ELC Resonator-based Metamaterial-inspired Electrically Small Antenna for WLAN/WiMAX

In this paper, two electric field driven LC resonator based metamaterial antennas have been proposed for WLAN and WiMAX applications. The performance of the proposed structures have been studied in order to characterize them as electrically small. In configuration 1, proposed structure exhibits a resonance at 3.5 GHz with an impedance bandwidth (vertical bar S11 vertical bar < -10 dB) of 3.4% and a peak gain of 1.1 dBi. The proposed antenna offers compact size with resonating element size of 0.07 lambda(0) x 0.12 lambda(0) x 0.02 lambda(0) where lambda(0) is free space wavelength at resonance frequency. In configuration 2, two parallel inductive arms and one capacitive arm are replaced with two parallel capacitive arms and one inductive arm which reduces the resonance frequency. The proposed structure operates at 2.5 GHz (impedance bandwidth = 6.4%) with resonating element size of 0.05 lambda(0) x 0.08 lambda(0) x 0.01 lambda(0) and a peak gain of 0.82 dBi. Radiation behavior for both structures is almost similar as they exhibit omni-directional radiation patterns in yz-plane and end fire radiation pattern in xy-plane with low cross polarization levels.