Super compact split ring resonators CPW band pass filters

Abstract

Coplanar waveguide (CPW) band pass filters consisting on signal-to-ground wire connections alternating with series gaps, and split ring resonators (SRRs) etched in the back substrate slide, underneath the slots, are presented for the first time. It is demonstrated that by properly tuning SRR dimensions, a narrow pass band below the cutoff frequency of the wired/gaped CPW structure can be obtained. The relevant characteristics of the designed structure are: insertion losses below 4 dBs in the allowed band, out of band rejection above 30 dBs, and very high transition slopes with only three SRR stages. Due to subwavelength operation of SRRs, the proposed structures are very compact with potential application to the fabrication of planar filters for future communication transceivers.