PERFORMANCE ENHANCEMENT OF TRI-BAND MONOPOLE ANTENNA FOR WLAN / WIMAX APPLICATIONS

Abstract

A novel tri-band monopole antenna applied to WLAN/WiMAX applications is proposed in this paper. The antenna comprises of two semicircles: one is fed by a microstrip line, and the other is shorted to the ground. By incorporating L-shaped strips, good filter as tri-band performance is achieved. The proposed antenna shows a good multi-band property to satisfy the requirement of WLAN in the 2.4/5.2/5.8 GHz bands and WiMAX in the 2.5/3.5/5.5 GHz bands. In addition, a near omni-directional radiation characteristic is also obtained. Experimental data show that the antenna can provide three separate impedance bandwidths of 400 MHz (centered at 2.6 GHz), 400MHz (centered at 3.4 GHz) and 1100 MHz (centered at 5.3 GHz) with two fine notched bands at the undesired bandwidths.