A Gm-Compensated 46-101 GHz Broadband Power Amplifier for High-Resolution FMCW Radars

A Gm-compensated 46-101 GHz broadband power amplifier (PA) for high-resolution FMCW radars is presented in this paper. For bandwidth (BW) expanding, a Gm compensator-based negative feedback chain is applied to the PA, compensating the large gain ripple caused by a high-k transformer (TF)-based ultra-wideband interstage matching network (IMN). Based on the proposed Gm-compensated technique, a flat and ultra-wideband power gain of the PA can be obtained with the high-k TF-based IMN. The proposed PA achieves a 55-GHz BW without additional area overhead and efficiency loss. 74.8% of the fractional BW is obtained with <0.3 dB gain ripple in 53-92 GHz. The PA reaches 17.1 dBm Psat and 27% peak PAE respectively, and the core area of the proposed PA in TSMC 40nm CMOS process is 0.1mm2.