Research On Waveguide Duplexer Technology Based On CNC Process In Millimeter Wave Ban

The advantages of millimeter-wave band applications in high-speed communications,radar detection,high-resolution imaging and other fields are increasingly obvious,especially in typical windows such as the W-band.In terms of short millimeter-wave components,rectangular waveguide is the preferred transmission line structure,with advantages such as high Q value,low loss,high power capacity,and easy assembly to system.Thanks to the progress of high-precision machining technology,this type of components has been widely reported.Diplexers(even multiplexers),as one of the key components in the millimeter-wave detection/communication systems,can separate or combine the spectral signals of different bands,and promote the development of receiver system to cover more bands.Therefore,based on domestic high-precision CNC technology,this dissertation focuses on three types of millimeter-wave band waveguide diplexers.The contents in this dissertation are summarized as follows:1.A hybrid-coupled broadband waveguide diplexer working on W-band.In order to solve the problem of insufficient spectral coverage in the W-band ultra-wideband communication system,a W-band broadband waveguide diplexer is proposed firstly.The main contents include: a broadband waveguide diplexer architecture design is proposed based on hybrid-coupled principle;the optimal design of the all-W-band waveguide diplexer is proposed combined with high-pass filter structure;and the W-band diplexer was prepared with CNC technology.The measured results exhibit that low insertion loss,full bandwidth,high isolation and other performances,verifying the feasibility of the design and process.In addition,the component structure also has the characteristics of easy processing and easy spread spectrum.2.W-band star-junction waveguide diplexer based on all-resonator structures.In order to meet the application requirements of compact waveguide diplexer,a design of W-band narrowband waveguide diplexer based on all-resonator is proposed.The main contents include:the realization methods and advantages and disadvantages of capacitive and inductive coupling of cavity structures in waveguide circuits;a narrow band star junction waveguide diplexer design is proposed based on the coupling matrix principle;especially,hybrid coupling structure is introduced to overcome the shortcomings of small size and reduce the difficulty of fabrication;and then,fabrication of component is completed based on CNC technology.The measurement present that the component have high isolation and low loss characteristics,as well as simple structure and miniaturization.3.WR-3 band manifold-coupled waveguide diplexers based on H-plane and E-plane Y-junction.In order to meet the application requirements of both broadband performance and compact structure,two H-plane and E-plane Y-junction manifold-coupled diplexers have been fabricated at the end of this dissertation.The main contents include: summarizing and analyzing the influence of Y-junction performance on the broadband performance of diplexer;the design of H-plane Y-junction waveguide diplexer is proposed based on the fourth-order filter structure;Further,the design of wider E-plane Y-junction waveguide diplexer is realized based on the 6-order filter structure;The measured loss,isolation,and other performance are highly consistent with the simulation results,which verify the conclusion that the Y-junction parameter control can achieve broadband diplexer response,the E-plane diplexer can easily achieve wider bandwidth,and the manifold-coupled diplexer has high isolation.