Satellite Communications Operations

Satellite Communications will pertain to the “ground” segment of the communications network. Since the ground segment market is located on the ground and not in space, the reliability assurance requirements are very different. However, the application and network reliability are still paramount to the market and the user community involved in satellite communications.

Satellite communications find its applications in the following areas:

1. Radio broadcasting.
2. TV broadcasting such as Direct-to-Home (DTH).
3. Internet applications such as providing a connection for data transfer, GPS applications, internet surfing, etc.
4. Voice communications.
5. Research and development sensor telemetry.
6. Military applications and navigations.

The ground segment of the satellite communications industry covers many different market applications. Some markets deal with data transmission and are typically small aperture (small antenna realization) configurations. Other applications for TV broadcasting or lower frequency networks will have very large antenna structures (earth-stations).

For most of these applications the drivers for reliability testing are:

1. Overall cost of the satellite network demands high probability of success.
2. Maintenance cost (down-time) leads to lost revenue since most ground segment is leased or pay-per-use market.
3. Maintenance cost for repair/replacement of expensive subsystems.
4. System return-on-investment (ROI) plans are usually “long-life” expectations (>>10 years of service).
5. Maintenance is not easy to accomplish due to remote location of the system.
6. Performance degradation with age drives maintenance service costs and lower ROI.

Accel-RF has extensive experience testing GaN devices for use in space and many other applications. Turnkey, customized solutions offer a proven way to move forward boldly with designs with the confidence that performance and reliability will meet the mission requirements.

A single test doesn’t exist that will ensure satellite components will do the job as intended. Different application requirements place parts in wildly varying conditions.

Test facilitators must design tests that approximate the conditions of space and understand how to analyze the data obtained to know what adjustments to make. For GaN to operate in this arena successfully and reliably, qualification must occur at several points along the product life cycle.

1. Intrinsic reliability: Before a device can be added to the Bill of Materials for a module earmarked for a satellite, the expected lifetime must be quantified to ensure it will operate well beyond the expected mission life. This is typically accomplished through Accelerated Life Testing, which can provide valuable lifetime estimates in a reasonable period of time. Results and physical and chemical analysis of the feedback of the tested device to the process engineers to fine-tune and improve the reliability of future lots until a formula suitable for space is finalized.
2. Device-level quality: Once production begins, manufacturers rely on burn-in testing to weed out defective parts from the population. Analyzing data from burn-in trials helps determine what adjustments can be made on higher-level assemblies in order to improve yield.
3. Application-specific operating life: System integrators benefit from testing that places the device under the exact conditions expected when in-use. This can include using the planned modulation scheme for communications satellites or even involve subjecting the part to environmental factors, such as extreme temperature or radiation.

Testing at just one point on the supply chain will not provide confidence in the reliability necessary for these operations. Space program officials and vendors have begun moving toward a coordinated understanding of what is needed to fully qualify the use of GaN devices in space.

Accel-RF designs solutions for any phase of the development process. Accel-RF engineers have planned the entire line of testing solutions to work together or to integrate with existing equipment.

The Automated Accelerated Reliability Test Set is the industry standard for performing intrinsic reliability analysis through accelerated life testing. Its modularity also allows true application-specific operating life testing to be performed on devices intended for space applications. The RF-Biased Burn-In System supports testing a large quantity of devices at once to screen out potential early failures that would be unacceptable in a satellite.

The modular design of the equipment makes it easy to customize to fit the application. Test labs can retrofit existing setups instead of configuring entirely new testbeds for each device. Setting up different test environments in the same space quickly and cost-effectively is a huge advantage and time saver.

Accel-RF has worked with the European Space Agency (ESA) to provide testing solutions for that agency’s advanced Earth environmental studies. They understand the complexities and pressures of successful space operations. Every device in every component in every system must function flawlessly for the program to meet its goals. The only way to achieve this level of performance is through rigorous testing programs that provide accurate statistical data. That data must be correctly interpreted and in a format that is easy to share up and down the supply chain.

Accel-RF believes in partnering with the customers it serves. Its experts understand every aspect of reliability testing at each phase of a project. They help customers understand what they need to test, perform the test in the best way, and correctly interpret the resulting data.

Accel-RF doesn’t just sell testing equipment and leave you on your own to learn how to use it. The engineers at Accel-RF view themselves as educators whose job it is to help solve problems. They pride themselves in explaining each necessary step in the process in a way that everyone understands. They believe it is essential for everyone to know what tests are needed and why they are required.

When performance goals are extreme like they are in space operations, that sort of teamwork and dedication to customer success can easily spell the difference between failure and mission accomplished.