Fully Integrated Sub-Terahertz Frequency Stabilized Sources and Transceivers for 5G Communications and Beyond

With the advancements in hardware implementations, throughput of wireless communication systems has been improved significantly but is still fundamentally limited by the channel bandwidth. The push to find wider channel bandwidths has led to the inevitable increase in carrier frequencies for beyond 5G communications, where vast amounts of unallocated frequency bands in the millimeter wave/sub-Terahertz spectrum enable new high-speed short-range communication systems. Key contributions in this dissertation include: high-power, high-efficiency sub-THz signal and chirp generation, integration of digital phase locked loop with THz building blocks, and novel high data-rate wireless transceiver design for line-of-sight communications.

The first part of the thesis focuses on frequency stabilized high-power, high-efficiency sub-THz signal generation, which includes two works: a 170-176 GHz radiator with an on-chip frequency stabilization loop optimized by a systematic gain plane based approach and a fast back-to-lock digital phase locked loop based 192-210 GHz chirp generator. The second part of the thesis describes two novel wireless transmitter chips using direct sub-THz FSK/BPSK modulation. The BPSK chip supports a 10-cm wireless link at single channel data rate of 20 Gb/s and consumes only 25 mW dc power, which advances one widely referred figure of merit, energy efficiency per bit per cm, by 7x.

Chair: Professor Ehsan Afshari