GaAs low-high doped MESFET MMIC power amplifier for CDMA/AMPS dual-mode cellular telephone

Abstract

An MMIC power amplifier using low-high doped GaAs MESFETs (LH-MESFETs) has been developed for a CDMA/AMPS dual mode cellular telephone. It is fully integrated on one chip (2.5 x 2.9 mm(2)) including all matching circuits. For CDMA operation at frequency of 836.5 MHz, an efficiency of 25% adjacent channel leakage power of -29 dBc at 885 kHz, and -48 dBc at 1980 kHz were obtained with an output power of 27.25 dBm and V-dd = 4.7 V. In AMPS operation, 30.5 dBm output power was obtained with 27.5 dB gain and 47% efficiency. The experimental results show that the gate periphery of LH-MESFETs and size of MMIC are much smaller than in previously reported similar amplifiers using conventional MESFET technology. This MMIC power amplifier is suitable for dual mode cellular applications.