J B Gunn discovered periodic fluctuations of current passing through the n-type GaAs specimen when the applied voltage exceeded a certain critical value. In these diodes, there are two valleys, L & U valleys in conduction band and the electron transfer occurs between them, depending upon the applied electric field. This effect of population inversion from lower L-valley to upper U-valley is called Transfer Electron Effect and hence these are called as Transfer Electron Devices (TEDs).
Applications of Gunn Diodes
Gunn diodes are extensively used in the following devices −
- Radar transmitters
- Transponders in air traffic control
- Industrial telemetry systems
- Power oscillators
- Logic circuits
- Broadband linear amplifier