Research On W-band Multi-frequency Ridge Waveguide Cavity Filter

W-band multi-band radio frequency devices can not only solve the problem of congestion of available frequency bands caused by the continuous increase of current low-frequency communication protocols,but also reduce the number of radio frequency devices to a certain extent,thereby promoting the miniaturization of communication equipment.Integrated.The W-band multi-frequency ridge waveguide bandpass filter has excellent performance due to its small size and many stray radio waves that can be filtered at the same time,which fits the current development direction of microwave radio frequency communication equipment.In order to ensure that the energy loss of radio waves is minimized during transmission,rectangular waveguides are used to transmit radio waves.In this thesis,by studying the working methods of rectangular waveguide and rectangular cavity,two different W-band multi-frequency ridge waveguide cavity filters are designed,and they are successfully fabricated by using the UV-LIGA process.(1)This thesis studies the transmission characteristics of rectangular waveguides and the resonance characteristics of rectangular resonant cavities,and designs a rectangular waveguide that can simultaneously transmit TE₁₀ and TE₂₀ modes of transverse electric(TE)waves.The structure is optimized so that it can have two bandpass bands in the W-band.The two bandpass frequency bands are 94.50GHz?99.19GHz and 103.76GHz?108.56GHz,and the 3d B fractional bandwidth(FBW)is 4.84%and 4.52%respectively.The minimum insertion loss is 96.56GHz and 107.39GHz,and their values are 0.00035d B and 0.00056d B.(2)This thesis increases the order of the cavity filter by designing the source(S)port and load(L)port as resonant cavities,and studies the harmony of coupling windows,resonant columns,and resonant cavities of different sizes.The effect of the vibration block on the performance of the cavity filter,a highly selective single-ridge waveguide three-band-pass cavity filter is designed.The centers of the three bandpass frequency bands are 99.18GHz,102.40GHz and 106.07GHz,and the corresponding insertion losses are 0.84d B,0.27d B and0.23d B respectively.The out-of-band suppression at the upper frequency 96GHz and the lower frequency 108GHz are-61.69d B and-126.34d B,respectively.(3)In order to make the prepared cavity filter samples have a lighter weight under the premise of ensuring high accuracy,two different ridge waveguide cavity filters are finally selected to SU-8 2100 negative photoresist.The materials are all processed and prepared by UV-LIGA process.Then,set up a microwave test platform consisting of Agilent N5224 A vector network analyzer and R&S ZC110 spread spectrum module,and test the electromagnetic performance of the prepared samples.The relative bandwidth of the dual-frequency and triple-frequency filters is The absolute errors are 6.9%and 0.23%,respectively.