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Electrical and Electronics Engineering publications abstract of: 12-2009 sorted by title, page: 0
» “AQUA”: A New Audio Quality Monitoring Algorithm for the Performance of DRM Receivers in Fading Channels
Abstract:
This paper presents a new audio quality monitoring algorithm: ldquoAQUArdquo for assessing the performance of Digital Radio Mondiale (DRM) receivers. AQUA targets performance evaluation of consumer grade receivers in fading channels objectively. Consumer grade DRM receivers do not generally possess a Receiver Status and Control Interface (RSCI), which prohibits the possibility of analysing digitally decoded audio bit stream after reception. AQUA relies on the analysis of the received analog audio output signal instead. The paper describes the development of the AQUA algorithm and the measurement system used for receiver audio quality testing. The performance of AQUA is compared to conventional RSCI derived metrics like Bit Error Rate (BER) and Frame Error Rate (FER) of the decoded audio data. A series of tests are conducted in a variety of propagation conditions using a DRM dedicated testing system with a fading channel emulator. It is shown that FER estimates using AQUA are in good agreement with conventional FER figures derived from RSCI in different fading channel scenarios. This allows AQUA to be used as a reliable alternative to conventional FER performance analysis for automated objective testing of DRM receivers.
Autors: Nasr, K.M.;
Appeared in: IEEE Transactions on Broadcasting
Publication date: Dec 2009, volume: 55, issue:4, pages: 781 - 789
Publisher: IEEE
 
» 1.28 terabit/s (32x40 Gbit/s) wdm transmission system for free space optical communications
Abstract:
We review a novel Free Space Optical (FSO) system that represents a significant breakthrough in the area of FSO communications. The system encompasses a pair of novel terminals: these allow direct and transparent optical connection to common single mode fibers and include a dedicated electronic control unit that effectively tracks the signal beam wandering due to atmospheric turbulence and mechanical vibrations. Further improvement in the signal power stabilization is achieved by means of saturated EDFAs. These solutions allow to realize a new FSO system, which is tested in a double-pass FSO link between two buildings in Pisa, Italy. When the terminals are fed by common WDM signals they allow enough power budget and margins to support a record high capacity transmission (32Ăż40 Gbit/s), with a enormous improvement of stability (six hours with no error burst). During day-long transmission, the system behavior has been deeply characterized to correlate any increase of bit error ratio (BER) to the FSO control parameters.
Autors: Ciaramella, E.;Arimoto, Y.;Contestabile, G.;Presi, M.;D'Errico, A.;Guarino, V.;Matsumoto, M.;
Appeared in: IEEE Journal on Selected Areas in Communications
Publication date: Dec 2009, volume: 27, issue:9, pages: 1639 - 1645
Publisher: IEEE
 
» 1.3?m emitting GaInNAs/GaAs quantum well resonant cavity LEDs
Abstract:
The electrical and optical characteristics of a set of MBE-grown 1.3?m emitting GaInNAs/GaAs quantum well (QW) resonant cavity light-emitting diodes (RCLEDs) have been analyzed as a function of the growth temperature of the distributed Bragg reflector (DBR) and the contact alloying. The RCLEDs consist of a ?-long microcavity delimited on one side by an 8-pair AlAs/GaAs DBR and on the opposite side by a metallic mirror, with the QW located at one of the antinodes of the standing wave. The structures are designed for extraction of the light through the substrate. Room-temperature electroluminescence at 1.3?m is demonstrated with 38% In...
Autors: M., Montes , A., Guzmán , A., Trampert , A., Hierro
Appeared in: Solid-State Electronics
Publication date: Dec 2009
Publisher: Elsevier B.V.
 
» 10-kV SiC MOSFET-Based Boost Converter
Abstract:
10-kV silicon carbide (SiC) MOSFETs are currently being developed by a number of organizations in the U.S. with prospective applications in high-voltage and high-frequency power-electronic systems. The aim of this paper is to demonstrate the high-frequency and high-temperature capability of 10-kV SiC MOSFETs in the application of a dc/dc boost converter. In this study, 10-kV SiC MOSFET and junction barrier Schottky (JBS) diode were characterized and modeled in SPICE. Following this, a dc/dc boost converter based on a 10-kV 10-A MOSFET and a 10-kV 5-A JBS diode was designed and tested under continuous operation for frequencies up to 25 kHz. The boost converter had an output voltage of 4 kV, an output power of 4 kW, and operated with a junction temperature of 174degC for the SiC MOSFET. The fast-switching speed, low losses, and high-temperature operation capability of 10-kV SiC MOSFETs demonstrated in the dc/dc boost converter make them attractive for high-frequency and high-voltage power-conversion applications.
Autors: Jun Wang;Xiaohu Zhou;Jun Li;Tiefu Zhao;Huang, A.Q.;Callanan, R.;Husna, F.;Agarwal, A.;
Appeared in: IEEE Transactions on Industry Applications
Publication date: Dec 2009, volume: 45, issue:6, pages: 2056 - 2063
Publisher: IEEE
 
» 15 GHz High-Isolation Sub-Harmonic Mixer With Delay Compensation
Abstract:
A 15-GHz high-isolation sub-harmonic mixer (SHM) with delay compensation is demonstrated in this letter using 0.35 SiGe heterojunction bipolar transistor (HBT) technology. The proposed SHM consisting of two parallel stacked-LO mixer cores with opposite LO I/Q inputs substantially improves port-to-port isolation. A mathematical analysis regarding the isolation properties is also included in this letter. Further, a conventional stacked-LO SHM (w/o compensation) is also implemented with the same device sizes and bias conditions for a fair comparison. SHMs w/ and w/o compensation have similar conversion gain of 9/10 dB and noise figure of 14/13.5 dB when . However, the delay compensation technique improves the 2LO-RF/IF isolation by 34/35 dB, the LO-RF/IF isolation by 8/9 dB, and the RF-IF isolation by 22 dB.
Autors: Syu, J.-S.;Meng, C.;
Appeared in: IEEE Microwave and Wireless Components Letters
Publication date: Dec 2009, volume: 19, issue:12, pages: 810 - 812
Publisher: IEEE
 
» 2-tier hierarchical frame-based queueing for guaranteed delay performance in packet-switched networks
Abstract:
In this letter, we introduce a novel packet scheduling algorithm, so called 2-tier Hierarchical Frame-based Queueing (2tHFQ) that provides a deterministic delay bound without sorting operation complexity. The key idea of 2tHFQ is to divide a given frame into multiple sub-frames with frame indices assigned, and then transmit input packets according to the frame index hierarchy. We analytically predict how delay bound at a node depends on the number of sub-frames. Through NS-2-based network simulations, we also demonstrate a better performance of 2tHFQ under increased traffic loads and a well-controlled packet delay by varying sub-frame numbers.
Autors: Ti, D.-H.;Kim, J.;
Appeared in: IEEE Communications Letters
Publication date: Dec 2009, volume: 13, issue:12, pages: 968 - 970
Publisher: IEEE
 
» 24-GHz ultra-wideband transmitter for vehicular short-range radar applications
Abstract:
This paper presents a 24-GHz transmitter for ultra-wideband short-range radar applications fabricated in a 0.13-μm SiGe:C BiCMOS technology. The circuit is composed of a frequency synthesiser, based on 24-GHz voltage-controlled oscillator in an N-integer phase-locked loop (PLL), a RF switch delivering a 0-dBm output power, and a tunable rectangular pulse generator, whose pulse width covers a range between 0.5 and 1.2 ns. The transmitter has been developed for a flip-chip bumping assembly on a module with an UWB antenna. Assuming a 10.5-dBi antenna gain, it is compliant with European Telecommunications Standards Institute (ETSI) transmission mask and is able to cover the main automotive applications addressing both a resolution better than 0.1 m and maximum unambiguous range of 15 m.
Autors: Scuderi, A.;Ragonese, E.;Palmisano, G.;
Appeared in: IET Circuits, Devices & Systems
Publication date: Dec 2009, volume: 3, issue:6, pages: 313 - 321
Publisher: IEEE
 
» 3-D perception and modeling
Abstract:
Autonomous robots are increasingly suited for operations in unstructured application domains. One impressive example is the result of the Defense Advanced Research Projects Agency (DARPA) Grand Challenge 2005, where five teams managed to get autonomous vehicles to complete a 213-km track in the Mojave desert. Some conditions of the Grand Challenge do not hold for space robotics, especially the availability of a drivable track defined by global positioning system (GPS). In general, it can be argued that space robotics and especially planetary exploration have to deal with one of the most challenging unstructured environments. There is absolutely no infrastructure, the cost of mission failure is very high, and many core sensors that form the foundations of intelligent autonomous behaviors are not space proof, yet. However, autonomy is not a binary all or nothing property. Intelligent autonomous functions can supplement different levels of teleoperation. In the context of the 2008 Lunar Robotics Challenge (LRC) of the European Space Agency (ESA), the Jacobs Robotics team investigated three-dimensional (3-D) perception and modeling as an important basis of autonomy in unstructured domains. Concretely, the efficient modeling of the terrain via a 3-D laser range finder (LRF) is addressed. The underlying fast extraction of planar surface patches can be used to improve situational awareness of an operator or for path planning.
Autors: Birk, A.;Vaskevicius, N.;Pathak, K.;Schwertfeger, S.;Poppinga, J.;Buelow, H.;
Appeared in: IEEE Robotics & Automation Magazine
Publication date: Dec 2009, volume: 16, issue:4, pages: 53 - 60
Publisher: IEEE
 
» 30 Gbit/s 64-QAM transmission over 60 km SSMF using phase-noise cancelling technique and ISI suppression based on electronic digital processing
Abstract:
30 Gbit/s (5 Gsymbol/s) 64-QAM real-time transmission over 60 km SSMF without any dispersion compensation has been experimentally demonstrated for the first time. Intersymbol interference caused by the limited frequency bandwidth of electrical components in the transmitter and receiver was compensated using a pre-equalisation technique based on electronic digital processing. Phase-noise cancelling based on a polarisation-multiplexed pilot-carrier was employed, allowing use of a light source with a linewidth as large as 200 kHz. A bit error rate of <10-4 was achieved even after SSMF transmission without using error correction.
Autors: Nakamura, M.;Kamio, Y.;Miyazaki, T.;
Appeared in: Electronics Letters
Publication date: Dec 2009, volume: 45, issue:25, pages: 1339 - 1340
Publisher: IEEE
 
» 3D Stacked Arrays of Fins and Nanowires on Bulk Silicon
Abstract:
The development of a particular etching recipe involving two sequences of a Deep Reactive Ion Etching followed by an isotropic etching step for the realization of 3D stacked arrays of fins and nanowires on bulk silicon is reported. Such a recipe can be used among the new processes and designs developed to control the shape and formation of such 3D structures. Applications in microelectronics (stacked field effect transistors) and microsystems (arrays of MEMS resonators and photonic structures) are foreseen.
Autors: M., Bopp , P., Coronel , C., Hibert , A.M., Ionescu
Appeared in: Microelectronic Engineering
Publication date: Dec 2009
Publisher: Elsevier B.V.
 
