Double‐ring slot antenna with tree‐shaped coupling strip for WLAN 2.4/5‐GHz dual‐band applications

A novel design of double-ring slot antenna with tree-shaped coupling strip for 2.4/5-GHz dual-band applications is presented in this paper. Two concentric slot rings are proposed in order to determine the certain resonated frequencies of two desired bands (5.20–5.55 and 5.55–5.80 GHz) and the inner circular disk depicts the range of 2.27–2.51 GHz. A tree-shaped coupling strip is designed with branches to couple the inner circular disk and with leaves to couple the double ring slot, respectively; therefore, it can simultaneously enhance the bands' responses using impedance-matching techniques. This is a compact microstrip antenna for IEEE 802.11a/b WLAN applications. The simulated and experimental results for the frequency responses, radiation patterns, and current distributions are presented and discussed. © 2005 Wiley Periodicals, Inc. Microwave Opt Technol Lett 47: 374–379, 2005; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21173