Band-pass filter using dual magnetic resonances

Recently, there has been great interest in using the metamaterial resonators as constituent particles for the design of band-pass and band-reject filters. In this paper, a dual-band band-pass filter using loop split ring resonator with dual magnetic resonances is proposed. The single loop split ring is made of simple conducting strip with winding geometry. Simulated transmission and phase properties predict that there are two magnetic resonances near 8.4GHz and 9.2GHz. Dual bands of negative permeability are verified using the retrieval procedure. Then, the filter is designed by combination with periodically loop split rings and narrow short connecting wires which is based on coplanar waveguide (CPW) structure. The short connecting wires make the structure have negative effective permittivity with broad frequency range. Combined with the negative permeability loop split ring etched on the back of the CPW, two pass bands appear near 8.2GHz and 9.2GHz. Since rings are much smaller than signal wavelength at resonance and can be easily tuned, it has great prospects in application based on left-handed property.