Compact metamaterial inspired conformal dual-band antenna loaded with meander lines and fractal shaped inductor for Wi-Fi and WiMAX applications

In this study, a novel metamaterial inspired compact cylindrical conformal dual-band antenna with a shunt fractal inductor and bottom patch is proposed. The conformal antenna consists of three meander lines type unit cells of composite right/left-handed metamaterials for modification and compactness. To improve the operating bandwidth in the first band i.e at 2.45 GHz, a shunt fractal inductor with large inductance is proposed. A similar patch with a slot along the bottom side is additionally used for better impedance matching. The second band at 3.5 GHz is obtained due to the loading of two meander line unit cells on the patch as parasitic elements. The proposed conformal antenna is placed on a 15 mm radius cylinder whose equivalent planar dimension is 0.48 lambda(g) x 0.36 lambda(g) (where lambda(g) is the guided wavelength). Asymmetrical coplanar waveguide feed is implemented. Measurement results showed that the proposed cylindrical conformal antenna achieves a wideband -10 dB fractional bandwidth of 44.5% and a gain of 1.26 dBi at the operating frequency of 2.45 GHz and 4.5% of bandwidth and a gain of 2.2 dBi at the 3.5 GHz. The radiation efficiency is 70 and 86% at the said frequencies respectively. There is good agreement between measured and simulation data.