“Standard SMA connectors are used worldwide in a variety of applications in large quantities due to their small size and light weight. Therefore, they are also preferred in space telecom missions,” explains Mr. David Raboso, Technical officer for this ESA ARTES 5 contract. “However, this type of connector has serious limitations in terms of RF power handling due to the internal air gap, among other design characteristics. In a low-pressure or vacuum environment these air gaps can lead to corona discharge and multipactor effects.”
The requirements for cables and connectors in space-flight applications of low weight and high power handling capabilities are becoming harder to meet. Also low Passive Intermodulation (PIM) performance is important as future satellites will be using multicarrier technology more often, explains Mr. Raboso. This forces industry to optimise the connectors even further.
“A feasibility study and a thorough modelling and simulation resulted in a trustworthy design of the PSM connector,” says Mr. Raboso.
The feasibility study was followed by the building of a prototype to conduct an extensive test campaign. Recent high power tests carried out at the joint ESA-VSC high power RF laboratory in Valencia (ES) at 438 MHz, showed that the PSM connectors withstand 1500 watts which implies an improvement of 50 per cent compared to other powerful connectors such as TNC.
Another test conducted at 1124 MHz showed the connectors could withstand 1500 watts (pulsed). Using CW signals (power handling tests) the lab managed to go at least up to 100 watts at this same frequency.
“The very promising test results of the new PSM connector prototype show the feasibility of a small and low-weight connector for high power handling and low PIM,” says Mr. Raboso.
The PSM connector is fully optimised with regard to corona, multipactor and PIM effects as well as thermal power dissipation. It will offer massive weight and cost savings for future space telecom missions. Corona tests were run to at least 60 watts with no problems. Patents for the connector are pending.
The project is planned to be completed with a second design step comprising the product development and the space qualification of the PSM connector. Industry partners involved in this project are HUBER+SUHNER AG (Switzerland), EPFL-LEMA (Switzerland), and IHF TU Darmstadt (Germany).
"We appreciate the opportunity to participate in the ARTES program and the very helpful guidance by the technical officer," says Dr. Karstensen of HUBER+SUHNER AG. "The excellent collaboration between ESA, Ecole Polytechnique Federale Lausanne, Technical University Darmstadt and us, combining the individual strengths and competencies of the partners, has resulted in a new connector design with outstanding high-power capabilities."
For more information, see the contact link located in the column on the right side of this page. For further information regarding ARTES 5, see the links located in the column to the right.