The Experts below are selected from a list of 204 Experts worldwide ranked by ideXlab platform
F Moraveji - One of the best experts on this subject based on the ideXlab platform.
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a wide band low power high slew rate voltage feedback Operational amplifier
IEEE Journal of Solid-state Circuits, 1996Co-Authors: F MoravejiAbstract:A wide-band low-power voltage-feedback Operational amplifier on a 3 GHz, 40 V complementary bipolar technology is described. The class AB input stage takes advantage of some current-boost transistors which enhance and linearize the slew-rate during large-Signal Operation without increasing the power consumption. The triple-buffered output stage provides 100 mA of load current maintaining good linearity. Since the circuit design and technology development were concurrent, several different circuits were stepped into one wafer to fully characterize the process and identify the best product candidates. The low-current version of this chip has a quiescent current of 2.5 mA, 2000 V//spl mu/s slew rate and gain bandwidth of 110 MHz. The medium-current version draws only 6.5 mA of current at the same supply voltage while the slew rate increases to 3500 V//spl mu/s and bandwidth to 210 MHz. Both parts are Operational from +/-2.75 V to +/-18 V supply range. Die size is 51 mils by 76 mils on a poly-emitter CB process.
Victor L. Granatstein - One of the best experts on this subject based on the ideXlab platform.
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analytical theory of frequency multiplying gyro traveling wave tubes
Physics of Plasmas, 2001Co-Authors: Gregory S. Nusinovich, W Chen, Victor L. GranatsteinAbstract:The theory is developed which describes analytically the gain and bandwidth in frequency-multiplying gyro-traveling-wave-tubes. In this theory the input waveguide is considered in the small-Signal approximation. Then, in the drift region separating the input and output waveguides, the electron ballistic bunching evolves which causes the appearance in the electron current density of the harmonics of the Signal frequency. The excitation of the output waveguide by one of these harmonics is considered in a specified current approximation. This makes the analytical study of a large-Signal Operation possible. The theory is illustrated by using it to analyze the performance of an existing experimental tube.
C R Bolognesi - One of the best experts on this subject based on the ideXlab platform.
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94 ghz large Signal Operation of alinn gan high electron mobility transistors on silicon with regrown ohmic contacts
IEEE Electron Device Letters, 2015Co-Authors: Diego Marti, Stefano Tirelli, Lorenzo Lugani, Jeanfrancois Carlin, N Grandjean, Valeria Teppati, Marco Malinverni, C R BolognesiAbstract:We report the first 94-GHz ( $W$ -band) large-Signal performance of AlInN/GaN high-electron-mobility transistors (HEMTs) grown on high-resistivity silicon (111) substrates. A maximum output power density of 1.35 W/mm and peak power-added-efficiency of 12% are measured at 94 GHz. The devices exhibit a dc maximum current drain density of 1.6 A/mm and a peak transconductance of 650 mS/mm. In small-Signal Operation, cutoff frequencies ${f} _{\rm T}/ {f} _{\mathrm {MAX}}=141/232$ GHz are achieved. The large-Signal performance of our AlInN/GaN HEMTs on silicon at 94 GHz stills lags the best reported results one on SiC substrates but nevertheless confirms the tremendous interest of GaN-on-Si HEMT technology for low-cost millimeter-wave electronic applications.
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alinn based hemts for large Signal Operation at 40 ghz
IEEE Transactions on Electron Devices, 2013Co-Authors: Stefano Tirelli, Lorenzo Lugani, Diego Marti, Jeanfrancois Carlin, N Grandjean, C R BolognesiAbstract:We report the large-Signal performance of high electron mobility transistors (HEMTs) fabricated on GaN- and AlN-capped AlInN/GaN epilayers grown on semi-insulating SiC substrates. Large-Signal measurements at 10 and 40 GHz are presented with both gate and drain dynamic loadlines to clarify the factors limiting the high-power performance. Devices fabricated with AlN-capped epilayers show a marginal advantage in terms of higher current and reduced dispersion, but GaN-capped epilayers perform better in terms of reduced short-channel effects and better channel control. In large-Signal Operation at 40 GHz, both device types delivered power densities in excess of 4.5 W/mm. A maximum power density of 5.8 W/mm is achieved on GaN-capped devices which is, to the best of our knowledge, the highest power density reported at 40 GHz in AlInN/GaN-based HEMTs.
N Rinaldi - One of the best experts on this subject based on the ideXlab platform.
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small Signal Operation of semiconductor devices including self heating with application to thermal characterization and instability analysis
IEEE Transactions on Electron Devices, 2001Co-Authors: N RinaldiAbstract:A rigorous mathematical treatment of dynamic self-heating in semiconductor devices is presented. Two formulations for the admittance parameters are given. The thermal behavior of the device is referred to device temperature in the first formulation, and to ambient temperature in the second. Contrary to previous work, nonlinear thermal effects are included. An analytical model for the thermal resistance is derived which confirms the relevance of these effects. Applications of the above results to device modeling and thermal characterization are studied in detail by means of numerical simulations. Possible sources of inaccuracies are evidenced. Finally, it is shown that the differential analysis of thermal feedback provides a general and rigorous means to determine the conditions for the onset of thermally-induced instabilities.
Sam Yagar - One of the best experts on this subject based on the ideXlab platform.
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real time traffic Signal optimization with transit priority recent advances in the Signal priority procedure for optimization in real time model
Transportation Research Record, 1998Co-Authors: Mark Conrad, Franclois Dion, Sam YagarAbstract:Real-time traffic Signal optimization software was developed using object-oriented techniques based upon the SPPORT (Signal Priority Procedure for Optimization in Real Time) model. SPPORT is a rule-based model that provides specialized mechanisms for transit priority. Based upon a flexible discrete-event traffic simulator that realistically models the effects of transit Operations on the general flow of traffic, and equipped with rules designed to provide effective transit priority while still giving appropriate consideration to other traffic, SPPORT generates Signal timings to minimize an objective function in which transit vehicles may be weighted as deemed appropriate in relation to other traffic. In developing this software, the SPPORT model was extended to support user-defined intersection configurations, multiphase traffic Signal Operation, and a more advanced form of transit priority that considers both nearside and mid-block transit stop locations. The fundamental concepts of the SPPORT model and ...
