Broadband stacked shorted patch antenna for mobile communication handsets

Two designs of stacked shorted patch antennas with a low profile (antenna height less than 5 mm) and a wide bandwidth (larger than 10%) suitable for applications for GSM 1800 and GSM 900 cellular systems, respectively, are presented. In the designs, the upper and lower shorted patches have a common shorting wall, and are both printed on a dielectric substrate. Wide impedance bandwidth is obtained by adjusting the lengths of the upper and lower patches to be slightly different, leading to the excitation of two closely excited resonant modes. The experimental results are presented and discussed.