A 2-GHz Highly Linear Ef ficient Dual-Mode BiCMOS Power Ampli fier Using a Reconfigurable Matching Network Hajir Hedayati, Student Member , IEEE

Abstract

A highly linear, ef ficient, two-stage p ower ampli fier for high-data-rate wireless applications is presented. The linearity is greatly improved by adding an auxiliary ampli fier to the main bipolar transistor ampli fier in a feed-forward approach to cancel out the nonlinearity terms. The ef ficiency enhancement is achieved using a switchable biasing and a recon figurable output-matching network based on the available input pow er which is monitored by an on-chip envelope detector. The PA is fabricated using 0.25- m SiGe:C BiCMOS technology and works at 2 GHz with a supply voltage of 2.5 V. The experimental res ults show a gain of 13 dB and a maximum output power of 23 dBm with a PAE of 38%. The 1-dB output power compression point is 21 dBm with a 32% PAE. The 6-dB power back-off PAE is 23%. The and terms are 41 and 44 dB below the fundamental tone for the 21-dBm output power, respectively. The EVM has been measured to be 30.7 dB at 15-dBm average output powe r using IEEE 802.16e standard WiMAX 64QAM modulated signal. By employing the lineariza- tion technique, EVM and ACLR are improved by 4.5 and 5 dB, respectively, for a WiMAX 6 4QAM 10-MHz signal bandwidth at 14-dBm average output power.