Single low voltage supply operation GaAs power MESFET amplifier with low-distortion gain-variable attenuator for 1.9-GHz personal handy phone systems

A GaAs power amplifier with a low-distortion, 10-dB gain attenuator has been developed for 1.9-GHz personal handy phone system (PHS). Single low 2.4-V supply operation was achieved by using power MESFETs with p-pocket layers. Furthermore, on account of an attenuator with cascaded shunt FET structure, very low 600-kHz adjacent channel leakage power (ACP) with sufficient, constant output power was attained regardless of any controlled gain. An output power of 21.1 dBm, a low dissipated current of 157 mA and a high power-added efficiency of 37.2% were obtained with ACP of -55 dBc.