Predicting the Performance of a Very Large, Wideband Rolled-Edge Reflector
Authors: Anil Tellakula, William R. Griffin, and Scott T. McBride
Achieving a very large quiet zone across a wide frequency band in a compact range system requires a physically large reflector with a suitable surface accuracy. The size of the required reflector dictates attention to several important processes such as how to manufacture the desired surface across a large area and the practicality of transportation and installation. This inevitably leads to the segmentation of the reflector into multiple panels; which must be fabricated, installed, and aligned to each other to conform to the required geometry. Performance predictions must take into account not only the surface accuracy of the individual panels, but also their alignment errors.
This paper presents the design approach taken on a recent project for a compact range system utilizing a blended rolled-edge reflector that produces a 5 meter quiet zone across a frequency range of 350 MHz to 40 GHz. It discusses the physical segmentation strategy, the fabrication methodology, the intermediate qualification of panels, the panel alignment technique, and the laser-based metrology methodology employed. Performance analysis approach and results will be presented for the geometry as conceived, and then for the realized panelized reflector as machined and aligned.