The Design Of Triangle Bandpass Filters Based On Substrate Integrated Waveguide And Complementary Split Resonators

As a vital component among the RF and Microwave devices of radio communication systems,the parameters of the filter has a great impact on the whole RF system indices.As an important component of microwave system,microwave filters with advantages of compact size and high performance are in large demand.Therefore,the resesrch on the miniaturization and high performance of the filter has always been a hot topic.With the development of filters,the structure of Substrate Integrated Waveguide(SIW)has been widely studied due to its unique structure and electromagnetic characteristics.The structure of SIW is as light,compact,easy to be processed and integrate with the planar circuit as microstrip,and it has the same radiation loss and high power capacity as traditional waveguide.At the same time,in order to miniaturize the SIW structure further,the multi-mode SIW technology has been widely studied and innovated by researchers,and people have achieved fruitful research results.The main research work of this paper is to combine the multi-mode SIW technology with Complementary Split Ring Resonators(CSRR)technology to design SIW bandpass filter with high performance.First of all,this article briefly introduces the basic concepts of microwave filter design and basic design methods,such as the classification basis of microwave filter,basic performance and main design theory,the low-pass prototype filter for the filter design of the original model,and briefly illustrates its basic response model of lumped parameters and the frequency conversion.At the same time,the method of realization of RF filters is also discussed briefly.Secondly,this paper demonstrates the basic structure and calculation formula of SIW,and introduces the principle and design method of multimode SIW filters.Meanwhile the basic principles of CSRR,and CSRR's application in SIW filter design and multi-mode SIW filter design are presented in this article as well.All of These provide an important way to design SIW filter.Finally,combining with the multimode SIW technology,triangular SIW cavity and CSRR technology,we design dual-mode SIW bandpass filter with CSRRs.By introducing perturbation via hole in the cavity of filters and etching CSRRs in the metal surface,we get the good performance of compact band-pass filters.Then a double-layer SIW filter using triangle cavity is constructed simultaneously.At last,two filters are fabricated and measured.Simulation and meaurement results show filters exhibits high performace and compact size which indicates that both of the filters meet the design requirements.