Bandwidth enhancement in coplanar waveguide-fed slot antennas designed for wideband code division multiple access/wireless local area network/ worldwide interoperability for microwave access applications

A multiband coplanar waveguide-fed slot antenna design is proposed for use in wireless and mobile communication applications. This antenna was designed on a single-layer printed circuit board FR4 substrate featuring a permittivity ε_r = 4.4, a loss tangent tan δ = 0.0245 and a thickness of h = 1.6 mm. The antenna consists of a T-shaped signal strip and a U-shaped conducting strip placed on the upper side of the T-shaped signal strip. After simply tuning the slot parameters of the ground plane, the proposed antenna can be used in the following operations: wireless local area networks at 2.4/5.2/5.8 GHz, worldwide interoperability for microwave access at 2.5/3.5/5.5 GHz and wideband code division multiple access at 1.92-2.17 GHz. The -10 dB bandwidth measured for the proposed antennas was 109.2% (1.85-6.3 GHz). The bandwidth was enhanced by choosing suitable combinations of the upper and lower ground slots. The geometrical parameters were examined to optimise the performance of the proposed antenna. The results of the return loss, far-field H- and E-planes radiation patterns, gain and radiation efficiency of the proposed antenna are presented and discussed herein. The antenna size of the radiation area and the ground plane was 50 × 50 mm². Detailed simulations and experiments were conducted to optimise broadband operations, and the measured results concurred with the simulated results.