Quadrature and Single-Channel Low-Cost Monostatic Radar Based on a Novel 2-Port Transceiver Chain

A new radar architecture that features a compact size and only one radio frequency (RF) active device was designed, fabricated, and tested for small motion detection and human range tracking. Unlike conventional board-level radar systems, it contains a single antenna and does not use any low noise amplifier (LNA) or circulator in the RF front end. The I/Q amplitude and phase imbalance present on the system were measured to be
${< }1{\%}$
and 5.17°, respectively. Besides the local oscillator (LO), there is no other active device consuming dc power. The fabricated radar system has dimensions of
$36\times72$
mm (
${L} \times {W}$
) and a power consumption of 290 mW in continuous operation. Moreover, a 24-GHz single-channel radar system was designed, fabricated, and tested using the proposed architecture. The dimensions of fabricated board are
$24\times27$
mm (
${L} \times {W}$
) and total power consumption of 800 mW dissipated by the LO. The range tracking capabilities of the implemented radar systems were demonstrated by successfully tracking the range of a human target walking back and forth on a hallway. Moreover, the high sensitivity of the proposed quadrature 2-port monostatic Doppler radar was demonstrated by effectively measuring a sinusoidal movement with an amplitude of
$2.5 \mu \text{m}$
with a 5.8-GHz carrier.