Design of cross-coupled dual-band filter with equal-length split-ring resonators

A compact dual-band bandpass filter using equal-length split-ring resonators (SRRs) is proposed in this paper. The two-resonance frequency response of equal-length split-ring resonator is described in detail. A cross-coupled dual-band filter with four equal-length split-ring resonators is designed. Several finite out-of-band attenuation poles are realized to improve the selectivity of the proposed filter. The measurement of the filter is in good agreement with the simulation.