Design and Optimization of a Novel Compact Broadband Linearly/Circularly Polarized Wide-Slot Antenna for WLAN and WiMAX Applications

Abstract

A novel topologically modified structure of a compact low profile wide-slot antenna for broadband applications is presented. The antenna comprises a modified E-shaped slot with unequal arm lengths in the ground plane, and a parasitic quasi-rectangular loop placed coplanar with the feedline. For exciting orthogonal modes with equal amplitude, a single-point feeding technique with an asymmetrical geometry of the coplanar waveguide is used to feed the antenna. A multi-stage EM-driven optimization is used to rigorously optimize all the parameters for best impedance bandwidth and axial ratio bandwidth. The total footprint of the antenna is only 0.71 λg^2 and a 41% impedance bandwidth along with 33% axial ratio bandwidth has been achieved which covers several WLAN and WiMAX bands.