A 22-37 GHz Broadband Compact Linear Mm-Wave Power Amplifier Supporting 64-/256-/512-QAM Modulations for 5G Communications

This paper presents a transformer-based broadband compact linear millimeter-wave (mm-Wave) power amplifier (PA) for fifth-generation (5G) communications. A prototype PA is implemented in 90nm SiGe BiCMOS. The PA achieves 17.4dB S
₂₁
at 29.2 GHz with a 3dB bandwidth (BW
_-3dB
) from 21.8GHz to 37GHz. The PA achieves 20.9/20.3 dBm saturated output power (P
_sat
) and 43.7/39.8% peak power added efficiency (PAE
_max
) at 24/28GHz. The P
_1dB
and PAE at P
_1dB
(PAE
_p1dB
) are 20.6/19.4dBm and 41.0/38.1% at 24/28GHz. The PA demonstrates 0.6Gb/s 64-QAM signals at -25.1/-25.0dB rms error vector magnitude (EVM) with 12.6/10.5dBm average Pout (P
_avg
) and 17.5/12.6% average PAE (PAE
_avg
) at 24/27GHz, respectively, without digital predistortion (DPD). The PA also demonstrates 0.9Gb/s 512-QAM signals at -30.1dB rms EVM with 8.9dBm P
_avg
and 10.0% PAE
_avg
at 24GHz without DPD.