Doherty power amplifier with dynamic power dividing network for enhanced efficiency

摘要

In this paper, we present a high efficiency Doherty power amplifier (PA) employing dynamic power dividing network which automatically adjusts the input power division ratio in accordance with the level of input power to enhance efficiency. Doherty PA circuit parameters of each amplifier are determined by basic performance analysis according to the datasheet. Simulated circuits through Advanced Design System (ADS) exhibit an improvement of 4% at a 6 dB back-off point from its saturated output power (PSAT) than that of a conventional Doherty PA. Implemented Doherty PA using two Freescale MRF6S27015N laterally diffused metal oxide semiconductor (LDMOS) field-effect transistors (FETs) achieves excellent drain efficiency of 46.5% at a 6 dB back-off point from PSAT, which is 2% higher than conventional Doherty PA.