Announcements
Non magnetic RF coaxial connectors
Non magnetic coaxial connectors are used primarily inside MRI medical equipment
MRI medical equipment consist of a computer, a large magnet that surrounds the patient, and RF coils. The magnet creates a strong uniform static magnetic field (0.3 - 7 Tesla) in a chamber where the patients lie.
The quality of the picture depends above all on the homogeneity of the magnetic field and on the signal noise ratio. So, any connector located in the magnetic field, should be transparent relative to the field, that means its relative permittivity should be equal to 1.
With standard connectors, when an external magnetic field is applied, a magnetization appears inside the connector. This magnetization generates a disturbing field, thus the quality of the picture is poor and many corrections have to be made.
There are so-called "non magnetic" coaxial connectors that use non magnetic materials as brass, gold, silver or bronze and avoid the use of materials like stainless steel or nickel plating. This type of connectors has not a sufficient non magnetism level when the connexion takes placeinside the magnetic field.
Product characteristics
Our connectors are chosen to be implemented in these coils because they are manufactured with materials specially adapted to non magnetism(with µr relative permittivity close to 1), each rod being selected based on a direct measurement with a vibrant magnetometer.
Center contacts are gold plated over a copper underplate and bodies are plated with BBR, diamagnetic alloy of copper-stain-zinc or with GBR, diamagnetic alloy of copper-stain-zinc with a gold strike.
Manufacturing a Radiall non magnetic connector involves a special production, led in an appropriate environment where tools are located and where all precautions are taken to avoid any contact with ferromagnetic materials during the screw machining and cleaning process.
This technology is applicable to almost all our coaxial connectors series and is already available for SMB,MMCX and SMA series
Non magnetic connectors for space applications
The medical market is not the only one to use non magnetic connectors.
There are also used in specific space environment,mainly for satellites involved in scientific missions.
In this type of environment, another data is essential: the compliance with ESA/SCC specification is needed to become supplier.
Radiall has a range of SMA products, fully ESA qualified, that meets the residual magnetism required by the ESCC 3402 generic specification and the ESCC 3402/001-002 and 003 detailed specifications, connectors are made in Beryllium copper, Gold plated, Copper underplated.