angle control of the WECS, and the DC-link voltage control, respectively. By using the proposed method, the wind turbine blade stress is mitigated as the pitch action in high-frequency domain is reduced. In addition, the DC-link capacitor size is reduced without the charge/discharge action in low-frequency domain. A chopper circuit is used in the DC-link circuit for stable operation of the WECS under-line fault. Effectiveness of the proposed method is verified by the numerical simulations.
Autors: Uehara , A.;Pratap , A.;Goya, T.;Senjyu , T.;Yona, A;Urasaki, N;Funabashi, T.;
Appeared in: IEEE Transactions on Energy Conversion
Publication date: Jun 2011, volume: 26, issue:2, pages: 550 - 558
Publisher: IEEE
 
» A Counterexample to “ Positive Realness Preserving Model Reduction With Norm Error Bounds”
Abstract:
We provide a counterexample to the error bound for the difference of a positive real transfer function and its positive real balanced truncation stated in “Positive realness preserving model reduction with norm error bounds,” IEEE Trans. Circuits Syst, I, Fundam. Theory Appl., vol. 42, no. 1, pp. 23–29 (1995). The proof of the error bound is based on a lemma from an earlier paper, “A tighter relative-error bound for balanced stochastic truncation,” Syst. Control Lett., vol. 14, no. 4, 307–317 (1990), which we also demonstrate is false by our counterexample. The main result of this paper was already known in the literature to be false. We state a correct error bound for the difference of a proper positive real transfer function and its positive real balanced truncation and also an error bound in the gap metric.
Autors: Guiver, C.;Opmeer, M. R.;
Appeared in: IEEE Transactions on Circuits and Systems I: Regular Papers
Publication date: Jun 2011, volume: 58, issue:6, pages: 1410 - 1411
Publisher: IEEE
 
» A damaged visco-plasticity model for pressure and temperature sensitive geomaterials
Abstract:
This study is primarily intended to describe the behaviour of non-associated geomaterials within the framework of thermodynamics. By postulating a free energy and a dissipation function, a pressure dependent constitutive model is derived. The model is then used to solve a coupled temperature-displacement problem where shear heating feedback, multiple creep mechanisms and their induced continuum damage are included. The results show that the frictional behaviour of geomaterials in the crust has a high influence on faults orientations. In addition, the model reveals that damage nucleates in the viscous temperature-sensitive lower crust.
Autors: A., Karrech , K., Regenauer-Lieb , T., Poulet
Appeared in: International Journal of Engineering Science
Publication date: Jun 2011
Publisher: Elsevier B.V.
 
» A Data Throughput Prediction and Optimization Service for Widely Distributed Many-Task Computing
Abstract:
In this paper, we present the design and implementation of an application-layer data throughput prediction and optimization service for many-task computing in widely distributed environments. This service uses multiple parallel TCP streams to improve the end-to-end throughput of data transfers. A novel mathematical model is developed to determine the number of parallel streams, required to achieve the best network performance. This model can predict the optimal number of parallel streams with as few as three prediction points. We implement this new service in the Stork Data Scheduler, where the prediction points can be obtained using Iperf and GridFTP samplings. Our results show that the prediction cost plus the optimized transfer time is much less than the nonoptimized transfer time in most cases. As a result, Stork data transfer jobs with optimization service can be completed much earlier, compared to nonoptimized data transfer jobs.
Autors: Yin, Dengpan;Yildirim, Esma;Kulasekaran, Sivakumar;Ross, Brandon;Kosar, Tevfik;
Appeared in: IEEE Transactions on Parallel and Distributed Systems
Publication date: Jun 2011, volume: 22, issue:6, pages: 899 - 909
Publisher: IEEE
 
