MDA Space have announced a technology breakthrough for MDA AURORA, saying they have successfully performed digital beamforming with a Ka-band direct radiating array (DRA) using direct sampling, calling it a “first in the industry.”
SpaceQ corresponded with Guillaume Lamontagne, Chief Architect of the MDA Satellite Systems business area about the announcement and what it means for MDA AURORA.
MDA AURORA is a software-defined digital satellite product line: standardized satellites that use specialized chips (often Field Programmable Gate Arrays, or FPGAs) to provide “software-defined” capabilities instead of fixed ones. Lamontagne said that the AURORA satellites will “enable our customers…to gradually modify the configuration of the satellite via software uploads,” which will flexibly “reconfigure what the satellite is doing, where our beams are pointing, [and] where services are offered.”
Both GlobalStar and TeleSat Lightspeed will be using AURORA-based broadband satellites in their constellations, and Lamontagne said that “earlier this year, we also launched our AURORA D2D satellite product.”
Phased arrays and Ka-band beamforming
Key to many of these AURORA applications is communications based on phased array beamforming. Phased array beamforming is a familiar technology that is used for both terrestrial and space-based communications, using a large array of small transmitters to “beamform” signals by changing the transmitters’ phase and amplitude. By using these arrays, they can directly target a number of different points at the same time, allowing one transmitter to directly service a large number of receivers, without the power usage and heat generation issues that would be caused by broadcasting on a similar scale.
Lamontagne explained that the recent innovation is in the details: performing “direct sampling at the Ka-band frequency.” The Ka-band is the 27-40 gigahertz radar band, and is increasingly popular for allowing higher-bandwidth communication than other radar bands, like the 12-18 gigahertz Ku-band.
Digital beamforming using the Ka-band was possible in the past; but as Lamontagne explained, however, it usually involved “intermediate frequency conversion,” where you would need to convert the signal into a different intermediate frequency, then have receivers “use an analog-to-digital converter to sample that signal and do further processing.”
MDA Space overcame this problem, and demonstrated that they can send and receive Ka-band signals directly, without this extra layer of frequency conversion.
Lamontagne said the achievement involved overcoming several challenges. Iit required rethinking the ASICs (Application Specific Integrated Circuits) that perform the direct sampling; he said that “there’s a lot of careful design and architecture thinking that needs to happen” in order to ensure that there isn’t noise interference between the high-speed digital signals. He said that heat was also a concern; while their transmitter array “generates less heat than competing solutions,” it still generates enough heat that “there are challenges in being able to dissipate the heat properly.” This is an especially important challenge in the vacuum of space.
It required some work, but Lamontagne said that “we overcame all those challenges with a lot of innovation and design cycles that led to this demonstration.”
MDA said that the technology is being developed and demonstrated in a laboratory “at the company’s manufacturing facility in Montreal,” including “a DRA prototype that will ultimately be connected to an onboard processor (OBP) prototype to demonstrate the full communication chain between a gateway ground station and a user terminal.”
When asked, Lamontagne said that this is “only one of the steps,” and that it is part of a “larger development plan which is embedded into at least one constellation currently being built for customers,” and will “make it into orbit once this constellation is launched.” While this may refer to TeleSat Lightspeed, Lamontagne did not get into specifics on which company or which constellation he was referring to.
Potential key advantages
By switching to direct sampling, Lamontagne said that they open up a number of potential advantages.
The reduction in complexity, power consumption and cost “enables business cases for our customers,” Lamontage said, letting them “offer services at a more competitive price.” And even in terms of the DRA itself, the change “enables us to have a lot more radiating elements without compromising heat generation, power consumption or cost.” The direct sampling helps to create “beams that are more focused,” he said, “that establish a better link with the users on the ground, eventually giving the users a better quality of service.”
MDA also said that “MDA AURORA™ enables the DRA to deliver signals where they are needed and when they are needed, while maximizing the use of the satellite resources.”
Potential applications
In their news release, MDA said that MDA AURORA and its Ka-band DRAs signal a “breakthrough” in “satellite communication systems that support broadband connectivity and 5G networks,” adding that these capabilities are “particularly valuable for satellite operators seeking to support 5G networks and the growing demand for data-intensive services, where high-speed, low-latency connectivity is essential.”
When asked about whether these capabilities allow for direct-to-smartphone or Internet-of-Things (IoT) connections, Lamontagne said that AURORA and its beamforming capabilities can be used for a variety of different markets: the “business-to-business broadband market, 5G NTN (non-terrestrial network) markets for direct-to-device applications,” and for “Internet of Things applications,” among others.
These different applications function at different frequencies, Lamontagne said, but “the technology we develop is flexible in that regard…it can operate at multiple frequencies with some design changes [and is] scalable depending on the actual customer and user needs.”
In the release, Luigi Pozzebon, Vice-President of Satellite Systems at MDA Space, said that MDA AURORA is “a highly flexible and adaptable solution that can be tailored to meet each customer’s specific requirements”, and that the demonstration “is a critical step towards delivering those advanced capabilities that will help customers compete in the rapidly evolving satellite communications market.”
Lamontagne added that a key part of the research is ensuring MDA AURORA customers will enjoy “a solution that will help them be competitive” with “some major players in the industry,” including those “embarking in those large LEO constellations [including] direct-to-device constellations.” It will, he said, help their customers “address this market in the most cost-effective way.”
