Composite right/left-handed transmission-line based wideband antenna for WLAN, WiMAX and WiFi applications

In this article, a new and compact wideband antenna is presented based on metamaterial composite right/left-handed transmission-line (CRLH-TL) structures. The proposed wideband planar antenna provides enhanced gain performance and is optimized for bandwidth, efficiency and radiation patterns. The CRLH-TL is realized by embedding two inverted F-shaped slots inside a rectangular radiation patch which is inductively grounded through a metal via-hole. The antenna is constructed using two CRLH-TL unit-cells to cover the frequency span from 3.1 GHz to 5.4 GHz, which corresponds to a fractional bandwidth of 54.11%. The overall size of the antenna is 11 mm × 7.4 mm × 0.8 mm or 0.15λ
₀
×0.1λ
₀
×0.011λ
₀
, where λ
₀
is free space wavelength at the operating frequency of 4.25 GHz. The antenna has a maximum gain and radiation efficiency of 6.4 dBi and 89.04%, respectively, at 5.4 GHz. The proposed antenna finds application in various wireless technologies including WLAN, WiMAX and WiFi.