Compact Triple Band Metamaterial Antenna Based on Modified Electric-field Coupled-LC Resonator

In this paper, a compact triple band metamaterial antenna based on modified electric-field coupled (ELC) resonator is presented. The modification to the conventional ELC is achieved by the use of strip lines to enhance the capacitive coupling of the capacitive gaps and a stub printed at the back of the resonator. The unit cell’s macroscopic parameters were not affected by the structural modifications as the electric moment dominates the magnetic moments in the ELC response. By employing this structure, three resonance frequencies at 1.65 GHz, 3.5 GHz and 5.8 GHz are obtained. The overall size of the antenna is 40 mm × 45 mm (0.22λ o × 0.24λ o ) with the unit cell size of 12 mm × 11 mm (0.066λ o × 0.060λ o ) at 1.65 GHz. The peak gain of 2.10 dBi and radiation efficiency of 97% is obtained at 5.8 GHz. The proposed antenna has advantages of being compact, small and suitable for WiMAX (3.5 GHz) and WLAN (5.8 GHz) applications. The simulated and measured return losses and the radiation patterns are presented and compared.