Design of the antenna processing subrack, a new beamformer for LOFAR

LOFAR2.0 is an upgrade of the Low-Frequency Array, or LOFAR, the world's largest low-frequency radio telescope which will significantly improve its sensitivity and overcome several limitations found during the last 10 years of operation. The core of each LOFAR station are the digital beamformers, called antenna processing subracks (APS), where all antenna signals are digitized and digitally processed to form beams on the sky. The APS has boards ranging from high-speed, high-density digital processing to low-noise RF electronics, to high-current power converters. The designs of the LOFAR2.0 beamformer are presented, showing how a balanced was struct between performance and cost, while it can be produced in high volumes, and is easy to install and maintained in the field. The first LOFAR station has been upgraded with new beamformers and the first results will be presented, which demonstrate the new capabilities LOFAR2.0 will have with the new beamformer.