Compact 2.4/5‐GHz dual‐band annular‐ring slot antenna with circular polarization

This article presents a compact dual-band circularly polarized annular-ring slot antenna for 2.4/5-GHz WLAN applications. The radiating elements consist of two concentric annular-ring slots cut on the center of the ground plane, operating at 2.4- and 5-GHz bands, respectively. A pair of rectangle notches is placed between two annular-ring slots to guarantee that the antenna can operate well at high band. The antenna is fed by a 50 ohm microstrip at the top and the substrate material is FR-4. It has a compact size (40 mm × 40 mm × 1.6 mm) and can be integrated easily with other RF front-end circuits in WLAN operations. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 1848–1852, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24487