By Anne Wainscott-Sargent

Phased array antenna innovators gathered during Satellite 2021 to debate what makes a perfect antenna and the key design constraints that must be tackled before these antennas can achieve scale and deliver multi-orbit, affordable connectivity.

Traditionally viewed as high-end and costly systems that only the government programs could afford, electronically steerable antennas, or ESAs, are now one of the hottest areas of innovation thanks to the coming of LEO megaconstellations that require a more agile antenna.

So, what is a perfect antenna?

“The perfect antenna is the antenna that the customer uses but never thinks about, never worries about,” said NXTCOMM CTO Carl Novello during the Sept. 9 Satellite 2021 panel, Overcoming Design Constraints to Build the Perfect, Low-cost Antenna. He explained that there is never only one perfect antenna; it has to be deployed in mass and in scale, and above all be simple.

Keep it Simple

“There aren't virtually any antennas in a transmit-receive environment that are scaled to the millions. And until you have that millions’ dirt under your fingernails, how do you begin to define the perfect antenna? We need to do a better job as an industry of making things simple. Simple is perfect,” Novello said.

Key to defining the perfect antenna is also understanding the intended user – whether it’s a retail consumer, military user, first responder, or a cabin crew serving airline passengers, since “perfect means very different things in each one of those use cases,” he explained.

Paul Klassen, VP of Engineering for Kymeta, further defined simplicity as meaning “simple to manufacture, simple to calibrate, simple to optimize and simple to deploy,” while NexTenna CEO Dedi Haziza said to achieve true scale, you must be able to scale in both size and frequency.

“If you have common technology that allows you to scale in both dimensions, that will enable you to build the perfect antenna because you can really leverage your developments at every stage, and not have to start from scratch," said Haziza.

He said the key to enabling global LEO internet service is not just providing a low-cost terminal, but also providing the highest G/T, or power gain-to-system noise temperature, which translates to lower cost per bit per Hz per watt.

The Cost Factor

All agreed that the antenna’s cost is a critical factor, with Novello urging the audience to consider the role the industry, including operators who set the operational parameters and airtime costs for service, play in influencing the ultimate cost of antenna hardware.

“Nobody talks about the satellite capacity…the airtime…and the implications of that on the hardware,” he said. The panelists then addressed design constraints to building the perfect ESA. For Ball Aerospace, the key is to design from what’s already existing today.

Ryan Jennings, senior manager for SATCOM Strategy and Products at Ball Aerospace, noted that investments in 5G have had “a huge impact” on ESAs by leveraging technology advancements and economies of scale. “We’ll continue to see costs and power [requirements] go down based on investments in those technologies,” he said.

System Mindset

NXTCOMM’s Novello considers the biggest set of constraints at the system level – “Are we actually designing with a system in mind?” He noted that today’s RF engineers are not only expected to be experts in their field, but also must understand how the user and the satellite operator think and the ins and outs of the business model.

He disagreed with the idea that 5G innovations will be impactful in the near term to the satellite sector, noting that many 5G advances, from frequency range and noise figures have little pragmatic applicability to the satellite market at least today. He said the future for satcom is best served by building on 5G RFIC design innovation and building from there.

Kymeta’s Klassen said his company has solved the antenna challenge, and that their “real focus…is on the terminal.” Specifically, design constraints related to compatibility of the modem interfaces, which drives the overall design of the terminal.

“Calibration, optimization and testing are critical to making sure that you’re delivering a quality product and are paramount and solving that for mass production,” he said.

Scale first, then Standardize

On the question of standardization, the panelists debated whether the time is now to standardize around a common set of requirements for flat panels to help speed adoption. NexTenna’s chief executive argued the benefits of working with constellations and chipset companies to create a basic standard that could come from the likes of Google, Facebook, Qualcomm or a combination of those firms.

Novello said other industries didn’t embark on standardizing hardware until after the initial scaling of technology. “Otherwise, you kill innovation,” he said. “I don’t disagree that we as an industry need to standardize, I just disagree with when we do that.”

Need for One Voice

NXTCOMM's Carl Novello (center) talks to Satellite 2021 audience members after the panel. (Photo credit: Anne Wainscott-Sargent)

Novello suggested that antenna suppliers get together and identify as a group what the perfect antenna “ideal state” would be and come to a consensus on the “painful issues” facing antenna designers across the board.

“Then we start opening up – what can you do for us on the modem side? What can you do for us on the satellite side? We can speak with more of one voice,” he said, advising a “crawl, walk, run” approach that begins first with understanding that the industry has the problems right, and then working together to make sure that the common ones can be addressed before moving towards “a sensible, reasonable workable good standard.”

Yet by some accounts the industry is moving further away from common ground. Jennings of Ball Aerospace pointed to all the closed managed service networks. “Everyone is doing their own thing.” He cited as an example, how modem interfaces are completely different and use different frequency bands.

“It makes our jobs really hard. It just drives costs. I think a lot of satellite operators don't think that far ahead. They're thinking about the space segment all the time and how do I manage that cost? But if you can't make a cost-effective terminal to work on…they really drive us to do things that are hard, are expensive and not advantageous for their own business case,” he said.

“What's missing in the whole satellite industry is a standard modem,” said Haziza, noting that without a standard modem, there is no way to interface with SpaceX “because they have their own.” OneWeb also will soon have their own modem. “That piece – that standardization -- will allow you to do whatever you want on the other parts of the terminal,” he said.

The concept of establishing a flat panel antenna alliance resonated with panel moderator Whitney Lohmeyer, who leads the Olin Satellite + Spectrum Technology & Policy (OSSTP) Group, focused on developing satellite communications technology and spectrum policy. She asked the group which companies they would want at the table.

Kymeta’s Klassen said service providers will need to be part of the conversation, especially given how vertically integrated they are becoming. “I think they’re going to have some challenges in their future. Coming together is the way to go about it.”