Tunable Gunn oscillator by semiconductor surface loading

A tunable and amplitude-modulated Gunn oscillator is obtained by semiconductor surface loading. The load is partial and covers the cathode. The oscillation frequency depends on the distance X between the anode and the edge of the surface-loading semiconductor and can be varied continuously over a range of about 6:1. As X approaches zero, an amplitude-modulated pulse is obtained. These effects may be explained by the coexistence of two high-field regions in the structure. The method also gives a measure of the domain-growth time.