DBBC3 Towards the BRAND EVN Receiver

Paper in proceeding, 2019

The DBBC3 is a flexible VLBI backend and environment that supports a wide range of observational needs via a suite of FPGA firmware types. The hardware can sample up to eight 4 GHz-wide baseband signals and convert to digital streams over multiple 10GE links on fibre. The development team has an ongoing development programme that has enhanced existing modes and introduced new desired modes as user requirements evolve. Three dierent firmware types for observing have been implemented which will be briefly summarised: Direct Sampling Conversion (DSC), arbitrary selection of bands (OCT), Digital Down Conversion (DDC). These modes cover all the requirements of astronomical, VGOS and legacy geodetic VLBI of the present, but also of the near future. At the same time the DBBC3 is an important platform for additional new modes to be implemented for the BRAND receiver. This paper describes the use of the DBBC3 for the receiver development, pointing out which element in the current DBBC3 structure will be part of the BRAND receiver in order to simplify its introduction into the existing VLBI environment at telescopes with a DBBC3 backend.