Investigation of a millimeter-wave Gunn-diode frequency converter

An experimental study is made of the conversion properties of millimeter-wave Gunn diodes operating in the negative-impedance mode, the diodes having various levels of doping and being load-stabilized at bias voltages above the threshold. The noise coefficient amounted to 19 dB while the highest conversion (gain) coefficient was about 10 dB. The experimental results are shown to agree with theoretical results based on an iterative solution of nonlinear equations derived from phenomenological equations of the balance of mean energy and mean drift velocity of electrons for an energy-dependent effective mass. It is concluded that Gunn diodes in the negative-impedance mode can be effectively used as frequency converters, providing for amplification during conversion in the millimeter-wave range.