Novel Nested Split-Ring-Resonator (Srr) for Compact Filter Application

In this paper, a novel miniaturized nested split-ring resonator (SRR) structure is proposed.The nested SRR structure incorporates multiple split-ring resonators in a compact nested structure, and has more split gaps than the conventional SRR structure.Compared with conventional SRR, this nested SRR has better performance on miniaturization and high-Q value.To verify good characteristics of the proposed resonator structure, a novel resonator-embedded band-pass filter (BPF), which is constructed by four nested resonators, is designed.This novel BPF is very compact and has good in-and out-band performances.The proposed nested SRR unit cell has size of 0.04λ g × 0.04λ g (λ g is the signal wavelength at the 2.4 GHz central frequency of the pass-band).Its stop-bands are extended 0.5 ∼ 2 GHz at lower band and 2.7 ∼ 5.4 GHz at upper band with a rejection level of higher than 20 dB, and its 1-dB pass-band is 2.2 ∼ 2.55 GHz with 1.8 dB optimized insertion loss.The measured and simulated results are well complied with each other.