Power, linearity and noise performance of AlGaN/GaN power HEMTs are measured at different gate-to-source bias conditions in order to study the influence of self-heating on RF performance. Additionally, a load-pull sys...
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Power, linearity and noise performance of AlGaN/GaN power HEMTs are measured at different gate-to-source bias conditions in order to study the influence of self-heating on RF performance. Additionally, a load-pull system, capable of measuring intermodulation distortion products under pulsed mode of operation, is implemented for the first time. This new system is used to investigate the impact of self-heating on power device linearity. Also, for the first time, the effect of the RF drive on thermal effects and power added efficiency (PAE) is investigated. This forms the basis of more accurate nonlinear models. Finally, thermal simulations of 2-finger GaN FETs are performed under pulsed and continuous regimes to determine the temperature distribution caused by a 5W/mm power dissipation density.
Each year at the beginning of a new academic semester, most advisors face a very common and particularly tedious and time consuming problem: deciding for each student what course schedule would be ideal for the follow...
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Each year at the beginning of a new academic semester, most advisors face a very common and particularly tedious and time consuming problem: deciding for each student what course schedule would be ideal for the following semester so that the student would graduate in the fastest possible time and also have his / her specific preferences and prerequisites satisfied. The factors that have to be considered vary from school specific requirements such as course prerequisites, corequisites, spring and fall offerings, to student specific ones, such as transferred credits or the subjective desire to choose or not a given choice. While some advisors might be able to derive reasonable solutions in reasonable amount of time, the process takes most of the advising time. The student will have to "trust" the advisor that the given schedule is the best choice, and in many cases the results will later on prove that the student could have actually graduated faster, or that specific school requirements have been violated or simply that the student's load and preference could have been balanced better. This paper presents a software application that can completely solve the presented problem. Once the school specific data and requirements have been set, for any specific student information, the application will search and output the schedules that will allow the student to graduate in the fastest number of semesters / quarters possible. Depending on the factors and data considered, the execution time varies from few seconds to few minutes. Currently, we have successfully tested and implemented the application at the University of Bridgeport, CT, USA.
In this paper, we present a highly integrated low-power direct conversion receiver MMIC for broadband wireless applications at C-band. This receiver chip is fabricated in a 0.6 /spl mu/m commercial GaAs MESFET process...
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In this paper, we present a highly integrated low-power direct conversion receiver MMIC for broadband wireless applications at C-band. This receiver chip is fabricated in a 0.6 /spl mu/m commercial GaAs MESFET process and operates on only 90 mW of dc power consumption. Using an integrated switched LNA and direct-coupled baseband amplifiers, this receiver demonstrates a conversion gain of 25 dB, NF of 6.7 dB, dc offset below -70 dBm, IIP2 of +20 dBm, and IIP3 of -15 dBm in the high-gain mode and +15 dBm in the low-gain mode at 5.8 GHz.
This paper presents a GaAs/AlGaAs HBT transmitter MMIC chip set consisting of a power amplifier, a mixer and a voltage-controlled oscillator (VCO) for 5.8 GHz OFDM applications. The performance of the transmitter in a...
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ISBN:
(纸本)0780366018
This paper presents a GaAs/AlGaAs HBT transmitter MMIC chip set consisting of a power amplifier, a mixer and a voltage-controlled oscillator (VCO) for 5.8 GHz OFDM applications. The performance of the transmitter in an OFDM system is investigated by means of envelope co-simulation of the circuit in an OFDM transmitter simulation platform that conforms to the IEEE 802.11a wireless LAN standard. To the best of our knowledge, this research represents the first reported implementation of an OFDM transmitter in GaAs HBT technology.
design equations for the 1 dB compression point and 3rd-order intermodulation point as a function of circuit and technology parameters are derived using a Volterra series expansion. Linearity analysis for both single ...
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ISBN:
(纸本)078037150X
design equations for the 1 dB compression point and 3rd-order intermodulation point as a function of circuit and technology parameters are derived using a Volterra series expansion. Linearity analysis for both single and double-balanced CMOS Gilbert mixers is examined. The transconductance stage using inductive degeneration is more linear than that using capacitive or resistive degeneration, and the single-balanced mixer is more linear than the double-balanced one at the same bias current and transconductance. The analytical predictions are verified with the Cadence SpectreRF circuit simulation and experimental data. Good agreement between the model predictions and experimental data is obtained.
Mobile commerce is more than a mobile and wireless extension of the Web-based e-commerce. It is being spurred by the mobile phone industry’s widespread support of the Wireless Application Protocol. WTLS (Wireless Tra...
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This article proposes an intelligent robot control system using off-line programming to teach precise assembly tasks for electronic components. The task investigated consists of three jobs: a heat-caulking test, solde...
This article proposes an intelligent robot control system using off-line programming to teach precise assembly tasks for electronic components. The task investigated consists of three jobs: a heat-caulking test, soldering on a circuit board, and checking soldering defects on the back cover of a camera. We investigated the remodeling of the most complicated cell among the 12 cells in a camera backcover assembly line in terms of accuracy and fault rate. We attempted to enhance soldering quality, to add task precision, to reduce the failure rate, and to increase the product reliability. We modified the cell structure, changed the robots, improved the soldering conditions, implemented real-time control of assembly with vision data, and realized an easier method of task teaching with off-line programming.
Because the supply voltage is not proportionally scaled with the device size, the further scaling down of CMOS devices is in turn accompanied with more and more severe hot-carrier reliability problems. Hot-carriers, t...
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ISBN:
(纸本)0769510256
Because the supply voltage is not proportionally scaled with the device size, the further scaling down of CMOS devices is in turn accompanied with more and more severe hot-carrier reliability problems. Hot-carriers, the high energy carriers due to high electric field in the channel, are injected into the gate oxide or cause trapping states generation between Si and SiO/sub 2/ interface, which is accumulated and causes long run reliability problems in devices and circuits. In this paper, we describe a systematic method to evaluate the circuit degradation due to hot-carrier stressing. First the substrate current and gate leakage current models are improved for more accuracy in predicting the lifetime of the devices and circuits. The hot-carrier stressing characterization is carried out for 0.18 /spl mu/m technology. The circuit performance degradation is then evaluated using the parameters extracted from 0.18 /spl mu/m technology for both digital logic circuits and RF circuits.
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