Research On Application Of Higher-Order Symplectic Multiresolution Time Domain Algorithm In Waveguide Structure Simulation

Rectangular waveguide is a typical representative of waveguide components,and it is also an indispensable power transmission and conversion device in microwave and millimeter wave circuits.Rectangular waveguides have the characteristics of large power capacity,simple structure,and low loss,so they are widely used in resonance systems,electromagnetic compatibility,antenna radiation,microstrip transmission lines,electromagnetic scattering,and light propagation and diffraction in optical devices et al.Therefore,the research on application of higher-order symplectic multiresolution time-domain algorithms in the simulation of rectangular waveguides has important guiding significance for analyzing and understanding the electromagnetic characteristics of other waveguide structures.From the perspective of computational electromagnetics,this paper applies higher-order symplectic multiresolution time-domain schemes with optimized symplectic integrator propagator.The electromagnetic characteristics of rectangular waveguides were analyzed in detail.The work of this paper is briefly described as follows:?1?Combine the characteristics of the waveguide to introduce the basic principle of higher-order symplectic multiresolution time-domain algorithm and the key technologies required for the simulation analysis of waveguide-type structures:the introduction of excitation sources,total field and scattering field systems,higher-order absorption boundary conditions,metal boundary conditions.?2?Solve the resonance frequency of the non-filled and semi-filled dielectric rectangular waveguide cavity,verify the correctness of higher-order symplectic multiresolution time-domain schemes basic program and the metal boundary processing technology.?3?Analyze the mode fields distribution of the lower-order modes?TE₀,TE₁,TE₂?of the asymmetrical slab waveguide,simulate the dynamic transmission process of the mode field,and analyze the refractive index of the cladding layer when the refractive index of the substrate and core layer is unchanged,the change law of the mode field distribution of the asymmetrical slab waveguide in the core layer when the rate changes.?4?The numerical simulation of the photonic band gap structure of the longitudinally arranged dielectric layer of the rectangular waveguide is carried out.The simulation results confirm the stop-band?forbidden-band?characteristics of the photonic band gap?PBG?structure of the waveguide dielectric layer.At the same time,the influences of the number of dielectric layers,the ratio of refractive index constant and the thickness ratio of dielectric layers on the characteristics of PBG structure are analyzed in detail.?5?In order to effectively absorb evanescent waves,the traditional lower-order perfectly matched layer absorbing boundary condition were improved,and the correctness of the higher-order modified PML absorbing boundary condition is verified by solving the cut off frequency of the rectangular waveguide.Finally,combining the scattering parameter extraction technology to solve the common problem of dielectric discontinuity inside the rectangular waveguide,and it is concluded that appropriate dielectric parameters can be set as needed to form a dielectric resonator and obtain the required transmission characteristics.