Analysis of Antenna Radomes by Ray Techniques. Part I. Point Source

A new method for attacking the radome problem is presented in this report. It improves the standard radome analyses in the two aspects: the description of the incident field, and the curvature of the radome surface as explained below. The radome is normally situated in the near-field zone of the antenna, which may be a horn, a slot, or an array. Taking into consideration the finite antenna size, we approximately replace it by an array of discrete point sources, each of which radiates a spherical wave. This approximation is different from that used in conventional techniques in which the incident field from the antenna is approximately represented by a spectrum of plane waves, instead of spherical waves. In calculating the wave transmission through the radome, the curvature of the radome is invariably ignored in conventional analyses. Our approach, however, does treat the radome as a curved surface by calculating the transmission of a spherical wave via ray techniques. In this part of the report, only the point source situated inside the radome is studied. Extensive numerical results show that the curvature of the radome may significantly modify the field transmitted through the radome. This modification cannot be accounted for by conventional radome analyses.