Design And Research Of Wide Stopband Filter Based On-Multi-mode Coupling

With the rapid development of modern communication technology,that put forward higher requirements for the performance of microwave components.For example,more miniaturization,high performance,easy integration,and low cost,the miniaturization of filter,The research of microwave filters that work at high frequencies has been a hot direction.Substrate Integrated wave-guide(SIW)is a novel wave-guide structure similar to a rectangular wave-guide that can be integrated into a dielectric Substrate,based on the advantages of SIW such as low insertion,small size,high power radiation,and easy integration,that can satisfy the communication requirement of microwave millimeter wave circuit.The design of wide stop-band band-pass filter(BPF)and a double pass-band filter of four cavities based on SIW technology.The basic design method is studied in detail.The main contents are as follows:Firstly,in this paper,that introduced research background,significance of the SIW research status and future development trend,also systematically expounds the basic theory of SIW filter design,including introduces the basic design knowledge of filter classification and main performance parameters,the equivalent calculation of SIW guided wave structure,the cross coupling technology of filter.The advantages of SIW technology and multi-mode coupling technology are described in detail.Based on analyzing practical application of filter design,It lays a foundation for the design of BPF in the following chapters.Secondly,in this paper,that discusses the mechanism of spurious passband SIW filter based on the resonator main mode.A high frequency wide stop-band band-pass filter is designed by using wide stop-band technology,right Angle coupling method and adding dumbbell slot bandstop structure technology.The measured results of the filter are basically consistent with the simulation test data.The measured results can reach more than 40 d B in the 21GHz-26 GHz frequency band and greater than 20 d B in the 26GHz-45 GHz frequency band.Simulation and test results showed that the filter has excellent wide stopband characteristic,that can meet the requirements of high transmission rate for wireless communication,and can be widely used in the microwave millimeter wave system.Finally,on the basis of the above design,this paper innovatively designs and produces a four-cavity wide stop-band double band-pass filter.The field resonance transmission mode was simulated by HFSS software,and after several adjustments of the sizes of the dumbbell slot band resistance structure,the high-order mode of the resonator was flexibly stimulated to produce dualfrequency response.The measured results show that the filter has good double-pass band performance,and can achieve a wide stopband of 22GHz-38 GHz,and the out-of-band inhibition can reach more than 30 d B,This design method is more flexible.The simulation results show that the double pass-band filter has good performance and can meet the practical requirements of the design of high frequency circuit system.