Implementation of Metamaterial Loading to Miniaturized UWB Dipole Antenna for WLAN and WiMAX Applications with Tunability Characteristics

Abstract

This paper presents a double-printed circular slot inscribed, hexagonal shape miniaturized dipole antenna featuring the ultra-wideband (UWB) characteristics with the implementation of linearly tapered feedline. The miniaturized UWB dipole antenna is designed for wireless applications wireless local area network (WLAN) and WiMAX by introducing a proposed metamaterial unit cell. Further, in comparison with the conventional UWB dipole antenna, miniaturization is achieved up to 35.89% and 16.67% with respective active patch area and antenna volume, respectively. The electrical dimension of the proposed antenna is 0.299 λ × 0.4385 λ × 0.0159 λ, of course, at lower frequency of 2.99 GHz. The use of metamaterial rectangular split-ring resonator and slotted ground structure witnessed the band achievements for wireless standards WLAN and WiMAX. The proposed structure is fabricated on FR4 substrate and tested. Impedance bandwidth of proposed antenna is obtained about 7.26% (2.39–2.57 GHz), 25.23% (2.91–3.75 GHz), and 16.92% (4.87–5.77 GHz) under simulation and 11.49% (2.38–2.67 GHz), 24.48% (2.94–3.76 GHz), and 15.99% (4.95–5.81 GHz) in measurement for WLAN (2.4–2.5, 5.150–5.250, and 5.725–5.825 GHz) and WiMAX (3.3–3.8 GHz) bands, respectively. Tunability between the wireless standards is demonstrated with the help of PIN diodes. The proposed design achieved high average gain of 3.31 and 2.06 dBi for simulation and measurement, respectively. The peak average radiation efficiency of 82.9% is observed during measurement mode. Experimental results are in good agreement with those obtained in the simulation of the proposed antenna.