Design Of Microwave Passive Devices Based On Multi-physics Coupling Simulation

The microwave cavity filter and the millimeter wave waveguide circulator are important components in the communication system,which have the functions of frequency selective filtering,isolation signal and the like.Under the influence of high power and ambient temperature,the cavity structure of the microwave cavity filter will be deformed,which will affect its electrical performance.For this reason,it is particularly important to reduce the influence of temperature drift on the electrical performance of the cavity filter.However,the millimeter wave waveguide circulator is mainly limited by the size of the bias magnetic field.It is difficult to determine whether the ferrite material is magnetically saturated and complete the magnetic circuit design of the circulator.So,the electro-magnetic analysis of the millimeter wave circulator is necessary to ensure the working state of ferrite under magnetization.Aiming at the above problems,this paper studies the temperature compensation of microwave cavity filter and completes the electro-magnetic analysis of the circulator based on multi-physics coupling analysis.By analyzing the relationship among the physics field in detail,the specific solving methods and strategies are given.The analysis of the operating state about the filter and the circulator facilitates the precise design of the cavity filter and the waveguide circulator.Firstly,this paper reviews the basic synthesis theory of filters and circulators?It focuses on the relationship between temperature changes and frequency in wave equations and analyzes the electromagnetic field distribution of different modes of circulators.Further,the coupling relationship between multiple physics fields is introduced in detail and the specific solution strategies and methods are given.On this basis,according to the given solution strategy,the temperature compensation design of the coaxial cavity filter is completed.At the same time,the relationship between the temperature variation of TE011 mode resonator and the required deformation is proposed.The multi-physics coupling analysis method is used to verify and realize the temperature compensation of TE011 mode resonator.Next,the ferrite in unsaturated state is theoretically analyzed and an electro-magnetic analysis of the C-band waveguide circulator is completed.Subsequently,a new type of broadband millimeter-wave dual-mode circulator structure was proposed.The multi-physics coupling analysis method was used to analyze the magnetic circuit and finally obtained the accurate design of the circulator.