Dual Band CRLH Metal Antenna for WLAN Applications

A composite right/left handed (CRLH) metamaterial antenna is proposed in this paper. The antenna is designed for WLAN IEEE 802.11 standard; where bands 2.4 GHz usage frequency 2401–2495 MHz and 5 GHz usage frequency 5170–5875 MHz worldwide. A composite right left handed metamaterial has combined effect of right handed and left handed metamaterial and which creates dual band resonance in the antenna. By providing shorting pin loading at edge of the radiating metal, the left handed metamaterial property is created in the antenna. The antenna occupies rectangular area of 38.2 ×\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\times$$\end{document} 29.1 mm2\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${{\hbox {mm}}}^2$$\end{document} and 6 mm air gap from ground plane. The return loss of -10\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$-10$$\end{document} dB is achieved over the bandwidth with promising peak gain of 2.3 dBi and 8.6 dBi for 2.4 GHz and 5 GHz band, respectively. The antenna is fabricated, and measured values are closely matching with simulation results. The proposed antenna has orthogonal radiation patterns and maximum efficiency of 84.2% and 90.3% for dual frequencies.