A dual-polarization single-layered antenna for GPS and ISM bands

A novel planer antenna which radiates dual polarized waves at two frequencies is presented in this paper. A combination of a dipole and spiral antenna gave the antenna that radiates circularly polarized waves at a GPS band, 1.5 GHz, and linear polarized waves at an ISM band, 2.45 GHz. The most attractive points of this antenna are that its structure is a single layer, is fed by only one port, and it does not need any phase-shifters for radiating circularly polarized waves. The performances of the antenna have been improved compared with our conventional single layered dual polarization antenna. Simulation results of return loss, radiation patterns and axial ratio of the antenna are delineated.