Design of printed antenna for USB dongle for IEEE 802.11 a/b/g application

A design of printed antenna with compact size for IEEE 802.11 a/b/g application is proposed. The antenna is printed on an FR4 substrate of thickness 1.6 mm and dielectric constant of 4.4. The size of the design is with the overall dimensions of 40 × 5 mm
²
and that of an antenna area is 14 × 5 mm
²
. The antenna consists of a T-shaped metal strip fed by 50-ohm mini-coaxial cable on the front side of the substrate, a long slot with inverted U-shaped, a U-shaped slot and a small slot printed on the back side of the substrate. The opened slot of inverted U-shape and the T-shaped metal strip are used to produce the bandwidth of the low band and high band. A very small slot very close to the feed point is to adjust impedance. The design with the small size of 40 × 5 mm
²
and good performances can be applied in USB dongle devices.