EMBRACE System Design and Realisation
Gideon W. Kant, Erik van der Wal, M. Ruiter, Paul Van Benthem · 2011
EMBRACE is an operational demonstrator for next generation radio telescopes.It demonstrates independent, multiple, wide field, wide band receiving antenna beams based on phased array technology.EMBRACE operates in the 500-1500 MHz frequency range and consist of two aperture array stations.Currently, the Westerbork and the Nanc ¸ay stations are being realised.The design and realisation has been performed in a multidisciplinary project with strong emphasis on the front end.During the project multiple design cycles were performed to find an optimal prototype suitable for large volume production.A major building block of the array is denoted as a tile.The final configuration of a tile has one control board with six identical hex-modules supporting 144 Vivaldi elements.Apart from the electronics, mechanics play a major role.One example is a radome concept which has been developed to combine a temperature stabilised environment for the front-end and maintaining an electromagnetic transparent view on the sky.In this paper a system overview of EMBRACE is presented and the background of the main design choices is discussed.Both engineering and astronomical testing can be performed concurrently.This is possible as each logical tile forms an autonomous functional item providing an operational signal path.Furthermore, the digital back-end can be partitioned.All required components have been designed, tested and verified using a bottom up approach.This approach resulted in a gradually growing complexity of the system while adding more verified components.The production of the subsystems included technologies like low cost laser-cut antenna assemblies, extruded profiles, printed circuit boards, tile frames and the radome itself.All hardware manufacturing has finished.Currently more than half of the Westerbork array has been built and the realisation of the Nanc ¸ay station is ramping up.