» 3D User Interfaces
Abstract:
The articles in this special issue present recent developments in research on 3D user interfaces. Topics covered include reality- and imagination-based interaction, pointing techniques, analysis of rapid aimed movements, temporal-data visualizations, and navigation of augmented CAD models.
Autors: Froehlich, Bernd;Bowman, Doug;
Appeared in: IEEE Computer Graphics and Applications
Publication date: Dec 2009, volume: 29, issue:6, pages: 20 - 21
Publisher: IEEE
 
» 5 GHz low power frequency synthesiser with dual-modulus counter
Abstract:
A 5 GHz low power frequency synthesiser with a dual-modulus counter (DMC) was fabricated in 0.18 μm CMOS technology. The DMC allows to reduce the power consumption and to provide the functionality of the divider without a swallower counter. The settling time takes no more than 5 μs with an adaptive bandwidth topology. The measured phase noise is -87 dBc/Hz and -119 dBc/Hz at 10 kHz and 1 MHz offset frequencies, respectively. The reference spurs level is lower than -55 dBc at 10 MHz offset. The proposed synthesiser covers frequencies between 5.14 and 5.86 GHz in steps of 20 MHz and consumes 16.4 mW at 1.5 V supply voltage.
Autors: Y.-F. Kuo;R.-M. Weng;
Appeared in: IET Circuits, Devices & Systems
Publication date: Dec 2009, volume: 3, issue:6, pages: 365 - 375
Publisher: IEEE
 
» In Situ Impact Analysis of Very High Heat Flux Transients on Nonlinear p-n Diode Characteristics and Mitigation Using On-Chip Single- and Two-Phase Microfluidics
Abstract:
The reliable operation of advanced integrated circuits (ICs) is impacted by the presence of randomly generated heat-flux transients. These transients can induce severe nonlinearities in the device response and can result in the degradation of ohmic contacts for p-n diodes as well as gate dielectric for metal–oxide field-effect transistors. In this paper, we focus on the impact and mitigation of steady-state and transient heat flux, with levels ranging from 0 to 250 . The impact analysis exercise focused on the heat-flux-induced nonlinear variation of the p-n diode power exponent factor . For the steady-state heat-flux scenario, the (forward bias voltage) characteristics yield a maxima point which is observed to decrease monotonically with an increase in diode temperature. The value is further useful for deriving other parameters, such as saturation current , series resistance , and the diode ideality factor . The transient heat-flux scenario yields a transient power exponent factor ( , maxima— ) which is distinct from the steady-state case. The shows an inverse dependence on instantaneou- s diode temperature. Transient mitigation is evident when the diode power exponent parameter is recovered under the application of single-phase as well as two-phase on-chip fluid flows. Finally, while our primary focus has been on transient mitigation, we have also looked at the feasibility of localizing transient heat sources based on temperature profiles generated using an on-chip distributed resistance temperature detector sensor array. In real-life ICs, the systematic localization and characterization of heat sources will be of interest in order to provide information on the origin of transients, thus leading to modifications in circuit design or process integration steps. [2009-0199]
Autors: Singh, S. G.;Duttagupta, S. P.;Agrawal, A.;
Appeared in: Journal of Microelectromechanical Systems
Publication date: Dec 2009, volume: 18, issue:6, pages: 1208 - 1219
Publisher: IEEE
 
» penMesh—Monte Carlo Radiation Transport Simulation in a Triangle Mesh Geometry
Abstract:
We have developed a general-purpose Monte Carlo simulation code, called penMesh, that combines the accuracy of the radiation transport physics subroutines from PENELOPE and the flexibility of a geometry based on triangle meshes. While the geometric models implemented in most general-purpose codes—such as PENELOPE's quadric geometry—impose some limitations in the shape of the objects that can be simulated, triangle meshes can be used to describe any free-form (arbitrary) object. Triangle meshes are extensively used in computer-aided design and computer graphics. We took advantage of the sophisticated tools already developed in these fields, such as an octree structure and an efficient ray-triangle intersection algorithm, to significantly accelerate the triangle mesh ray-tracing. A detailed description of the new simulation code and its ray-tracing algorithm is provided in this paper. Furthermore, we show how it can be readily used in medical imaging applications thanks to the detailed anatomical phantoms already available. In particular, we present a whole body radiography simulation using a triangulated version of the anthropomorphic NCAT phantom. An example simulation of scatter fraction measurements using a standardized abdomen and lumbar spine phantom, and a benchmark of the triangle mesh and quadric geometries in the ray-tracing of a mathematical breast model, are also presented to show some of the capabilities of penMesh.
Autors: Badal, A.;Kyprianou, I.;Banh, D. P.;Badano, A.;Sempau, J.;
Appeared in: IEEE Transactions on Medical Imaging
Publication date: Dec 2009, volume: 28, issue:12, pages: 1894 - 1901
Publisher: IEEE
 
» Bi4Ti3O12–5BiFeO3 Aurivillius intergrowth: Structural and ferroelectric properties
Abstract:
Aurivillus intergrowth Bi4Ti3O12–5BiFeO3 was demonstrated to be ferroelectric that evoked the possibility of achieving high temperature magnetoelectric property in this family of compounds. X-ray diffraction studies confirmed its structure to be orthorhombic [Fmm2; a=5.5061(11) Å, b=5.4857(7) Å, c=65.742(12) Å]. However, transmission electron microscopy established the random incidence of intergrowth at nanoscale corresponding to n=6 and n=7 members of the Aurivillius family. Diffuse ferroelectric orthorhombic to paraelectric tetragonal phase transition around 857 K was confirmed by dielectric and high temperature x-ray diffraction studies. Polarization versus electric field hysteresis loops associated with 2Pr of 5.2 μC/cm2 and coercive field of 42 kV/cm were obtained at 300 K.
Autors: Preethi Meher, K. R. S.;Varma, K. B. R.;
Appeared in: Journal of Applied Physics
Publication date: Dec 2009, volume: 106, issue:12, pages: 124103 - 124103-5
Publisher: IEEE
 
» -band Transmitter and Receiver for 10-Gb/s Impulse Radio With an Optical-Fiber Interface
Abstract:
A -band millimeter-wave transmitter and receiver that are based on impulse radio (IR) architecture were developed. The IR-based apparatuses have an optical-fiber input/output interface board that supports multi protocol signals (OC-192 and 10 GbE) and that implements a forward error correction (FEC), enabling 10-Gb/s data transmission both in space and fiber seamlessly. Analyzing an IR-based receiver model with simple on/off demodulation architecture, required signal-to-noise ratios were calculated for IR-based systems affected by various inter-symbol interference (ISI) levels. A millimeter-wave module used in the transmitter, consisting of a 6.5-ps pulse modulator with InP-based HEMTs and a band-pass filter formed on an alumina substrate, emitted wavelets, or RF pulses, with an average power of 26 dBm, occupying frequencies between 78–93 GHz. A front-end module used in the receiver, consisting of two cascaded low-noise amplifiers, an envelope detector, and a limiting amplifier, had a sensitivity of 36 dBm. In a back-to-back test where the transmitter and receiver were connected by a waveguide, disabling the FEC, error-free operation was achieved with a test pattern of PRBS at the OC-192 compliant data rate of 9.95328 Gb/s. Furthermore, using a horn antenna and enabling the FEC, radio transmission and reception in a distance of 20 cm were confirmed with a bit error rate of less than . These results confirmed the basic technologies for simple and compact IR-based systems, which could be used as an alternative to fiber optic cables.
Autors: Nakasha, Y.;Sato, M.;Tajima, T.;Kawano, Y.;Suzuki, T.;Takahashi, T.;Makiyama, K.;Ohki, T.;Hara, N.;
Appeared in: IEEE Transactions on Microwave Theory and Techniques
Publication date: Dec 2009, volume: 57, issue:12, pages: 3171 - 3180
Publisher: IEEE
 
» -Valued Quadratic Forms and Quaternary Sequence Families
Abstract:
In this paper, Zopf4-valued quadratic forms defined on a vector space over GF(2) are studied. A classification of such forms is established, distinguishing Zopf4-valued quadratic forms only by their rank and whether the associated bilinear form is alternating. This result is used to compute the distribution of certain exponential sums, which occur frequently in the analysis of quaternary codes and quaternary sequence sets. The concept is applied as follows. When t=0 or m is odd, the correlation distribution of family S(t), consisting of quaternary sequences of length 2 m-1, is established. Then, motivated by practical considerations, a subset S *(t) of family S(t) is defined, and the correlation distribution of family S *(t) is given for odd and even m.
Autors: Schmidt, K.-U.;
Appeared in: IEEE Transactions on Information Theory
Publication date: Dec 2009, volume: 55, issue:12, pages: 5803 - 5810
Publisher: IEEE
 
» A 1-GSample/s, 15-GHz Input Bandwidth Master–Slave Track-and-Hold Amplifier in InP DHBT Technology
Abstract:
A fully differential master–slave track-and-hold amplifier is designed and fabricated in a 210-GHz- InP DHBT process. Input bandwidth of 15 GHz, total harmonic distortion lower than 39 dB and a third harmonic rejection greater than 45 dB are measured for 1 GSample/s and 4 dBm single-ended input signal. Time domain measurements demonstrate the performances of dual track-and-hold amplifier for Nyquist, over-sampling and sub-sampling conditions. Design tradeoff for master and slave blocks are presented. Experimental results obtained for different feed-through capacitors show the effects of on bandwidth and isolation.
Autors: Bouvier, Y.;Ouslimani, A.;Konczykowska, A.;Godin, J.;
Appeared in: IEEE Transactions on Microwave Theory and Techniques
Publication date: Dec 2009, volume: 57, issue:12, pages: 3181 - 3187
Publisher: IEEE
 
» A 1.5 GHz phase-locked loop with leakage current suppression in 65 nm CMOS
Abstract:
In the nanoscale CMOS process, the problem of leakage current causes the performance of the analog circuits to degrade. The leakage current of a loop filter, which is realised by MOS capacitors, significantly degrades the jitter performance of a phase-locked loop. A leakage suppression circuit is presented by using a combination of switchable varactors and current sources to compensate the leakage of MOS capacitors in a loop filter. This PLL has been fabricated in a 65 nm CMOS process and the core area is 0.4 X 0.5 mm2. With the leakage suppression circuit, the peak-to-peak jitter and the rms jitter are 43 and 5.36 ps, respectively.The power is 17 mW for a 1.2 V supply.
Autors: J.-Y. Chang;S.-I. Liu;
Appeared in: IET Circuits, Devices & Systems
Publication date: Dec 2009, volume: 3, issue:6, pages: 350 - 358
Publisher: IEEE
 
» A 10:1 Unequal Wilkinson Power Divider Using Coupled Lines With Two Shorts
Abstract:
A novel unequal Wilkinson power divider is presented. A coupled-line section with two shorts is proposed to realize the high characteristic impedance line, which cannot be implemented by conventional microstrip fabrication technique due to fabrication limitation. The proposed coupled-line structure is compatible with single layer integration and can be easily designed based on an even-odd mode analysis. As a design example, a 10:1 Wilkinson power divider at 2 GHz is fabricated and measured. The measured bandwidth of is about 16%, and the isolation is better than . The measured amplitude balance between output port 2 and port 3 is between and , and the corresponding phase difference is between 0 and 4.6 .
Autors: Li, B.;Wu, X.;Wu, W.;
Appeared in: IEEE Microwave and Wireless Components Letters
Publication date: Dec 2009, volume: 19, issue:12, pages: 789 - 791
Publisher: IEEE
 
» A 18 GHz Broadband Stacked FET Power Amplifier Using 130 nm Metamorphic HEMTs
Abstract:
A broadband power amplifier (PA) with a 3 dB power bandwidth of 72% is presented using metamorphic high electron mobility transistors (mHEMTs). A stacked FET structure, where transistors are series connected to combine voltage swings, is employed to overcome relatively low breakdown voltages of mHEMTs. Series-connected PA's show much higher load impedance compared to the parallel combined transistors, which allows output matching to be realized in the low quality (Q)-factor region, providing the broadband performance. The fabricated PA using quadruple-stacked 130 nm mHEMTs has a gain of 21.2 dB and saturated output power of 26.4 dBm with power added efficiency (PAE) of 33% at the design frequency of 18 GHz. The 3 dB output power bandwidth is from 10 to 23 GHz.
Autors: Lee, C.;Kim, Y.;Koh, Y.;Kim, J.;Seo, K.;Jeong, J.;Kwon, Y.;
Appeared in: IEEE Microwave and Wireless Components Letters
Publication date: Dec 2009, volume: 19, issue:12, pages: 828 - 830
Publisher: IEEE
 
» A 2.6-GHz fully integrated CMOS power amplifier using power-combining transformer
Abstract:
A 2.6-GHz power amplifier was implemented with a 0.18 [mu]m RF CMOS process. The matching networks were fully integrated without any external components. To increase the output power, the power combining technique was adopted and realized by a 2:1 on-chip transformer, which was designed to provide an optimum load for the power cell. The measured efficiency of this power combining transformer is about 75% at 2.6 GHz. The proposed power amplifier exhibits maximum output power of 26.7 dBm with power-added efficiency of 18.1%. The power gain is 13.6 dB under 3.3 V supply voltage. Moreover, this letter shows good agreement between simulated and measured results.
Inc. Microwave Opt Technol Lett 52: 299-302, 2010; DOI 10.1002/mop.24910
Autors: Hwann-Kaeo Chiou, Hsien-Yuan Liao, Chien-Chung Chen, Shih-Ming Wang, Cheng-Chung Chen
Appeared in: Microwave and Optical Technology Letters
Publication date: Dec 2009
Publisher: Wiley InterScience
 
» A 3.51-to-3.8 GHz divide-by-3 injection-locked frequency divider
Abstract:
This article proposes a divide-by-3 frequency divider (FD) with quadrature outputs fabricated in the 0.18-[mu]m CMOS technology. The current reuse and the back-gate coupling techniques are adopted. Measured results show that the free-running frequency is from 1.173 to 1.25 GHz. The proposed FD can cover the input frequency from 3.51 to 3.8 GHz at the incident power of -3 dBm.
Inc. Microwave Opt Technol Lett 52: 490-493, 2010; Published online in Wiley InterScience (www.interscience. wiley.com). DOI 10.1002/mop.24920
Autors: Yen-Chung Chiang, Ming-Fong Wu
Appeared in: Microwave and Optical Technology Letters
Publication date: Dec 2009
Publisher: Wiley InterScience
 
