mm-wave Transistors & Integrated Circuits

December 1, 2006
Professor Mark Rodwell, Electrical and Computer Engineering, University of California, Santa Barbara

I will summarize the following activities: InP bipolar transistors and ICs based upon them: Our present best devices, at 250 nm emitter width, exhibit 650 GHz power gain cutoff frequencies. Efforts are under way to scale these to 125 nm and 65 nm, with the goals of 440 GHz digital clock rates (divider metric) and ~700 GHz amplifiers. We are currently designing 340 GHz power amplifiers with 250 nm devices. We are also desiging microwave Op-amps with very low simulated intermodulation distortion obtained by strong negative feedback III-V MOSFETs: We have started a collaboration with 10 other research groups with the goal of developing MOSFETs with InGaAs and InP channels. We will briefly summarize both the potential benefits and limitations of compound semiconductor channels for MOS VLSI. mm-wave SiGe and CMOS ICs Silicon MOSFETs now have bandwidth sufficient for 100 GHz amplification, and SiGe devices substantially more. While reduced cost in high-volume applications is a worthwhile motivation for mm-wave Si, a better motivation would be new and novel applications enabled by the availability of very large numbers of transistors operating at very high frequencies. Several examples will be discussed, including very large monolithic array transmitters, mm-wave sensor networks employing radar/imaging techniques, and mm-wave communications links employing imaging techniques for spatial-division multiplexing (mm-wave-MIMO).

Mark Rodwell is Professor in the Electrical and Computer Engineering Department at UCSB. He received his Ph.D. in Electrical Engineering from Stanford University in 1988. He worked at AT&T Bell Laboratories during 1982-1984. His research group works to extend the operation of electronics to the highest feasible frequencies. Particular interests include InP bipolar transistors and high frequency IC design in both III-V and Silicon VLSI. His group's work on GaAs Schottky-diode ICs for subpicosecond / mm-wave instrumentation was awarded the 1997 IEEE Microwave Prize. Prof. Rodwell was elected IEEE Fellow in 2003.