Podcast: Ken Buer on phased array antennas

How the technology and a growing global network position Viasat for the future


In this episode of the Viasat Podcast, host Alex Miller talks with Ken Buer, chief technical officer for our Viasat Arizona office, about phased array antenna technology and the shift to Commercial Satellite Internet (CSI) applications. As Buer explains, CSI is a pivot away from purpose-built satellites, such as those created by the U.S. Government, to a model where commercial satellite operators such as Viasat provide a more economical solution that also affords customers the latest, updated technology and a global network. He also details how phased array antennas with beam-forming capabilities will be key to realizing the most benefit out of CSI.

Topics discussed in this podcast episode:

  • CSI improvements via a new generation of phased array antennas, which have the ability to electronically form beams to work with multiple satellites as well as for moving objects such as planes, ships and trains
  • How several locations within Viasat are collaborating on phased array antenna designs aimed at improving their performance as well as reducing their cost
  • How flat-panel phased array antennas can be ideal for things such as fighter aircraft, where the ability to move the antenna quickly is vital and the low-profile design reduces drag
  • Viasat’s vertically integrated model and how Buer, as a system designer, says it give him the freedom to better optimizing how software is integrated with hardware
  • The company’s ability to provide end-to-end security and capability

Listen to the podcast


Alex Miller: Hello and welcome to the Viasat podcast. I’m Alex Miller with the editorial team and in this episode, we’re speaking with Ken Buer, Chief Technical Officer for our Viasat office in Tempe. The topic is about some pretty interesting technology on the commercial satellite internet side and how it aligns with the needs of our customers, both in the commercial sector, as well as with defense agencies in the US and among our allies. This is set against the backdrop of our upcoming satellite constellation, ViaSat-3, which will offer global coverage and an unprecedented amount of capacity to serve these and other customers. So, Ken, thanks for being on the podcast. You’re a first timer, so welcome.

Ken Buer: Hi. Good to be here.

Alex Miller: You just told me you’re coming at us from, you’re in Tennessee somewhere, right?

Ken Buer: Right. Yeah. Up in the Smoky Mountains in Eastern Tennessee.

Alex Miller: All right. That’s great. First off, I wanted to ask if you could describe your role at Viasat here just a little bit, your background and what you’re typically working on here and with the team in Tempe.

Ken Buer: Yeah, sure. My background is mostly RF and microwave and started probably 30 years ago doing integrated circuit design, module design, and then worked my way up the chain into subsystem design, and even full payload and system design like we’re doing now for ViaSat-3, ViaSat-4. I spend a lot of time nowadays working on our advanced satellite systems and thinking about what we’re going to do next after ViaSat-3, after ViaSat-4.

Alex Miller: Wow. That sounds like some pretty intense work. You’re right at the at the epicenter of what Viasat’s up to on the satellite realm.

Ken Buer: It’s a lot of fun.

Alex Miller: We know that the satellite communications ecosystem is ever changing, but the area of Commercial Satellite Internet, sometimes called CSI, is particularly interesting, giving the move away from purpose-built satellites like the Department of Defense here in the US is known for. Can you touch on some of the key points about why this is the case and some of the changes that we’re seeing?

Ken Buer: Yeah, sure. Just like everyone else, the DOD has exponential growth in the amount of data that they need and the data communication that they have to support. Since they operate on a global scale, they also need to be able to move around. And SATCOM has to be a central part of that strategy on how to solve that problem. In the past, some DOD has had a lot of purpose-built satellites and most of the time that was to fill some niche missions that no commercial equivalent existed. But, over time, they’re not able to keep up with the demand growth. So, what they need to do is augment that with commercial systems and the technology cross-over point, I think has been reached in commercial SATCOM where it’s not being driven by the government anymore or government research in government niche markets. It’s really been driven by the commercial side and economies of scale that come with huge amounts of commercial SATCOM data so the Defense Department and other government customers can now take advantage of that, and they don’t need their purpose-built satellites for every single mission. That crossover points been happening in SATCOM and I think it’s accelerating.

Alex Miller: It’s something we’ve talked a lot about with some of the different guests on the podcast and also in our corporate blog, because there’s a lot of interesting things going on that really opens up a lot of opportunities, not just for the for the government, but some of our commercial customers as well. If we could, let’s dive a little deeper into some of the technology itself, which some of this what we’re talking about involves multiple bands, multiple beams and even satellites in different orbits, and how a new generation of what are called phased array antennas can really make this happen. Can you sketch out a little bit about what that looks like and a little bit about how a phased array antenna works?

Ken Buer: A phased array antenna is really a whole bunch of really small antennas, and that’s where the array part of it comes into effect. It’s basically hundreds or thousands of small antennas that get added up to become a larger antenna. We use sort of time and phase delay to maximize SNR (signal to noise ration) of a signal in a particular direction of interest. We call that process beamforming, because it gives us a high gain antenna in a single direction from a whole bunch of really low gain antennas that you add up. By changing the way we add them up, the phases of time delays, we can steer that beam around. We can also electronically hop it instantly from one part of the sky to a different part of the sky and that’s really useful. The other thing we can do is use the beamforming process to minimize interference that may be coming from a different direction than the signal of interest. That helps us become immune to some of the jamming or just other interference and noise sources that might be out there in the military EMI environment.

