# Digital Beamforming Radar



## tomahawk6 (12 Mar 2008)

http://www.defensetech.org/archives/004058.html   

This month Lockheed Martin released a 280-word statement from its radar research headquarters in New Jersey announcing a breakthrough test of an advanced radar platform. And while the tech world shrugged, people watching the evolution of radar saw another step for a system that could have a dramatic effect on future world affairs, from American missile-tracking platforms in the Czech Republic to the ship-based defense of the Taiwan Straits.

The new radar system, called digital beamforming, could become a game-changing technology that may help defeat an overwhelming attack on U.S. warships by missiles. It could also answer one of the chief complaints about ballistic missile defense systems -- that decoys or other countermeasures could easily hide a warhead and spoof interceptors. If placed on satellites, new spy and environmental monitoring missions become possible from orbit.

All this comes as an improvement to an existing system called phased-array radar. While traditional radars spin their faces to seek targets, phased-array radars guide a reflective beam electronically from a stationary panel. They can track things by moving the main beam very quickly, within microseconds, at numerous targets. But the phased array systems cannot seamlessly track multiple targets at the same time without losing resolution. Lockheed's improvement on these radars allows true simultaneous tracking, with each target followed by a dedicated radar beam.

Digital beamforming, then, combines the cutting edges of antenna and digital technologies: A radar array digitizes the signals it receives, preserving all the incoming information. This data is then used to form as many radar beams as necessary to track as many objects as appear. The crucial advantage to this approach is the ability to confidently cover a vast area with a single system.

Lockheed for the first time has been testing a digital beam array to locate and track live targets -- in this case, commercial and military aircraft coming in and out of the Philadelphia area. "The hard part was how we combined all the data...to form the individual beams," Scott Smith, program manager for the radar system at Lockheed, tells PM. Commercially available high-speed digital electronics and advanced signal processors have become advanced enough to allow this data processing to occur, and that in turn has enabled digital beamforming to become practical for use outside a lab.

One key component to all phased-array radars is transmit/receive modules. These inch-long modules increase the power of the transmitted signal, ready the system to receive responses and steer the beam to find targets. Lockheed engineers have used new materials in digital beamforming t/r modules that make them tough enough to hold up to harsh use. By using heat-tolerant silicon carbide in the modules, more power can be pumped through them, giving the radar a longer range and a very precise targeting ability.

Digital beamforming radars will likely find their first homes on ships that track missile threats to U.S. fleets. Those threats will come from ballistic launches hundreds of miles away or from high-speed missiles launched from submarines or warplanes. The Russian government has been busy selling sea-skimming, antiship missiles to China that are designed to overwhelm the U.S. fleet's radars, so the ability to track multiple, fast-moving threats could become vital in the Taiwan Straits. But a digitized phased array radar can handle many incoming signals at once, and should be able to discern real threats from bits of metal or shaped decoy balloons. So somewhere a Chinese admiral is frowning at Lockheed's news, and a Taiwanese general is smirking.

The development could even fuel Russian paranoia over its nuclear deterrent and make its leadership more intransigent about U.S. radar bases, ostensibly established to protect Europe from Iranian missiles, on its border in Eastern Europe. One way to beat radar systems is to overwhelm them with signals, including decoys.
Therefore, beamforming can change missile defense equations in favor of the defenders. "Russian analysts examining the [missile defense] system would conclude that, at some unforeseen future time...it might be able to engage many hundreds of targets," a 2007 Arms Control Association report noted. "Such possibilities, however remote they would seem, would certainly conjure up apocalyptic threats to Russia's national survival."

Maybe not so remote: If the radar ground stations that the U.S. wants to establish in the Czech Republic are upgraded with beamforming technology, they could spot Russian missiles just after launch, follow as many missiles as could be put into the air, track inbound warheads amid intentionally scattered decoys and shoot down the real threats. The balance of power in Europe could shift as Russia loses its deterrent edge.

Read more on this and other high-tech headlines from our friends at Popular Mechanics on Military.com.

-- Christian


----------

