Microwave microscopic principle

It is interesting to note that no matter what kind of microwave vacuum device, most electron devices fimction based on the principles of velocity modulation, electron bunching, and electrodynamic induction for microwave generation and ampHfication. The only microwave vacuum devices not based on velocity modulation, electron bunching, and electrodynamic induction are monolithicaUy developed solid-state vacuum diode or triode. These devices are microscopically small and incorporate cathodes. The operating electric fields are strong enough for cold emission from the cathode. 

---