A Study of Dual/Triple-Band Microstrip-Fed Slot Antenna Design for WLAN/WiMAX Communication Systems

Abstract

This paper presents a study of dual/triple-band simple slot antenna fed by microstrip line for WLAN and WiMAX communications systems. The first proposed antenna consists of a rectangular slot with rectangular-ring strip at the centre of a rectangular ground plane and microstrip line feed at the centre for excitation. The simulation results of the return loss of the first proposed antenna can cover the frequency range at 2.32-2.48 GHz (WLAN 2.4 GHz), and 5.49-6.11 GHz (WLAN/WiMAX 5.8 GHz). The first proposed antenna is extended by inserting an L-shaped slot in rectangular-ring strip to create third frequency WiMAX at 3.5 GHz band and it can control resonant frequency band operations. The simulation results of the proposed antenna are analyzed by using IE3D Software. The measurement results of triple-band slot antenna of return loss (S11), the first resonant frequency has an impedance bandwidth of 240 MHz (2.45-2.69 GHz), which covers the 2.5 GHz WLAN/WiMAX bands. The second resonant frequency has an impedance bandwidth of 170 MHz (3.45-3.62 GHz) at 3.5 GHz frequency band (WiMAX 3.5 GHz). The third resonant frequency has an impedance bandwidth of 600 MHz (5.7-6.3 GHz), covering the 5.8 GHz WLAN/WiMAX bands. Moreover, the proposed antenna can control a shift of the resonant frequency. The radiation patterns of the proposed antenna in E-plane and the H-plane are bi-directional and omni-directional.