» A DCVSL Delay Cell for Fast Low Power Frequency Synthesis Applications
Abstract:
In this paper, a low-cost, power efficient and fast Differential Cascode Voltage-Switch-Logic (DCVSL) based delay cell (named DCVSL-R) is proposed. We use the DCVSL-R cell to implement high frequency and power-critical delay cells and flip-flops of ring oscillators and frequency dividers. When compared to TSPC, DCVSL circuits offer small input and clock capacitance and a symmetric differential loading for previous RF stages. When compared to CML, they offer low transistor count, no headroom limitation, rail-to-rail swing and no static current consumption. However, DCVSL circuits suffer from a large low-to-high propagation delay, which limits their speed and results in asymmetrical output waveforms. The proposed DCVSL-R circuit embodies the benefits of DCVSL while reducing the total propagation delay, achieving faster operation. DCVSL-R also generates symmetrical output waveforms which are critical for differential circuits. Another contribution of this work is a closed-form delay model that predicts the speed of DCVSL circuits with 8% worst case accuracy. We implement two ring-oscillator-based VCOs in 0.13 m technology with DCVSL and DCVSL-R delay cells. Measurements show that the proposed DCVSL-R based VCO consumes 30% less power than the DCVSL VCO for the same oscillation frequency (2.4 GHz) and same phase noise ( dBc/Hz at 10 MHz). DCVSL-R circuits are also used to implement the high frequency dual modulus prescaler (DMP) of a 2.4 GHz frequency synthesizer in 0.18 m technology. The DMP consumes only 0.8 mW at 2.48 GHz, a 40% reduction in power when compared to other reported DMPs with similar division ratios and operating frequencies. The RF buffer that drives the DMP consumes only 0.27 mW, demonstrating the lowest combined DMP and buffer power consu mption among similar synthesizers in literature.
Autors: Turker, D. Z.;Khatri, S. P.;Sanchez-Sinencio, E.;
Appeared in: IEEE Transactions on Circuits and Systems I: Regular Papers
Publication date: Jun 2011, volume: 58, issue:6, pages: 1225 - 1238
Publisher: IEEE
 
» A Decentralized Approach for Anticipatory Vehicle Routing Using Delegate Multiagent Systems
Abstract:
Advanced vehicle guidance systems use real-time traffic information to route traffic and to avoid congestion. Unfortunately, these systems can only react upon the presence of traffic jams and not to prevent the creation of unnecessary congestion. Anticipatory vehicle routing is promising in that respect, because this approach allows directing vehicle routing by accounting for traffic forecast information. This paper presents a decentralized approach for anticipatory vehicle routing that is particularly useful in large-scale dynamic environments. The approach is based on delegate multiagent systems, i.e., an environment-centric coordination mechanism that is, in part, inspired by ant behavior. Antlike agents explore the environment on behalf of vehicles and detect a congestion forecast, allowing vehicles to reroute. The approach is explained in depth and is evaluated by comparison with three alternative routing strategies. The experiments are done in simulation of a real-world traffic environment. The experiments indicate a considerable performance gain compared with the most advanced strategy under test, i.e., a traffic-message-channel-based routing strategy.
Autors: Claes, R.;Holvoet, T.;Weyns, D.;
Appeared in: IEEE Transactions on Intelligent Transportation Systems
Publication date: Jun 2011, volume: 12, issue:2, pages: 364 - 373
Publisher: IEEE
 
» A Decoupling Approach for Low-Complexity Vector Perturbation in Multiuser Downlink Systems
Abstract:
In this letter, we propose an efficient algorithm which reduces the complexity of conventional vector perturbation schemes by searching the real and imaginary components of a perturbation vector individually. To minimize a performance loss induced from the decoupled joint search, we apply diagonal precoding at the transmitter whose parameters are iteratively optimized to maximize the chordal distance between subspaces spanned by the real and imaginary components. We also propose a simple non-iterative method with a slight performance loss which can achieve a significant complexity reduction compared to the conventional vector perturbation schemes.
Autors: Park, Seok-Hwan;Han, Hyeon-Seung;Lee, Sunho;Lee, Inkyu;
Appeared in: IEEE Transactions on Wireless Communications
Publication date: Jun 2011, volume: 10, issue:6, pages: 1697 - 1701
Publisher: IEEE
 
» A Dedicated Monitoring Infrastructure for Multicore Processors
Abstract:
On-chip monitoring of environmental information, such as temperature, voltage, and error data, is becoming increasingly important. To address this need, a low-overhead architectural approach to monitor data collection and use in multicore systems is described. A key aspect of our standalone monitoring subsystem is a low-complexity, on-chip network designed to transport monitor data with multiple priority levels. Collected monitor information is evaluated by a dedicated processor. Experimental results using architectural and interconnect simulators show that the new low-overhead subsystem facilitates employment of thermal and delay-aware dynamic voltage and frequency scaling. In contrast to using existing on-chip interconnect resources to communicate monitor data, the new subsystem provides necessary bandwidth for monitor data traffic without impacting application data traffic. Synthesis results show that our dedicated monitoring approach consumes about 0.2% of multicore area and power resources for an 8-core system based on AMD Athlon 64 processor cores.
Autors: Zhao, J.;Madduri, S.;Vadlamani, R.;Burleson, W.;Tessier, R.;
Appeared in: IEEE Transactions on Very Large Scale Integration Systems
Publication date: Jun 2011, volume: 19, issue:6, pages: 1011 - 1022
Publisher: IEEE
 
