Dual-mode power amplifier for LTE handset applications using BiFET technology

In this paper, dual mode output power amplifiers with high and low power mode for LTE handset applications have been presented. Recent compound semiconductor technology enables the PA designers to integrate InGaP/GaAs HBT with pHEMT on the same wafer, so called BiFET technology. Simple addition of the pHEMT switch for controlling high and low power mode to enhance the efficiency at lower output power makes it easy to design and implement the advanced transmitter for 4G wireless communications such as LTE. The fabricated power amplifier showed 19% PAE at 17dBm LPM (low power mode) and 36% at 27dBm HPM (high power mode) meeting all 3GPP output spectrum mask. It shows less than 2.5% EVM for all output power level from 824 ~ 849MHz (UMTS band 5).