A 19.7–38.9-GHz Ultrabroadband PA With Phase Linearization for 5G in 28-nm CMOS Process

This letter presents an ultrabroadband power amplifier (PA) with AM–phase modulation (PM) linearizer in a 28-nm bulk CMOS process for 5G millimeter-wave (mm-Wave) mobile communications. To enable the 5G mm-Wave multigigahertz broadband, a pMOS linearizer in power stage is introduced to achieve broadband AM–PM linearization. The proposed linearized PA achieves a 3-dB gain bandwidth (BW) from 19.7 to 38.9 GHz (65.5%) covering multiple 5G bands. The measured OP
_{1 dB}
is 12.7 dB ± 0.6 dB from 22 to 38 GHz, and the PAE is larger than 25% from 21 to 36 GHz (50%). For 100-MHz 64-quadratic-amplitude modulation (QAM) orthogonal frequency-division multiplexing (OFDM) signal, this PA obtains a linear output power of 8.5 dBm/8.3 dBm/8.8 dBm under error vector magnitude (EVM) of −25 dB with modulated PAE of 11.0%/11.0%/11.9% at 23 GHz/28 GHz/38 GHz, respectively. Moreover, the measured back-off power from OP
_{1 dB}
to linear output power is 4.7 dB/3.9 dB/3.7 dB at 23 GHz/28 GHz/38 GHz.