A Highly Linear and Efficient Differential Power Amplifier with 35-dBm Saturated Output Power, 65% Peak PAE by Reducing Base Voltage Peaking in InGaP/GaAs HBT Process for Handset Applications

This paper presents a 2.3-2.7 GHz differential power amplifier (PA) with improved linearity and efficiency by transformer-based second harmonic trapping linearization (TBSL) for fifth-generation new radio (5G NR) applications. The proposed TBSL effectively reduces the input capacitance nonlinearity by reducing the base voltage peaking. Although TBSL has a very low quality factor, it does not affect the operation of fundamental. Therefore, it can operate at broadband of frequencies. The proposed differential PA is implemented in a
$\mathbf{2}-\boldsymbol{\mu} \boldsymbol{m}$
InGaP/GaAs heterojunction bipolar transistor (HBT) process. Using the continuous wave (CW) signal, the PA achieves a gain of 35–39 dB, a saturated output power of 35 dBm, and a peak power added efficiency (PAE) of 63–65 % over 2.3-2.7 GHz. The PA with NR 20-MHz QPSK cyclic prefix (CP) signal having a peak-to-average power ratio (PAPR) of 10.83 dB achieves average output power of 28–29 dBm and PAE of 27 % in adjacent channel leakage ratio (ACLR) of -34 dBc.