Raytheon’s GaN-based Lower Tier Air and Missile Defense Sensor (LTAMDS) radar for Patriot Missile Defense System

A full-size mock-up of Raytheon’s Lower Tier Air and Missile Defense Sensor (LTAMDS) radar.

The Raytheon is using extensive automation and a new generation of high-efficiency gallium nitride materials to accelerate development of the Lower-Tier Air & Missile Defense Sensor, LTAMDS.

On October 2019, the Army gave Raytheon a new kind of contract for a new kind of radar. Originally envisioned as simply an upgrade for the iconic but aging Patriot missile defense system, the Lower-Tier Air & Missile Defense Sensor has evolved into a multi-purpose radar that can share data with multiple kinds of command posts and launchers, not just Patriot, over the Army’s new IBCS network. Its components use gallium nitride (GaN), instead of the traditional gallium arsenide (GaS), which means less electrical energy wasted as heat and more pouring out of the radar to detect incoming threats at greater distances.

In this interview, sponsored by Raytheon, the company’s Integrated Air & Missile Defense director, Bob Kelley, talks to Breaking Defense about what makes LTAMDS different.

Raytheon have our own nationally certified GaN Foundry on our site of our manufacturing facility in Andover, Massachusetts. So we’re literally manufacturing the GaN chips about a couple hundred yards away from where we turn those into circuit cards, so that we can make GaN radio frequency elements to go onto the front of a radar antenna.

So once those GaN chips are made, they come over to the circuit card assembly line, and from that point on there is very little touch labor. What you have is you have people that are supervising machines that are making these chips. It’s not that people can’t make great circuit cards, but you’re going to be far more efficient and you’re going to make a lot more.

The machines are calibrated that every single card will be identical. Now, you need the humans there to make sure that it’s identically right, not identically wrong, because if the first one’s wrong they’re all going to be wrong. But we take a lot of steps with a lot of quality control and testing to make sure that those are all done properly.

Something else that’s new this time around is adding some larger robots to our factory. We literally have a robot taking those circuit cards — that were assembled on a circuit card assembly line by machines — and delivering those circuit cards to another robot, and that robot will put them in place and install them on onto the radar.

A Patriot radar is still a very viable radar on the battlefield today, and we have partners that are purchasing them, but there’s a lot of human touch labor on there, because some of the designs are a few decades old. This makes it so that we can create and manufacturer a radar in a much shorter period of time — and that’s one of the things that is what’s allowing us to go quickly here and meet the Army’s ambitious timeline.

Use of Gallium Nitride in LTAMDS

GaN the power efficiency. So our radar takes power in and then it needs some of that power to power all the internal systems inside the radar: There’s a whole bunch of signal processors, there’s a cooling system — just like your car, there’s all these auxiliary things that have to be operating to make the radar work.

The GaN left with an amount of power that you are going to try to turn into radio frequency power, to push out and do things that radars do – detect, identify, classify, discriminate. The ranges and altitudes that you can do that at is a function of the efficiency of your RF transmitters and how much power you’re putting in.

The gallium nitride is the efficiency, the output, the power output efficiency is unparalleled by any technology that’s out there today. With the same amount of input power, you can see much further, see much higher and see much clearer.

That’s important when you want to build a ground-based air defense radar that has to be able to be driven around, that you want to be able to deploy on, say, a C-17 aircraft from the United States to some hotspot in the world. Well, that will limit you on the size that your radar can be.

This is not Raytheon’s first gallium nitride radar we’ve made. But with the improvements Raytheon made to gallium nitride over the past five to 10 years, we’re calling this next-gen GaN technology. The efficiency on this radar far exceeds the efficiency on any other GaN radars that we produce. The main LTAMDS array is roughly the same size as the array on a Patriot, but provides more than twice the performance of the Patriot that’s out there today on the battlefield.

The battlefield is nonlinear today. You can be attacked by tactical ballistic missiles, cruise missiles, electronic attack in the form of jamming, UAVs, fifth gen fighters. And they can bring them all in the same time and space to overwhelm your sensor capability. It’s gotten to the point now, with the evolution of the threat and where the threat is going, that there is a requirement to have 360 degree protection. Raytheon built three fixed and staring arrays, so that we are always looking in all directions.

© 2020, GDC. © GDC and www.globaldefensecorp.com. Unauthorized use and/or duplication of this material without express and written permission from this site’s author and/or owner is strictly prohibited. Excerpts and links may be used, provided that full and clear credit is given to www.globaldefensecorp.com with appropriate and specific direction to the original content.

Be the first to comment

Leave a Reply

This site uses Akismet to reduce spam. Learn how your comment data is processed.