Class A power amplifier in 180 nm CMOS at C-band with integrated DC switch for efficient FMCW positioning radar

A two stage class-A power amplifier optimized for FMCW positioning radar is presented. Fully integrated in 180 nm CMOS technology, the circuit features an integrated DC power supply switch for efficiency enhancements during the idle mode and RF isolation. The trade-offs for DC switch design and the corresponding speed implications are discussed. At a supply voltage of 2.4 V and a center frequency of 5.75 GHz, a RF gain of 12.5 dB, a 1 dB compression point of 17.3 dBm, and a RF isolation better than 28 dB at 3 dBm input power, are measured. Due to the DC switch a high drain efficiency of 16.2 % can be achieved over the full operation time of the positioning system.