CRLH ZOR ANTENNA OF A CIRCULAR MICROSTRIP PATCH CAPACITIVELY COUPLED TO A CIRCULAR SHORTED RING

Abstract

In this paper, a novel Metamaterial (MTM) CRLH Zeroth Order Resonance (ZOR) Circular microstrip patch antenna is proposed to have a monopole antenna pattern due to the completely closed loop of a magnetic current around the structure, and reduced proflle and size due to the left-handedness. Difierent from other ZOR antennas of 1D periodic arrays with shorted patches, we suggest 1 circular patch capacitively coupled to 1 circular shorted ring to have ZOR and i1st resonance modes. The antenna is designed and modeled with equivalent circuits for the coaxial-fed central patch and the circular shorted ring and verifled by the comparison with 3D EM simulation of the physical structure. The no-phase variation at the ZOR (2.4GHz) and the i1st resonance mode (2GHz) as the metamaterial properties are proven with electric fleld distributions and far-fleld patterns. The measurement shows there exist the ZOR and the i1 resonance modes despite the frequency shift from the simulation, which is proven by the monopolar radiation pattern and broadside radiation pattern, respectively. So the advantages of the proposed antenna will be addressed with the low-proflle monopole at the ZOR and the size reduction efiect at the i1st resonance.