The Cryo-PAF at Parkes is a 98 dual-polarisation element cryogenically cooled Phased Array Feed (PAF) that will be installed on the Parkes radio-telescope operating in a frequency range of approximately 700MHz – 2 GHz. One of the challenges with the large number of signal paths required in such a design is the location and efficient implementation of analogue-to-digital conversion (ADC) and data packetizing and transmission. We have chosen to pursue a design where the RF signal chains and ADCs are co-located in a multiply partitioned module directly behind the PAF elements and low noise amplifiers. Frequency channelized data is transmitted to the beam-formers located some hundreds of metres away in the base of the telescope. The digitisation and data transmission module (JIMBLE) is based around a multiple RF input RF System on Chip (RFSOC) field programmable gate array (FPGA) with data transmission and timing provided over optical interconnections.

I will present the JIMBLE module under design, and highlight the overall design philosophy and also the Electromagnetic Compatibility (EMC), timing and synchronisation, form factor and thermal challenges we are facing and how we have chosen to address them.