Compact SRR loaded UWB circular monopole antenna with reconfigurable characteristics

A compact split ring resonator (SRR) loaded, coplanar waveguide (CPW) fed ultrawideband (UWB) circular monopole antenna having reconfigurable characteristics is presented in this paper. The SRRs are placed symmetrically on the back side of the CPW fed planar monopole antenna as shown in Fig. 1. The propagating signal excites the magnetic resonance of the SRR which prohibits transmission around the frequency determined by the SRR´s geometry and the constitutive parameters of the substrate and thereby yields in weak radiation around that frequency. However, placing a shunt wire along lateral direction (x axis) in the x-y plane along the CPW line thereby effectively shorting the CPW yields interesting characteristic. When the shorting wires are placed parallel to the plane and located along the center of the SRR separated by the dielectric thickness, h, the structure exhibits complimentary characteristics. This simple but insightful idea is used to reconfigure the planar UWB monopole antenna into a narrow band antenna radiating at the resonance frequency of the SRR.