The Fss In The Waveguide Filter

With the development of modern wireless communications, more request is need for waveguide filters and diplexers ,such as small size, good frequency-selectivity, low insertion loss and farther parasitic bands. The purpose of this thesis is to study and design new compact waveguide filters and diplexers with these characteristics. The main works are summarized as follows:Systematic filter design theories are reviewed and bring forward two kinds of FSS (frequency selective surface)irises:The bandpass FSS and the bandstop FSS. Using them,we design two waveguide filters.And with the bandpass FSS and the bandstop FSS combination,we designed a novel FSS waveguide filter,moreover we get it to manufacture. Compared with directly-coupled waveguide filter, to realize the same design goal, the sizes of waveguide filter is minimized. Otherwise, a compact diplexer in the X-band is constructed.