Antenna and payload test strategy of large spacecraft's in compensated compact ranges

Large compensated compact ranges are designed for antenna and payload testing of spacecraft antennas and payload units. The Compensated Compact Range concept (CCR) of Airbus does have two major advantages for such measurements. First of all a small cross-polarization (<; -40 dB) for frequencies ≥ 3 GHz due to the compensating reflector design. In addition they provide a scanning capability of the test zone due to the short effective focal length of the reflector system. The first item is a necessary condition for precise spacecraft antenna measurements at which the cross-polar performance is an important requirement. The second one, the scanning capability, is an interesting feature for deployed antennas of large spacecraft's. It can be easily utilized for antenna testing as well as fully radiated payload testing scenarios with uplink and downlink path. State-of-the-art telecommunication satellites with huge antenna farms are challenging test objects for the standard compact range of the last 20 years, the CCR 75/60. A more convenient test situation for such large test objects is given for larger CCR facility types, e.g. the CCR 120/100 with 8 m diameter for the central telecommunication satellites test zone size or the CCR 150/120 with 10m test zone size. However, even in the smaller facility medium and large spacecraft's can be tested by using the above mentioned scanned test zones by applying de-focused range feeds and a flexible specimen positioner system. This paper addresses practical implementations, achieved performance figures of the latest installations and inherent limitations by the utilization of the scanned quiet zones at a CCR test facility for antenna and payload testing.