Adaptive low profile array antennas for smart car antenna systems

This paper presents a new type of mobile phone vehicle antenna, which is implemented as a phased array of multiple short antennas. Therefore highly efficient low profile antennas with vertical dimensions less than a quarter wavelength can be realized. Array antenna pattern synthesis, based on a combined method of highly accurate measurements and mathematical optimization, allows optimization of the required omnidirectional pattern on the vehicle as well as adaptive beam steering. Optimum reception performance can be achieved by using the same set of antennas in diversity mode. In spite of the comparatively low technical effort and the small dimensions, this highly effective antenna configuration opens now the possibility for smart antenna application in vehicles.