Super-Regenerative Oscillator Integrated Metamaterial Leaky Wave Antenna for Multi-Target Vital Sign and Motion Detection

A new kind of metamaterial (MTM) leaky wave antenna (LWA) integrated with a super-regenerative oscillator (SRO) architecture is proposed for the first time. As a proof of concept, the proposed radar sensor, including a one-dimensional (1D) MTM LWA and a tunable voltage-controlled oscillator (VCO), is designed to perform frequency-dependent space mapping with the main-beam angle sweeping from −50
$^\circ $
to +30
$^\circ $
with respect to the varying frequency from 1.85 to 2.85 GHz. The proposed SRO-integrated MTM LWA system is operated in the logarithmic mode with a quench signal imposed at the drain port of transistor. Experiments have been conducted to show that vital sign information for two human targets can be successfully detected when they are located along different scanning angles of −10
$^\circ $
and −30
$^\circ $
, respectively. Furthermore, compared with MTM LWA radar sensor based on the self-injection-locked (SIL) architecture, vibrating motion at a farther distance can be detected accurately using the proposed radar sensor, indicating a higher sensitivity with reduced system complexity.