The ISIS Multi-Junction Varactor as a Pulsed Millimeter Wave Harmonic Generator

Millimeter-wave varactor diodes of greatly improved power generation capability have been developed using multi-layer epitaxial GaAs material. These are "stacked" multijunction diodes in a monolithic form, with as many as three active varactor junctions in series. Single diode power output as high as 10 W peak has been obtained at 35 GHz in pulsed service as a frequency doubler. At 44 GHz, in continuous service, 2.5 W has been obtained. In both cases, the efficiencies exceeded 50%.