Application of cubic high dielectric resonator metamaterial to antennas

A dielectric metamaterial structure was proposed, using cubic high dielectric resonators (CHDRs) in a cubic lattice structure, embedded periodically in a low dielectric background (Kim, 2006). These cubic resonators have degenerate TE and TM modes, at the same frequency. This CHDR metamaterial has negative refractive index characteristics in a specific frequency band, which can be changed by varying one of three factors, the size of CHDRs, the lattice constant, and the dielectric constant of CHDRs. The CHDR epsiv_r=30, background epsiv_r=2.08 metamaterial slab was positioned over a patch antenna to improve its directivity. The operating frequency of the patch antenna is 5.2GHz. The CHDR metamaterial lens was placed over the patch antenna with the spacing of 15mm. The metamaterial components were selected in this application for the impedance matching of the metamaterial lens to reduce the reflection loss. As a result, the directivity of the patch antenna was improved from 4.67 (6.69dBi) to 11.94 (10.8dBi) without degrading the radiation efficiency.