A 37–43GHz VSWR-Resilient Load-Isolated Doherty Power Amplifier Achieving 26% Average PAE at 36Gb/s in 45-nm SOI CMOS

This paper presents a compact 40-GHz load-isolated Doherty power amplifier (PA) architecture with enhanced resilience to antenna voltage standing wave ratio (VSWR) variations. Doherty VSWR Resiliency is achieved by isolating the Doherty load-modulation network from the antenna through placing the network before the cascode transistor. The proposed PA achieves a peak output power (Psat) of 20 dBm, an output 1-dB compression point (OP1dB) of 19 dBm, and a power gain of 17.5 dB at 40GHz, with a small-signal gain bandwidth from 35.5 to 44.5 GHz. Peak power-added efficiency (PAE) exceeds 39%, while 25.5% PAE is achieved at 6-dB power back-off (PBO) from Psat, with performance maintained over the 37–43 GHz frequency range. Under 64-QAM modulated signal operation, the PA achieves an average output power (Pavg) of 16 dBm at 0.6 Gb/s with 30% average PAE, and 15.5 dBm at 36 Gb/s with 26% average PAE. The proposed architecture demonstrates VSWR-resilient operation, maintaining an average PAE above 24.5% under worst-case 2:1 VSWR phase conditions. The PA occupies a compact core area of 0.225 mm².