Compact CPW-fed tri-band antenna with a defected ground structure for GSM, WLAN and WiMAX applications

Abstract

In this paper we propose and investigate a unique compact FR4 based CPW-fed tri-band antenna for wireless applications. The antenna comprises frequency shifting strips and a defected ground structure (formed by combining of metallic strips and cutting of an L-shaped slot from the ground). The proposed antenna provides three different impedance bandwidths of 0.57, 0.98 and 1.59 GHz which are sufficient to cover the frequency band of GSM 1800/1900, WLAN 5.5/5.8 GHz and WiMAX applications. The developed antenna has a size of 17-20 mm and operates over frequency ranges 1.50–2.08, 5.25–6.23 and 9.10–10.69 GHz centered at 1.702, 5.802 and 10.102 GHz, respectively. The antenna was designed and simulated using Ansoft HFSS software. The antenna’s characteristics such as reflection coefficient, radiation pattern, impedance bandwidth and VSWR are presented.