Analysis of multi-reflector antennas by dynamic ray tracing

The antenna of the radio observatory in Arecibo is currently fed by line feeds that correct for the spherical aberrations of the reflector. To improve the bandwidth and the sensitivity of the radiotelescope the line feeds will be replaced with a dual-reflector feed system. A computer code is described that is based on an efficient geometrical optics (GO) ray tracing technique. The code, called the TRT code, is related to the procedure of dynamic ray tracing used in seismics, which means that the complete complex ray field amplitude (and polarization for EM waves) is traced. The code also makes use of the paraxial-ray approximation, applied by considering each individual ray as an axis. In addition to the GO analysis, the code gives asymptotic information about the diffraction losses. This is obtained by the diffraction tracing techniques of the transition region theory (TRT). The characters of the TRT code are noted.<>