Loop-Type Ground Radiation Antenna for Dual-Band WLAN Applications

A compact ground radiation method for 2.45 and 5.5 GHz wireless local area network (WLAN) applications is proposed. This method is based on two different loop-type current modes that are excited in the ground plane and separately operated at 2.45 and 5.5 GHz, producing a very small-sized antenna with good radiation efficiencies and wide impedance bandwidths. The proposed radiation method requires a small ground clearance of 8.5 mm × 4.5 mm for installing the antenna element. The experimental result shows that a good impedance matching performance is simultaneously achieved at the dual frequency bands and the -10 dB bandwidths are obtained as 120 MHz and 720 MHz at the 2.45 and 5.5 GHz frequency bands, respectively, and good radiation performance is achieved.