Maltese-cross coaxial balun-fed antenna for GPS and DCS1800 mobile communication

A novel antenna in the shape of a Maltese cross has been developed for GPS satellite and DCS1800 personal communication system application. This antenna exhibits good circular polarization (axial ratio <2 dB) and impedance performance over a bandwidth wide enough to cover the frequency band for GPS and DCS1800 reception. The addition of an adjustable clamp and tapering of the shape of the radiating elements improved the overall design. The gain of this antenna has been sufficiently high to compensate for the power loss due to polarization mismatch for the reception of a linearly polarized GSM/DCS1800 signal. A modular design and integration approach is presented to obtain the circular polarization required for GPS application.