Research And Design Of X-Band SIW Interference Filter

As a kind of two-port network,filter has the characteristic of specific frequency selection.In the modern telecommunication equipment and all kinds of control system,the application of filter is very extensive.The quality of its performance often affects the quality of the whole communication system.With the continuous development of radio frequency and microwave technology,electromagnetic spectrum resources become increasingly scarce.Therefore,the wireless communication system has put forward new requirements for the index and performance of the filter.For example,high selectivity,small volume,easy integration,large power and small loss,etc.Substrate Integrated Waveguide(SIW)is a good form of transmission line to implement high-performance filters,which has the advantages of high Q value,low loss and planar structure weight and easy integration of rectangular Waveguide.If the filter selectivity is further improved,lower rectangular coefficient and lower insertion loss can be realized.Optical filters have their own advantages.Optics and electromagnetism can be linked by means of the electromagnetic theory of light.Through the analysis of the phase superposition technique of electromagnetic wave,it is found that the interference effect is equivalent to frequency selectivity,the interference effect is equivalent to frequency selectivity.Since the interference cavity only has dielectric loss,it has less metal loss compared with the traditional filter,so the insertion loss will be lower on the original basis.This paper studied the SIW Q's relationship with the various design parameters,a transmission line as the basis of filter design structure,the performance of the transmission line is crucial,through simulation and record the experiment data,and then in the fitting of the Q value and MATLAB,the relationship between the curve and the corresponding relation between the various parameters so as to realize the design of high Q value of SIW transmission lines: Q 1895,S11 <-40 d B,S21 > 0.5 d B.On this basis,a SIW structure six-cavity generalized Chebyshev filter is designed,through the topological structure design,coupling matrix calculation and simplification,resonator and coupling structure design,The overall model building and debugging.Completion indicators are as follows: center frequency: 10 GHz,bandwidth: 50 MHz,S11<-20 d B,S21>-1d B.Then the research and design of the interference cavity was carried out.First,the establishment of a single interference cavity and the influence of the width and Angle of the interference cavity on the S parameter were studied.Then,the four-cavity and six-cavity generalized Chebyshev filters were built.