Study On Cascading Technology For Substrate Integrated Waveguide (SIW) Bandpass Filters

Substrate integrated waveguide (SIW) filters have advantages of small volume, light weight, low cost, easy processing, ease of integration, have the advantages of both microstrip filters and waveguide filters, so SIW filters have a broad application prospect in many kinds of communication systems. This thesis mainly studied the design of SIW dual-mode bandpass filters, first studied the single cavity of narrow-band dual-mode bandpass filters design techniques, drawn several techniques to adjust the bandwidth,at last designed a single cavity dual-mode bandpass filter with relative bandwidth of 3%. On this basis, this thesis further studied the technique of multiple cavities cascading, investigated the influence of various parameters on the frequency response, processed the real and measured. Then the thesis studied the two cavities cascading with a window and using probe in different planes, the cascading of three cavities using microstrip and using probe in different planes, and the cascading of four cavities using microstrip by using the simulation software. The results of simulation are ideal, with narrow relatively bandwidth, great restraint outside the band and small insertion loss.