Synthesis of vehicular antenna NVIS radiation patterns using the method of characteristic modes

The method of characteristic modes is used in a novel application for the design of vehicular antennas optimised for near vertical incidence skywave (NVIS) propagation. The technique treats any structure and its associated antenna as one by computing their characteristic orthogonal functions or modes. The appropriate excitation and control of key modes allows selected radiation patterns to be synthesised, with significant improvements over that from a conventional whip.