A 16.5-31.6 GHz Broadband Bidirectional Front-end with 16.1dBm OP1dB and 26.8% PAE1dB in 40nm Bulk CMOS

This paper presents a broadband bidirectional front-end that eliminates the antenna-side switch to enhance performance and save area. A reused matching network integrates transmit/receive switching, matching, and gm-boosting, with coupling-polarity-reversal switches to improve T/R isolation. An adaptive bias (ADB) circuit is utilized to improve transmitter linearity, and a magnetically-electrically coupled resonator (MECR) is employed in the low-noise amplifier (LNA) to achieve wide-band low-noise performance. Fabricated in 40-nm bulk CMOS process, the prototype covers a continuous 3-dB bandwidth from 16.5 to 31.6 GHz. The power amplifier (PA) achieves a gain of 16.4 dB, a saturated power (Psat) of 16.5 dBm, and an output 1-dB compression point (OP1dB) of 16.1 dBm. It also exhibits a maximum PAE of 27% and a PAE at OP1dB of 26.8%. The LNA achieves a gain of 14.6 dB, a noise figure (NF) of 4.8-6.2 dB, and an maximum input 1-dB compression point (IP1dB) of -4.8 dBm.