High Efficiency X and Ku Band Gunn Devices: Emitter-Controlled Negative Resistance Triode.

Abstract : Experimental verification at X-band frequencies of the operating principle of the GaAs emitter controlled negative resistance triode (ECNRT), a new microwave source, is presented. Such devices are fabricated in the form of liquid epitaxially-grown, etched-mesa, interdigitated transistor structures having 10 micrometers wide emitter stripes. DC electrical properties are enalyzed. Values of h sub fe lie in the range 2-100 and are limited by a nondiffusive current component in the emitter-base junction. The main causes of nonuniformity of the injected electron density in the collector region are analyzed; these are emitter current crowding, de-biasing along emitter fingers, electron spreading in the base, and electron spreading in the collector. Emitter crowding and electron spreading in the base are significant but are not judged to affect operation adversely. (Author)