Gain Enhancement of Junction PHEMT Power Amplifiers for Cellular Phones

摘要

In this paper, we report a significant gain enhancement of junction pseudomorphic high electron mobility transistors (JPHEMTs) for wideband code division multiple access (W-CDMA) power amplifiers (PAs). By employing a novel device design characterized by a gate-drain recessed structure, gate gold plating, and optimized device parameters such as doping concentration and barrier layer thickness in the epitaxial structure, a 3.0 dB gain enhancement was achieved with 52% power added efficiency (PAE) at a 17.2 dBm output power (P_(out)), a -40 dBc adjacent channel leakage power ratio (ACPR), and a supply voltage of 3.5 V in a 1.95 GHz W-CDMA class-AB operation. This novel device was developed by making changes and improvements to our existing mass production technology, the Microwave Monolithic Integrated Circuit (MMIC) process.