A 28V over 300 W GaAs heterojunction FET with dual field-modulating-plates for W-CDMA base stations

This report presents an L/S-band over 300 W GaAs heterojunction FETs (HJFETs) amplifier for 28V operation. We employed "dual field-modulating-plates (dual-FP) technology", in which one of the FP electrodes is connected to the gate and the other to the ground. The newly developed push-pull amplifier, with four dual-FPFET chips, demonstrated 55.1dBm (320W) CW output power with a 14.0dB linear gain and a maximum power-added efficiency (PAE) of 57% at 2.14GHz. Under two-carrier W-CDMA signals, it showed high drain efficiency (nd) of 30% and low IM3 of -37dBc at Pout of 47.5dBm. To our knowledge, this is the best performance ever reported among high power amplifiers for W-CDMA base stations.