Harmonic generation by electron beam pattern motion—the Bermutron

The description and theory of a method of generating harmonics of a microwave signal by deflection of an electron beam are presented, Examples of deriving output power at harmonics of the deflection frequency for either circular or linear deflection patterns and for both waveguide and cavity output are treated. The system is unusual in that there is power transfer between two streams of energy that are essentially orthogonal to each other in space. Moreover, since coupling of a wave is to the virtual motion of a space charge, which can move at any speed, there is no limitation on the phase velocity of the wave in the output coupler. While emphasis in this paper is on the output coupler, the practical problem of beam deflection is also treated. Finally, the principle of operation is demonstrated. Experiments with prototype models have produced up to 2 watts of 34-Gc power from an 8.5-Gc input, or a conversion efficiency of -24 db to this fourth harmonic.