Device line characterization of Gunn diodes using six-port techniques

A device line characterization system using a six-port reflectometer with a built-in impedance tuner is reported. Device line measurements on a Gunn diode mounted in a coaxial fixture were performed at the Ka-band to optimize experimentally the output microwave power in the oscillation mode. In addition to its relatively low cost, an inherent advantage of the instrumentation used is that the large-signal reflection coefficient of negative resistance devices can be measured at the actual power level that exists in practice