Research Of Terahertz Tunable Filter

Terahertz wave is widely used in various fields duo to its many remarkable characteristics.In particular,THz wave has been widely studied by scholars for its unique advantages in the field of communication.Terahertz tunable filter,as the key passive components,is an important component of terahertz reconfigurable communication system,and widely used in multifunctional receiver,electronic warfare and so on,so the development of high performance THz tunable filter is vital to the development of the terahertz integrated communication system.Combined with the MEMS technology,the design of a novel tuning scheme to achieve high performance terahertz tunable filter is the focus of this paper.The main work of this paper is as follows:Firstly,The basic principle and the key points of the design of the micro actuator are described in detail,and the advanced PolyMUMs processing technology is selected based on the latest development of MEMS technology.Based on the filter synthesis theory,the stability condition of the tunable filter is introduced.Combined with the filter synthesis theory,a fast design method of the H-plane coupled waveguide bandpass filter is proposed.These works lay a theoretical foundation for the design of the micro actuator and the design of the terahertz tunable filter.Secondly,The cascaded Bimorph microactuator which can provide perpendicular displacement and the U-shape microactuator which can provide parallel displacement based on the drving mode of heat are simulated and optimized by Ansys software,finally complete the layout drawing,processing,assembly and testing.The test results of the Bimorph microactuator are up to expectations,and the performance of the U beam microactuator is failed,and then analyses the cause.Thirdly,Four kinds of novel tuning methods based on waveguide are firstly proposed which can be used in the terahertz band,avoiding the influence of the microactuator is as the premise of the design in order to achieve high performance for those methods.Two kinds of tuning methods can be used in the design of terahertz tunable bandpass filter,and the other two can be used in the design of terahertz tunable bandstop filter,and the feafibility of those methods is verified by HFSS software.Finally,By analyzing the principle of EBG structure,we infer that the aking cascaded bimorph microactuator have absorbing properties,and is adjustable.The inference is verified by using terahertz time-domain spectroscopy system.This novel design method provides valuable experience for the future development of tunable terahertz absorbers.