A Compact Broadband Planar Antenna for GPS, DCS-1800, IMT-2000, and WLAN Applications

A compact broadband planar antenna is developed for global positioning system (GPS), DCS-1800, IMT-2000, and WLAN handsets. The planar antenna consists of an S-strip and a T-strip which are separately printed on the two sides of a thin substrate (no via process is involved in the fabrication). The antenna size is only 18 mm$\,\times\,$7.2 mm $\,\times\,$0.254 mm which is more compact than previously published antenna configurations. The bandwidth of the planar antenna is enhanced by the mutual coupling between the S-strip and the T-strip. It has been demonstrated by simulation and experiment that the compact planar antenna can achieve a bandwidth of more than 50% for return loss $< {-}$10 dB with an almost unchanged radiation pattern.