Ray tracing technique for shaping a dual reflector antenna system

Abstract

In radio astronomy applications, antennas having the highest aperture efficiencies are requested. In order to meet this request, a reflector shaping program for dual reflector antennas has been developed. The design procedure is based on the geometrical optics where differential equations have been formulated to define the ray trace of the antenna system. Recently, the fourth generation programming language MATLAB has become well known for its numerical computing environment and very useful three-dimensional data visualization functions. The authors wished to make a dual reflector shaping program by a ray tracing method in MATLAB. In this paper, details of the program are explained, and antenna ray tracing results are shown visually by three-dimensional viewgraphs. The numerical results are compared with the theoretical ones to confirm the correctness of the developed shaping program for a Cassegrain dual reflector antenna system. For uniform aperture distribution the first side lobe level is numerically obtained as -17.59 dB, which can be further reduced through shaping to -24.67 dB and -30.65 dB for parabolic and squared parabolic, respectively.