Kahn-technique transmitter for L-band communication/radar

Abstract

This Kahn-technique (Envelope Elimination and Restoration) transmitter operates at 1.2 GHz and produces a PEP output of 50 W. It employs a GaN-HEMT class-F RF-power amplifier, class-S modulators, and a digital signal processor. An overall (driver + final) efficiency of 50 percent or more is maintained over the top 6 dB of the output range. The driver and final are operated to maximize overall efficiency and the predistortion corrects for amplitude and phase errors. While originally intended for pulsed radar applications, the transmitter is capable of producing a wide variety of signals with good linearity and average efficiency.