A Broadband 2.1 GHz LDMOS Power Amplifier with 700 MHz Bandwidth Implementing Band-pass Filter-Based Matching Networks

Abstract

In this paper we are presenting a power amplifier based on an RF power LDMOS transistor at 2.1 GHz with a bandwidth of 700 MHz implementing broadband impedance matching networks (BIMN) in band-pass form. The device parasitics modelled as a series RLC structure are absorbed in the input and output matching networks by proper design of matching networks in band-pass form using two different synthesis methodologies. The S21 of the amplifier shows 11.2 dB of maximum small signal gain with 2.4 dB ripple along a 700 MHz bandwidth at 2.1 GHz and S11 better than −7dB for 1. 64-2.34GHz. The band-pass matching networks are entirely designed by transmission lines modeling the behavior of the resonant parallel shunt and series LC structures that characterize a band-pass circuit. The amplifier should be able to deliver 1W of maximum output power at saturation.