A novel compact composite power cell for high linearity power amplifiers in InGaP HBTs

Abstract

A novel compact composite power cell design employing the circuit feedback concept between the input and output ports of the power transistor is proposed for realizing high linearity and high efficiency power amplifiers. The RF performance is compared between conventional and the novel compact composite power cells using a class A amplifier operating at 1.71 GHz. At the same DC biasing conditions, the composite power cell shows the output power 1 dB compression point improvement over a conventional cell from 18dBm to 23dBm, while its power added efficiency at P1dB point is increased to 47% from 16%. Furthermore, the third order intercept point of the composite transistor PA achieves 7 dB improvement over the conventional PA, from 29 dBm to 36 dBm.