Electron Flow Modulation in Double-Gap Cavity With a Multiple Ratio of the Two Modes Frequencies

The study presents the calculation and optimization of the double-gap cavity designs for a klystron-type multipath frequency multiplier. This construction allows to achieve a multiplied (equal to two) ratio of the frequency of the highest (
${3}\pi $
) mode to the frequency of the main (
${2}\pi $
) mode lying in the
Ka
-range. The design was optimized using a nondimensional quality parameter that combines the main electronic and electrodynamic characteristics of resonators. The features of the electron flow bunching when passing through a double-gap cavity in the two-frequency mode are studied using the 3-D numerical modeling methods. Analysis of the results showed that depending on the ratio of the voltages effective amplitudes generated by electric fields of the main and highest modes, two modulation modes are possible. They are nonsinusoidal modulation, which allows increasing the efficiency at the input signal frequency, and frequency multiplication regime, in which the frequency of the electron flow bunches at the output of the resonator doubles.