Miniaturization of a Waveguide Bandpass Filter Based on Split Ring Resonators (SRR)

As known the split ring resonators (SRRs) are used to design metamaterial structures. In this paper the SRR is used as an aperture of resonant irises in a waveguide bandpass filter. The equivalent circuit for the SRR is a parallel LC-circuit. According to this fact, a model of a 3-d order Chebyshev waveguide bandpass filter has been designed (Central frequency – 6.5 GHz). The length of the designed structure is determined by the quarter-wavelength transmission lines. The aim of the work is to reduce the length of the designed waveguide bandpass filter based on resonant irises with the SRR by 2 times. Electromagnetic analysis shows that the length decrease of the filter doesn’t extremely change the S-parameters and passband of the designed filters.