An investigation of multiple domain Gunn effect oscillators

The quenched multiple domain mode of oscillation is proposed in GaAs Gunn diodes. Operating conditions for this mode are explored by means of a computer simulation and a simplified linearized-lumped analysis that was developed to generate waveforms for quenched domain devices. Optimum efficiency is seen when a maximum number of "hybrid sized" domains are packed into a device which is operated at the transit frequency associated with the width of a domain. By reducing the voltage across a device, nonhybrid sized domains form and the device operates at less than peak efficiency. The investigation includes a discussion of device performance when nonidentical but comparably sized domains are present in the device. Experimentally, multiple domain devices have been fabricated using diodes with coplanar contacts. The experimental results tend to confirm the existence of multiple domains in the diodes as well as the results of our analysis.