UPML Boundary Adapted to High-Q FDTD Algorithm and Its Application in High-Power Microwave Source With High-Q Value

In the simulation of high-power microwave (HPM) devices (relativistic magnetron) with high- $Q$ value and resonant cavity, the high-quality-factor finite-difference time-domain (FDTD) algorithm and perfectly matched layer absorption boundary are essential. In this article, the reason for numerical divergence caused by the Gedney uniaxial-anisotropic perfectly matched layer (UPML) absorption boundary model under the high-quality-factor FDTD algorithm is analyzed, and a novel UPML absorption boundary model based on the high-quality-factor FDTD algorithm is derived. Afterward, the absorption boundary model is implemented in existing software and its absorption effect is verified in the Cartesian coordinate system and cylindrical coordinate system; the relative reflection error of the 10–15 layers high-quality-factor FDTD algorithm UPML absorption model is less −70 dB. Finally, the absorption boundary module is applied to simulate the HPM device-relativistic magnetron. The reliability of the algorithm module is further verified by comparing the simulation results with the experimental results.