A multi-branch monopole antenna for dual-band cellular applications

A monopole antenna with two branches, but still having one feed point, is proposed for the dual-band cellular applications. Simulation results of a dual-band antenna are presented. As shown in the results, the input impedances at the center of both bands are about 50 /spl Omega/. Therefore, an additional matching network is not necessary. This means there is no efficiency loss due to adding matching networks. The radiation patterns are basically omnidirectional. Although the GSM and DCS bands are used here, similar results can be obtained for the 900 MHz and 2.4 GHz ISM bands. The antenna can be made on a single-sided printed circuit board.