FDTD Analysis of On-Glass Dipole Antenna Mounted in Full-Scale Vehicle on Flat Earth

Automobiles are equipped with various sensing and/or communication antennas to ensure comfortable and safe driving. The development of higher performance automotive antennas necessitates the design and analysis of the antenna installed on a full-scale automobile under real environmental conditions, including the surface of the Earth. This study investigates a dipole antenna installed on the inner surface of a windshield glass of a car using the finite difference time domain (FDTD) method. The novel near-field-to-far-field transformation formula, based on the equivalence theorem, is implemented into the original FDTD method to calculate the far-field patterns of an on-glass antenna-mounted car on a flat earth. The transformation formula is derived from the dyadic Green’s function of a two-layer model consisting of air and a homogeneous medium. The validity and effectiveness of the method are confirmed first by comparison with theoretical results for a short dipole antenna. The subsequent analysis focuses on a full-size sedan-type vehicle equipped with a dipole antenna placed on a flat earth, offering valuable insights for the design of automotive on-glass antennas.