A compact tunable metamaterial filter based on split-ring resonators

A tunable metamaterial filter is designed based on split-ring resonators(SRRs) in this paper. The metamaterial filter has a compact size of 15 mm×20 mm, and miniaturization is realized by using the SRRs. By loading tunable devices, the continuous operation of the filter is realized at X band(from 10.7 GHz to 12 GHz), the bandwidth is about 13%, the minimum return loss is 35 dB, and the maximum insertion loss is 0.37 d B. The results illustrate that the metamaterial filter shows the compact size, wide bandwidth and good band pass characteristics.