A Novel and Compact Wideband Doherty Power Amplifier Architecture for 5G Cellular Infrastructure

Abstract

This paper presents a novel and compact wideband Doherty power amplifier (PA) architecture with a broadband characteristic. An improved impedance configuration is introduced in the load modulation network (LMN) to provide wider bandwidth. As well as it eliminates the need for an output impedance matching network (IMN). Hence the designed device is compact. This approach is a synthesis of key concepts derived from the conventional Doherty PA and the analysis of LMN. For the proposed Doherty PA architecture analytical solution and its thorough analysis are presented. A prototype is designed using commercial GaN transistors that exhibit more than 18% fractional bandwidth in the frequency spectrum from 3.07 to 3.68 GHz. It has been observed that the proposed DPA provides an average output power of 37.0-38.0 dBm with 38.0-45.0% efficiency. Furthermore, it supports a peak-to-average power ratio (PAPR) of 6 dB with an efficiency of 54-68% and peak power of 43.0-44.0 dBm. Proposed Doherty PA also achieved adjacent channel leakage ratio (ACLR) of −32 dBc (without any linearization techniques), output third order intercept (TOI) at 50 dBm and input TOI at 39 dBm.