Computation of Start Oscillation Current and Coupling Coefficient in a Frequency-Doubling Gyroklystron Amplifier

The efficient operation of a frequency-doubling gyroklystron depends on the following crucial factors, namely stimulation of only the desired operational mode and suppression of surrounding competing modes. To attain this sensitive balance, an in-depth understanding of the start oscillation current (SOC) is required. In this paper, a numerical method has been developed to compute the SOC of a frequencydoubling gyroklystron amplifier. The impact of electron beam velocity ratio and quality factor on SOC is comprehensively investigated. The operational and competing modes of a Kaband frequency-doubling gyroklystron amplifier were calculated.