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Kevin Gard Research Projects
Advanced RF Transmitter Design for Deep Submicron CMOS (SRC-Freescale)
  Economies of scale gravitate the design of radio architectures towards advanced CMOS process technologies for high volume production. The migration from SiGe HBT bipolar to CMOS based architectures requires a fundamental re-design of the radio architecture and new circuit designs. However, technological innovations in advanced processes present new challenges for circuit design such as shrinking supply voltages and higher transconductance, gm, variation. Moreover, CMOS scaling from 130nm to 90nm and eventually to 45nm can impact standby current and DC gain due to increases in gate leakage due to tunneling effects related to thinner gate oxides. It is desirable to overcome these limitations by developing novel circuit designs which perform the same functions with comparable performance and yield without resorting to calibration loops and carrier detection. Time-to-market constraints make it difficult to invest the time and engineering resources necessary to make revolutionary developments in circuit and architectural designs which take advantage of advanced process technologies. However, there is a significant cost saving potential in successfully transitioning product lines to technologies with fewer processing steps and greater die output per wafer.
Nonlinear Analysis of Integrated Circuits for Wireless Communications
  Circuit designers are faced with the challenge of integrating transceivers for multiple wireless standards with conflicting specifications at increasingly higher frequencies and wider modulation bandwidths. However, it is not currently possible to perform transistor level simulation of a complete integrated radio transceiver within the context of a digital wireless standard. As a result, circuit designers cannot completely verify operation of circuit performance at the system level. New analysis techniques are needed to bridge the gap between circuit simulation and system analysis to permit evaluation of circuit performance at the system level. Behavioral modeling of circuits is a viable alternative to transistor level simulation for verifying system level performance of circuits. However, time to market considerations demand that the amount of time and effort involved in generating a model should be minimized. This raises questions regarding which models and extraction techniques quickly converge to an accurate solution for representing high frequency wideband integrated circuits.

Model development itself is not enough to bridge circuit and system design. Efficient analysis techniques using the models are needed to relate system performance metrics such as bit error rate (BER), symbol error rate (SER), frame error rate (FER), SNR, error vector magnitude (EVM), correlation coefficient (rho) directly to circuit performance.

SIAMES Standoff Inverse Analysis and Manipulation of Electronic Systems (MURI - US Army Research Office)
  This is a program to probe, locate and identify wireless electronic circuits using electromagnetic probing. We are have crafted a program that will contribute to the required fundamental understanding of the phenomena involved through theoretical developments; and will engage in experimental and modeling-based phenomenological investigations. In particular we will develop high power, wideband passive circuits with low passive intermodulation performance.