A Triple-Frequency, Vertex-Fed Antenna for WLAN\/WiMAX Applications [Antenna Applications Corner]

A triple-band antenna is essential in modern wireless applications to minimize interference from other communication systems by reducing the number of antennas installed on wireless devices. The proposed antenna can be utilized for Worldwide Interoperability for Microwave Access (WiMAX) (3.2-3.6 GHz), wireless local area network (WLAN) (5.15-5.35 GHz), and 5.8 GHz WLAN (5.725-5.825 GHz) applications. The antenna resonates at 3.24, 5.17, and 5.85 GHz and meets the desired requirement of voltage standing-wave ratio (VSWR) lower than 2. The pentagonal ring slot antenna is analyzed with and without an E-strip. With the E-strip, gain improvements of 1.41, 1.91, and 1.75 dB are achieved at 3.24, 5.17, and 5.85 GHz, respectively, and the measured results agree well with simulated values. The proposed antenna provides increased gain when compared with the existing triple-band designs reported in the literature.