Performance Control And Optimization Design Of Microwave Filter Based On Paper-based Metamaterials

Electromagnetic metamaterials have become an emerging field in recent years,which is a kind of artificial synthetic periodic structure with extraordinary electromagnetic properties that natural materials do not possess.With the aid of this electromagnetic metamaterial,the propagation direction of electromagnetic waves in the medium can be controlled,which plays a very important role in the application of microwave systems and circuits.At present,with the development of the information revolution,the amount of information is becoming more and more expanding,and the application of communication technology is increasing,resulting in a sharp increase in the corresponding spectrum demand,so that the electromagnetic environment is increasingly complex.As a key component in radar and communication systems,the microwave filters can effectively eliminate interference signals and obtain specific frequency signals.The difference in their own filtering performance will affect the entire communication system.Metamaterials,which are artificial synthetic materials with special properties,can be designed with their structure,parameters and materials to obtain microwave filters with excellent filtering performance.In this paper,the research and design of metamaterial based band-stop microwave filter has been carried out,and two microwave band-stop filters with excellent performance have been designed.The specific work of this paper is as follows:(1)The related theories of electromagnetic metamaterials and microwave filters are discussed in depth,and the working principle of metamaterial structures is analyzed by extracting the equivalent circuit model of the Split Ring Resonator and Rectangular Unit Structure.The working mechanism and performance indexes of microwave filters were studied,and the performance of microwave filters composed of single-layer and multi-layer electromagnetic metamaterials was analyzed and discussed,which laid a theoretical foundation for the subsequent design of tunable and bandwidth microwave filters.(2)Choosing paper as the metamaterial matrix material,based on the theoretical analysis of the Split Ring Resonator,the paper-based metamaterial band-stop filter was designed.By changing the opening direction of the Split Ring Resonator,the filtering frequency is adjustable.Finally,based on the flexible characteristics of paper and the theory of multi-layer superposition analysis of metamaterials,by folding the structure,a broadband microwave band-stop filter was obtained,and the conclusion was verified by experimental tests and electromagnetic simulation.(3)A microwave band-stop filter based on three-dimensional paper-based metamaterial was designed in the X-band.It has excellent band-stop filter characteristics at 11 GHz,and compared with the three-dimensional metamaterials made by traditional printed circuit boards,due to the internal strength of the fiber overlap in the paper,so its mechanical properties are excellent,and the structure has no deformation and fracture under the pressure of 7 MPa.At the same time,its preparation process also proposes a new idea for the preparation of complex three-dimensional structures,which has a larger application space.In summary,on the basis of paper-based metamaterials,this paper continuously optimizes the structure through experimental testing and electromagnetic simulation,and finally obtains a tunable microwave band-stop filter and a broadband microwave band-stop filter with a certain bearing capacity,which has certain research value for the design and application of electromagnetic metamaterials in microwave filters.