Design Techniques for Wideband and Low Phase Noise CMOS Sub-THz Signal Generation Systems
Room 2463 (Lifts 25-26), 2/F Academic Building, HKUST

Thesis Examination Committee

Prof Brahim BENSAOU, CSE/HKUST (Chairperson)
Prof Howard LUONG, ECE/HKUST (Thesis Supervisor)
Prof Pui In MAK, State-Key Laboratory of Analog and Mixed-Signal VLSI, University of Macau (External Examiner)
Prof Wing Hung KI, ECE/HKUST



Mm-Wave/sub-THz frequency range has attracted growing interest for rotational spectroscopy for its great potential in environment safety, homeland security and health care applications. An ultra-wideband and low-phase-noise mm-Wave and sub-THz signal generation is essential in a rotational spectroscopy system to improve its detection sensitivity. In this work, sub-THz signal generation systems with novel circuit techniques are proposed in CMOS process to achieve wideband and low phase noise.
Firstly, transformer-based magnetic-tuning technique is proposed to achieve wide frequency tuning range and low phase noise for W/D-band fundamental oscillators without varactors. Three design prototypes of a 110-GHz VCO, a 100-GHz QVCO and a 160-GHz VCO are proposed and demonstrated.
Secondly, an ultra-wideband sub-THz signal generation system is proposed employing a varactor-less quad-band VCO, a locking-range-enhanced dual-mode ILFD and self-mixing-based frequency multipliers for frequency extension. The signal generation system achieves a record frequency tuning range from 59 GHz to 276 GHz with FoMT of -190.4 dBc/Hz.
Thirdly, a scalable cascaded ILFM chain architecture is proposed based on the new harmonic extraction technique. A prototype of a cascaded two-stage ILFM-based sub-THz LO generation is demonstrated with an ultra-low power consumption of 2.5 mW, a frequency tuning range from 154 GHz to 195 GHz and a phase noise of -106.8 dBc/Hz at 10-MHz offset, corresponding to FoM of -186.5 dBc/Hz.
Finally, a fully integrated sub-THz frequency synthesizer is proposed leveraging a RF sub-sampling PLL cascaded with an ILFM-based mm-Wave LO generation chain and a sub-THz mixer. The sub-THz frequency synthesizer measures a frequency tuning range from 61-to-101 GHz, 122-to-137 GHz and 198-to-274 GHz, measures a phase noise from -79.3 dBc/Hz to -95.4 dBc/Hz at 1-MHz offset, achieves an integrated jitter of 124 fs and demonstrates an output power of -11 dBm and DC-to-RF efficiency of 0.16% above 200 GHz.
*** ALL ARE WELCOME !! ***

Room 2463 (Lifts 25-26), 2/F Academic Building, HKUST