Design of compact antenna for 2.4/4.9/5.2/5.8-GHz WLAN

The design of a compact antenna for wireless devices in the 2.4/4.9/5.2/5.8-GHz wireless local area network (WLAN) application is presented. The antenna consists of a U-element with microstrip-fed on one side of the substrate and an L-element connected to ground on the other side. The U-element generates a high-frequency band at around 5.5 GHz for the 4.9/5.2/5.8-GHz WLAN bands. The same U-element, by forming a loop element with the L-element and the ground, also generates a low-frequency band at 2.44 GHz for the low-WLAN band. The two radiating elements together have a compact size of 12.6 x 9 mm(2) and the whole antenna has a very small size of only 25 x 25 mm(2), including the ground plane. Computer simulation and measurement are used to study and optimize the antenna. For practical use of the design, the antenna is also designed on a mobile-phone printed-circuit board and studied using computer simulation and measurement. A simulation model of the feeding cable is included in simulation. Simulated and measured performances show good agreements. Finally, the effect of mobile phone housing is also studied using computer simulation. All results show that the antenna can cover all the 2.4/4.9/5.2/5.8-GHz WLAN bands; hence the proposed antenna is a very promising candidate for practical WLAN devices. (c) 2014 Wiley Periodicals, Inc. Microwave Opt Technol Lett 56:1360-1366, 2014