Dual-band F-shaped monopole antenna for 2.4/5.2 GHz WLAN application

Antennas occupying a small volume of the system are very attractive for wireless local area network (WLAN) or Bluetooth applications. To further reduce the antenna volume and decrease the fabrication cost, the WLAN antenna using an inverted-F strip integrated on the circuit board of a communication device has been demonstrated previously. However, the antenna is capable of single-band operation only. A novel dual-band F-shaped monopole antenna, which can easily be integrated on a circuit board, is proposed. The antenna comprises a vertical metal line and two (one upper and one lower) horizontal metal lines of different lengths, which are used for tuning the antenna´s first two resonant frequencies to achieve dual-band operation in the 2.4 GHz (2.4-2.484 GHz) and 5.2 GHz (5.15-5.35 GHz) bands for WLAN applications. The proposed antenna printed and integrated on a small region of a microwave substrate has a compact size of 10×15 mm² and is easily fed by a 50 Ω microstrip line printed on the same microwave substrate. Details of the design considerations for achieving dual-band operation, and experimental results of a constructed prototype for operating in the 2.4 and 5.2 GHz bands are presented.