The Optimization of U-shaped Cross Section Antenna with a Strip on a U-shaped Ground Plane for WLAN Applications

This article proposes an approach to increase the efficiency of the U-shaped cross section antenna. The Optimization of a wideband U-shaped cross section antenna on a U-shaped ground plane is presented suitable for WLAN in various applications. The proposed antenna has been developed from a single element of U-shaped cross-sectional antenna. A single element is easy to be composed for installing parabolic reflector and an array antenna. The strip is used for increasing the number of degree of freedom to adjust and enhance bandwidth. In addition, this antenna is not only simple impedance matching but it is low cost as well. Antenna structure design is analyzed by the FDTD method. In order to verify the simulation results, the proposed antenna is realized and experimentally examined. The simulated results of the return loss and the radiation patterns are also compared with the measured results after the antenna is fabricated. Both are in good agreement. The result of measurement revealed that the proposed antennas have impedance bandwidth of 29.2 % and 25.3 % (2:1 VSWR). The front-to-back ratio are 15 dB and 20 dB while the gain is 14 dBi and 15 dBi at the operating frequency of 2.45 GHz for single element with the offset parabolic reflector and 1 4  array structure, respectively. KeywordsU-Shaped Element Antenna; Broadband; Polarization; Tuning Stub