Multi-target Vital Sign Detection Using Metamaterial Leaky Wave Antenna-Integrated Super-Regenerative Oscillator

In this article, a new kind of metamaterial (MTM) leaky wave antenna (LWA)-integrated superregenerative oscillator (SRO) is introduced to detect multitarget vital sign signals. The proposed radar sensor with beam-scanning angle from -30 degrees to -10 degrees is designed, while oscillation frequency varies from 2.24 GHz to 2.48 GHz. A quench signal is imposed at the drain voltage of transistor in the circuit to operate the SRO-based radar sensor in the logarithmic mode. Experiment results show that the measured vital sign information for different targets at different locations, such as respiration rates and heartbeat rates, agree well with the ground truth. Meanwhile, the proposed SRO sensor using MTM LWA exhibits higher sensitivity with the further detectable distance compared to the SIL-based MTM LWA.