ABSTRACT
Global positioning systems (GPS) are very popular among civilian users for map positioning, scientific uses, and timing services. One of the most important components of a GPS is an antenna to provide stable communication between a satellite transmitter and a receiver. GPS antennas for the Ecall and OnStar safety systems are used with cellular phone antennas to supply rapid assistance to a driver involved in an emergency situation. The most common design for vehicle application is an active microstrip single-feed patch antenna. The parameters of a GPS antenna mounted on a vehicle differ from parameters measured on the ground plane. GPS technology joined with cellular phone equipment is used in the automotive industry to determine accurate vehicle locations. A variety of combined cell and GPS antenna designs are available for the automotive market. The antenna includes inner and outer patches installed on the top of the dielectric substrate.