Ken Buer: The other thing you can do with a phased array because you have all these degrees of freedom to add up the elements and the individual element antennas in different ways. You can make multiple beams and you can set up another set of summation that forms a beam in a different direction and through superposition, you end up using the hardware essentially to form many beams or, at least several beams. That’s just something that you can’t do with more traditional antennas, because a mechanically steered antenna takes a certain amount of time to move from one part of the sky to another and you certainly can’t point to different directions at once with a mechanical piece of hardware. Phased arrays can do things that other antennas can’t do and they also happen to be low profile, so that’s necessary in some applications where you have aerodynamic concerns or just height concerns on vehicles or things like that. There’s just a lot of things you can do with phased array technology that you couldn’t do with standard antennas, and that’s why they’re of interest.

Alex Miller: Is this similar to a lot of other technologies where as it gets more, as technology matures, that they get smaller?

Ken Buer: They certainly get better performance as time goes on and that can mean that the aperture is reduced in size, or you can use that improved performance just to get better SNRs or get higher gain antenna. There’s different ways you can use the advance in technology. One of those ways would be to make it smaller. The biggest one and sort of the biggest hurdle for phased arrays in the past has been cost. By taking advantage of technology advances, we’re able to reduce the cost to make some of these arrays affordable in applications that just wouldn’t have been affordable even a few years ago.

Alex Miller: Right. I know our office in Switzerland is working on some of this phased array technology. Is it also some of that going on in Tempe or Duluth or here in the US?

Ken Buer: Yeah, we’re working cooperatively across a lot of sites in Tempe, Arizona, we do a lot of customized C-design. Since these these phased arrays are very intense on the customized C front, we do a lot of that design in Arizona. The actual antenna design is done in Switzerland, and then our Atlanta group does some final assembly test certification, fitting it on aircraft, things like that. It’s a pretty big cooperative effort across a lot of different groups inside Viasat.

Alex Miller: Yeah, that makes a lot of sense, especially when you think about how vertically integrated we are that there’s different parts of the company that can kind of pitch in on one big project like this. We can see a lot of benefits of this type of antenna in many applications, but for the military, that kind of flexibility seems like it carries a lot of weight. What’s changing that makes the paradigm for this new tech so dynamic today and in the next few years?

Ken Buer: Military has been using phased arrays for a long time and mostly in radar systems, places where they need to be able to hop beams across the sky really quickly. But, they’ve been really expensive, hundreds of millions of dollars in a lot of cases. They were traditionally made from gas or gallium arsenide and gallium nitride technology that building the elements was a whole RF module or whole radio build essentially in and of itself. You have to have thousands of those, or at least hundreds of those to build the array and it got really expensive, large power intensive. Even with all of that, cost was the main barrier to widespread usage, especially in communications. And so we’re hitting another one of these technology crossover points where the commercial market is driving technology to start to eclipse the DOD, both in terms of cost and performance, and a large reason for that is that we’re moving to silicon based technology, and everyone knows silicon wafers and silicon chip technology is very widespread in consumer products, it’s very widespread in pretty much all products, but it’s set up for really high volume and low cost applications. So that’s nice. The other thing it has going for it is that you can integrate a lot more functions, digital functions along with RF functions on the same chip, which makes the overall end to phased array can be a lot smaller, can be a lot more power efficient and certainly a lot easier to assemble. That makes it a lot lower cost even if the chip technology weren’t already cheaper. Just the fact that you can do all this integration of single IC is super helpful in being able to build something at scale that has a lot of electronics in it.

Alex Miller: Yeah. When you think about a fleet of aircraft like the military has, you can see how advantageous it would be to have these kinds of antennas on pretty much everything. Is that the direction they’re going?

Ken Buer: Yeah. I think the places where phased arrays make most sense or are those places where the features of a phased array can be used most effectively and are needed most and are most valuable. On fighter aircraft, for example, the low profile is really advantageous. The ability to move the antenna quickly is really advantageous. Everyone knows, even though some of these military platforms are very expensive, it’s not going to help to add a very expensive antenna onto an already very expensive platform. They do have to be cost-conscious as well as having all these other requirements that are very tough to meet. I think our approach is to make those requirements a design constraint rather than a building and sort of a build and process control problem. What I mean by that is a lot of phased array manufacturers in the past have relied on very difficult, expensive and device physics intense solutions that sort of require very, they end up being very expensive because the technology behind them is hard to build, has to be really tightly controlled, has to be tuned, has to be perfect, and that makes them very expensive. In our case, we’re using silicon technology that is really made for volume and we’re turning some of these other military requirements, such as the electromagnetic environment and some of the other features that we need to have for these military arrays, we’re making those design parameters. We’re designing in the ability to do automated digital alignment instead of manufacture, tuning and test. It’s really moving from what I think of as 1980s or 1970s technology into the state of the art world of system on chip and very highly integrated RF electronics.