» A Deterministic Equivalent for the Analysis of Correlated MIMO Multiple Access Channels
Abstract:
In this article, novel deterministic equivalents for the Stieltjes transform and the Shannon transform of a class of large dimensional random matrices are provided. These results are used to characterize the ergodic rate region of multiple antenna multiple access channels, when each point-to-point propagation channel is modelled according to the Kronecker model. Specifically, an approximation of all rates achieved within the ergodic rate region is derived and an approximation of the linear precoders that achieve the boundary of the rate region as well as an iterative water-filling algorithm to obtain these precoders are provided. An original feature of this work is that the proposed deterministic equivalents are proved valid even for strong correlation patterns at both communication sides. The above results are validated by Monte Carlo simulations.
Autors: Couillet, R.;Debbah, M.;Silverstein, J. W.;
Appeared in: IEEE Transactions on Information Theory
Publication date: Jun 2011, volume: 57, issue:6, pages: 3493 - 3514
Publisher: IEEE
 
» A Diffusion Approach to Network Localization
Abstract:
The localization of nodes on a network is a challenging research topic. It arises in a variety of applications such as communications and sensor network analysis. We propose a computational approach to recovering the positions of network nodes given partial and corrupted distance measurements, and the positions of a small subset of anchor nodes. First, we show how to derive geometrically adaptive diffusion bases defined over the entire network, given only partial distance measurements. Second, we propose to utilize several diffusion bases simultaneously to derive multiscale diffusion frames. Last, we utilize the diffusion frames to formulate a regression based extension of the anchor points coordinates to the entire network. We experimentally show that under a wide range of conditions our method compares favorably with state-of-the-art approaches.
Autors: Keller, Y.;Gur, Y.;
Appeared in: IEEE Transactions on Signal Processing
Publication date: Jun 2011, volume: 59, issue:6, pages: 2642 - 2654
Publisher: IEEE
 
» A Digital CMOS Parallel Counter Architecture Based on State Look-Ahead Logic
Abstract:
We present a high-speed wide-range parallel counter that achieves high operating frequencies through a novel pipeline partitioning methodology (a counting path and state look-ahead path), using only three simple repeated CMOS-logic module types: an initial module generates anticipated counting states for higher significant bit modules through the state look-ahead path, simple D-type flip-flops, and 2-bit counters. The state look-ahead path prepares the counting path's next counter state prior to the clock edge such that the clock edge triggers all modules simultaneously, thus concurrently updating the count state with a uniform delay at all counting path modules/stages with respect to the clock edge. The structure is scalable to arbitrary -bit counter widths (2-to- range) using only the three module types and no fan-in or fan-out increase. The counter's delay is comprised of the initial module access time (a simple 2-bit counting stage), one three-input and-gate delay, and a D-type flip-flop setup-hold time. We implemented our proposed counter using a 0.15- m TSMC digital cell library and verified maximum operating speeds of 2 and 1.8 GHz for 8- and 17-bit counters, respectively. Finally, the area of a sample 8-bit counter was 78 125 m (510 transistors) and consumed 13.89 mW at 2 GHz.
Autors: Abdel-Hafeez, S.;Gordon-Ross, A.;
Appeared in: IEEE Transactions on Very Large Scale Integration Systems
Publication date: Jun 2011, volume: 19, issue:6, pages: 1023 - 1033
Publisher: IEEE
 
» A Distortion-Aware Intelligent Context Aggregation Agent for Smart Environments
Abstract:
The proposed intelligent context-aggregation agent (ICAA) can adapt to environmental contexts and effectively suppress transmission redundancies, increasing energy effectiveness and prolonging a network's lifetime.
Autors: Chen, Huan;Cheng, Chih-Chuan;
Appeared in: IEEE Intelligent Systems
Publication date: Jun 2011, volume: 26, issue:3, pages: 42 - 49
Publisher: IEEE
 

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