A Digital-Calibrated Transmitter-to-Receiver Isolator in Radar Applications

A digital-calibrated isolator for radar is proposed to improve transmitter-to-receiver isolation in this letter. The proposed isolator consists of feedforward and digital-calibrated circuits to cancel the transmitter-to-receiver leakage power. The proposed isolator is implemented in 0.18-
$\mu$
m CMOS technology which shows 27.3 dB isolation while consuming 13.5 mW dc power. The
${\rm OP}_{1\,{\rm dB}}$
of the transmitter-to-antenna is better than
${+}13.5$
dBm.