» A 405-nW CMOS Temperature Sensor Based on Linear MOS Operation
Abstract:
This brief presents a CMOS temperature sensor suitable for ultralow-power applications. With a MOS transistor operating in the linear region, a linear relationship between delay and temperature can be obtained. A differential sensing architecture is utilized to reduce the signal offset and increase the effective signal-to-noise ratio. A design methodology concerning power optimization and improved sensor linearity is also presented. The sensor, which occupies 0.0324 , is fabricated using the TSMC 0.18- one-polysilicon six-metal (1P6M) process. Measurement results show that the sensor consumes 405 nW with a 1-V supply at 1 ksample/s at room temperature. An inaccuracy value of to from 0 to 100 after calibration is achieved.
Autors: Law, M. K.;Bermak, A.;
Appeared in: IEEE Transactions on Circuits and Systems II: Express Briefs
Publication date: Dec 2009, volume: 56, issue:12, pages: 891 - 895
Publisher: IEEE
 
» A bandpass filter with adjustable bandwidth and predictable transmission zeros
Abstract:
In this article, a microstrip bandpass filter with an adjustable bandwidth and predictable transmission zeros is proposed. The proposed filter is implemented by combining two hairpin edge-coupled resonators with interdigital capacitors. Compared to typical edge-coupled filters, the proposed filter provides a wider bandwidth resulting from a higher coupling strength between its resonators. To further increase the coupling and consequently the bandwidth, a pair of etched slots in the ground plane is used. By adjusting the geometrical parameters of the interdigital capacitors and etched slots, the bandwidth can be easily adjusted. The filter features two transmission zeros, which are determined by means of the semi-analytical model developed as part of this work. Furthermore, the proposed filters can be cascaded to obtain a sharper cutoff frequency response. Frequency responses of the filters from measurements are in good agreement with those simulated using IE3D in the 5-9 GHz range.
Inc. Int J RF and Microwave CAE, 2010.
Autors: Li Zhu, Vijay Devabhaktuni, Chunyan Wang, Ming Yu
Appeared in: International Journal of RF and Microwave Computer-Aided Engineering
Publication date: Dec 2009
Publisher: Wiley InterScience
 
» A benchtop, ultrafast infrared spectroscopic imaging system for biomedical applications
Abstract:
We discuss the potential biomedical applications for a novel infrared spectroscopic microimaging system. A tunable, table top solid-state laser has been coupled to a commercial infrared microscope, fitted with a modified high resolution infrared camera, to create a unique tool for midinfrared imaging. The system is capable of performing broadband imaging at a diffraction-limited spatial resolution, as is demonstrated here by spatially resolved spectroscopy of polymer test samples with a spectral resolution of 20 cm-1. The large pulse energies (tens of microjoules) offer previously unobtainable combinations of high signal-to-noise levels and rapid data collection times which are superior to current stand-alone laboratory instruments by many decades. Coupled with the short (100 ps) short pulse duration, these characteristics promise to make a wide range of time-resolved and reflection mode imaging experiments possible with live biological systems.
Autors: Amrania, Hemmel;McCrow, Andrew;Phillips, Chris;
Appeared in: Review of Scientific Instruments
Publication date: Dec 2009, volume: 80, issue:12, pages: 123702 - 123702-6
Publisher: IEEE
 
» A Biomedical Implantable FES Battery-Powered Micro-Stimulator
Abstract:
The integrated circuit (IC) designs of an implantable functional electrical stimulation (FES) battery-powered micro-stimulator are presented in this paper. The battery is recharged by receiving power magnetically through a coil under supervision of a power management unit. To limit the heat generation on the stimulator when a large magnetic field is present, an on-chip rectifier is capable of limiting the induced voltage and reducing heat generation by providing a low impedance path. The same coil is also used for generating and receiving magnetic fields such that the distances among 16 different stimulator pairs can be estimated simultaneously. To facilitate different clinical applications, a bio-potential sensor is also included. The micro-stimulator can output mono-phasic stimulation current from an 8-bit exponential digital to analog converter (DAC) that has a range between and . The stimulator communicates with an external master control unit through a 400-MHz wireless link that can support a bit rate of 2.486 MB/s in high speed mode. The total number of stimulators that the communication system can support is 852.
Autors: Lee, E.;Matei, E.;Gord, G.;Hess, P.;Nercessian, P.;Stover, H.;Li, T.;Wolfe, J.;
Appeared in: IEEE Transactions on Circuits and Systems I: Regular Papers
Publication date: Dec 2009, volume: 56, issue:12, pages: 2583 - 2596
Publisher: IEEE
 
» A Biomolecule Compatible Electrical Model of Microimpedance Affinity Biosensor for Sensitivity Improvement in Cell Detection
Abstract:
Microimpedance affinity biosensors using interdigitated electrodes are being extensively employed for label free and rapid detection of bacteria molecules. To improve the sensitivity of such sensors, it is required to maximize the antibody immobilization and bacteria captured for an applied input concentration through proper quantification and also optimize the electrode geometry to achieve maximum signal to noise ratio. In this paper, a biomolecule compatible electrical model has been developed which quantifies the number of immobilized antibody and captured bacteria by simple calculations from impedance spectroscopy results which are comparable to the accuracy obtained by conventional time consuming and sometimes expensive...
Autors: C.RoyChaudhuri , R.Dev, Das
Appeared in: Sensors and Actuators A: Physical
Publication date: Dec 2009
Publisher: Elsevier B.V.
 
» A biplanar robot navigation system for the distal locking of intramedullary nails
Abstract:
Distal locking is the key procedure of the intramedullary nailing operation. It is difficult to precisely locate the locking path, and intraoperative radiation exposure is also a serious problem. The advantages and disadvantages of different approaches applied in this operation are summarized.A biplanar robot navigation system for the distal locking of intramedullary nails is presented. The novel mechanical structure and the surgical process are introduced. Then the positioning accuracy of the robot is experimented and validated.The positioning precision of the biplanar robot is tested, and the average error is 0.24 mm. The tibia sawbone is used for distal locking to test the accuracy of the robot navigation system. The maximal deviation between the drilling centre and the nail hole centre is 0.44 mm.The biplanar robot has the advantages of high positioning accuracy, operational stability and safety. It can be used not only for the distal locking of intramedullary nails but also for other orthopaedic surgeries that demand precise positioning.
Autors: Hu Lei, Luan Sheng, Wang Manyi, Wang Junqiang, Liu Wenyong
Appeared in: The International Journal of Medical Robotics and Computer Assisted Surgery
Publication date: Dec 2009
Publisher: Wiley InterScience
 
» A brief discussion of abbreviations [From the Editor]
Abstract:
Abbreviations are a wonderful invention. They help us to say a lot in a very little space. This was very important in the early development of wireless communication, where Morse code was the radio operator's character set. Long words and phrases required relatively long periods of time to be transmitted using this rather slow, narrow bandwidth communications method. To try to correct this problem, radio operators devised and borrowed from telegraph operators standard abbreviations such as the Q code to represent common phrases. For example, QTH referred to the radio operator's location, QRM was radio interference, and QSL meant please acknowledge receipt of this message.
Autors: Neuman, M.R.;
Appeared in: IEEE Engineering in Medicine and Biology Magazine
Publication date: Dec 2009, volume: 28, issue:6, pages: 3 - 3, 8
Publisher: IEEE
 
» A Bulk-Current Model for Advanced MOSFET Technologies Without Binning: Substrate Current and Fowler-Nordheim Current
Abstract:
A bulk-current model for advanced metal oxide semiconductor field effect transistors (MOSFETs) is proposed and implemented. The model consists of an impact ionization mechanism, the drain to bulk current and a tunneling mechanism, the gate to bulk current, and requires totally 21 model parameters covering all bias conditions. The simulated results with the parameter values reproduce measurements for any device size without binning. Validity of the model has been tested with circuits, which are sensitive to the change of the stored charge due to impact ionization current and tunneling current. Copyright © 2010 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.
Autors: Ryosuke Inagaki, Norio Sadachika, Dondee Navarro, Mitiko Miura-Mattausch, Yasuaki Inoue
Appeared in: IEEJ Transactions on Electrical and Electronic Engineering
Publication date: Dec 2009
Publisher: Wiley InterScience
 
» A C-band wideband 360° analog phase shifter design
Abstract:
This article proposes a reflection-type wideband 360° analogue phase shifter in microstrip form. It employs a 3-dB branch-line coupler circuit to achieve a wideband operation and two varactor-diode circuits to achieve 360° phase shift. Formulas are derived to optimize the dimensions of the microstrip lines in the coupler and the varactor-diode circuits for wideband operation and minimizing frequency dependency of the output phase. Experimental results show that the design has a 360° phase-shift range and 1 dB insertion loss, with a 500-MHz operation bandwidth at the center frequency of 6.5 GHz. ©2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52: 355-359, 2010; DOI 10.1002/mop.24938
Autors: M. X. Xiao, S. W. Cheung, T. I. Yuk
Appeared in: Microwave and Optical Technology Letters
Publication date: Dec 2009
Publisher: Wiley InterScience
 
» A Cantilever Sensor With an Integrated Optical Readout for Detection of Enzymatically Produced Homocysteine
Abstract:
Microcantilever sensors have been recognized as a promising sensor platform for various chemical and biological applications. One of their major limitations is that the measurement of cantilever displacement typically involves elaborate off-chip setups with free-space optics. An improved device, known as the optical cantilever, has been proposed recently to eliminate the external optics. The response of the optical cantilever is measured on-chip through integrated waveguides. However, this method has been previously demonstrated only for devices operating in air, whereas most chemical and biological samples are in solution state. We present the first optical cantilever capable of operation in liquid. We test it with the detection of homocysteine with a minimal concentration of 10 M. The minimal measurable cantilever displacement and surface stress are 5 nm and 1 mN/m, respectively. The presented device will be used in studies of a homocysteine-producing bacterial pathway for the purpose of drug discovery. It can also be extended to various other chemical- or biological-sensing applications by selecting an appropriate surface coating.
Autors: Koev, S. T.;Fernandes, R.;Bentley, W. E.;Ghodssi, R.;
Appeared in: IEEE Transactions on Biomedical Circuits and Systems
Publication date: Dec 2009, volume: 3, issue:6, pages: 415 - 423
Publisher: IEEE
 
» A Capacitive MEMS Viscometric Sensor for Affinity Detection of Glucose
Abstract:
This paper presents a capacitively based microelectromechanical systems affinity sensor for continuous glucose monitoring (CGM) applications. This sensor consists of a vibrating Parylene diaphragm, which is remotely driven by a magnetic field and situated inside a microchamber. A solution of poly(acrylamide-ran-3-acrylamidophenylboronic acid) (PAA-ran-PAAPBA), a biocompatible glucose-sensitive polymer, fills the microchamber, which is separated from its surroundings by a semipermeable membrane. Glucose permeates through the membrane and binds reversibly to the phenylboronic acid moiety of the polymer. This results in a viscosity change of the sensing solution, causing a detectable change in the Parylene diaphragm vibration which can be measured capacitively. Experimental results demonstrate that the device is capable of detecting glucose at physiologically relevant concentrations ranging from 30 to 360 mg/dL. The response time of the sensor to glucose concentration changes is approximately 1.5 min, which can be further improved with optimized device designs. Excellent reversibility and stability are observed in sensor responses, as highly desired for long-term CGM. [2009-0171]
Autors: Huang, X.;Li, S.;Schultz, J.;Wang, Q.;Lin, Q.;
Appeared in: Journal of Microelectromechanical Systems
Publication date: Dec 2009, volume: 18, issue:6, pages: 1246 - 1254
Publisher: IEEE
 
» A Chaotic Clonal Selection Algorithm and its Application to Synthesize Multiple-Valued Logic Functions
Abstract:
In this paper, a chaotic clonal selection algorithm (CCSA) is proposed to synthesize multiple-valued logic (MVL) functions. The MVL function is realized in a multiple-valued sum-of-products expression where product is indicated by MIN and sum by TSUM. The proposed CCSA, in which chaos is incorporated into the clonal selection algorithm to initialize antibodies and maintain the population diversity, is utilized to learn a given target MVL truth table. Furthermore, an adaptive length strategy of antibodies is also introduced to reduce the computational complexity, whereas an improved affinity function enables the algorithm to find less product terms for an MVL function. Simulation results based on a large number of MVL functions demonstrate the efficiency of the proposed method when compared with other traditional methodologies. Copyright © 2010 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.
Autors: Shangce Gao, Qiping Cao, Zhiqiang Zhang, Zheng Tang
Appeared in: IEEJ Transactions on Electrical and Electronic Engineering
Publication date: Dec 2009
Publisher: Wiley InterScience
 
» A CMOS True Single-Phase-Clock Divider With Differential Outputs
Abstract:
This letter presents a true single-phase-clock (TSPC) divider that takes a single-ended input signal while producing differential outputs. The differential outputs are generated by properly coupling the waveforms of two TSPC dividers. Implemented using TSMC 0.18 CMOS technology, the divider is capable of operating from 0.6 to 5 GHz. The phase deviation and amplitude difference of the differential outputs are less than 1.7 degree and 0.41%, respectively, below 3 GHz. The core circuit size of the TSPC divider is .
Autors: Chang, C.-W.;Emery Chen, Y.-J.;
Appeared in: IEEE Microwave and Wireless Components Letters
Publication date: Dec 2009, volume: 19, issue:12, pages: 813 - 815
Publisher: IEEE
 
» A CMOS vector lock-in amplifier for sensor applications
Abstract:
The design of an integrated lock-in amplifier is discussed, specifically conceived for the detection of low-level signals at a harmonic of the drive frequency in magnetically excited resonant structures. The circuit includes in-phase and quadrature analogue signal processing channels, whose outputs feed an integrated ?? analogue to digital converter. The circuit can be operated in different configurations, depending on the application requirements: in particular, by combining the digitized outputs of the two channels, vector operation can be obtained. The entire analogue chain, including the ?? modulator, was designed using fully differential elaboration. The circuit was developed in a , dual...
Autors: Cristiano, Azzolini , Alessandro, Magnanini , Matteo, Tonelli , Giovanni, Chiorboli , Carlo, Morandi
Appeared in: Microelectronics Journal
Publication date: Dec 2009
Publisher: Elsevier B.V.
 
