Multipactor test system

Multipactor test system

Today’s technology requires more and more speed in data transfer (Internet, data streaming, etc.). Therefore, satellites need more and/or wider communication channels. At the same time, a higher transmission power is required to maintain the same signal-to-noise ratio.

RF components used in satellites must be able to withstand these so-called ‘multipactor’ effects. This is a phenomenon in radio frequency wave guide components that occurs when a charged particle in space hits the wall of a wave guide component. This charged particle, when it has enough energy, will free one or more electrons from the metal wave guide wall. The electric field in the wave guide (generated by the emitted RF power) will accelerate this electron until it in turn hits the other side, releasing more electrons. Under the right conditions, this will lead to exponential electron multiplication leading to severe damage or even destruction of the RF component.

Raditeq has successfully developed and delivered a second generation, Multi-Carrier, High Power, Microwave Test System for Multipactor testing. This system is used to test satellite components in the Ku band for their sensitivity to “multipactor” effects.

The Multi-Carrier Test System is based on the RadiCentre® modular test system, in combination with six (6) modulated, high power carriers of 400 Watts each.

A high power OMUX (multiplexer) is used to combine all six carriers into a single RF output.

In addition, special ‘nulling’ modules are used to control the phase angles between the 6 carriers within 3 degrees. This is required to achieve the maximum peak voltage when combining the 6 independent carriers.

The most challenging part of the system is that all phase angles must be measured and controlled, even when the carriers are modulated with complex signals.

The goal of the system is to generate and amplify an accurate Multi-Carrier signal to simulate real-life multipactor effects before launching the satellite into orbit. Thus, preventing unexpected satellite failures in space.