antenna with impedanzanpassungssystem for motor vehicles

摘要

This invention relates generally to an improved system for connecting an integrated antenna to a car's ground point. The antenna matching system comprises a conductor (B) connected between an antenna element (A) and a first end of a feeder conductor (1) of a coaxial cable (C). A first end of the shielding conductor (2) of the coaxial cable is open, and a second end of the shielding conductor is adapted for its connection to a ground connection point (E) of a vehicle. The length of the conductor is selected to provide an inductive effect which substantially cancels the capacitive component of the antenna at the band of operation. The invention provides a matching system for the antenna of a motor vehicle, that allows to tune the antenna to the designed frequency independently of the selected ground point in the vehicle, so that a greater grade of freedom is obtained to design the antenna matching circuit.