650-W high-efficiency amplifier for 704 MHz

This RF-power module is a building block for a multi-kilowatt high-efficiency power amplifier system. The module employs five GaN-FET class-F RF power amplifiers with a low-loss Gysel splitter and combiner. Envelope Elimination and Restoration is used to maintain efficiency over a wide range of amplitudes. It achieves an efficiency of 79 percent for power outputs from 380 to 650 W, and an efficiency of 70 percent for all outputs above 90 W. The drive power is only 12 W.