A 16.4-dBm 20.3% PAE 22-dB Gain 77 GHz Power Amplifier in 65-nm CMOS Technology

We present a compact W-band power amplifier (PA) for automotive radar application in 65-nm CMOS technology. The circuit adopts a pseudo-differential push-pull configuration based on transformers (TFs) which offer highly efficient and flexible matching networks with minimized area occupancy. We have set the optimal output resistance close to 50
$\Omega $
, design guidelines in sizing active devices for each stage, and the corresponding transformers were presented for optimal power efficiency based on an analysis of surrounding matching networks. Working under a supply voltage of 1.3-V, the implemented 77GHz PA achieved a 3-dB gain bandwidth of 9-GHz (72.5–81.5 GHz), a peak gain of 22.4 dB, a saturated power (
$P_{sat}$
) of 16.4 dBm, and a peak power-added efficiency (PAE) of 20.3%. The area for the core layout is only 0.05 mm
²
, which demonstrates the highest power density among the recently reported W-band CMOS PAs.