E-surface Of The Metal Diaphragm Waveguide Filter

This dissertation is a part of the research project,"millimeter wave synthetic aperture radar (SAR) " ,which is the pre-researchful item of the Elelctric 10th Institute of Ministry of Information Industry.It's aim is to improve performance of stop-band of waveguide band-pass filter(BPF). A Ka-band BPF would be developed and used in the rardar system.A novel E-plane metal insert waveguide filter is presented in this paper. Comparing to conventional E-plane waveguide filter,great improvments have been made in stop-band attenuation of a BPF. It also overcomed the dificulty to realize characteristics BPF with fractional bandwidth greater than about 5% in the form of multi-metal insert waveguide filter. The analysis method adapted in this paper is the conservation of complex power technique combining even and odd mode analysis method,more accurate results have been obtained when correction to the errors due to electrical wall condition in the section of the metal septum is introduced . To synthesize a E-plane metal septum waveguide BPF,the equivalent circuit model of metal septum in rectangular waveguide E-plane is established at first. The susceptance due to discontinuity of the sections of the septum is accounted for.Then construction parameters of the BPF is determined applying network synthesis theory.By the accurate model and highly efficient iteration algorihtm ,the E-plane metal suptum waveguide BPF can be designed rapidly and accurately.It turn out that the CAD package could design the E-plane waveguide BPF effectivly and accuratly. It would be helpful in engineering applications. Using the CAD package,a single E-plane metal insert BPF,a double E-plane metal insert BPF and a new five-resonator Ka-band BPF were designed and tested.The theory and experiment results are in good agreement.