Sharif Digital Repository

In recent years, semiconductor devices have incrementally taken the place of microwave tubes beneficially. However, microwave tubes are still indispensable in very high voltage usages (10 Kilowatts to 10 Megawatts) and high frequencies (Gigahertz and higher). Concerning that these tubes are of the most sensitive and expensive parts of such systems, protection measures are of high importance. One of the phenomena that cause failure or degradation of tubes is electric arc in cathode of the tubes and dissipating energy due to that. In order to prevent the tubes from undergoing such harm, protection must be put into consideration. Furthermore, the limit of this dissipating energy determines the...