Planar Gunn Diode Research Articles

Voltage tuning of concentric planar Gunn diodes

Voltage tuning of Gunn oscillations in the frequency range 1.5–8.5 GHz has been achieved by using planar Gunn diodes with concentric contacts. Frequency against voltage curves are presented for three diodes with somewhat different contact geometries, each of them having a tuning range of more than one octave. This simple method of tuning over large frequency ranges is of great potential interest. The production process using evaporation and etching is described.

Failure mechanisms in Gunn diodes

Observations on electrical properties of planar Gunn diodes and on failure mechanisms using Sn–Ag and In–Au contacts are reported. A conducting channel of Sn(In) is proved to be responsible for the final catastrophic failure. Excess heat is generated at the anode, where also the breakdown is observed to start. Mechanisms starting the breakdown (hole injection and combined ion drift and diffusion of impurities) are discussed.