Design Of Miniature Filter Based On Substrate Integrated Waveguide

With the rapid development of microwave technology,the traditional low-frequency communication resources become more and more scarce,5G high-frequency,Ka band,E-band communication and so on become the research hotspot.With the increase of communication frequency,microwave circuits and devices will be smaller,more compact,and require higher performance.Filter is an important microwave component in RF system,which is widely used in satellite communication,aerospace and other important fields.The miniaturization of filter is an important research direction.Substrate integrated waveguide is a new type of waveguide structure,which combines the advantages of traditional metal waveguide and microstrip line.It has the advantages of high integration,easy processing,small weight and low cost.It provides a direction for miniaturization of microwave devices.In this paper,two miniaturized X-band filters are designed based on the substrate integrated waveguide technology,the main work is as follows:1.The principle of SIW and HMSIW is studied,the theory of CSRR is analyzed,the traditional SIW loaded CSRR filter is simulated by HFSS software,and the structure of loaded dual-mode CSRR is proposed to solve the problem of bandwidth of traditional SIW loaded CSRR filter,a new miniaturized HMSIW filter loaded with dual-mode CSRR is designed.The filter works at 7.4GHz,the passband is 6.7 GHz-8.1 GHz,and the minimum return loss in the band is-73 dB,and the size is 5.3mm × 12.8mm× 0.254 mm.2.The principle of QMSIW miniaturization is studied and analyzed.The direct coupling QMSIW-CPW filter is simulated by HFSS.The transmission zero point is optimized by indirect coupling structure,which improves the frequency selection characteristics of QMSIW-CPW filter and achieves better out of band suppression effect.The filter works at 7.6GHz,the working bandwidth is 1.3GHz,the minimum return loss is-52 dB,and the size is 12.9mm × 20.6mm× 0.254 mm.3.The performance of the filter simulated in this paper is verified by the physical processing test.4.Summarize the problems encountered in the simulation and processing test of this article,analyze the reasons,and propose improvement methods and next research directions.