'Radio quiet' electronics to power the SKA-Low radio telescope

A team of researchers, engineers and technicians has developed so-called ‘SMART boxes’ to power the SKA-Low radio telescope, currently under construction at Inyarrimanha Ilgari Bundara, the CSIRO Murchison Radio-astronomy Observatory, in Western Australia. The SMART (Small Modular Aggregation RFoF Trunk) boxes provide electrical power to the SKA-Low telescope’s 131,072 antennas and collect signals received from the sky to go off-site for processing.

The Engineering & Operations team at the Curtin University node of the International Centre for Radio Astronomy Research (ICRAR) designed and built the first set of 24 SMART boxes, which were 10 years in the making. Tom Booler, Program Lead for Engineering and Operations at ICRAR, said they are the only electrical devices that must be placed among the antennas, creating a challenge for the sensitive equipment.

“The SKA-Low telescope will receive exquisitely faint signals that have travelled across the universe for billions of years,” Booler said. “To detect them, the SKA-Low telescope is being built in a pristine radio quiet zone far from the interference created by modern technology.

“It’s so radio quiet at the observatory site that the biggest potential source of interference is the electronics like ours, due to the proximity to the antennas. That meant our project had to meet the strictest radio emission requirements across the entire Australian SKA site.”

The researchers had to source special ‘radio quiet’ parts that emit minimal interference, replacing the more ‘noisy’ ones. The parts were wrapped in a specially designed case to prevent any stray radio waves from escaping and the boxes were tested at an electromagnetic test facility in South Africa.

“The ‘radio quiet’ results that the ICRAR-designed SMART boxes achieved were to the highest standards in radio astronomy,” Booler said. “A mobile phone on the surface of the moon would cause more interference to the antennas than the SMART boxes that sit among them.”

A contract to build up to 12,000 SMART boxes for the entire fit-out of the SKA-Low telescope has been awarded to AVI, a company based in Perth. AVI Managing Director Tony Routledge said his company was proud to be involved.

“Being part of the SKA project is an incredible opportunity for AVI to contribute what we have learnt over our 35 years of delivering hardened electronic systems to the defence, security and mining sectors,” Routledge said.

“Extreme temperatures, ingress protection and the low-noise requirements, coupled with the remoteness of this location offer more opportunities to learn and evolve.

“I think we are all eager to be a part of what findings may eventually be revealed by the radio telescope.”

Image caption: Each SMART box houses 12 front-end modules that convert electrical signals from the antenna to fibre-optic signals for transmission. Image credit: ICRAR.