PHYSICAL AND COMPUTATIONAL ASPECTS OF ANTENNA NEAR FIELDS: THE SCALAR THEORY

The main goal of the present paper is to analyze the structure of the near field radiated by scalar point sources. The motivations for this study are the strong connection with interaction problem and the need for some insights to be utilized in the later, much more involved study of the full-wave vectorial case. We first suggest that the radial direction is the most convenient at the current time for observing the structure of the near field and proceed to derive the radial Green's function of the problem in a simple analytical closed form. The obtained expressions are then studied and their physical features are illuminated, especially in connection with the engineering radiation problem. The overall understanding of the near field problem obtained here will help in guiding the devolvement for the more complicated sources sometimes encountered in applications and theory.