» A Cold Microplasma Jet Device Suitable for Bio-medical Applications
Abstract:
This paper presents a cold plasma jet operating at 20 kHz AC under atmospheric pressure. The micro plasma jet nozzle has a porous alumina dielectric installed between the outer anode and the inner hollow cathode. While nitrogen gas is injected through the hollow cathode and the porous dielectric, an electrical discharge occurs when an AC voltage is applied. This discharge produces a micro plasma jet that is ejected from the micro holes of the anode. The plasma jet device is operated at room temperature. The surfaces exposed to the plasma are modified to hydrophilic ones and the surface temperature increases...
Autors: Kangil, Kim , Geunyoung, Kim , Yong Cheol, Hong , Sang Sik, Yang
Appeared in: Microelectronic Engineering
Publication date: Dec 2009
Publisher: Elsevier B.V.
 
» A combined nanoplasmonic and electrodeless quartz crystal microbalance setup
Abstract:
We have developed an instrument combining localized surface plasmon resonance (LSPR) sensing with electrodeless quartz crystal microbalance with dissipation monitoring (QCM-D). The two techniques can be run simultaneously, on the same sensor surface, and with the same time resolution and sensitivity as for the individual techniques. The electrodeless QCM eliminates the need to fabricate electrodes on the quartz crystal and gives a large flexibility in choosing the surface structure and coating for both QCM-D and LSPR. The performance is demonstrated for liquid phase measurements of lipid bilayer formation and biorecognition events, and for gas phase measurements of hydrogen uptake/release by palladium nanoparticles. Advantages of using the combined equipment for biomolecular adsorption studies include synchronized information about structural transformations and extraction of molecular (dry) mass and degree of hydration of the adlayer, which cannot be obtained with the individual techniques. In hydrogen storage studies the combined equipment, allows for synchronized measurements of uptake/release kinetics and quantification of stored hydrogen amounts in nanoparticles and films at practically interesting hydrogen pressures and temperatures.
Autors: Larsson, Elin M.;Edvardsson, Malin E. M.;Langhammer, Christoph;Zoric, Igor;Kasemo, Bengt;
Appeared in: Review of Scientific Instruments
Publication date: Dec 2009, volume: 80, issue:12, pages: 125105 - 125105-10
Publisher: IEEE
 
» A Compact Forward Coupler Using Coupled Composite Right/Left-Handed Transmission Lines
Abstract:
A novel forward coupler using coupled composite right/left-handed (CRLH) transmission lines (TLs) is presented. Forward coupling is enhanced by the CRLH TLs, which have a considerable difference between the effective phase constants in the even and odd modes. A 10-dB forward coupler using the coupled CRLH TLs is simulated and experimentally demonstrated in the -band. Its coupled-line length is reduced to half that of the conventional right-handed forward coupler with the same coupling.
Autors: Hirota, A.;Tahara, Y.;Yoneda, N.;
Appeared in: IEEE Transactions on Microwave Theory and Techniques
Publication date: Dec 2009, volume: 57, issue:12, pages: 3127 - 3133
Publisher: IEEE
 
» A Compact Reverberation Chamber for Hyper-Rayleigh Channel Emulation
Abstract:
Recent propagation measurements conducted for emerging applications such as vehicle-to-vehicle communications and wireless sensor systems have illustrated that present worst-case channel models are not sufficient to characterize the small-scale propagation effects seen. New theoretical models have thus been proposed but existing emulation environments do not create sufficiently severe channel conditions. In this work we present the design of a compact, reconfigurable channel emulator (CRCE) specifically designed to create Ricean, Rayleigh and hyper-Rayleigh fading environments in a repeatable manner. The bench-top sized chamber leverages concepts seen in reverberation chambers but in addition to a mechanical stirrer varies the multipath environment through the use of multiple antennas. Emulated channels illustrating space-, time- and frequency-selective behaviors are presented.
Autors: Frolik, J.;Weller, T. M.;DiStasi, S.;Cooper, J.;
Appeared in: IEEE Transactions on Antennas and Propagation
Publication date: Dec 2009, volume: 57, issue:12, pages: 3962 - 3968
Publisher: IEEE
 
» A compact step recovery diode subnanosecond pulse generator
Abstract:
A compact Ultra-Wideband subnanosecond pulse generator is described in this article. The fundamental part of the generator consists of a step recovery diode (SRD), which works as a waveform edge sharpener. The SRD is included in a compact pulse-forming network, which is used to form a narrow Gaussian pulse. Theproposed circuit solution utilizes the performance of the SRD effectively with minimal requirements regarding the driver stage of the generator. The measurements show the waveform and power spectrum of the Gaussian pulse that is generated. ©2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52: 438-440, 2010; Published online in Wiley InterScience (www.interscience. wiley.com). DOI 10.1002/mop.24945
Autors: Pavel Protiva, Jan Mrkvica, Jan Machá[ccaron]
Appeared in: Microwave and Optical Technology Letters
Publication date: Dec 2009
Publisher: Wiley InterScience
 
» A comparative study of directivity enhancement of microstrip patch antennas with using three different superstrates
Abstract:
In this article, we present the results of a comparative study of three different types of superstrates used to enhance the directivity of a microstrip patch antenna. The three superstrates are frequency selective surface (FSS) with dipole elements; a dielectric slab; and a double negative (DNG) slab. We find that microstrip antennas (MPAs) covered either by an FSS or a plain dielectric slab superstrate provide higher directivities than that realized by using a DNG superstrate.
Inc. Microwave Opt Technol Lett 52: 327-331, 2010; DOI 10.1002/mop.24898
Autors: Raj Mittra, Yanfei Li, Kyungho Yoo
Appeared in: Microwave and Optical Technology Letters
Publication date: Dec 2009
Publisher: Wiley InterScience
 
» A comprehensive analysis on scaling prospects of dual-bit channel engineered SONOS NOR-flash EEPROM cells
Abstract:
Scaling prospects of pre-cycled 2-bit channel engineered SONOS flash EEPROM cells are studied on cells co-doped with compensation and halo implant. The compensation implant is shown to work in long channel cells to optimize bit coupling, read disturb, and program speed. However, co-doping with compensation implant fails at short channel length to reduce read disturb thus bit coupling at safe read VD. The junction engineering scheme is shown as the possible alternative for successful scaling of cells to simultaneously reduce read disturb and bit coupling but at the expense of program speed, which seems detrimental for deep scaling of cells.
Autors: A., Datta , S., Mahapatra
Appeared in: Solid-State Electronics
Publication date: Dec 2009
Publisher: Elsevier B.V.
 
» A Comprehensive Shear-Testing Facility for Joint-Scale Solder Samples
Abstract:
This paper describes the design and commissioning of a comprehensive shear testing apparatus for joint-scale solder samples. It allows for conducting most testing methods that are usually performed on solder specimens at highest precision for different temperatures. in situ observation of the solder joint can also be performed for micro structural studies. The various design features and the specimen manufacturing process are explained in detail. Creep test results on Sn96.5Ag3.0Cu0.5 (SAC305) and eutectic Sn63Pb37 (SP) solder are presented. Secondary creep rate, saturated primary creep strain and transition times between creep phases are investigated to demonstrate the capabilities of the shear-testing facility.
Autors: Herkommer, D.;Reid, M.;Punch, J.;
Appeared in: IEEE Transactions on Components and Packaging Technologies
Publication date: Dec 2009, volume: 32, issue:4, pages: 800 - 807
Publisher: IEEE
 
» A Conceptual Design of Model Coil for the 40-T Hybrid Magnet Superconducting Outsert
Abstract:
The High Magnetic Field Laboratory of the Chinese Academy of Sciences will develop a 40-T hybrid magnet. The superconducting outsert, which consists of a NbTi coil and a coil, will provide more than 11 T of central field in a 580-mm bore. The superconducting coils will be wound of cable-in-conduit conductor (CICC) and cooled by flowing 4.5-K supercritical helium. A model coil of the coil has been designed and will be manufactured to develop the technology of cabling, jacketing, winding, heat treatment, etc., and the model coil can also simulate the performance of the superconducting coil under its operating conditions. This paper gives an overview of the conceptual design for the model coil and predicts its current-sharing temperature (Tcs).
Autors: Tan, Y.;Chen, W.;Pan, Y.;Wang, F.;Chen, Z.;Zhu, J.;Kuang, G.;
Appeared in: IEEE Transactions on Applied Superconductivity
Publication date: Dec 2009, volume: 19, issue:6, pages: 3790 - 3794
Publisher: IEEE
 
» A construction of 1-to-2 shared optical buffer queue with switched delay lines
Abstract:
Optical buffering is fundamental to contention resolution in optical networks. The current works on this line mainly focus on the emulation of dedicated input/output buffer queue by using switched fiber delay lines (SDL). It is notable that the shared buffer queue, where a common buffer pool is shared by all the input/output ports of a switch, has the potential to significantly reduce the overall buffer capacity requirement. As far as we know, however, no related work is available yet on the exact emulation of a shared optical buffer queue with SDLs. In this paper, we focus on the design of first in first out (FIFO) shared optical buffer queue based on the optical feedback SDL construction. The construction considered consists of an (M + 2) x (M + 2) switch fabric and M fiber delay lines FDL1, . . ., FDLM, where FDLi connects the ith output of the switch fabric with its ith input. We show that by setting the length of FDL1 as min(M + 1 Âż i, i), i = 1, . . . , M, such a construction can actually work as an 1-to-2 shared buffer queue. We then extend this emulation to the more general N-to-2 case.
Autors: Wang, X.;Jiang, X.;Pattavina, A.;Horiguchi, S.;
Appeared in: IEEE Transactions on Communications
Publication date: Dec 2009, volume: 57, issue:12, pages: 3712 - 3723
Publisher: IEEE
 
» A Correlation for the Detection of Time and Frequency Offsets
Abstract:
A correlation is proposed for use to detect time and frequency offsets in a received signal in a digital transmission system. Applications include time and frequency synchronization in a single frequency network; pre-distortion for high power amplifiers in a transmitter. The correlation is formed with the products of two pairs of transmitted samples and received samples. The same correlation can be used to detect both time and frequency offsets in the received signal.
Autors: Hong Jiang;Purohit, V.;Wilford, P.A.;Jeanclaude, I.;Blineau, J.;
Appeared in: IEEE Transactions on Broadcasting
Publication date: Dec 2009, volume: 55, issue:4, pages: 752 - 760
Publisher: IEEE
 
» A CPW-fed broadband circularly polarized square slot antenna
Abstract:
A new broadband circularly polarized (CP) square slot antenna with coplanar waveguide fed is proposed. Two symmetrical E-shaped slits embedded in opposite corners of ground plane are designed to obtain an excellent CP bandwidth. Simulated results show that the broadband performance is formed by three resonant modes. Some key parameters are studied to analysis the characteristics of the proposed antenna. Measured results show that the 3 dB axial ratio bandwidth is larger than 32.8% relative to the center frequency of 2165 MHz and the impedance bandwidth is as large as 54.8% with voltage standing wave ratio (VSWR) [le]2.
Inc. Microwave Opt Technol Lett 52: 409-412, 2010; DOI 10.1002/mop.24904
Autors: Qing-Xin Chu, Shu Du
Appeared in: Microwave and Optical Technology Letters
Publication date: Dec 2009
Publisher: Wiley InterScience
 
» A critical assessment of computer tools for calculating composite wind turbine blade properties
Abstract:
The purpose of this paper is to critically assess several computer tools for calculating the inertial and structural properties of wind turbine blades. The theoretical foundation of each tool is briefly summarized, and the advantages and disadvantages of each tool are pointed out. Several benchmark examples, including a circular aluminium tube, a highly heterogeneous section, a multi-layer composite pipe, an isotropic blade-like section and a realistic composite wind turbine blade are used to evaluate the performance of different tools. Such a systematic and critical assessment provides guidance for wind turbine blade engineers to choose the right tool for effective design and analysis of wind turbine blades.
Autors: Hui Chen, Wenbin Yu, Mark Capellaro
Appeared in: Wind Energy
Publication date: Dec 2009
Publisher: Wiley InterScience
 
