Design And Fabrication Of Dual Band Waveguide Bandpass Filter Based On Ultraviolet Lithography

Dual-band waveguide band-pass filter is a key passive device for filtering signals in dual-band or even multi-frequency wireless communication systems.How to improve its frequency selection characteristics and realize its miniaturization has become a hot spot in the microwave radio field.Rectangular waveguides are widely used in microwave frequency bands due to their low loss,high power capacity,and ease of interconnection with measurement systems.In this paper,by exploring and researching cross-coupled band-pass filters,a dual-band waveguide bandpass filter with simple structure,wide frequency band,low loss,and high out-of-band rejection is designed and processed by UV-LIGA technology.Through summarizing the research theories and design concepts of dual band filters at home and abroad,starting from the design theory of waveguide band-pass filter,combined with the cross-coupling theory of resonant cavity.Using HFSS electromagnetic simulation software for modeling and simulation,a single-band waveguide band-pass filter with center frequencies of 80 GHz and 100 GHz was designed,and the related structural parameters were scanned and analyzed.The effect of the parameter change on the filter performance was found.A dual band waveguide bandpass filter is designed and simulated by using waveguide branch junction to connect two single band waveguide bandpass filters.Considering the structural model of the dual-band waveguide band-pass filter and the connection method of the test system,the processing of the dual-band waveguide band-pass filter was completed by UV-LIGA technology,and metallization processing and structure packaging were performed.The 3D morphology of the structure was observed and measured by confocal microscope before the structural packaging.The test results showed that the height error was small and the surface was smooth,which proved the feasibility of the processing plan.The waveguide flange used for the test was prepared,and the electromagnetic performance of the dual band waveguide bandpass filters was tested.The test results are basically the same with the simulation results,which has a certain significance for the development of the following dual band waveguide bandpass filters.