Radio Astronomy Antennas by the Thousands

Abstract

Large number of microwave antennas of size and surface accuracy appropriate for the Square Kilometre Array (SKA) have not been manufactured previously. To minimize total cost, the design needs to be much more carefully considered and optimized than would be affordable for a small number of antennas. The required surface area requires new methods of manufacture and production-line type assembly to be considered. A blend of past antenna construction technology, creativity, and new technology is needed to provide the best possible telescope for the proposed SKA science goals. The following key concepts will be discussed with respect to reflector antennas and many supporting photographs, figures and drawings will be included.

Surface and supporting structure — comparison of panels with a one-piece shell as produced by hydroforming.

Combined reflector and mount geometry — performance/cost materially governed by this geometry which must be optimized for SKA requirements which are significantly different from typical communications antennas

Types of fully steerable mounts — king post, turntable bearing and wheel and track

Pointing accuracy — factors effecting cost, non-repeatable and repeatable errors

Axis drive concepts — traction devices, gears, screws, etc.

Life cycle costs — maintenance and power costs must be considered

Synergistic design — all of the above factors must be considered together with the wideband feed and receiver system to optimize the whole system