High-frequency radio links offer high capacity but suffer from high propagation losses. For useful range, we must supplement the performance of the Si CMOS VLSI RF beamforming ICs with efficient high-power amplifiers for the transmitters and low-noise amplifiers for the receivers.


In power amplifiers, high efficiencies are obtained though high transistor gain and through class B, Doherty,  and/or load modulation. All require fmax many times the signal frequency. We are therefore developing multi-THz InP bipolar power transistors. In receivers, low transistor noise is obtained by a high ratio of the transistor cutoff frequency to the signal frequency. We are therefore developing multi-THz InP MOS-HEMT field-effect transistors.


We have demonstrated self-aligned nm InP bipolar transistors with regrown extrinsic base regions showing extremely low base contact resistivities. This technology will ultimately enable multi-THz transistors.

Team Leader

Mark Rodwell

Mark Rodwell (Ph.D. Stanford University 1988) holds the Doluca Family Endowed Chair in Electrical and Computer Engineering at UCSB. He directs the SRC/DARPA Research Center for THz Communications and Sensing, and manages the UCSB Nanofabrication Lab.  His research group develops nm and THz transistors, and millimeter-wave and sub-mm-wave integrated circuits. The work of his group and collaborators has been recognized by the 2010 IEEE Sarnoff Award, the 2012 IEEE Marconi Prize Paper Award, the 1997 IEEE Microwave Prize, the 1998 European Microwave Conference Microwave Prize, and the 2009 IEEE IPRM Conference Award.



M.J.W. Rodwell, Y. Fang, J. Rode J. Wu, B. Markman, S. T. ŠuranBrunelli, J. Klamkin, and M. Urteaga, “100-340GHz Systems: Transistors and Applications,” presented at the IEEE International Electron Devices Meeting, San Francisco, CA, USA, Dec. 1-5, 2018.

Y. Fang, J. P. Sculley, M. E. Urteaga, A. D. Carter, P. D. Yoder and M. J. W. Rodwell, "Design of InP Segmented-collector DHBTs with Reduced Collector Transit Time τcfor Large Power Bandwidth Power Amplifiers," 2018 76th Device Research Conference (DRC), Santa Barbara, CA, 2018, pp. 1-2.