IMPATT diode
（重定向自IMPATT）
An IMPATT diode (IMPact ionization Avalanche Transit-Time diode) is a form of high-power semiconductor diode used in high-frequency microwave electronics devices. They have negative resistance and are used as oscillators to generate microwaves as well as amplifiers. They operate at frequencies between about 3 and 100 GHz or more. A main advantage is their high-power capability. These diodes are used in a variety of applications from low-power radar systems to proximity alarms. A major drawback of using IMPATT diodes is the high level of phase noise they generate. This results from the statistical nature of the avalanche process.