The 54th Research Institute of China Electronics Technology Group Corporation (CETC54) recently completed its subreflector, the first major part of China’s prototype dish antenna for the SKA project. The subreflector is the part of the antenna that focuses the signal bounced off the dish – or main reflector – into the receiver.
In 2013, the SKA Organisation sent out requests to research organisations and commercial partners to participate in the analysis and final design of the SKA components. Ten teams – called consortia – were established to start design work on the different parts of the project, with each consortium composed of international partners who are leaders in their field.
The Dish Consortium is tasked with establishing a final design for the SKA dish antenna, and currently studies three prototype antennas: the DVA-1 in Canada, DVA-C in China, and MeerKAT-1 in South Africa.
The Chinese subreflector was developed by Zheng Yuanpeng’s team at CETC54’s Joint Laboratory for Radio Astronomy Technology (JLRAT). Made of carbon fibre reinforced polymers, it is 5-m wide and weighs 248 kg. One month was needed to produce it once the mould was ready. Tested by photogrametry, the subreflector has a surface accuracy of 0.24 mm (rms).
Meanwhile, the manufacturing of the mould for the 15-m diameter main reflector is nearly finished. “Achieving the desired surface accuracy over such a large size is a significant challenge, but completing the subreflector was a significant step towards manufacturing the main reflector”, the JLRAT/CETC54 team said.
China plans to manufacture, integrate, and test its antenna design in just a few months.
Once completed, design options taken from the three prototype antennas will be analysed, and their construction costs estimated for a cost-performance comparison. Preliminary and detailed designs of the chosen antenna structure will then be carried out, with detailed drawings as well as manufacturing and verification test plans for the design of the pre-production SKA prototype antenna.
The SKA will complete its phase 1 detailed design in 2016 and enter construction in 2018, with start of early science expected in 2020.