Intelliconnect – a supplier of interconnect products for many leading American and European defense, medical and marine OEMs – through its CryoCoax brand is providing a range of cryogenic interconnect solutions. CryoCoax is a division of Intelliconnect dedicated to the manufacture and supply of RF Interconnects and subsystems for Cryogenics applications in the fields of quantum computing, space, defense, medical, test and measurement, education, research amongst many others.
For a customized order, CryoCoax successfully provided cable and connector systems for milli-Kelvin dilution fridges. The customer had a requirement to develop processes, procedures, supply chains and test regimes to manufacture their ‘sticks’. The customer is now established and happily receiving defect-free product for the past 5 years.
Dilution refrigerators are routinely used to provide sub-Kelvin temperatures for quantum physics research, there is also a growing use in quantum computing applications. For many of these applications, coaxial cables are used to connect the control electronics at room temperature to devices at the lowest temperature stage of the dilution refrigerator.
The coaxial cables are commonly incorporated into modular inserts sometimes known as ‘coax sticks’ or ‘coax trees’. These inserts help with customisation of the dilution refrigerator and often use cables of different materials at the various temperature stages. Cable having Niobium Titanium conductors is a popular choice at the low-temperature stages to take advantage of its superconducting properties.
Challenges & Solutions
Providing reliable connections and predictable RF performance can be a challenge, particularly with some of the exotic materials. The conventional method of terminating semi-rigid cables is to solder the connectors; however, Niobium-Titanium is very difficult to solder. Solder joints can also present issues at sub-kelvin temperatures.
CryoCoax first of all tried ultra-sonic soldering which, despite a significant outlay on equipment, failed to work. After looking at several options, the design team developed a clever crimp/clamp solution which, while achieving similar electrical performance (Insertion loss/VSWR), removed to need for soldering altogether.
Another challenge was that due to the extremely high cost of these exotic and fragile cables, it was essential to minimise waste in the production process. The team spent a huge amount of time effort and money in developing techniques and tooling in order to reduce process waste.
Transportation was another issue. With a product that potentially was 2 m long with a multitude of layers of multiple cables, the team was dealing with something both large, unwieldy and incredibly delicate. With the help of packaging suppliers, CryoCoax engineered a special packaging solution involving bespoke foam inserts and ribbed tubing which has successfully overcome the issue.
Cryogenic RF Interconnect Solutions
The cryogenic temperature range has been defined to be from 120 K (−150 °C) to absolute zero (0 K or −273 °C). Most electronic and RF components are usually designed to operate at a temperature ranging anywhere from -40 °C to +85 °C. Components need to be specially designed to operate at ultra-low temperatures found in cryogenic environments.
Intelliconnect through its CryoCoax brand is a leading manufacturer and supplier of Cryogenic products in the USA, Europe and the Far East. CryoCoax is SC21 accredited to a silver standard which is a business quality and improvement qualification designed to provide a continuous improvement program and assure supply chain performance. Silver Award proves more than 96% on-time delivery and 99.5% quality.
Products offered by CryoCoax include cables, cable assemblies, attenuators, adaptors and connectors, including the award-winning solderless connector series and unique high-density connectors as well as a range of non-magnetic connectors and adaptors.
Click here to view accreditations of CryoCoax.
Click here to view cables and connectors from CryoCoax.
Click here to learn more about the use of cryogenic RF components.