IMPATT DIODES

The acronym IMPATT (pronounced “IM-pat”) comes from the words impact avalanche transit time. We won’t concern ourselves in this book with the exact nature of this effect, except to note that it’s similar to negative resistance. An IMPATT diode is a microwave oscillating device like a Gunn diode, but it is manufactured with silicon rather than gallium arsenide.
An IMPATT diode can be used as a low-power amplifier for microwave radio signals. As an oscillator (a circuit that generates rf ac), an IMPATT diode produces about the same amount of output power, at comparable frequencies, as a Gunn diode.