Effects and Modeling of GaN PA Distortion in TDD Mode Using 5G NR Signal

This paper discusses the modeling of self-heating effects in a GaN PA driven by time division duplexing (TDD) using 100 MHz 3GPP new radio signal. The time invariant Generalized Memory Polynomial (GMP) with ∼200 coefficients was not enough for catching thermal memory up to 400 µs. Hence, GMP was combined with exponentially drifting complex gain, implemented with 1st order IIR filters, resulting in just 0.2 dB reduction in NMSE compared to full time-varying GMP.