Mixed tunneling and avalanche mechanisms in p-n junctions and their effects on microwave transit-time devices

Analytical models of dc and small-signal characteristics for Read-type diode structures are given which incorporate both tunneling and avalanche mechanisms. A "dead-space" analysis is shown to be fundamental to accurate models of thin generation regions. Pure tunneling and pure avalanche appear as the two limiting cases of the general models. In the pure tunneling limit, the diode oscillator will operate in the tunnel transit-time (TUNNETT) mode. The TUNNETT oscillator would be attractive for low-noise and medium power and efficiency applications. For diode structures which operate between the pure TUNNETT and IMPATT modes, there exists a noise performance-output power tradeoff. Computer solutions of the analytical models, for specific diode structures and operating conditions, are given, and the results are discussed and compared with experimental results whenever possible.