PhD Defense: "Design and Characterisation of Circuits for Next-Generation Wireless Communications Systems"

Robert Maurer

June 30th (Friday), 2:00pm
Harold Frank Hall, Room 4164 (ECE Conference Room)

Demand for wireless data transfer has been increasing rapidly with the rise of smart devices and mobile video streaming. With dozens of wireless applications currently in use and only a finite bandwidth to work with, engineers are challenged to both expand the upward frequency limit of high-performance, high-efficiency wireless systems and to increase the spectral efficiency of the frequency bands already in use. The development of deep sub-micron silicon-on-insulator transistor technology and powerful computer-aided circuit designing tools have allowed us to create more affordable silicon-based phased array ICs at frequencies previously achieved only in military applications. The 5th generation of mobile systems (5G) is now expected to use this type of IC to offer increased wireless data capacity in densely-populated areas using mm-wave frequencies. Demand for wireless data is only expected to continue rising, particularly as new IoT applications such as autonomous vehicles become commercially viable.

The work presented here addresses both the need to expand the usable frequency spectrum and the need to increase spectral efficiency in already available bands. It includes a design for an analog beamforming matrix for a spatially-multiplexed phased array receiver in silicon SOI technology, low-power high-linearity w-band amplifiers in InP HBT technology, and ultra-wideband mm-wave power amplifiers in InP HBT technology. Spatially multiplexed phased array transceivers have the potential to greatly increase the spectral efficiency of mm-wave frequency bands by re-using frequency spectrum for many data channels. This type of system can be used to create short-range high-capacity line-of-sight wireless networks for crowded city squares or event venues. Mm-wave power amplifiers and high-linearity amplifiers in advanced 130 nm InP HBT technology offer an IC performance boost which pushes the frequency limits of feasible power-efficient wireless systems.

The measured power amplifier ICs produce output power of larger than 16.5 dBm at the 3-dB gain compression condition from 50 GHz to 100 GHz, and a small signal gain of 15 dB over a 90 GHz 3-dB bandwidth. The peak power-added efficiency (PAE) is larger than 8% over that same frequency range. At 90 GHz, the ICs produce 22 dBm of saturated output power and 14.7% PAE. The measured high-linearity amplifier ICs demonstrate an output-referred 3rd order intercept (OIP3) of 22 dBm, a gain of 6.4 dB, and a noise figure below 7 dB at 100 GHz. New designs for an analog MIMO beamforming matrix IC, a 100-165 GHz power amplifier, and an improved low-power high-linearity amplifier will also be discussed.

About Robert Maurer:

Rob received his B.S. in electrical engineering from the University of Notre Dame in 2011. He has been in the PhD program at UCSB as a member of the Rodwell high frequency electronics research group since 2011, and is expected to complete his PhD requirements and graduate in June of 2017. From 2011-2014, he worked as a devices engineer, fabricating nm-scale 30-THz schottky mixer diodes for a project with ONR. In early 2015, he switched over to IC design and designed W-band wideband PAs and low-power high-linearity amplifiers in a new 130 nm InP HBT technology for the DARPA ACT program. In 2016, he designed multi-beam beamforming ICs for MIMO applications as a part of the NSF Giganets program.

Hosted by: Professor Mark Rodwell