Ka-Band Dual Input Stacked 22 nm CMOS FDSOI Power Amplifier with Transformer-Based Power Combiner

A Ka-band dual input, three stack power amplifier (PA) is designed and fabricated using 22nm CMOS FDSOI. The PA output matching is implemented with a transformer-based combiner, which allows tuning the load with bias and input drive settings. The PA shows maximum output power, gain, one dB output power compression point (P
_1dB
) and power added efficiency (PAE) of 19.5dBm, 11.5dB, 14.1dBm and 17%, respectively, measured at 29.5 GHz. Measured amplitude to phase modulation (AM-PM) stays at very low level, below 0.7° up to P
_1dB
and below 2.6° up to P
_3dB
. With a 100 MHz 64-QAM OFDM signal the PA achieves 8% error vector magnitude (EVM) and -28dBc adjacent channel leakage ratio (ACLR) at 6.3dBm and 7.6dBm output channel power, respectively.