Triple-service GPS-DAB/DMB-WiMAX patch antenna for automotive applications

In our modern world, there are a number of wireless communication systems and broadcasting services which must be integrated into vehicles. However, there is very limited space for a lot of gadgets, so the need for low-cost, compact but highly efficient antennas without the need of an amplifier is essential. This document describes a low-cost, small and rugged triple-service patch antenna which features GPS-service for navigation systems, DAB/DMB-reception for sound- & multimedia transmissions in L-Band as well as WiMAX in S-band for mobile Internet into vehicles. While GPS-satellite reception requires right-handed circular polarization with a main lobe pointing towards sky, DAB/DMB-and WiMAX-service requires omnidirectional reception in the horizontal plane with vertical polarization. This discrepancy is successfully solved by slot-loading the patch antenna and truncating edges, so that different modes are stimulated. While GPS and WiMAX are used jointly on one coaxial feeding port, another separate feeding point is applied for DAB/DMB reception, so that independent tuners can be attached. As the dual-service slot loaded, corner truncated patch antenna provides an antenna gain of about 5.5 dBi for GPS, a low-noise amplifier is not necessary.