Reseach On Design And Microfabrication Of 220GHz Terahertz Bandpass Filter

Between the millimeter wave and the light wave,the terahertz band has both of their merits,besides the advantages of low scattering,high safety,high transmittance,large channel capacity and small device size.Therefore,the terahertz band is an important direction for the research and development of future communication systems.As an important component of communication system,the filter can be used to remove interfering signals and receive signals in specific frequency bands.Due to the small device size,the fabrication of terahertz filter is difficult.Considering the difficulty of microfabrication and performance of the filter,the terahertz bandpass filter with simple structure,low insertion loss and large relative bandwidth is studied.In this work,the structural parameters affecting the performance of the terahertz bandpass filter are discussed,and a 220 GHz terahertz bandpass filter is designed and microfabricated.Firstly,the characteristics and advantages of terahertz wave are introduced.Secondly,the types of terahertz filters and their research status and development prospects at home and abroad are summarized.Based on the basic theoretical knowledge of the filter and the structure of tunable terahertz filter,the existing terahertz filter microstructure is studied and improved,and a terahertz bandpass filter with 225 GHz center frequency and 8.9% relative bandwidth is proposed.The effects of medium matrix material,medium matrix thickness,gear unit material,gear unit number,gear unit height,gear unit spacing,gear unit ring width and other parameters on the filter performance are studied,and the filter structure parameters satisfying the design index are optimized.The MEMS(Micro Electromechanical System)technology is used to manufacture the terahertz bandpass filter,and the obtained samples are tested for surface morphology and structural parameters.Finally,the quality of microfabrication is evaluated by comparison of the performance of the designed ideal filter and the actual obtained sample considering the fabrication tolerance.