Recent Development of Super-Regenerative Oscillator (SRO)-Based Vital Sign Radar Sensors

Radar sensors based on super-regenerative oscillator (SRO) architectures have recently been developed for vital sign detection of human targets. Owing to the intrinsic automatic gain control feature, compared with conventional radar sensor architectures, the SRO-based radar sensor can exhibit a very high sensitivity with a lower system complexity, as well as dc offset and null-point immunity. This paper reviews different designs of SRO radar sensors, including the use of a patch antenna and a metamaterial (MTM) leaky wave antenna (LWA) for vital sign detection, in which experimental results about vital sign detection for human targets are summarized to demonstrate the feasibility.