» A Cutsets-Based Unified Framework to Evaluate Network Reliability Measures
Abstract:
This paper presents a minimal cutsets-based unified framework to evaluate some commonly used reliability measures: -terminal, 2-terminal, and -terminal reliability. In doing so, the paper proposes a single algorithm, which generates the network node sets. From these node sets, depending on the reliability measure(s), only those node sets are kept, which contains at least one node from the specified node set. These selected node sets form link-minimal cutsets. These minimal cutsets are used as an input to multi-variable inversion-based sum-of-disjoint product approach to obtain the unreliability expression thereafter. By solving several network examples of varied complexities, the comparison with the existing approach is provided.
Autors: Mishra, R.;Chaturvedi, S. K.;
Appeared in: IEEE Transactions on Reliability
Publication date: Dec 2009, volume: 58, issue:4, pages: 658 - 666
Publisher: IEEE
 
» A Dedicated Two-Channel Phased-Array Receiver Coil for High-Resolution MRI of the Rat Knee Cartilage at 7 T
Abstract:
In the field of small animal studies, the array coil imaging has become increasingly important. In this paper, a dedicated two-channel array coil operating at 300 MHz (7 T) for high-resolution MRI (HR-MRI) of the rat knee cartilage is presented. The average gain in signal-to-noise ratio (SNR) compared to a 15-mm multipurpose surface coil was 2.2. This SNR gain was used to improve the spatial resolution of 3-D acquisitions by decreasing the voxel size from 59 times 59 times 156 mum3 to 51 times 51 times 94 mum3 without time penalty. Also, a set of two array coils was used to perform a simultaneous acquisition of both knee joints of a rat, maintaining the same scanning time without SNR or spatial resolution degradation compared to the single knee joint acquisition. This two-channel array coil is a key element to perform HR-MRI and extract cartilage morphological parameters such as thickness and volume.
Autors: Rengle, A.;Armenean, M.;Bolbos, R.;Goebel, J.-C.;Pinzano-Watrin, A.;Saint-Jalmes, H.;Gillet, P.;Beuf, O.;
Appeared in: IEEE Transactions on Biomedical Engineering
Publication date: Dec 2009, volume: 56, issue:12, pages: 2891 - 2897
Publisher: IEEE
 
» A delay-partitioning approach to the stability analysis of discrete-time systems?
Abstract:
This paper revisits the problem of stability analysis for linear discrete-time systems with time-varying delay in the state. By utilizing the delay partitioning idea, new stability criteria are proposed in terms of linear matrix inequalities (LMIs). These conditions are developed based on a novel Lyapunov functional. In addition to delay dependence, the obtained conditions are also dependent on the partitioning size. We have also established that the conservatism of the conditions is a non-increasing function of the number of partitions. Numerical examples are given to illustrate the effectiveness and advantage of the proposed methods.
Autors: Xiangyu, Meng , James, Lam , Baozhu, Du , Huijun, Gao
Appeared in: Automatica
Publication date: Dec 2009
Publisher: Elsevier B.V.
 
» A Design Methodology for Miniaturized Power Dividers Using Periodically Loaded Slow Wave Structure With Dual-Band Applications
Abstract:
This paper proposes an analytically-based approach for the design of a miniaturized single-band and dual-band two-way Wilkinson power divider. This miniaturization is achieved by realizing the power divider's impedance transformers using slow wave structures. These slow wave structures are designed by periodically loading transmission lines with capacitances, which reduces the phase velocity of the propagating waves and hence engender higher electric lengths using smaller physical lengths. The dispersive analysis of the slow wave structure used is included in the design approach to ensure a smooth nondispersive transmission line operation in the case of dual-band applications. The design methodology is validated with the design of a single-band, reduced size, two-way Wilkinson power divider at 850 and 620 MHz. An approximate length reduction of 25%–35% is achieved with this technique. For dual-band applications, this paper describes the design of a reduced size, two-way Wilkinson power divider for dual-band global system for mobile communications and code division multiple access applications at 850 and 1960 MHz, respectively. An overall reduction factor of 28%, in terms of chip area occupied by the circuit, is achieved. The electromagnetic simulation and experimental results validate the design approach. The circuit is realized with microstrip technology, which can be easily fabricated using conventional printed circuit processes.
Autors: Rawat, K.;Ghannouchi, F. M.;
Appeared in: IEEE Transactions on Microwave Theory and Techniques
Publication date: Dec 2009, volume: 57, issue:12, pages: 3380 - 3388
Publisher: IEEE
 
» A Design Procedure for Wideband Micropower Generators
Abstract:
We developed a design procedure for wideband electromagnetic micropower generators (WMPGs) based on piecewise-linear oscillators. We find that the dominant factors in the performance of this class of WMPGs are the stiffness ratio of the oscillator and the velocity of the moving structure at the point of impact with the stopper. We also find that designing these WMPGs requires additional steps beyond those required in the design of regular MPGs. The additional steps match the output power and bandwidth of the WMPG to the probability density function of environmental vibrations. While these steps add complexity to the design of WMPGs, they are shown to significantly increase harvested energy. [2009-0144]
Autors: Soliman, M. S. M.;Abdel-Rahman, E. M.;El-Saadany, E. F.;Mansour, R. R.;
Appeared in: Journal of Microelectromechanical Systems
Publication date: Dec 2009, volume: 18, issue:6, pages: 1288 - 1299
Publisher: IEEE
 
» A dipole approximation for a dielectric mixture based on the equal field energy method
Abstract:
In this paper, a dipole-energy approximation for calculating the electric field distribution and saturation charge of spheres in an infinitely large dielectric mixture has been carried out. The approximation rests on the assumption that the field energy of mixture calculated using two different methods have the same value. One way is considering that the mixture in a uniform field E0 as a uniform object of effective permittivity ?eff from a macroscopic point of view, where ?eff is seen as the average characteristic parameter of the object. The other way is assuming that the spheres in mixture are in the equivalent...
Autors: Fei, Lu , Qizheng, Ye
Appeared in: Journal of Electrostatics
Publication date: Dec 2009
Publisher: Elsevier B.V.
 
» A distributed scheduling framework for multi-user diversity gain and quality of service in wireless mesh networks
Abstract:
Wireless multi-hop, mesh networks are being considered as a candidate for wireless backhaul networks which carry data traffic between access networks and the wired Internet. Although existing scheduling algorithms have been adopted for the wireless backhaul networks, they do not yield good performance. In this paper, we study the computational complexity of finding the optimal link schedule for the wireless mesh networks with time-division-duplexing (TDD) operations. We show that the problem of finding the optimal schedule for the mesh networks is #P-complete. Consequently, we propose a heuristic distributed scheduling algorithm and a link utility function for wireless mesh networks. Performance analysis shows that our proposed framework is of linear-time complexity and the proposed utility function makes the long-term throughput allocation converge to the desired level which is proportional to the requirements specified by the routing protocol in use to guarantee quality of service (QoS). Moreover, we show that our framework maintains strong temporal correlation of interference, which is required to ensure proper channel predictions for distributed scheduling and power control. Finally, we compare our scheduling algorithm with a previously proposed "tree" scheduling and a centralized "ideal" scheduling. Simulation results reveal that the proposed algorithm achieves high efficiency in terms of network objective as well as the overall network throughput.
Autors: Hou, Y.;Leung, K.K.;
Appeared in: IEEE Transactions on Wireless Communications
Publication date: Dec 2009, volume: 8, issue:12, pages: 5904 - 5915
Publisher: IEEE
 
» A Dual-Band CMOS Voltage-Controlled Oscillator Implemented With Dual-Resonance LC Tank
Abstract:
A new fully integrated, dual-band CMOS voltage controlled oscillator (VCO) is presented. The VCO is composed of n-core cross-coupled Colpitts VCOs and was implemented in 0.18 m CMOS technology with 0.8 V supply voltage. The circuit allows the VCO to operate at two resonant frequencies with a common LC tank. The VCO has two control inputs, one for continuous control of the output frequency and one for band switching. This VCO is configured with 5 GHz and 12 GHz frequency bands with differential outputs. The dual-band VCO operates in 4.78–5.19 GHz and 12.19–12.61 GHz. The phase noises of the VCO operating at 5.11 and 12.2 GHz are dBc/Hz and dBc/Hz at 1 MHz offset, respectively, while the VCO draws 3.2/2.72 mA and 2.56/2.18 mW consumption at low/high frequency band from a 0.8 V supply.
Autors: Jang, S.-L.;Wu, Y.-K.;Liu, C.-C.;Huang, J.-F.;
Appeared in: IEEE Microwave and Wireless Components Letters
Publication date: Dec 2009, volume: 19, issue:12, pages: 816 - 818
Publisher: IEEE
 
» A Dual-Band Unequal Wilkinson Power Divider With Arbitrary Frequency Ratios
Abstract:
This letter presents a theoretically rigorous investigation and experimental verification for an asymmetrical, unequal power divider working at dual frequency bands. Through the even- and odd-mode analysis that can be applied to dual-band, unequal power divider by assuming virtual open and short points, analytically exact solutions have been derived for the design parameters values. For verification of this analysis, commercially available software including ADS and CST MWS based on circuit theory and full-EM theory, respectively, and already-established equations have been adopted.
Autors: Ahn, S.;Lee, J. W.;Cho, C. S.;Lee, T. K.;
Appeared in: IEEE Microwave and Wireless Components Letters
Publication date: Dec 2009, volume: 19, issue:12, pages: 783 - 785
Publisher: IEEE
 
» A Dynamic Quality-Adjustable H.264 Video Encoder for Power-Aware Video Applications
Abstract:
This paper proposes a dynamic quality-adjustable H.264 baseline profile (BP) video encoder that comprises 470 Kgates and 13.3 kB SRAM in a core size of 4.3 4.3 using TSMC 0.13 1P8M CMOS technology. Exploiting parameterized algorithms for motion estimation and intra prediction, the proposed design can dynamically configure the encoding modes with the design trade-off between power consumption and video quality for various video encoding applications. In addition, the proposed basic unit (BU)-based rate control hardware can maintain a constant and stable bit rate for network video transmission. It achieves real-time H.264 video encoding on CIF, D1, and HD720@30 frames/s with 7 mW to 25 mW, 27 mW to 162 mW, and 122 mW to 183 mW power dissipation in different quality modes.
Autors: Chang, H.-C.;Chen, J.-W.;Wu, B.-T.;Su, C.-L.;Wang, J.-S.;Guo, J.-I.;
Appeared in: IEEE Transactions on Circuits and Systems for Video Technology
Publication date: Dec 2009, volume: 19, issue:12, pages: 1739 - 1754
Publisher: IEEE
 
» A family of space-time block codes achieving full diversity with linear receivers
Abstract:
In this paper, we propose a design scheme for a family of space-time block codes (STBCs) that achieve full diversity when linear receivers, such as zero-forcing (ZF) or minimum mean square error (MMSE) receivers, are used. New STBCs obtained based on this design scheme are characterized by their special structure that combines/overlays orthogonal STBCs (OSTBCs) and Toeplitz codes together, which are called Group Orthogonal-Toeplitz Codes (GOTCs). By choosing different parameters, codes with different symbol rates and orthogonality can be obtained. It is indicated that the existing STBCs achieving full diversity with linear receivers, such as the Toeplitz codes and overlapped Alamouti codes (OACs) recently proposed in the literature and the OSTBCs are three members of the GOTCs with different parameters. It is also shown that the time-reversal space-time block codes (TR-STBCs) and delay diversity codes (DDCs) for frequency selective channels are equivalent to OACs and Toeplitz codes, respectively, and thus they both can achieve full space-frequency diversity with only linear receivers. Furthermore, simulations show that with linear receivers, GOTCs outperforming the above mentioned three codes can be obtained from the proposed design scheme.
Autors: Wang, H.;Xia, X.-G.;Yin, Q.;Li, B.;
Appeared in: IEEE Transactions on Communications
Publication date: Dec 2009, volume: 57, issue:12, pages: 3607 - 3617
Publisher: IEEE
 
» A Finite-Oxide Thickness-Based Analytical Model for Negative Bias Temperature Instability
Abstract:
Negative bias temperature instability (NBTI) in PMOS transistors has become a serious reliability concern in present-day digital circuit design. With continued technology scaling, and reducing oxide thickness, it has become imperative to accurately determine its effects on temporal circuit degradation, and thereby ensure reliable operation for a finite period of time. A reaction–diffusion (R–D)-based framework is developed for determining the number of interface traps as a function of time, for both the dc (static NBTI) and the ac (dynamic NBTI) stress cases. The effects of finite oxide thickness, and the influence of trap generation and annealing in polysilicon, are incorporated. The model provides a good fit with experimental data and also provides a satisfying explanation for most of the physical effects associated with the dynamics of NBTI. A generalized framework for estimating the impact of NBTI-induced temporal degradation in present-day digital circuits, is also discussed.
Autors: Kumar, S. V.;Kim, C. H.;Sapatnekar, S. S.;
Appeared in: IEEE Transactions on Device and Materials Reliability
Publication date: Dec 2009, volume: 9, issue:4, pages: 537 - 556
Publisher: IEEE
 
