Broadband power amplifier linearity enhancement under carrier aggregated stimulus using an auxiliary impedance branch

Abstract

High impedance at the drain of a transistor at low frequencies can cause significant distortions in power amplifiers (PAs). This problem is exacerbated by concurrent dual-band signal transmissions required by carrier aggregation. In this paper a technique is proposed which uses a parallel auxiliary impedance branch at the transistor's drain node to maintain low drain impedance for an extensive range of low frequencies, thus improving the PA's linearity and linearizability while it is under dual-band signal transmission.