A 77-GHz Fully Integrated Power Amplifier for Automotive Radar Application in 40-nm CMOS

This paper presents a compact 77-GHz four-way differential power combined power amplifier for automotive radar application. At E-band, the insertion loss of matching network and power combining network are the limiting factor for the power amplifier's performance. In this work, the insertion loss of the matching networks is reduced by taking advantage of the proposed coplanar waveguide differential transmission line with floating substrate noise shielding grids. The voltage-current power combining method that takes care of impedance matching and power combining is adopted to decrease the insertion loss from power combining and output matching network. The power amplifier is implemented in a 40 nm CMOS process. From 69 to 85 GHz, the power amplifier delivers more than 19 dBm output power with the maximum $P_{sat}$ of 19.7 GHz at 77 GHz. The final layout power amplifier achieves 19.4 dB peak small signal gain, and the maximum PAE is 22.7 %.