Design considerations for beamwaveguide in the NASA Deep Space Network

Abstract

Retrofitting an antenna that was originally designed without a beamwaveguide (BWG) introduces special difficulties because it is desirable to minimize alteration of the original mechanical truss work and to image the actual feed without distortion at the focal point of the dualshaped reflector. To obtain an acceptable image, certain geometrical optics (GO) design criteria are followed as closely as possible. The problems associated with applying these design criteria to a 34-m dualshaped Deep Space Network (DSN) antenna are discussed. The use of various diffraction analysis techniques in the design process is also discussed. The geometrical theory of diffraction (GTD) and fast Fourier transform (FFT) algorithms are particularly necessary at the higher frequencies, while physical optics (PO) and spherical wave expansions (SWE) proved necessary at the lower frequencies.

An analysis of near fields of 34m antennas of JPL/NASA Deep Space Network

“…The DSN antenna system that has been analyzed is a Cassegrain system composed of two reflectors with surfaces that are rotationally symmetric and whose shapes were optimized to avoid blockage of the subreflector, maximize peak gain and minimize received noise [1]. Figure 1 shows a 3D view of the antenna system.…”

“…This has not been previously done in any detailed and accurate fashion, since most of the attention in the antenna design and analysis has been put into calculating the far-field gain patterns, and even then mostly on the main beam and the first few sidelobes. The main aims of the original design and analysis of these shaped dual reflector systems were primary maximizing peak gain and minimizing the noise entering the highly sensitive receivers [1]. Recently, however, some effort has been put into a first order and approximate calculation of the near fields [2].…”

Solution and Design Technique for Beam Waveguide Antenna System by Using a Parallel Hybrid-Dimensional FDTD Method

“…EAM waveguide antenna system has been widely used in deep space detection because of its high gain and low side lobe [1], [2]. The antenna system consists of a feed horn, a waveguide and a Cassegrain reflector with large electrical dimension and its total size may reaches several hundred wavelengths.…”

Novel solutions to low-frequency problems with geometrically designed beam-waveguide systems

“…The design of the upper section of the BWG is based on geometrical optics (G.O.) criteria introduced by Mizusawa and Kitsuregawa in 1973 [1,2], which guarantees a perfect image from a reflector pair. The system was initially designed (Phase 1) for operation at 8.45 GHz (X-band) and 32 GHz (Ka-band) and has less than 0.2-dB loss (determined by comparing the gain of a 29-dB gain horn feeding the dual-shaped reflector system with that obtained using the BWG system) [3,4].…”