The TRAPATT diode is a high-efficiency microwave generator derived from the Trapped Plasma Avalanche Triggered Transit mode device. It is a p-n junction diode that forms a trapped space charge plasma within the junction region. In operation, a high field avalanche zone propagates through the diode, filling the depletion layer with a dense plasma of electrons and holes that become trapped. This trapped plasma allows the TRAPATT diode to operate at lower frequencies than conventional diodes. Typical parameters include a power of 1.2 kW at 1.2 GHz and a maximum efficiency of 75% at 0.6 GHz, with an operating frequency range of 0.5 GHz to 50 GHz.