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 pre-sented. 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.