A novel proximity fed gap coupled microstrip patch array for wireless applications

Abstract

Design and development of a novel dual-band microstrip patch array antenna suitable for WLAN and WiMAX applications are presented. The proposed array configuration is obtained by employing two parasitic patches gap coupled to the driven elements of a single layer proximity fed 2 × 1 microstrip patch array configuration. The proposed dual-band array has the advantages of enhanced bandwidth and gain. The feed patches are excited by proximity feeding method and the parasitic patches are excited by gap-coupling. This microstrip patch array provides resonances at two frequencies of 2.584 GHz (2.412–2.629 GHz) and 3.508 GHz (3.469–3.541 GHz). This novel configuration has a measured gain of 8.51 dBi and 5.8 dBi in lower and upper bands with an impedance bandwidth of 8.16% and 2.05% respectively. Additionally, to enhance the front to back ratio at the upper resonant frequency, a metal plate is placed at the back side of the array antenna. This modified proximity fed gap coupled array provides directional radiation patterns with improved gains. Re-configurability in the form of beam steering is obtained in the modified array configuration by varying the air gap between the ground plane and metal plate. The simulated results are in good agreement with the experimental ones.