Embracing the New Space Age: Overcoming Multipaction

The move from a small group of manufacturers producing satellites for the government to the emergence of a large ecosystem of new space manufacturers who want to move at “commercial speeds” has challenged the Space industry and the electronic component suppliers who support them. Among these challenges is the influx of engineers and designers who are new to the unique demands that space places on electronic systems.

Leveraging Decades of Experience

NASA and other similar organizations have accumulated a body of knowledge which is made available to designers, however being unaware of potential challenges makes it impossible to design for them. Decades of Aptiv's experience and flight heritage across the entire interconnect portfolio becomes an invaluable resource for engineers designing new Space interconnect systems. The experience of engineers who have been part of deep space missions, GEO satellite designs and complex harnesses for a variety of launch platforms is an unparalleled resource for designers.

Aptiv's engineers have dealt with many of the unique challenges of designing electronics for Space, including multipaction, derating and temperature extremes. In this blog post, we’ll take a deeper look into the risks and challenges of multipaction and how Aptiv engineers work to mitigate its negative effects on space electronics.

Understanding Multipaction

Multipaction is a phenomenon that typically arises in high-power RF microwave transmission systems, including devices such as amplifiers, antennas, coaxial cables and connectors, operating in a high vacuum environment. Space communication systems and earth observation systems are examples of vacuum electronic systems that can be susceptible to multipaction.

What is Multipaction?

Multipaction occurs when electrons emit from a surface and subsequently accelerate by the electric field. If these electrons strike the surface again, they can cause secondary electron emission, creating a cascade effect. When factors such as gaps between conductors, internal geometry, and frequency exist to support a resonance, an electron avalanche condition occurs. Multiplication is a concern for nearly any high power application deployed at high altitude and vacuum, especially in space related applications in so-called Earth Observation systems.

Risks Associated with Multipaction

In orbit, the risks associated with multipaction are magnified due to extreme conditions, long mission durations, and the inability to perform repairs. Multipaction can lead to electron avalanches within the device, resulting in destructive pressure buildup during discharge, leading to reduced efficiency, degraded performance, and even catastrophic failure of the microwave device.

Mitigating Multipaction Effects

To mitigate the effects of multipaction, Aptiv engineers utilize various techniques such as careful design of the internal geometry, surface treatment to reduce electron emission, venting, and the use of specialized materials with low secondary electron emission properties.

Aptiv's comprehensive approach includes vetting materials for their performance and reliability in vacuum electronics, developing testing procedures to replicate space communication environments, and improving simulation models that accurately model resonant cavity multipaction effects and dielectric breakdown. This approach helps Aptiv effectively collaborate with design engineers to address multipaction concerns.

Simulation and Testing Techniques

Modeling a space electronics system is often performed using tools like Ansys HFSS. Aptiv engineers work closely with designers to simulate the critical elements of the electronics. We minimize assumptions to ensure that simulations accurately reflect the actual materials and geometries, making them more effective. Aptiv engineers incorporate best practices and well established design principles to limit the potential for electron avalanches to occur.

We then validate simulations using state-of-the-art testing techniques. Test chambers, in conjunction with network analyzers, high power amplifiers and multipaction test benches are all employed to ensure the predicted performance of Aptiv's models accurately reflect what occurs in the real world. Aptiv engineers work closely with designers to demonstrate and validate the performance of the connection system. As Aptiv Engineers say, “Actual testing is key.”

Ensuring Mission Success

Appropriate material selection, highly accurate modeling, and rigorous system testing mitigates multipaction and corona effects in high power RF in vacuum electronics. This maximizes system performance and provides the greatest assurance that the connection system will meet or exceed the mission requirements.

Paving the Way for Future Innovations

As the space industry continues to evolve, Aptiv remains at the forefront, leveraging decades of experience and expertise to support the new wave of space manufacturers. Our commitment to excellence ensures that we are not only meeting the current challenges but also paving the way for future innovations in space electronics.