A Magnetron with Two Energy Outputs: Simulation and Experiment

This chapter presents the theoretical and experimental results of creating the new magnetron design with two energy outputs (or dual-output magnetron) to solve the problems for frequency tuning, improve its stability, and extend application possibilities. Due to their extensive use in various human endeavors, including military technology, industry, agriculture, research, and medicine, magnetrons have become the most well-known and effective microwave generators. The modified magnetron's primary usefulness has been identified both empirically and theoretically. The availability of a second energy output in the anode block is the primary differentiating characteristic of this magnetron (for instance, in contrast to the standard magnetron with a single output). The mathematical models for the electron-wave interaction and the resonant anode block are described. The anode block's dispersion properties for cavities with different shapes are provided. According to theory, the interference of RF fields excited several times in the resonant anode block made up of tiny and large cavities (resonators) leads to the formation of the total RF field in the interaction space. For the PIC simulation of electron-wave interaction in the dual-output magnetron, the non-linear system of equations is stated as a self-consistent system containing the equation of motion (for electron stream), the equation of excitation (for RF field), and Poisson's equation for calculating the space-charge field. The fundamental feature of the self-consistent system of equations is a new algorithm for determining the Coulomb interaction forces. Implementing the mathematical model made it possible to gain new knowledge about the magnetron's physical processes and determine its output characteristics. On the operating frequency of ~ 13.34 GHz, at an anode voltage of 495 V, a magnetic field of ~ 0.25 T, and with air cooling of the magnetron, there were obtained the following limiting values: the RF output power of ~ 14.6 W and the power conversion efficiency of ~ 40.8%. Applying the second energy output extended the magnetron's functionality and implemented the modes of frequency tuning (adjustment) and stabilization. The simulation results are in good agreement with the experiment. As a result, these studies have demonstrated the viability of computational experiments for modeling the physical phenomena in a magnetron's interaction space and the resonant systems' electrodynamic features. The electrodynamic properties of rising-sun systems with various cavity designs are simulated, and the findings are given. It is demonstrated that a rising-sun system with a "hole-and-slot" structure has more options when selecting an oscillation's operational mode's resonant frequency.