A high efficiency commercial GaAs MESFET power amplifier for PCM/CIA applications at 2.45 GHz

A low cost commercial, high performance two stage GaAs MESFET power amplifier has been developed for the 2.4 GHz Industrial, Scientific, and Medical (ISM) frequency band targeting portable wireless LAN applications. The amplifier is housed in a low cost plastic surface mount package, making it well suited for insertion into low profile PCM/CIA formats. Measured performance has demonstrated 24 dBm output power with greater than 65% power added efficiency when operated in gain compression with a 5 volt supply. Harmonic rejection greater than 18 dBc and 30 dBc is achieved on 2nd and 3rd order harmonics, respectively. On chip bias and power level control circuitry allows adjusting the output power level over a 20 dBc range with a single analog control voltage. Stringent cost goals are achieved by limiting chip size, choosing inexpensive plastic packaging, and by selecting an appropriate amplifier topology which places some components off chip.