Avalanche transit time diode - consists of two zones of opposite conductivity, with base zone sandwiched between them

摘要

The base zone is doped with dissociation centres. The concentration of the base zones is such, that when the diode is biased in the blocked direction, and an avalanche breakdown is started, a barrier layer thickness (W beta) is smaller than the critical barrier layer thickness (WK) which must be present if the diode impedance has to have at the required frequency a negative real component. The diode has + and - electrodes on either side. Next to the + electrode (7) there is an N+ layer followed by an N- layer, an N+ layer and a P+ layer next to the - electrode (6).