» A Flexible Infrastructure for Multilevel Language Engineering
Abstract:
Although domain-specific modeling tools have come a long way since the modern era of model-driven development started in the early 1990s and now offer an impressive range of features, there is still significant room for enhancing the flexibility they offer to end users and for combining the advantages of domain-specific and general-purpose languages. To do this, however, it is necessary to enhance the way in which the current generation of tools view metamodeling and support the representation of the multiple, “ontological” classification levels that often exist in subject domains. State-of-the-art tools essentially allow users to describe the abstract and concrete syntaxes of a language in the form of metamodels and to make statements in that language in the form of models. These statements typically convey information in terms of types and instances in the domain (e.g., the classes and objects of UML), but not in terms of types of types (i.e., domain metaclasses), and types of types of types, and so on, across multiple classification levels. In essence, therefore, while they provide rich support for “linguistic” metamodeling, the current generation of tools provides little if any built-in support for modeling “ontological” classification across more than one type/instance level in the subject domain. In this paper, we describe a prototype implementation of a new kind of modeling infrastructure that, by providing built-in support for multiple ontological as well as linguistic classification levels, offers various advantages over existing language engineering approaches and tools. These include the ability to view a single model from the perspective of both a general-purpose and a domain-specific modeling language, the ability to define constraints across multiple ontological classification levels, and the ability to tie the rendering of model elements to ontological as well as linguistic types over multiple clas- sification levels. After first outlining the key conceptual ingredients of this new infrastructure and presenting the main elements of our current realization, we show these benefits through two small examples.
Autors: Atkinson, Colin;Gutheil, Matthias;Kennel, Bastian;
Appeared in: IEEE Transactions on Software Engineering
Publication date: Dec 2009, volume: 35, issue:6, pages: 742 - 755
Publisher: IEEE
 
» A Framework for Ubiquitous Content Sharing
Abstract:
Examining three content-sharing scenarios reveals requirements for a generic content-sharing framework. The SharedLife framework helps combine different content types and balance user control versus effort when sharing information.
Autors: Kroner, A.;Schneider, M.;Mori, J.;
Appeared in: IEEE Pervasive Computing
Publication date: Dec 2009, volume: 8, issue:4, pages: 58 - 65
Publisher: IEEE
 
» A Fully Quantum Asymptotic Equipartition Property
Abstract:
The classical asymptotic equipartition property is the statement that, in the limit of a large number of identical repetitions of a random experiment, the output sequence is virtually certain to come from the typical set, each member of which is almost equally likely. In this paper, a fully quantum generalization of this property is shown, where both the output of the experiment and side information are quantum. An explicit bound on the convergence is given, which is independent of the dimensionality of the side information. This naturally leads to a family of REacutenyi-like quantum conditional entropies, for which the von Neumann entropy emerges as a special case.
Autors: Tomamichel, M.;Colbeck, R.;Renner, R.;
Appeared in: IEEE Transactions on Information Theory
Publication date: Dec 2009, volume: 55, issue:12, pages: 5840 - 5847
Publisher: IEEE
 
» A General Approach for Fabricating Arc-Shaped Composite Nanowire Arrays by Pulsed Laser Deposition
Abstract:
Here, a new method is demonstrated that uses sideways pulsed laser deposition to deliberately bend nanowires into a desired shape after growth and fabricate arc-shaped composite nanowire arrays of a wide range of nanomaterials. The starting nanowires can be ZnO, but the materials to be deposited can be metallic, semiconductor, or ceramic depending on the application. This method provides a general approach for rational fabrication of a wide range of side-by-side or "core-shell" nanowire arrays with controllable degree of bending and internal strain. Considering the ZnO is a piezoelectric and semiconductive material, its electrical properties change when deformed. This technique has potential applications in tunable electronics, optoelectronics, and piezotronics.
Autors: Yue Shen, Jung-Il Hong, Sheng Xu, Shisheng Lin, Hao Fang, Su Zhang, Yong Ding, Robert L. Snyder, Zhong Lin Wang
Appeared in: Advanced Functional Materials
Publication date: Dec 2009
Publisher: Wiley InterScience
 
» A Generalized Dual-Frequency Transformer for Two Arbitrary Complex Frequency-Dependent Impedances
Abstract:
The purpose of this letter is to propose a dual-frequency transformer for two arbitrary complex frequency- dependent impedances (ACF-DIs) and present a generalized T-junction power divider (T-JPD) operating at dual-band with arbitrary power-dividing ratios based on the proposed transformer. By the rigorous analysis of transmission line theory, the closed-form design equations for this generalized transformer are obtained. Using the analytical design method, a kind of generalized T-JPD can be designed to operate at two different frequencies with different power-dividing ratios. Furthermore, numerical examples are simulated and a microstrip T-JPD operating at 1 and 2.4 GHz with different power-dividing ratios (1.5 and 2 dB, respectively) is fabricated. Good agreements between the simulated and measured results can be observed.
Autors: Wu, Y.;Liu, Y.;Li, S.;Yu, C.;Liu, X.;
Appeared in: IEEE Microwave and Wireless Components Letters
Publication date: Dec 2009, volume: 19, issue:12, pages: 792 - 794
Publisher: IEEE
 
» A generalized model for Kalman filtering of motion information in video compression
Abstract:
In this paper, we tackle the problem of motion estimation in video compression. Since Full Search Algorithms (FSA) present the disadvantage of adding a high computational burden to the encoder, fast search techniques have been used in conjunction with predictive filtering, in such a way to guarantee an acceptable quality with an affordable complexity. The aim of this work is to propose a novel framework for Kalman filtering of motion information in compressed video sequences. The merits of our new framework are twofold: First, using an appropriate formulation of the system equations, several shortcomings inherent with former models in the...
Autors: Joumana, Farah , Ralph, Mounzer
Appeared in: AEU - International Journal of Electronics and Communications
Publication date: Dec 2009
Publisher: Elsevier B.V.
 
» A growth diagram for plasma-assisted molecular beam epitaxy of GaN nanocolumns on Si(111)
Abstract:
The morphology of GaN samples grown by plasma-assisted molecular beam epitaxy on Si(111) was systematically studied as a function of impinging Ga/N flux ratio and growth temperature (730–850 °C). Two different growth regimes were identified: compact and nanocolumnar. A growth diagram was established as a function of growth parameters, exhibiting the transition between growth regimes, and showing under which growth conditions GaN cannot be grown due to thermal decomposition and Ga desorption. Present results indicate that adatoms diffusion length and the actual Ga/N ratio on the growing surface are key factors to achieve nanocolumnar growth.
Autors: Fernandez-Garrido, S.;Grandal, J.;Calleja, E.;Sanchez-Garcia, M. A.;Lopez-Romero, D.;
Appeared in: Journal of Applied Physics
Publication date: Dec 2009, volume: 106, issue:12, pages: 126102 - 126102-3
Publisher: IEEE
 
» A high level synthesis design flow with a novel approach for efficient design space exploration in case of multi-parametric optimization objective
Abstract:
This paper introduces a novel approach to rapid Design Space Exploration (DSE) and presents a formalized High Level Synthesis (HLS) design flow with multi-parametric optimization objective using the same design space exploration approach. The proposed approach resolves issues related to DSE such as the precision of evaluation, time exhausted during evaluation and also automation of the exploration process. During DSE a conflicting situation always exists for the designer to concurrently maximize the accuracy of the exploration process and minimize the time spent during DSE analysis. This technique is capable of drastically reducing the number of architectural variants to be analyzed...
Autors: Anirban, Sengupta , Reza, Sedaghat , Zhipeng, Zeng
Appeared in: Microelectronics Reliability
Publication date: Dec 2009
Publisher: Elsevier B.V.
 
» A hybrid PSO technique for procuring VAR ancillary service in the deregulated electricity markets
Abstract:
This paper develops a new market-based technique for acquiring VAR ancillary service in the electricity market. The main objective of the developed market is to enable transmission operator "TO" to procure VAR service in a long term contract from the critical VAR providers that satisfy minimum VAR service payment while maintaining system security. Reactive power control problem for voltage stability is introduced into the VAR market problem in an explicit manner for normal and emergency states. An integration of particle swarm optimization "PSO" is presented with successive linear programming "SLP" for dealing with the VAR ancillary service problem. The problem...
Autors: E.E., El-Araby , Naoto, Yorino
Appeared in: International Journal of Electrical Power & Energy Systems
Publication date: Dec 2009
Publisher: Elsevier B.V.
 
» A joint PHY/MAC cross-layer design for UWB under power control
Abstract:
Power control (PC) is a critical parameter for the design and evaluation of UWB-based WPAN networks due to its distributed control nature and non-fixed topology. The main issues in UWB PC are the channel gain fluctuations induced by indoor channel fluctuation and interference arising from narrowband systems. In this paper we introduce a joint PHY/MAC technique for DS-UWB power control design by exploiting the high time resolution of the UWB signal for channel gain improvement and mitigate the narrowband interference to reduce transmitted power. The results indicate that the proposed approach achieves better BER and throughput over previous works.
Autors: Rashid A., Saeed , Sabira, Khatun , Borhanuddin Mohd, Ali , Khazani, Abdullah
Appeared in: Computers & Electrical Engineering
Publication date: Dec 2009
Publisher: Elsevier B.V.
 
» A K-Band CMOS Quadrature Frequency Tripler Using Sub-Harmonic Mixer
Abstract:
A low-power frequency tripler is designed by using the sub-harmonic mixer configuration for K-band applications. The proposed circuit features quadrature signal generation, applicable to LO signal synthesis in millimeter-wave wireless transceivers. It achieves conversion gain of 5.7 dB at the output frequency of 21 GHz. Implemented in a 0.18 CMOS technology, the circuit consumes power of 7.5 mW with 1.5 V supply voltage. The entire die occupies an area of .
Autors: Kuo, C.-N.;Chen, H.-S.;Yan, T.-C.;
Appeared in: IEEE Microwave and Wireless Components Letters
Publication date: Dec 2009, volume: 19, issue:12, pages: 822 - 824
Publisher: IEEE
 
» A Ka-band frequency synthesizer using LTCC technology
Abstract:
This article is dedicated to the research on a Ka-band frequency synthesizer based on low-temperature cofired ceramics (LTCC) technology. This module is composed of an X-band phase locked loop (PLL) frequency synthesizer and a millimeter-wave quadrupler. In this design, all devices and filters which buried in the substrate are in the same Ferro-A6M LTCC board. Measurements show that the Ka-band LTCC frequency synthesizer covers 34.8-35.2 GHz with a minimal step of 40 MHz, low-phase noise (<-83 dBc/Hz @1 kHz), low-spurious level (-62 dBc), fast-hopping time (<15us). The board size is 33 cm2. So far as we know, this is the first time to realize a LTCC frequency synthesizer module on a single LTCC board in millimeter wave band.
Inc. Microwave Opt Technol Lett 52: 319-322, 2010; DOI 10.1002/mop.24947
Autors: Mingzhou Zhan, Pinjie Qiu, Tao Yang, Ruimin Xu, Bo Yan, Weigan Lin
Appeared in: Microwave and Optical Technology Letters
Publication date: Dec 2009
Publisher: Wiley InterScience
 
» A Krylov subspace based low-rank channel estimation in OFDM systems
Abstract:
We investigate a low-rank minimum mean-square error (MMSE) channel estimator in orthogonal frequency division multiplexing (OFDM) systems. The proposed estimator is derived by using the multi-stage nested Wiener filter (MSNWF) identified in the literature as a Krylov subspace approach for rank reduction. We describe the low-rank MMSE expressions for exploiting the time correlation function (TCF) of the channel path gains. The Krylov subspace technique requires neither eigenvalue decomposition (EVD) nor the inverse of the covariance matrices for parameter estimation. We show that the Krylov channel estimator can perform as well as the EVD estimator with a much smaller rank. Simulation...
Autors: J., Oliver , R., Aravind , K.M.M., Prabhu
Appeared in: Signal Processing
Publication date: Dec 2009
Publisher: Elsevier B.V.
 
» A leader-followers model of transmission augmentation for considering strategic behaviours of generating companies in energy markets
Abstract:
This paper suggests an integrated mathematical framework developed based on the leader-followers game for augmentation of transmission networks. Transmission Network Service Provider moves first and designs the horizon year transmission system. Generating Companies compete for having the highest share from the energy market and they find their equilibrium point using the Nash equilibrium concept. Finally, Market Management Company receives the planning schedule of transmission system and the energy offer prices and clears the market. In addition to the exact mathematical modelling of the interested players of transmission planning problem, the methodology can design the future transmission system not only for...
Autors: M.R., Hesamzadeh , N., Hosseinzadeh , P.J., Wolfs
Appeared in: International Journal of Electrical Power & Energy Systems
Publication date: Dec 2009
Publisher: Elsevier B.V.
 
