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

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.