Lockheed Martin
These structures are being erected in Clear, AK to house one part of the GaN-based S-band LRDR system. (Courtesy of Lockheed Martin)

GaN Gives a Boost to Long-Range Radar System

May 5, 2020
Solid-state technology such as GaN power semiconductors is playing larger roles in modern radar systems including in the S-band Long-Range Discrimination Radar (LRDR) system.

As the number of low-earth-orbit (LEO) satellites grows, the question may arise whether the greater long-distance threat to those satellites comes from a guided missile or falling space debris. In both cases, the Long-Range Discrimination Radar (LRDR) leverages solid-state S-band radar technology to keep track of objects traveling through the atmosphere. The LRDR is taking shape under the guidance of the Missile Defense Agency (MDA) and is being developed by Lockheed Martin

The LRDR radar system is an example of what can be accomplished by using high-power gallium nitride (GaN) power transistors for amplification of a radar’s target-illuminating transmit signals in place of traditional microwave power sources such as magnetrons. The system is a vital defensive asset, given that the number of ground-based, long-distance detectors is limited but the number of threats (and the decoys that attempt to hide them from radar systems) is growing.

Carl Bannar, vice-president of Lockheed Martin’s Integrated Warfare and Surveillance Systems business, notes the importance of the signal-processing algorithms: “Our offering meets the MDA’s vision for LRDR by pairing an innovative radar discrimination capability with proven ballistic missile defense algorithms.”

The LRDR system represent the company’s largest solid-state radar program, with extensive testing performed at Lockheed Martin’s Solid State Radar Integration Site (SSRIS) in Moorestown, NJ. The radar system will start with two large antenna arrays based on a modular architecture formed with multiple antenna sub-arrays. Arrays will be constructed of multiple antenna panels, each about 27 ft. high. The MDA plans on the long-range radar as part of a layered network of radar systems capable of tracking ballistic data to protect the mainland U.S. against ballistic missile threats. 

Lockheed Martin, www.lockheedmartin.com