Wide band SRR-inspired slot antenna with circular polarization for wireless application

In this paper, wideband slot antenna based on SRR-inspired structure with circular polarization in 2-3.8 GHz for WLAN and WiMAX applications is designed. Metamaterial are highly attractive in antenna and microwave applications because of their negative permittivity and permeability. In this paper, SRR-inspired are employed to miniaturize and modify the antenna frequency and obtain CP (circular polarization). In order to achieve this CP characteristic by controlling the antenna current distribution, SRR-inspired loads are used and for improving axial ratio, a special shape of slot and corner truncation are implemented. The final antenna has bi-directional pattern with circular polarization and wideband in range of 2-3.8 GHz for WLAN applications with gain of 2-3.5 dBi. The size of prototype patch antenna is 40 × 40 mm which is fabricated on FR-4 low cost substrate with εr = 4.4 and thickness of 1.6 mm. It is simulated by HFSS and CST microwave studio commercial full wave software's. In addition, the designing process of the prototype antenna is explained completely and the experimental results are compared with the simulation one. The efficiency of final antenna is more than 90%.