IMPATT Diode and Microwave Generation

Vocabulary flashcards covering IMPATT diode fundamentals, construction, operating principles, and characteristics.

IMPATT diode

A high power microwave semiconductor diode (Impact Ionization Avalanche Transist Time diode) that operates under reverse bias and exhibits negative resistance at a microwave frequency.

Carrier transit time effect

The combined effect of avalanche delay and transist time delay that produces approximately $180^\frac{}{}$ phase difference between an applied voltage and a resulting current, causing negative resistance.

Avalanche region

The region in an IMPATT diode where impact ionization and avalanche multiplication take place.

Drift region

The region in an IMPATT diode through which generated charge carriers travel under the influence of an electric field.

Anode and Cathode

Terminals used in an IMPATT diode to apply the external reverse bias voltage.

Impact ionization

The process where energetic charge carriers accelerated by a strong electric field collide with semiconductor atoms and generate additional electron-hole pairs.

Avalanche multiplication

A chain reaction in which newly generated carriers are accelerated by an electric field and collide with other atoms, producing increasing numbers of electron-hole pairs.

Transit time

The time required by generated charge carriers to travel through the drift region.

Negative resistance

The property exhibited when microwave current becomes approximately $180^\frac{}{}$ out of phase with applied microwave voltage, supplying energy to the microwave circuit for oscillation power.

Disadvantages of IMPATT diode

It produces high noise, requires a high reverse bias voltage, and can exhibit significant heat generation.