| The Terahertz waves usually refer to electromagnetic waves in the frequency band of 0.1 to 10 THz,which have the characteristics of high bandwidth,high penetration,and low energy.They could be used in imaging,security inspection,radar communications,biomedicine and other fields.For natural materials,since their response to electromagnetic waves in the terahertz band is very limited,it is difficult to realize terahertz devices.Metamaterial,as a kind of materials composed of artificially constructed micro structure units,can exhibit supernormal physical properties that do not exist in natural materials by adjusting the microstructure of metamaterial.The appearance of metamaterial provides an important means for people to adjust and control the electromagnetic wave in terahertz band.In recent years,terahertz technology and devices based on metamaterials have become a research hotspot in the current scientific and technological field.Among them,the terahertz filter,as an important type of device in the field of terahertz communication,has achieved many important research results after recent years of development.Of course,there are still some problems in the research process.The terahertz broadband filters,as an example,have some problems such as narrow filter bandwidth and poor filter performance.Based on this,this thesis reports a metamaterial terahertz broadband pass filter made of a bimetallic ring.We construct a theoretical model of the resonant unit by using CST Microwave Studio.By changing the geometrical dimensions such as the distance and radius of the bimetallic ring and the thickness of the polyimide substrate,the structural parameters of the broadband and high transmittance terahertz filter are obtained.The results show that the filter can achieve a passband bandwidth of 0.54 THz under 0.1?1.2 THz,and the terahertz wave transmittance in the passband is as high as 93%,which provides a theoretical solution in THz broadband communication,imaging and other technologies. |
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