A broadband circularly polarized polygon slot antenna design by particle swarm optimization

A broadband circularly polarized antenna with six-edge irregular polygon shaped slot for WLAN applications was proposed in this study. To produce a broadband circular polarization, the slot shape of the proposed antenna is designed and optimized by particle swarm optimization method. Results of the optimized antenna show that wideband characteristics of S11 and AR cover 2.45 GHz (2.4-2.484 GHz) WLAN band. The impedance bandwidth is 17.6 % (2.25-2.68 GHz) while the axial ratio bandwidth is 28.57 % (2.1-2.8 GHz). The antenna performs LHCP waves in the broadside direction and an average gain of about 3.5 dBic across the operating band.