New Fractal and Photonic Crystal Resonators for Multi-Beam Microwave Vacuum Devices

The results of 3D modeling of a new class of cavity resonance systems - double gap quasi-fractal resonators (DGQFR), promising for use in multi-beam klystrons are presented. They contain inside the cylindrical body a tree-like structure of N self-similar resonant elements formed as a result of applying a finite number of iterations to the selected fragment (polygon). Studies have shown that by selecting the optimal parameters of the quasi-fractal it is possible to effectively control the frequency of the main π-mode. Thus, by introducing a perturbing edges in the volume of the resonator to adjust the frequency of the π- mode within wide limits without significant effect on the frequency of π- mode. This makes it possible to implement frequency multiplicity modes (F2/F1=2, F3/F1=3) in one resonator. The use DGQFR in high-efficiency MBK operating in the microwave range allows to reduce the size of these devices. It is shown that the obtained research results intended for use in the microwave range, can be transferred to the area of millimeter and submillimeter wavelengths. Possible variants of the three-dimensional structure of the defect for the double gaps quasi-fractal photon resonator are proposed.