Near-field investigations to determine the lines of constant phased for an airborne position-finding antenna-system

A method is presented which makes it possible to calculate the scattered field very close to the surface of a perfectly conducting body as well as the surface itself. The method is based on the representation of the scattered field by an integral over the surface current distribution. The integrand is treated by identical transformations in such a way that the singular terms can be integrated analytically, while the remaining nonsingular terms are integrated numerically. The surface current distribution is determined by the magnetic field integral equation. The theory is validated by experiments by means of the scattered field of a metallic cube with an edge length of a wavelength. The normal and tangential electric near-field of the cube is measured by small probes, and the results are compared with those of the theory. The theoretical results of the near-field distribution of a cube and an airplane are presented using lines of constant phase.<>