1-W Millimeter-Wave Gunn Diode Combiner

A simple modular approach for combining many Gunn devices has been developed. By cascading the two diode wafer modules, output power of 1 W was achieved in the 45-GHz range from eight Gunn devices with combining efficiency greater than 90 percent. The overall dc-to-RF conversion efficiency of the eight-diode combiner was about 2 percent. The circuit adjustment was easy and no spurious oscillations were observed during the experiment.