Vacuum Applications for SMA Feedthroughs

SMA feedthroughs are constructed using a basic coaxial configuration and are perfect for high-frequency signal transmission applications like microwave and radio communications systems.

SMA coaxial feedthroughs excel in high and ultra-high vacuum (HV/UHV) systems due to their low electrical impedance (50Ω) and low noise capacities.

While vacuum feedthrough connectors fulfill various functions in HV/UHV applications, they must first adhere to several key requirements. The connector must be guarded from electromagnetic interference and must be hermetically sealed.

In the construction of the feedthrough, the materials used must be rated for superior performance in extreme temperatures (as low as the cryogenic regime) and vacuum compatibility. The part should also allow for signal transmission at the frequencies required in the system.

Vacuum Applications for SMA Feedthroughs

Allectra creates and provides SMA feedthroughs that excel in these main requirements for efficacy. For high-frequency signal processes in HV/UHV environments, Allectra’s high vacuum coaxial feedthroughs are the ideal solution.

What is an SMA Feedthrough?

Also called subminiature version A connectors, SMA feedthroughs were initially created in the 1960s, integrating a minimalistic screw-type interface with a coaxial cable.

With a single thread coupling and low electrical impedance, SMA connectors were the ideal choice for antenna connections because of their inherent compatibility with radiofrequency.

SMA feedthroughs are most effective for signals in the range of DC to around 18 gigahertz (GHz) and are mainly used for signal processing in this bandwidth in HV/UHV applications.

The robust physical construction of SMA feedthroughs empowers their electronic performance, consisting of high durability metal units in either floating or grounded designs.

SMA Feedthroughs from Allectra

A range of SMA coaxial feedthroughs for high-frequency signal transmission in vacuum conditions are provided by Allectra. The main product ranges are the 242-SMAD27G, the 242-SMA-D18G, and the 242-SMA 50, available with various configurations to meet the exact requirements of the end-user.

Beginning with the 242-SMA 50, this line of miniature coaxial connectors provides frequency ratings from DC to 6.5 GHz and offers accurate 50 Ω impedance. The range includes both single- and double-sided configurations, with floating or grounded shield variations with up to four male connectors fixed onto a single flange as standard.

For example, the 242-SMADF50-C40, is a floating shield, double-sided connector for up to 6.5 GHz. Whereas the 242-SMA D18G C40-4 has four double-sided high-frequency SMA connectors on one flange for up to 18 GHz.

The latest 242-SMAD27G uses SuperSMA technology to provide an exceptional 27 GHz frequency with lowest signal damping.

Double-sided connectors are beneficial because the feedthrough can be secured directly to a regular Allectra in-vacuum cable from the 380-SMA product line.

The superior manufacturing abilities of Allectra means that the amount of SMA connectors on one flange can be increased or combined with Allectra’s range of Sub-D feedthroughs for example.

This information has been sourced, reviewed and adapted from materials provided by Allectra Limited.

For more information on this source, please visit Allectra Limited.


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