Study Of Terahertz Filter Based On Flexible Metamaterials

Terahertz technology develops very fast in recent years. In addition to traditional THz generation and detection equipment, the terahertz devices like terahertz filters and absorbers which can improve the transmission performance have also become a central issue. Therefore, the research about how the parameters of terahertz filter influences performance and how to design an excellence terahertz filter has become one of major research focus. Metamaterial is a synthetic material with special properties. With Appropriate design, metamaterial can be fabricated as a terahertz filter and its emergence has provided great convenience for the research and design THz devices.In this thsis, based on flexible metamaterials, THz filters are designed and studied through theoretical analysis and simulation. The effects of parameters on the performance of THz filters are discussed and a new terahertz filter with excellent performance is designed.Firstly, by reading relevant literature to find out the nature of metamaterials, a variety of single layer THz metamaterial structures are proposed in the sub-micron scale, which is suitable for the MetalMUMP’s process, such as square loop rejector, circular loop rejector and so on. Theory about THz filters fabricated by multilayer metamaterials is analyzed and discussed to make up lots of multi-THz metamaterial filter structures which based on single layer.Then, single and multi-layer metamaterial structures are simulated by CST Microwave Studio simulation platform. Influence of various parameters on the performance of THz filters is studied and discussed, such as width and length of the metal strip, the distance from the single metal structure to its boundary, and the distance between the two layers of the multilayer metal structure and so on. Simultaneously, many THz filters are designed. The width of bandstop frequency is about0.5THz, The peak of absorption is above95%through the whole bandstop and the average slope of the rising edge exceed115dB/THz. a lot of experience in the design and simulation is accumulated.Finally, based on the research and bold innovation, a new metamaterial terahertz band stop filter with great performance is designed and simulated. The center frequency of this filter is1.45THz. The width of bandstop frequency is about1.5THz and the peak of absorption is above99.9%through the whole bandstop. The average slope of the rising edge exceeds450dB/THz. This metamaterial structure is very innovative and has a certain significance and research value.