Multi-band annular slot antenna for WLAN applications

A novel multi-band antenna is presented. The structure principle is based on the annular slot antenna. It consists of associating on the same microstrip fed line several of these elementary radiating elements. Each annular slot is then designed to work at one of the desired frequencies. The concept is validated on a dual-band (2.4 GHz and 5.2 GHz) topology, which has been defined to assure a good frequency coverage of the two WLAN standards: Bluetooth and the low band of Hiperlan2.