A Uniplanar Triple-Band Dipole Antenna Using Complementary Capacitively Loaded Loop

A uniplanar compact metamaterial-inspired triple-band dipole antenna is designed and proposed for wireless local area network (WLAN) and Worldwide Interoperability for Microwave Access (WiMAX) applications. By introducing two pairs of complementary capacitively loaded loop (CCLL) slots into a uniplanar bow-tie antenna, two notched bands can be generated to form a triple-band operation. The antenna is directly fed by a 50-
$\Omega $
microstrip line and a microstrip-to-coplanar-stripline (CPS) transition as a wideband balun. Antenna parameters, including voltage standing-wave ratio (VSWR), radiation patterns, and gain, are obtained by numerical simulations and experimental measurements. The results show that the proposed antenna can provide triple-band operation at 2.21–2.77, 3.33–3.95, and 5.04–6 GHz with the VSWR less than 2 to achieve 2.4/5.2/5.8-GHz WLAN and 2.5/3.5/5.5-GHz WiMAX applications.