W-band On-chip Vital Sign Radar Sensor using GaAs MMIC Super-Regenerative Oscillator

This paper introduces a low-power, highly sensitive W-band (75-110 GHz) super-regenerative oscillator (SRO)-based vital sign radar sensor with a SIW monopole antenna integrated. The proposed radar sensor is implemented using the $0.1-\mu m$ GaAs pHEMT technology. Operating at the center frequency of 85.283 GHz, the proposed super-regenerative oscillator leverages 100 Hz and 20 kHz sinusoidal quench signals for control during the target detection. Experimental results validate the effectiveness of the proposed sensor in identifying the displacement frequency of an actuator along with human target vital signs. The achieved results show good agreement with the ground truth. Moreover, compared to the self-injection-locked (SIL) detection scheme, the proposed SRO radar sensor demonstrates superior characteristics, such as lower power consumption, higher sensitivity, and low system complexity.