Comparative analysis of Luneberg spherical lens designs

Abstract

Formulation of the problem. The development of modern mobile satellite communication systems dictates the need for the development of multipath antennas having: high values of the directional coefficient, low level of side lobes, a large number of scanning beams in a wide viewing sector without distortion in the azimuthal and angular planes. Multipath antenna systems based on spherical Luneberg lenses have these advantages. Despite their advantages, the spherical lenses of Luneberg did not find wide practical use due to the complexity of the design, the high cost of production, and the large mass (in some cases). Thanks to the progress in the field of artificial media, the emergence of new production methods, various designs of spherical Luneberg lenses have been developed. The use of artificial dielectrics allows you to create inexpensive, lightweight spherical Luneberg lenses. One widely used method of creating an artificial environment is to use partial air filling dielectrics. Luneberg lenses based on such media can have various designs: based on a dielectric ball with radial holes of variable diameter, from electrically small dielectric cubes of variable size, from a set of perforated dielectric disks, etc. For the manufacture of such lenses, various manufacturing technologies can be used, for example, three-dimensional printing, CNC machine. Purpose. Comparative analysis of the characteristics of two structures of the spherical Luneberg lens with the aim of working at frequencies above 9 GHz: from a set of perforated dielectric disks, from dielectric cubes of different sizes. Results. The results of comparative analysis of two designs of the spherical Luneberg lens are presented. The procedure of synthesis of each structure is considered. Design dependencies of effective dielectric constant used in development of investigated spherical lenses of Luneberg are given. Possible methods of technical implementation for each lens are considered, as well as important features that should be taken into account when designing and technical implementation. The weight of each structure was estimated. Conclusions about mechanical strength were made. Based on numerical modeling using the Weyland method, a comparison of directional properties in a wide frequency band was made. Conclusions have been drawn about the similarity and difference in directional characteristics. Practical importance. The scientific and technical results obtained in the article will be useful in choosing the design of the Luneberg lens from artificial dielectrics, depending on the specified technical requirements, and production conditions.