Following the completion of the Atacama large-millimeter/submillimeter array (ALMA), an initiative emerged to develop a radio telescope that would provide a two-orders-of-magnitude increment in sensitivity over existing facilities at meter-to-centimeter wavelengths. To achieve this goal, a radio telescope is needed with a collecting area of up to 1 km2. A 500-meter aperture spherical telescope (FAST) has been proposed as an engineering demonstrator. The main reflector should overcome the issues of narrow bandwidth due to line feed and spherical error from the spherical reflector. B.Y. Duan and J.L. Du from China's Xidian University examine the active cable-mesh main reflector's potential in detail.
The researchers delve into the design, mechanics analysis, and shape adjustment of the active cable-mesh reflector. The cablemesh reflector of FAST is a spatial cable mesh. For larger antennas, triangular facet has been proven to lead to the fewest number of structural members in order to meet both accuracy and electromagnetic (EM) performance requirements. A cable-mesh structure with a triangular network is therefore adopted as the supporting structure.
In terms of mechanics, the active cable-mesh reflector for FAST must overcome surface accuracy adjustment and the surface error induced by facet approximation. The proposed method for surface accuracy adjustment, which aims at the active cable-mesh reflector, provides numerous benefits. According to the simulation, for example, it widens the operation frequency to roughly 130 MHz to 8.8 GHz. See "On Analysis and Optimization of an Active Cable-Mesh Main Reflector for a Giant Arecibo-Type Antenna Structural System," IEEE Transactions on Antennas and Propagation, May 2007, p. 1222.