Alex Miller: It’s interesting, I was talking to Craig Miller, who heads up government systems here at Viasat. He was talking about some of these networks that use a lot of different pieces that come together and how the military is really trying to pull those together into a unified network and talked about how Viasat sort of ideally suited to pull together those elements into that unified system. How do you see that applying to these SATCOM ecosystems on the defense side?

Ken Buer: I think Craig’s right. We have a robust defense business. We know what they need. We know their unique requirements, we know their constraints. On the other side, we have a thriving and rapidly growing commercial business that drives innovation, drives operational efficiency, as well as economies of scale. We have a global reach through our satellite network. We’re positioned really well to come in and solve some of these problems that have been pretty tough to solve for the military customers for a long time. In addition to that, we have staff that sort of move back and forth between the government and commercial side. Being able to seamlessly move people from commercial to government projects gives us the ability to sort of cross fertilize those two markets. That means that the people that are working on state of the art government projects have a good background and understanding of what we’re doing on the commercial side and being able to leverage that technology really well. I think we’re positioned to take advantage of this inflection point where not only in the way that we see the technology, but also in the way that the company is organized, structured and using our staff experience and culture to make that happen. I think a lot of people miss the importance of having both a really robust commercial business and a really robust government business because the advantages of being able to move technology learnings back and forth between those two markets is, really powerful and, and Viasat can do that really well because our businesses are so well balanced.

Alex Miller: That leads me to my next question was just about that vertical integration where Viasat’s a company that has come to be making its own satellite payloads all the way down to the modems at the other end and the terminals, the antennas in the middle. It’s different from a lot of how satellite companies used to work, where they kind of just buy things from a lot of different places. How does that look from your vantage point that vertical integration.

Ken Buer: As a system designer, I think the vertical integration gives me a lot more degrees of freedom. The ability to do trades between what things get implemented in hardware, what things get implemented in software, what happens on the space side, what happens on the ground side of a system even dividing up functionality between a central gateway location or distributed to a whole bunch of user terminals and even into the service plans we offer. There’s a lot of degrees of freedom that we have available to us when we design this and optimize the system that individual component suppliers or even system or subsystem suppliers like people that build satellites but don’t operate the system, don’t know what the right trades are to make. That’s a really powerful thing and it allows us to sort of remove some of these traditional interface barriers where you’re building to some standard interface. Whether that interface made sense 20 or 30 years ago really may or may not make sense today. Without those barriers in place, we’re able to move faster. We’re able to be more innovative, more efficient, and ultimately offer better service to our customers without having to expend more resources to get there. That’s a really important thing because as SATCOM moves into the commercial market more mainstream, we end up having to be really efficient or we’re going to get priced out of the market. It’s really important to make the right trades and to stay flexible enough that we can adapt to future needs.

Alex Miller: Yeah, it makes a lot of sense. Thinking about Viasat as a supplier to government, it was actually 36 years ago that was how the company started out was providing, I can’t remember what the product was. Was it modems? I don’t think you were around then.

Ken Buer: It was a UHF modem I think.

Alex Miller: Okay. That history goes way back. I know we have a lot of veterans here at Viasat and we pride ourselves on being able to kind of speak that language. How important is that kind of relationship as we look at all of these changes on the horizon?

Ken Buer: Well, I think it’s really important. I mentioned before with this ability to move both people, knowledge, and our R&D that we can apply to both sides of the business. R&D that we can do that we can apply to both government and commercial applications is twice as valuable as a company that does R&D for just one of those two things. We try to set up our R&D to be able to be very applicable to both the commercial market and the defense market. That’s a big, powerful thing. I think a lot of people underestimate that because as one example, our competitors might be able to offer a phased array antenna or a sensor to the government, but we can offer a phased array antenna or sensor that is combined with an entire end-to-end communication system, including global coverage backed by our ViaSat-3 satellite network and using our state of the art encryption technology. We can provide an end-to-end solution. Most of the, even the large primes don’t have a global SATCOM network that they can rely on to give the government what they really want, which is an end-to-end capability, not just an antenna.

Alex Miller: Yeah, absolutely. Well, Ken Buer, thanks so much for taking the time to be on the podcast today. I know you’ve got a lot going on as you’re starting to think past ViaSat-3, and onto ViaSat-4 and and beyond. So thanks for your time.

Ken Buer: Oh, you’re welcome.

Alex Miller: Thanks for listening to the Viasat podcast. If you know someone you think would be interested in what you’ve heard on this episode, please share. You can always find the latest episodes on our blog at Viasat.com And you can subscribe at Apple Podcasts, Stitcher, Spotify, or just about anywhere you get your podcasts.