High efficiency frequency multipliers using substrateless Schottky diodes

We report on high efficiency frequency multipliers for the frequency range 150-500 GHz. These frequency multipliers use the whiskered substrateless Schottky diode that provides minimum series resistance and improved heat sink capabilities. Recently a doubler efficiency of 40% at 150 GHz and tripler efficiencies of 19% (P/sub out/=5.6 mW) at 267 GHz, 16% (P/sub out/=5.5 mW) at 300 GHz and 8% (P/sub out/=2 mW) at 480 GHz are the highest efficiencies that have been achieved.