Popis: |
This paper presents a novel approach for designing planar multimode wideband bandpass fllters with good selectivity. The multimode resonator is composed of an open-ended microstrip line with length of half-wavelength (‚=2) and several radial-line stubs. By using difierent kinds of radial-line loaded stubs, difierent kinds of responses including three-pole and four-pole bandpass fllters can be realized. Depending on electric fleld distribution and equivalent circuit model, the characteristics of the fllter are analyzed. To verify the proposed method, two fllters are implemented. The measured results exhibit good agreement with the simulation. |