Baritt diode – Working and Applications:
The barrier-inject transit time (BARITT) diode is basically a back-to-back pair of diodes biased into reach-through condition. It belongs to the transit-time microwave diode family. In this diode microwave oscillation occurs due to the thermionic injection and diffusion of minority carriers across the forward-biased barrier and a 3π/2 transit angle of the injected carriers traversing the drift region.
BARITT diodes tend to be low in power and efficiency but have good signal-to-noise (S/N) performance and are useful as local oscillators in microwave receivers. Its structure is like that shown in Fig. 8.65. It has small-signal negative resistance so that self starting oscillation can be had.