Surface Configuration Design of Cable-Network Reflectors Considering the Radiation Pattern

Abstract

Since the curved surface of a cable-network reflector is generally approximated by regular flat facets, the electromagnetic performance of the cable-network reflector is determined by the size and shape of the facets. In many cases, the geometric approximation errors of the facets are periodically distributed on the surface, which can result in strong grating lobes. First, in this paper, the periodicity of the geometric approximation error and the effects of this periodicity on the EM performance are investigated. Second, the periodic geometric approximation errors of the regularly faceted configurations are disturbed by three proposed approaches, and three new types of surface configurations are thus formed. The first approach is to introduce radial direction disturbance parameters, the second one is to change the shape of the outlines and the last one is to use a Penrose-tiling-like configuration. The first two approaches are carried out in combination with the optimization strategies. Finally, the effects of the mentioned disturbance parameters on the EM performance are simulated, and some numerical examples are given to show that the surface configurations proposed in this paper can reduce the grating lobes level obviously, without either decreasing the gain or increasing the structural complexity of the cable-network reflectors.

Effect of Panel Misalignment Error Distribution on the Radiation Pattern of Leighton Chajnantor Telescope’s Antenna

“…Following Ruze (1966), Rahmat-Samii (1983) proposed an efficient computation method that considers non-uniform surface rms errors to characterize the influence of different random surface errors on the average power pattern, such as gain loss and sidelobe level. For the periodic geometric approximation error, Zong et al (2014) studied its impact on the radiation patterns of cable network reflectors and proposed three approaches to weaken these effects. Haddadi & Ghorbani (2016) proposed a general formulation using the physical optics (PO) approximation method and functional calculus to analyze the influence of surface distortion on the radiation characteristics of reflector antennas.…”