Multi-Target Concurrent Vital Sign and Location Detection Using Super-Regenerative Oscillator-Based Metamaterial Pulsed Radar

This paper presents a new kind of super-regenerative oscillator (SRO)-based metamaterial (MTM) pulsed radar to detect multi-target vital sign signals and locations simultaneously. A triangular waveform of 100 Hz is imposed as the quench signal to operate the radar system under the SRO mode. A MTM leaky wave antenna (LWA) is incorporated to scan from -30° to +25° with the frequency changing from 2.22 GHz to 2.79 GHz. Modulated by the quench signal, the proposed SRO radar can generate pulse train-like waveforms. As such, the distance can be obtained by calculating the time of flight between the transmitted and received signals through the cross-correlation method in the time domain. Experimental results show that the proposed SRO-based MTM pulsed radar sensor can detect the target location accurately. Furthermore, the proposed SRO-based MTM pulsed radar can also detect Doppler signatures at the same time, where measured actuator vibration frequency as well as multi-target vital sign information agree well with the ground truth.