Partition Analysis of DVR Model for Broadband GaN Doherty PA under Different Nonlinear States

In this paper, the partition distribution of the decomposed vector rotation (DVR) model is analyzed and discussed, a general rule of partition selection for PA under different nonlinear states are described. The AM/AM characteristic of an in-house designed GaN broadband Doherty power amplifier (DPA) is analyzed under different nonlinear conditions with different stimulus. The performance of the DVR model for the device under test (DUT) with different threshold values are compared and discussed. Comparison between the selected optimal DVR model based on the proposed general rule, the standard DVR model, and the Volterra series based models are given, superior performance is obtained, which demonstrates the efficacy of the proposed modeling approach.

I. Introduction

With the approaching to the fifth generation (5G) of the wireless communication systems, the extremely broad bandwidth and high peak-to-average power ratio (PAPR) requirement of the 5G new radio (5GNR) signals have present a huge challenge to the entire wireless systems [1]. The RF PAs, as one of the most important component in the system [2], exhibits significant nonlinearity and memory effects, which have a big impact on the signal quality of the systems, especially when under a 5GNR signal excitation [3].