A NOVEL CIRCULAR SLOT ANTENNA WITH TWO PAIRS OF T-SHAPED SLOTS FOR WLAN/WIMAX APPLICATIONS

Abstract

A novel circular slot antenna with two pairs of T-shaped slots is proposed for satisfying WLAN and WiMAX applications simultaneously. The proposed antenna consists of a 50› microstrip feed line with a tuning stub on the top and a circular slot ground plane with an embedded straight strip and two pairs of etched T-shaped slots on the bottom side. By carefully adjusting the length of the straight strip, the proposed antenna can operate in two separate bands. With the use of two pairs of T-shaped slots, a new resonant frequency has been excited, and the impedance bandwidth can be widened. The measured results show that the 10dB return loss bandwidths of the proposed antenna are 760MHz (3.18{3.94GHz) and 1002MHz (5.05{6.07GHz), which can cover both 5.2/5.8GHz WLAN bands and 3.5/5.5GHz WiMAX bands. The design evolution and parametric study of the proposed antenna are presented to provide information for designing and optimizing such an antenna. Furthermore, good omnidirectional radiation patterns with appreciable antenna gain are obtained over the operating bands.