Research On High-performance Filter And Diplexer Based On Substrate Integrated Waveguide

The development of communication technology has posed greater challenges to the RF circuits.As a key component of the communication system,RF circuits need to achieve higher performance and more diverse functions to meet the various needs of communication in various industries.In the field of RF circuits,the role of passive components in RF circuits is pivotal in order to meet the service needs of 5G communication systems with high capacity and multiple frequency bands.Substrate integrated waveguide RF devices have the advantages of high power capacity,low loss,low cost low radiation loss and easy integration,which are widely used in the development and design of microwave RF passive components.For diplexers and dual passband filters,the specific studies in this thesis are as follows:1.A substrate integrated waveguide diplexer with metal via holes and slot perturbation is designed.The introduction of a metal through-hole in the resonant cavity of the substrate integrated waveguide can change the electric field distribution in the resonant cavity,which in turn affects the frequency of the resonant mode of the substrate integrated waveguide.Based on the metal through-hole and slot perturbation techniques,several deformed forms of substrate integrated waveguide filters can be designed.In order to enhance the isolation degree and reduce the circuit area of the diplexer,a new embedded feeder isolation network is designed to generate transmission zeros in the low and high frequency channels,respectively,and combine two reasonably designed channel filters,which are optimized by design simulation to obtain the proposed diplexer,which has the advantages of high isolation degree,compact size and high frequency ratio.2.A substrate integrated waveguide low-pass bandpass dual passband filter is designed.Quasiset total parameters are used to implement the low-pass filter with emphasis on the suppression of out-of-band parasitic passbands.The bandpass filter is obtained using magnetic coupling between the resonant cavities of the substrate integrated waveguide,and the operating mode is TE101 mode.The starting point and innovation of the design is the integration of the low-pass filter into the band-pass filter,which is equivalent to a low-pass filter in parallel with the band-pass filter,which is a compact dual-pass band filter with a high-quality factor.3.A folded substrate integrated waveguide diplexer loaded with a patch resonator is designed.A compact fourth-order quasi-elliptic function filter is realized by embedding a classical triangular chip resonator in the folded substrate integrated waveguide.The filter has excellent insertion loss,out-ofband rejection performance,and then the low and high frequency channel filters are combined and tuned by a step impedance transmission line.The bandwidth of the designed diplexer is expanded,the low and high frequency channel frequencies are closer,the out-of-band rejection is excellent,and the structure size is small.The diplexer is processed and tested to verify the feasibility of this design.