» A Low Power and High Resolution Data Logger for Submarine Seismic Monitoring
Abstract:
The design, implementation and characterization of a digital waveform recorder for ocean bottom seismic monitoring is here reported. The system is capable of synchronously acquiring, and logging on a flash memory bank, four high resolution signals. Thanks to a very careful design of the system architecture and by using robust digital signal processing techniques, two main conflicting issues have been addressed: a high dynamic range, better than 120 dB, usually obtained with high energy demanding converters, and a power consumption as low as 250 mW, hence allowing to easily increase the time of a continuous submarine monitoring session up to...
Autors: Gioacchino, Fertitta , Antonio Di, Stefano , Giuseppe, Fiscelli , Giuseppe C., Giaconia
Appeared in: Microprocessors and Microsystems
Publication date: Dec 2009
Publisher: Elsevier B.V.
 
» A Low Voltage Quadrature VCO Implemented With Series Frequency Doublers
Abstract:
Using the transformer coupling technique, this letter presents a new quadrature voltage-controlled oscillator (QVCO) with bottom series-coupled transistors. The proposed CMOS QVCO has been implemented with the TSMC 1P8M CMOS process, and the die area is . At the supply voltage of 1.0 V, the total power consumption is 3.56 mW. The free-running frequency of the QVCO is tunable from 5.43 GHz to 5.92 GHz as the tuning voltage is varied from 0.0 V to 1.0 V. The measured phase noise at 1 MHz frequency offset is at the oscillation frequency of 5.5 GHz and the figure of merit (FOM) of the proposed QVCO is .
Autors: Jang, S.-L.;Lee, T.-S.;Hsue, C.-W.;Liu, C.-C.;
Appeared in: IEEE Microwave and Wireless Components Letters
Publication date: Dec 2009, volume: 19, issue:12, pages: 819 - 821
Publisher: IEEE
 
» A Low-Power Wide-Range I-V Converter for Amperometric Sensing Applications
Abstract:
This paper presents for the first time experimental results of a current-to-voltage converter that can be used for amperometric sensing of currents ranging from 1 pA to 1 A. The design strategy is optimized to achieve low power levels and, hence, make the circuit suitable for use in a wearable or implantable sensor. The power reduction is mostly achieved by combining transistors operating in the weak inversion region with floating-gate metal–oxide semiconductor devices and three different gain settings. The power consumption under normal operation is 9.82 W.
Autors: Rodriguez-Villegas, E. O.;
Appeared in: IEEE Transactions on Biomedical Circuits and Systems
Publication date: Dec 2009, volume: 3, issue:6, pages: 432 - 436
Publisher: IEEE
 
» A Lower Error and ROM-Free Logarithmic Converter for Digital Signal Processing Applications
Abstract:
In this brief, we propose a lower error and ROM-free logarithmic converter. The proposed converter can lead to area-efficient hardware implementation as it avoids the need for a ROM by employing simple computation units for logarithmic approximation. Our proposed logarithmic conversion algorithm partitions the exact logarithmic curve into two symmetric regions such that the slopes in the two regions that are used for logarithmic approximation are inversed. Simulation results show that the proposed algorithm achieves an error range and percentage error range of only 0.045 and 3.339%, respectively, which outperforms previously proposed one-region and two-region conversion methods. We have implemented the proposed logarithmic converter using 0.13- CMOS technology, and the latency is 2.8 ns. The proposed converter can be used to reduce the overhead of computation-intensive operations for real-time digital-signal-processing applications.
Autors: Juang, T.-B.;Chen, S.-H.;Cheng, H.-J.;
Appeared in: IEEE Transactions on Circuits and Systems II: Express Briefs
Publication date: Dec 2009, volume: 56, issue:12, pages: 931 - 935
Publisher: IEEE
 
» A luminescence lifetime assisted ratiometric fluorimeter for biological applications
Abstract:
In general, the most difficult task in developing devices for fluorescence ratiometric sensing is the isolation of signals from overlapping emission wavelengths. Wavelength discrimination can be achieved by using monochromators or bandpass filters, which often lead to decreased signal intensities. The result is a device that is both complex and expensive. Here we present an alternative system—a low-cost standalone optical fluorimeter based on luminescence lifetime assisted ratiometric sensing (LARS). This paper describes the principle of this technique and the overall design of the sensor device. The most significant innovation of LARS is the ability to discriminate between two overlapping luminescence signals based on differences in their luminescence decay rates. Thus, minimal filtering is required and the two signals can be isolated despite significant overlap of luminescence spectra. The result is a device that is both simple and inexpensive. The electronic circuit employs the lock-in amplification technique for the signal processing and the system is controlled by an onboard microcontroller. In addition, the system is designed to communicate with external devices via Bluetooth.
Autors: Lam, Hung;Kostov, Yordan;Rao, Govind;Tolosa, Leah;
Appeared in: Review of Scientific Instruments
Publication date: Dec 2009, volume: 80, issue:12, pages: 124302 - 124302-7
Publisher: IEEE
 
» A medical tactile sensing instrument for detecting embedded objects, with specific application for breast examination
Abstract:
In this paper, having considered the tactile sensing and palpation of a physician in order to detect abnormal masses in the breast, we simplified and then modelled the tissue containing a mass and used contact elements to analyse the tactile sensor function.By using the finite element method, the effects of the mass existence appeared on the surface of the tissue. This was due to exerting mechanical load on the modelled tissue surface. Following this, a tactile sensing instrument called the 'tactile tumour detector' (TTD) was designed and constructed. This device is able to detect abnormal objects in the simulated models by making contact with model surfaces. In order to perform a series of precise experiments, a robot that could hold the tactile probe was used. The velocity of the linear movement of the probe is low enough to ensure that the tissue behaves in the linear elastic range, so that dynamic effects can be neglected.The maximum value of stresses was chosen as the comparison criterion. The variation of this criterion vs. the mass parameter changes was investigated and good agreements between numerical and experimental results were obtained. Moreover, the sensitivity and specificity of TTD and clinical breast examination (CBE) in the detection of breast masses, in comparison to sonography as the 'gold standard', were calculated by performing clinical trials on 55 cases.
Autors: Sayyed Mohsen Hosseini, Seyed Mohsen Towliat Kashani, Siamak Najarian, Farzad Panahi, Seyed Morteza Mousavi Naeini, Afsaneh Mojra
Appeared in: The International Journal of Medical Robotics and Computer Assisted Surgery
Publication date: Dec 2009
Publisher: Wiley InterScience
 
» A memory-efficient parallel string matching for intrusion detection systems
Abstract:
As the variety of hazardous packet payload contents increases, the intrusion detection system (IDS) should be able to detect numerous patterns in real time. For this reason, this paper proposes an Aho-Corasick algorithm based parallel string matching. In order to balance memory usage between homogeneous finite-state machine (FSM) tiles for each string matcher, an optimal set of bit position groups is determined. Target patterns are sorted by binary-reflected gray code (BRGC), which reduces bit transitions in patterns mapped onto a string matcher. In the evaluations of Snort rules, the proposed string matching outperforms the existing bit-split string matching.
Autors: Kim, H.;Hong, H.;Kim, H.-S.;Kang, S.;
Appeared in: IEEE Communications Letters
Publication date: Dec 2009, volume: 13, issue:12, pages: 1004 - 1006
Publisher: IEEE
 
» A message-passing approach for joint channel estimation, interference mitigation, and decoding
Abstract:
Channel uncertainty and co-channel interference are two major challenges in the design of wireless systems such as future generation cellular networks. This paper studies receiver design for a wireless channel model with both timevarying Rayleigh fading and strong co-channel interference of similar form as the desired signal. It is assumed that the channel coefficients of the desired signal can be estimated through the use of pilots, whereas no pilot for the interference signal is available, as is the case in many practical wireless systems. Because the interference process is non-Gaussian, treating it as Gaussian noise generally often leads to unacceptable performance. In order to exploit the statistics of the interference and correlated fading in time, an iterative message-passing architecture is proposed for joint channel estimation, interference mitigation and decoding. Each message takes the form of a mixture of Gaussian densities where the number of components is limited so that the overall complexity of the receiver is constant per symbol regardless of the frame and code lengths. Simulation of both coded and uncoded systems shows that the receiver performs significantly better than conventional receivers with linear channel estimation, and is robust with respect to mismatch in the assumed fading model.
Autors: Zhu, Y.;Guo, D.;Honig, M.L.;
Appeared in: IEEE Transactions on Wireless Communications
Publication date: Dec 2009, volume: 8, issue:12, pages: 6008 - 6018
Publisher: IEEE
 
» A method for atomic force microscopy cantilever stiffness calibration under heavy fluid loading
Abstract:
This work presents a method for force calibration of rectangular atomic force microscopy (AFM) microcantilevers under heavy fluid loading. Theoretical modeling of the thermal response of microcantilevers is discussed including a fluid-structure interaction model of the cantilever-fluid system that incorporates the results of the fluctuation-dissipation theorem. This model is curve fit to the measured thermal response of a cantilever in de-ionized water and a cost function is used to quantify the difference between the theoretical model and measured data. The curve fit is performed in a way that restricts the search space to parameters that reflect heavy fluid loading conditions. The resulting fitting parameters are used to calibrate the cantilever. For comparison, cantilevers are calibrated using Sader’s method in air and the thermal noise method in both air and water. For a set of eight cantilevers ranging in stiffness from 0.050 to 5.8 N/m, the maximum difference between Sader’s calibration performed in air and the new method performed in water was 9.4%. A set of three cantilevers that violate the aspect ratio assumption associated with the fluid loading model (length-to-width ratios less than 3.5) ranged in stiffness from 0.85 to 4.7 N/m and yielded differences as high as 17.8%.
Autors: Kennedy, Scott J.;Cole, Daniel G.;Clark, Robert L.;
Appeared in: Review of Scientific Instruments
Publication date: Dec 2009, volume: 80, issue:12, pages: 125103 - 125103-8
Publisher: IEEE
 
» A Method for Automatic Fall Detection of Elderly People Using Floor Vibrations and Sound—Proof of Concept on Human Mimicking Doll Falls
Abstract:
Falls are a major risk for the elderly people living independently. Rapid detection of fall events can reduce the rate of mortality and raise the chances to survive the event and return to independent living. In the last two decades, several technological solutions for detection of falls were published, but most of them suffer from critical limitations. In this paper, we present a proof of concept to an automatic fall detection system for elderly people. The system is based on floor vibration and sound sensing, and uses signal processing and pattern recognition algorithm to discriminate between fall events and other events. The classification is based on special features like shock response spectrum and mel frequency ceptral coefficients. For the simulation of human falls, we have used a human mimicking doll: ldquoRescue Randy.rdquo The proposed solution is unique, reliable, and does not require the person to wear anything. It is designed to detect fall events in critical cases in which the person is unconscious or in a stress condition. From the preliminary research, the proposed system can detect human mimicking dolls falls with a sensitivity of 97.5% and specificity of 98.6%.
Autors: Zigel, Y.;Litvak, D.;Gannot, I.;
Appeared in: IEEE Transactions on Biomedical Engineering
Publication date: Dec 2009, volume: 56, issue:12, pages: 2858 - 2867
Publisher: IEEE
 
» A Methodology for Realizing High Efficiency Class-J in a Linear and Broadband PA
Abstract:
The design and implementation of a class-J mode RF power amplifier is described. The experimental results indicate the class-J mode's potential in achieving high efficiency across extensive bandwidth, while maintaining predistortable levels of linearity. A commercially available 10 W GaN (gallium nitride) high electron mobility transistor device was used in this investigation, together with a combination of high power waveform measurements, active harmonic load–pull and theoretical analysis of the class-J mode. Targeting a working bandwidth of 1.5–2.5 GHz an initial power amplifier (PA) design was based on basic class-J theory and computer-aided design simulation. This realized a 50% bandwidth with measured drain efficiency of 60%–70%. A second PA design iteration has realized near-rated output power of 39 dBm and improved efficiency beyond the original 2.5 GHz target, hence extending efficient PA operation across a bandwidth of 1.4–2.6 GHz, centered at 2 GHz. This second iteration made extensive use of active harmonic load–pull and waveform measurements, and incorporated a novel design methodology for achieving predistortable linearity. The class-J amplifier has been found to be more realizable than conventional class-AB modes, with a better compromise between power and efficiency tradeoffs over a substantial RF bandwidth.
Autors: Wright, P.;Lees, J.;Benedikt, J.;Tasker, P. J.;Cripps, S. C.;
Appeared in: IEEE Transactions on Microwave Theory and Techniques
Publication date: Dec 2009, volume: 57, issue:12, pages: 3196 - 3204
Publisher: IEEE
 
» A Microfluidic Affinity Sensor for Detection of Cocaine
Abstract:
We present a microfluidic aptamer-based biosensor for specific cocaine detection. The device consists primarily of a microchamber packed with aptamer-functionalized microbeads that act as a sensing surface, integrated with an on-chip heater and temperature sensor. The sensor employs a Förster resonance energy transfer (FRET) system in which a fluorophore-quencher pair of Carboxyfluorescein and Dabcyl generates a signal-on response to cocaine. We demonstrate device operation by successfully detecting cocaine with a four orders of magnitude linear response in micromolar to nanomolar concentrations. The detection limit of the device is further lowered to 10 pM by concentration of a highly diluted cocaine...
Autors: John P., Hilton , Thai Huu, Nguyen , Renjun, Pei , Milan, Stojanovic , Qiao, Lin
Appeared in: Sensors and Actuators A: Physical
Publication date: Dec 2009
Publisher: Elsevier B.V.
 
