UC Santa Barbara
Design and Characterization of Circuits for Next-Generation Wireless Communications Systems
- Author(s): Maurer, Robert
- Advisor(s): Rodwell, Mark
- et al.
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-um 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 achievable by only 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 in this dissertation addresses both the need for expanding the usable frequency spectrum and the need to increase spectral efficiency in 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 backhaul for crowded city squares or event venues. Mm-wave power amplifiers and high-linearity amplifiers in new 130 nm InP HBT technology represent 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 w-band high-linearity amplifier are also outlined in this dissertation.