Compact antenna structures for mobile handsets

In this paper, novel compact antenna structures for mobile handsets are studied. The antennas are based on non-resonant coupling elements, which are used to optimally couple to the characteristic wavemodes of the chassis. The resonances for the antenna structures are created with matching circuits. Two different antenna models are designed based on the novel antenna structure. From each model, single-band prototypes for the E-GSM900 and GSM1800 systems are constructed. The volume of the smaller antenna model is only 1.3 cm/sup 3/. Both models meet the bandwidth and SAR requirements of the E-GSM900 and GSM1800 systems. Efficiencies are high and the radiation patterns are suitable for use in mobile handsets. The measurement results of the constructed prototypes suggest that the compact antenna structure studied in this paper has great potential for use in mobile handsets.