Using a synthesis methodology for the design of automotive antenna systems

The handling of the radio channel is an important aspect that determines the working capability of a mobile communication system. Since the channel behavior is influenced by the environment, which leads to a different behavior in different environments, the antenna design (synthesis) becomes environment dependent (time-variant) as well. In this paper, a capacity maximizing approach to design automotive antenna systems for time-variant channels based on the approach of sampling antennas is presented. Real world constraints such as the available space, transmit power, the number and arrangement of the antennas are taken into account. Besides the theory, different examples for optimizing Single-Input-Single-Output (SISO) and 2×2 Multiple-Input-Multiple-Output (MIMO) systems for Car-to-Car (C2C) communication will be presented and compared. In total up to 16 possible antenna locations on the vehicle are considered and compared. A three-dimensional ray-tracing tool calculates the communication channels used for this synthesis approach. The results show that directive antenna elements, which focus in ± driving direction, can be used to increase the capacity particular in safety-critical C2C scenarios.