Asymmetric CPW-fed electrically small metamaterial- inspired wideband antenna for 3.3/3.5/5.5 GHz WiMAX and 5.2/5.8 GHz WLAN applications

Abstract

In this work, a new concept is introduced to enhance the bandwidth of metamaterial (MTM) inspired antenna. The MTM inspired antenna mainly comprises a single split-ring resonator and a hexagonal-shaped closed ring resonator with asymmetric coplanar waveguide feed, which leads to antenna compactness. The physical dimension of the intended antenna is 17 mm × 20 mm × 1.6 mm. Due to MTM loading, the antenna achieves more compactness with ka = 0.87 < 1 resulting in a smaller electrical dimension of 0.18λ0 × 0.21λ0 × 0.017λ0 at 3.24 GHz. The intended antenna provides a wider bandwidth ranges from 3.06 GHz to 5.89 GHz with a percentage impedance bandwidth of 63.24% due to the merging of two resonating modes into a single passband. The proposed antenna provides a gain greater than 2 dBi for the entire working band with a maximal gain of 3.65 dBi at 5.2 GHz and radiation efficiency greater than 85% for the complete working band. Also, the antenna shows a consistent radiation pattern throughout the working band and hence the intended antenna is appropriate for 5.2/5.8 GHz WLAN IEEE 802.11 a/h/j/y, and 3.3/3.5/5.5 GHz WiMAX IEEE 802.16e applications.