Why Schottky diodes are suitable for microwave region?
It is a simple metal semiconductor interface exhibiting non – linear impedance and is basically an extension of the point contact diode. When the diodes are forward biased current follows because of majority carrier from semiconductor into the metal. Minority carriers are virtually absent compared with p-n junction diodes.
The I-V characteristics is similar to the p-n junction diode, but have steeper I-V slope, lower series resistance R, lower breakdown voltage and smaller forward turn – on voltage.
Schottky barrier diodes are increasingly being used as a low noise mixer replacing tunnel diodes and varactors, due to their low cast, simple structure and reliability noise figure of 4 to 5 dB are common. Applied in a CW Radar as a Balanced mixer and finally in microwave field to detect the microwave frequency.
Compare and contrast the bunching operation in a two cavity klystron and reflex klystron.
What are cross field device? What role does the dc magnetic field play in their normal operation?
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Fig. 20(a)