» A Micropower Tilt-Processing Circuit
Abstract:
This paper describes a novel analog circuit for extracting the tilt angle from the output of a linear microelectromechanical-system accelerometer. The circuit uses the accelerometer signal, together with the gravitational acceleration vector, to generate the tilt signal. Using a current-mode representation with metal–oxide semiconductor devices operating in weak inversion, the appropriate trigonometric function has been realized to compute tilt. Furthermore, implementing a long-time constant filter to extract the mean tilt level provides adaptation to the static tilt level. Specifically, this circuit has been designed as part of an implantable vestibular prosthesis to provide inclination signals for bypassing dysfunctional otolith end organs. The circuit has been fabricated in AustriaMicroSystems 0.35- m 2P4M complementary metal–oxide semiconductor technology, and this paper presents the theory, implementation, and measured results.
Autors: Constandinou, T. G.;Georgiou, J.;
Appeared in: IEEE Transactions on Biomedical Circuits and Systems
Publication date: Dec 2009, volume: 3, issue:6, pages: 363 - 369
Publisher: IEEE
 
» A Microstrip Antenna Array for Indoor Wireless Dynamic Environments
Abstract:
A planar microstrip antenna array with a Butler matrix has been implemented to form a microstrip antenna array that has narrow beamwidth, circular polarization, and polarization diversity. This microstrip antenna array improves the system performance in indoor wireless dynamic environments. A circularly polarized microstrip antenna array is designed such that it consists of four identical linearly polarized patches. A 2 2 planar microstrip antenna array and a 4 4 Butler matrix have been designed and simulated using advanced design system and Matlab software. The measured results show that a combination of a planar microstrip antenna array and a 4 4 Butler matrix creates four beams; two of these beams have right-hand circular polarization and the other two have left-hand circular polarization.
Autors: Elhefnawy, M.;Ismail, W.;
Appeared in: IEEE Transactions on Antennas and Propagation
Publication date: Dec 2009, volume: 57, issue:12, pages: 3998 - 4002
Publisher: IEEE
 
» A miniature frequency synthesizer module in W-band
Abstract:
This article is dedicated to the research on a miniaturized W-band multiplied phase-locked frequency synthesizer. This module adopts microwave frequency synthesizer and multiplying scheme. It is composed of a C-band phase-locked loop (PLL) frequency synthesizer and a millimeter-wave (mm-wave) ×4 × 3 multiplier chain. Measurements show that the W-band multiplied frequency synthesizer module covers 92.4-95.6 GHz with a minimal step of 40 MHz, low phase noise (better than -75 dBc/Hz@10 kHz in the whole output frequency band), sufficient power (-5.7 dBm to -3.6 dBm), and only a very compact size of 9.8 cm long ×9.5 cm wide ×2.7 cm high.
Inc. Microwave Opt Technol Lett 52: 412-416, 2010; DOI 10.1002/mop.24915
Autors: Mingzhou Zhan Ruimin, Xu Weigan Lin
Appeared in: Microwave and Optical Technology Letters
Publication date: Dec 2009
Publisher: Wiley InterScience
 
» A Miniature Quadrifilar Helix Antenna for Global Positioning Satellite Reception
Abstract:
The design is described of a very compact quadrifilar helix antenna. A hollow ceramic rod is used as a dielectric load to reduce antenna size, which is only 2.7% of an air-loaded quadrifilar helix antenna. A simple equivalent circuit is established for the proposed quadrifilar helix antenna to demonstrate impedance characteristics. A self-phasing method for achieving circular polarization is also proposed. This method is convenient for tuning circular polarization. Additionally, a compact matching structure is designed to match the proposed antenna, which only utilizes short transmission-line sections and one capacitor. For experiments, the proposed antenna is designed at 1.575 GHz such that it can be utilized for global position system. Measurement and simulation results agree. A hemispherical pattern with a beamwidth of 150 is measured. This circular-polarized pattern with a wide beamwidth is feasible for mobile applications.
Autors: Wang, Y.-S.;Chung, S.-J.;
Appeared in: IEEE Transactions on Antennas and Propagation
Publication date: Dec 2009, volume: 57, issue:12, pages: 3746 - 3751
Publisher: IEEE
 
» A Minimally Invasive Microdevice for Molecular Sampling and Analysis
Abstract:
In this paper, we present a new minimally invasive biopsy microdevice adapted to proteomic mass spectrometry analysis. The concept is born from a multidisciplinary collaboration in fields of proteomics, cancer research, and microtechnology. In mixing different skills, we have developed and manufactured a miniaturized biopsy device using microtechnology techniques in order to minimize tissue damage during surgical gesture. Dedicated chemically functionalized areas were added to the device in order to increase capture yield and specificity during tissue contact. Fields of application range from cancer research to the study of neurodegenerative diseases.
Autors: Cosnier, M.-L.;Martin, F.;Bouamrani, A.;Berger, F.;Caillat, P.;
Appeared in: IEEE Transactions on Biomedical Engineering
Publication date: Dec 2009, volume: 56, issue:12, pages: 2898 - 2904
Publisher: IEEE
 
» A Model-Based Approach to Families of Embedded Domain-Specific Languages
Abstract:
With the emergence of model-driven engineering (MDE), the creation of domain-specific languages (DSLs) is becoming a fundamental part of language engineering. The development cost of a DSL should be modest compared to the cost of developing a general-purpose programming language. Reducing the implementation effort and providing reuse techniques are key aspects for DSL approaches to be really effective. In this paper, we present an approach to build embedded domain-specific languages applying the principles of model-driven engineering. On the basis of this approach, we will tackle reuse of DSLs by defining families of DSLs, addressing reuse both from the DSL developer and user point of views. A family of DSLs will be built up by composing several DSLs, so we will propose composition mechanisms for the abstract syntax, concrete syntax, and model transformation levels of a DSL's definition. Finally, we contribute a software framework to support our approach, and we illustrate the paper with a case study to demonstrate its practical applicability.
Autors: Sanchez Cuadrado, Jesus;Molina, Jesus Garcia;
Appeared in: IEEE Transactions on Software Engineering
Publication date: Dec 2009, volume: 35, issue:6, pages: 825 - 840
Publisher: IEEE
 
» A modified belief propagation algorithm for code word quantization
Abstract:
Modern coding advances, including dirty paper coding and information hiding, require quantizing a given binary word to a code word. A 'good' solution would approach the rate-distortion bound in lossy source compression. Here we propose a simple variant on belief propagation which is observed to converge to a solution giving respectable rate-distortion performance. Comparisons with other recently proposed source quantization methods reveal that the proposed algorithm holds particular interest in short block-length applications, as encountered in packet-based communication systems.
Autors: Regalia, P.A.;
Appeared in: IEEE Transactions on Communications
Publication date: Dec 2009, volume: 57, issue:12, pages: 3513 - 3517
Publisher: IEEE
 
» A modified CPW-fed monopole antenna with very small ground for multiband WLAN applications
Abstract:
A modified planar monopole antenna with multiband operation for wireless local area networks (WLAN) is presented in this article. The antenna is composed of symmetrical hook-shaped strips and a horizontal strip on the top, both printed on an inexpensive FR4 substrate, and is fed by a coplanar waveguide (CPW) feedline. The measured results explore broadband dual-frequency operation with 2:1 VSWR impedance bandwidths range from 2.07 to 2.52 GHz and 5.07 to 6.62 GHz, which cover the 2.4/5.2/5.8 GHz WLAN operating bands. Also, good similar omnidirectional radiation patterns have been achieved.
Inc. Microwave Opt Technol Lett 52: 463-466, 2010; DOI 10.1002/mop.24940
Autors: Zheng Zhang, Yong Chang Jiao, Yue Song, Tian Ling Zhang, Shu Man Ning, Fu Shun Zhang
Appeared in: Microwave and Optical Technology Letters
Publication date: Dec 2009
Publisher: Wiley InterScience
 
» A Monolithic Dual-Color Total-Internal-Reflection-Based Chip for Highly Sensitive and High-Resolution Dual-Fluorescence Imaging
Abstract:
We report a dual-color total-internal-reflection (TIR)-based chip that can generate two overlapping evanescent fields with different wavelengths for simultaneous imaging of two types of fluorophores. We derived a general relationship among the dimensions of the components of the chip to guarantee the overlap of two evanescent fields. Optical simulation results also confirm the generation and overlap of two evanescent fields. Using Si bulk micromachining and poly(dimethylsiloxane) (PDMS) casting, our fabrication method integrates all miniaturized optical components into one monolithic PDMS chip. Thus, assembly is unnecessary, and misalignment is avoided. Our PDMS chip can be employed with various sample delivery platforms, such as glass slide, flow cell, microchannel, etc. We first demonstrated the capability of the chip by imaging TIR fluorescent spots of a mixture of two fluorophores, namely, fluorescein and tetramethylrhodamine. We then employed the chip to observe the Brownian motion of a mixture of nile-red and dragon-green 500-nm microbeads. Our chip could potentially be integrated into a micro-total analysis system for highly sensitive and high-resolution dual-fluorescence imaging applications. [2009-0188]
Autors: Le, N. C. H.;Dao, D. V.;Yokokawa, R.;Wells, J. C.;Sugiyama, S.;
Appeared in: Journal of Microelectromechanical Systems
Publication date: Dec 2009, volume: 18, issue:6, pages: 1371 - 1381
Publisher: IEEE
 
» A more efficient device for preparing model-membrane liposomes by the rapid solvent exchange method
Abstract:
We modified the original design for a rapid solvent exchange (RSE) device with the intent of making the RSE method (i) more efficient and (ii) easier to adopt and implement. Our modifications improved solvent-removal kinetics by a factor of 2, while reducing sample-prep time by a factor of 3. In this paper, we develop the kinetic model that informed the device revision and we address several RSE parameters that have not yet been discussed in the literature. We also provide detailed mechanical drawings and present solvent-removal efficiency data that confirm the improved performance of our device.
Autors: Buboltz, Jeffrey T.;
Appeared in: Review of Scientific Instruments
Publication date: Dec 2009, volume: 80, issue:12, pages: 124301 - 124301-5
Publisher: IEEE
 
» A Multiagent Fuzzy-Logic-Based Energy Management of Hybrid Systems
Abstract:
Hybrid energy systems (HESs) for renewable energy sources are an interesting solution to power stand-alone systems. However, the energy management of such systems is quite complex when it relies on a central controller. With a central controller, the energy management system (EMS) has to be redesigned when the configuration is changed (for example, with the addition of a new device). This paper proposes a distributed EMS to control the energy flow in the HES. This distributed controller is based on multiagent-system (MAS) technology. With this concept, a HES is seen as a collection of different elements that collaborate to reach a global coordination. The agent approach for HES is explained, and a MAS is presented. Finally, a simulation model of the HES controlled by a MAS is proposed, and the system reaction is detailed.
Autors: Lagorse, J.;Simoes, M.G.;Miraoui, A.;
Appeared in: IEEE Transactions on Industry Applications
Publication date: Dec 2009, volume: 45, issue:6, pages: 2123 - 2129
Publisher: IEEE
 
» A multilayer space-time-frequency coding scheme for MIMO-OFDM
Abstract:
We present a multilayer space-time-frequency (STF) coding scheme for wideband multiple-input multiple-output (MIMO) systems employing orthogonal frequency-division multiplexing (OFDM). With multiple receive antennas, we employ an iterative demodulator consisting of a low-complexity multilayer detector and a simple soft extrinsic combiner. The system performance is optimized by efficient power allocation among layers, as well as interleaver design and extrinsic scaling to reduce the extrinsic correlation. Simulation results demonstrate that the proposed multilayer STF coding scheme performs close to or even better than the optimized linear dispersion (LD) STF codes with maximum likelihood (ML) decoding. Unlike the existing STF codes, which need to be designed for different system configurations and channel statistics, the proposed multilayer STF strategy is a universal scheme that exhibit excellent performance under various conditions.
Autors: Yue, G.;Zhang, L.;Wang, X.;
Appeared in: IEEE Transactions on Wireless Communications
Publication date: Dec 2009, volume: 8, issue:12, pages: 6104 - 6114
Publisher: IEEE
 

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