A Ka-Band Mutual Coupling Resilient Stacked-FET Power Amplifier with 21.2 dBm OP1dB and 27.6% PAE1dB in 45-nm CMOS SOI

This letter presents a Ka-band mutual coupling resilient stacked-FET power amplifier (PA) in 45-nm CMOS silicon on insulator. Two sub-PAs with triple-stacked-FET to increase output-power (Pout) are combined through a quadrature hybrid coupler to keep robust and high performance in the scenario of mutual coupling among the phased-array antennas. A shunt inductor is introduced to deal with the performance deterioration caused by the transistors' parasitic capacitances and the magnetic coupling cancelling topology is adopted for a more compact layout. The measurement results show that the proposed PA achieves 21.2 dBm OP1dB with 27.6% PAE1dB and 22.2 dBm Psat with 28.8% peak PAE. The OP1dB and PAE1dB are beyond 21 dBm and 22% for a frequency range from 25 to 32 GHz, respectively. The maximum small-signal gain is 26.5 dB with <-19/-14 dB S11/S22. The simulated variation of Psat/OP1dB is less than 0.5/1.1 dBm under a strong voltage-standing-wave-ratio condition.