A Gunn diode oscillates in a number of different modes, such as transit-time, delayed domain, quenched domain, LSA, hybrid and relaxation modes. Among the various device groups capable of micro- wave power generation, the most important are Gunn diodes and avalanche diodes. Gunn diodes in turn. J. B. Gunn, "Microwave Oscillation of Current in III-V Semiconductors",. Solid State Commun., 1 88 .. Gunn diode mode of operation – parameter map. 0. | | s o d. tion of a Gunn diode operating in the domain mode. \Ye shall follow a procedure similar to that first sug- gested by Jlosher [l], in \I-hich he took the Gunn diode.


Author: Jodie Mitchell
Country: Seychelles
Language: English
Genre: Education
Published: 2 September 2015
Pages: 495
PDF File Size: 27.3 Mb
ePub File Size: 40.87 Mb
ISBN: 701-9-36347-584-2
Downloads: 87170
Price: Free
Uploader: Jodie Mitchell


Rather than having both p-type and n-type semiconductor, it only utilises n-type semiconductor where electrons are the majority carriers.

Gunn Diode Operation

The Gunn modes of gunn diode operation depends upon the very thin active region for its operation, it forms an ideal low power microwave RF oscillator, although it may also be used as an RF amplifier as well.

Gunn diode operation basics The operation of the Gunn diode can be explained in basic terms.

  • Gunn Oscillation Modes
  • TT mode vs LSA mode-difference between TT mode and LSA mode
  • Gunn diode operation at microwave frequencies

When a voltage is placed across the device, most of the voltage appears across the inner active region. As this is particularly thin this means that the voltage gradient that exists in this region is exceedingly high.


This negative resistance area enables the Gunn diode to amplify signals. This can be used both in amplifiers and oscillators. However Gunn diode oscillators are modes of gunn diode most commonly found.

Gunn diode characteristic This negative resistance region means that the current flow in diode increases in the negative resistance region when the voltage falls - the inverse of the normal effect in any other positive resistance element.

Explain any two modes of operation of GUNN diodes with schematics.

This phase reversal enables the Gunn diode to act as an amplifier and oscillator. Gunn diode operation at microwave frequencies At microwave frequencies, it is found that the dynamic action of modes of gunn diode diode incorporates elements resulting from the thickness of the active region.

When the voltage across modes of gunn diode active region reaches a certain point a current is initiated and travels across the active region. During the time when the current pulse is moving across the active region the potential gradient falls preventing any further pulses from forming.

Only when the pulse has reached the far side of the active region will the modes of gunn diode gradient rise, allowing the next pulse to be created.


It can be seen that the modes of gunn diode taken for the current pulse to traverse the active region largely determines the rate at which current pulses are generated, and hence it determines the frequency of operation.

To see how this occurs, it is necessary to look at the electron concentration across the active region. Transit time domain mode: When the bias field swings back above the threshold, a new domain is nucleated and the process repeats.

Thus oscillation occurs at the frequency of resonant circuit modes of gunn diode than at the transit time frequency.

Gunn Diode Operation ::

As a results, domains do not form. This situation occurs because the negative conductance is utilized without domain formation. There are too few carriers for domain formation within the transit time.

Related Post