Design of a Dual-Band High-Gain Antenna Array for WLAN and WiMAX Base Station

Abstract

A dual-band $3 \times 2$ antenna array with high gain is presented in this letter. A dual-band folded dipole antenna is utilized as the antenna array element. A broadband symmetric feed network is designed to maintain each array element with the identical current magnitude and phase. The antenna array has a low profile of 12 mm (about $0.1{\lambda _{\rm L}}$ ; ${\lambda _{\rm L}}$ is the wavelength in free space at the lowest operating frequency). Dual bands $2.3\!\sim\! 2.56$ and $3\!\sim\! 4.2~\hbox{GHz}$ for return loss (RL) being higher than 10 dB can be obtained in simulation, while two 10-dB RL bands $2.31\!\sim\! 2.51$ and $3.1\!\sim\! 4.15~\hbox{GHz}$ in measurement cover the wireless local area network (WLAN, $2.4\!\sim\! 2.48~\hbox{GHz}$ ) and Worldwide Interoperability for Microwave Access (WiMAX, $3.3\!\sim\! 3.8~\hbox{GHz}$ ). The measured results also show that this planar antenna array has a high gain $14.3\!\sim \!15.1~\hbox{dBi}\;(2.31\!\sim\! 2.51~\hbox{GHz})$ , $16.2\!\sim\! 17.3~\hbox{dBi}$ ( $3.1\!\sim\! 4.15~\hbox{GHz}$ ) in $ + { z}$ -direction and a low cross-polarization level $ .