Small signal analysis and optimization of the BARITT diode

Carriers are injected into the delay path of the BARITT structure with zero drift velocity, hence, diffusion can not be neglected in the small signal analysis. The inclusion of a diffusion region adjacent to the injection plane produces a more physically reasonable approach to the small signal analysis. This analysis is accomplished through a regional approximation. The three regions are the diffusion region (where diffusion dominates the conduction process) a low field region (where drift dominates but the carrier velocity has not reached the saturation velocity) and a high field region (where the carriers drift with a saturated velocity). The inclusion of the diffusion region removes the zero-velocity singularity which results in the conventional analysis and accounts for an appreciable delay which has been previously neglected. The device characteristics are optimized for various device parameters. The optimized device length and most probable value of the negative resistance are given, and a qualitative discussion of the physical origin of the behavior of the device characteristics is given.