After many years of predictability, the satellite communications industry is in the midst of a transformation. New players to the arena are driving a huge increase in satellite numbers, with lower earth orbit (LEO) constellations mostly responsible. LEO delivers a fresh perspective on satcom; its low latency and low cost opens many new opportunities. We´re seeing a massive increase of users of satellite communications, at costs that rival terrestrial networks. This drives economic growth in all regions of the world and even has potential to shape the geopolitical race between nations.

Changes on the ground to accommodate LEO

The rise of LEO is driving significant changes in the ground networks. If once a few large ground stations were enough, now one needs a multitude of smaller stations and a larger spread of access points across the world. On the user terminal side, to drive significant user adoption, the terminals must be cheaper and more user friendly. And here the Flat Panel and Electronically Steerable Antennas (FPAs and ESAs) are presenting an opportunity for rapid deployment, and rapid commercialization of LEO networks. Primary drivers being the low profile and low maintenance compared to a parabolic solution. The low profile allows easy integration on roofs, vehicles, or in general a quick deployment in the field. And the low maintenance relates to both ease of installation--plug and play, and almost no mechanical wear. So, in general, FPA is an ingredient in the massive adoption of new users, but at the same time it really gives a challenge to whole industry on how to effectively deploy such networks. 

Indeed, the challenge with LEO lies in its scale. Due to its low altitude, more satellites are needed to ensure continuous coverage. LEO satellites are only visible for short periods of time and appear to move across the sky, meaning that antennas must track their path and hand them over to the next antenna in the network. This is a hugely complex task and has resulted in a huge shake up at the ground segment. ESAs, which utilise phased array technology, utilise multiple antennas to create a high-gain beam which can be electronically steered to point in different directions without having to move the terminal, making them perfect for tracking LEO satellites. Terminals are designed to connect to multiple satellites at once, meaning that they can also be utilised for multi-orbit services, in which users benefit from the capabilities of LEO, MEO, and GEO at the same time. All in all, a great fit, if one closes an eye the downside of antenna performance change with angle and its effect on overall levels of interference. The physics of these antennas makes it so that the antenna performance changes depending on their “looking” angle. A parabolic antenna would generally maintain the radiation pattern and the overall gains (with some effect from ground on low elevation), regardless of the pointing angle. But the ESA antenna would degrade the further away the beam points from its nominal angle. This degradation involves an increase antenna beamwidth, a reduction in the G/T (gain over temperature) and in EIRP, essentially providing a regulatory challenge due to increase in interference as well as a degradation in the total throughput at lower angles. 

Is the industry ready for FPAs?

The commercialisation of FPAs has been rapid, and this trend is expected to continue, with the market estimated to register a CAGR of over 31% between 2024 and 2032. However, questions can be raised if this technology have reached an acceptable deployment momentum. 

There are a number of elements that are making this challenging right now. For one thing, LEO satellites are still very much on the way. While the numbers seem high, it is nothing compared to what is predicted in the future. Starlink is already successful, but its ESA technology is largely behind closed doors and is known to benefit from the large number of satellites deployed, making it so that the antennas do not need to track at low elevation angle, as there is always a satellite above. Other networks rely on a smaller number of satellites and there is where the challenge of performance arises. Furthermore, without many users, the new players face a scalability challenge, as the price of manufacturing can only decrease if there is a significant increase in sales. 

This is set to change and will likely change fast, but in the meantime, manufacturers are waiting for their biggest target customers to be ready. With a huge swathe of that customer base not ready, it is hard for manufacturers to get the appropriate feedback to ensure product readiness. This is also making it more or less impossible for regulators to generate standards and regulations as they need use cases and test data that is simply not available yet.

The FPA battleground

For Flat Panel Antenna manufacturers, the battle lines are being drawn. There are multiple different types of FPAs, using different technologies. As the market continues to grow, it remains to be seen whether all of the different types will survive or which technology will ultimately win. 

Meanwhile competition is increasing and the manufacturers that hope to be successful in this arena will need to create the most user-friendly antenna, with seamless integration and all at a reasonable price point. And this cost factor is a huge challenge. As the industry puts more and more pressure on manufacturers to keep prices down, how much will be lost in performance and how can we ensure we remain interference free?

The satcom industry is well aware of the impact low quality antennas can have on a ground segment. As an industry, we know all too well the challenges surrounding RF interference (RFI). Many lessons were learnt as we saw the number of parabolic antennas increase. Common reasons for RFI were identified, with poor quality equipment, alongside human error and mis-pointing, often the cause.

The developed of accepted performance and industry wide test procedure is not yet ready for ESA. There are known groups that are working on this challenge, particularly GSOA and SIG, who are attempting to connect the industry together on a common consensus on what should be acceptable. Their efforts, if successful, will allow the industry to move a step closer to a streamlined commercialization. The question though is still coming from both sides: what will the operators accept? And what can the manufacturers bring to the table? This two-sided approach reminds of the chicken and egg problem, and the likes of GSOA and SIG are really trying to put everyone at the same table to face the hard thing so that ultimately the industry can flourish. 

How testing can deliver competitive advantage

The creation of industry-acknowledged testing processes for FPAs benefit both the operators as they will know what to ask for and the manufacturers, which will know what to build and how to demonstrate performance. Having a common test procedure and the same way of looking at the results will be a way to know where the industry is and be able to compare different technologies with the same view, same as comparing apples. 

As of now, operators are not insisting on test procedures but if there were products that they knew to perform better than others, it might make them more inclined to guide their customers to using those. And of course, the customers themselves would potentially favour a well-performing product over others given the data to back that up. For manufacturers this means that they need to be creative on how they can position themselves in the market, and with what means they demonstrate their products.  

Testing a product within its own working environment is the only way to ascertain its true performance. This has long been a challenge within satcom, with traditional means of testing somewhat lacking when it comes to the complexities of this new technologies. Testing using drones is now enabling in-situ testing of antennas, allowing manufacturers to create their own dedicated and controlled test environment. It also allows them to do both a standard RF performance check, combined with a versatile dynamic satellite emulation, which when paired together gives you a much fuller picture of performance than previously possible. This type of testing ensures readiness for scalability by making products before constellations are ready, giving a huge competitive advantage in the time to market. 

Ensuring competitive edge and sustainability of spectrum
As an industry we need to ensure the long-term sustainability of spectrum to for the benefit of the entire ecosystem. Those well-performing products that can prove performance levels will gain a competitive edge, as will potentially those operators who keep their networks as error-free as possible.

The only way to ensure the sustainability of spectrum is to ensure that all parties utilizing RF signals are accountable. A coordinated approach must be agreed, not only to safeguard the environment, but to ensure a commercial level playing field. In-field testing must be integral to this approach in order to provide accurate readings. As we see the ground segment grow in complexity, it is likely that terminals could impact one another. Understanding an antenna’s true performance has never been as important as now. As business models grow in complexity, so does the risk of inefficiency. Testing will play an integral role in maintaining a ground segment capable of delivering to the demands of newspace.