UWB ring-shaped metamaterial antenna with modified phi-shaped SRR

In this paper, an ultra-wideband ring-shaped metamaterial antenna with modified phi-shaped split ring resonator has been proposed. The proposed antenna has a size of 35 mm × 37 mm × 1.6 mm and shows dual-band characteristics. The proposed metamaterial antenna has an impedance bandwidth of 14% (centered at 2.65 GHz) and 114.5% (centered at 7.25 GHz) for the first and second band respectively. Modified split ring resonator exhibits several higher order modes which is responsible for ultra-wideband behavior. The proposed antenna has an average gain of 1.6 dB with an average radiation efficiency of 98.8% for first band and an average gain of 2.65 dB with an average radiation efficiency of 81.5% for second band.