Navy Selects BAE Systems Circular Antenna Array for Shipboard Identification Friend-Foe (IFF) System

PATUXENT RIVER NAS, Maryland – US Navy air warfare systems experts required special circular shipboard antenna arrays for the AN/UPX-29(V) identification friend-foe (IFF) interrogator system aboard ships of surface warfare. They found their solution in the electronic systems segment of BAE Systems in Nashua, NH

Naval Air Systems Command officials at Patuxent River Naval Air Station, Md., announced on Tuesday a $13 million order from BAE Systems to supply six OE-120B electronically steerable antenna (ESA) arrays.

The BAE Systems OE-120 Antenna Array is an electronically steerable antenna that on-board operators can redirect in 50 microseconds to interrogate any target on the horizon. The antenna array supports the IFF interrogator as well as air traffic control beacon systems, and is designed for surface ships and land based installations.

The antennae are for the AN/UPX-29 onboard interrogator, which is a centralized IFF system that uses a challenge and response technique to distinguish friendly platforms in a multi-target environment.

Related: BAE to Provide IFF Interrogators Aboard Navy Ships to Identify Friendly and Enemy Aircraft

This contract amendment exercises an option to purchase six OE-120B antenna arrays — four for the Navy and one for the Government of Canada; and four OE-120B antenna array upgrade kits for the Navy and associated data.

The antenna array supports a wide range of systems including IFF, Secondary Surveillance Radar and Air Traffic Control Radar. The system provides constant fleet protection to navies around the world.

The OE-120B antenna arrays provide instant, multiple target identification that supports defense against today’s sophisticated airborne threats. It supports all standard IFF modes.

The antenna system adapts to land and maritime applications to support a variety of mission environments, and its electronically driven system architecture provides increased reliability and reduced maintenance. Its array configuration allows for smooth performance degradation in the event of a failure.

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The OE-120 electronically steerable antenna is suitable for the Navy’s Ticonderoga-class cruiser (CG 47), Arleigh Burke-class destroyer (DDG 51), Wasp-class amphibious assault ship (DG 1), amphibious ship San Antonio-class transport dock (LPD 17), aircraft carriers and the Japanese Kongo-class destroyer (FMS DD 173) – a version of the American Burke-class destroyer.

The AN/UPX-29(V) shipboard IFF interrogator, of which the OE-120B antenna is a part, distinguishes nearby friendly ships and aircraft during combat operations.

The AN/UPX-29(V) can process and store up to 400 targets, provide instantaneous interrogation on a target in 25 microseconds, electronically evaluate responses in mode 4, call up information on targets designated by the operator , display synchronized IFF targets with as many as four radars on 22 screens and interface with on-board computers.

At the heart of the OE-120 system is the AS-3134/UPX antenna array, which consists of 64 pairs of vertical radiating dipole antenna elements arranged in a circle on the ship’s mast. The system uses electronic beam steering to scan all areas around the vessel. Pairs of dipole antenna elements can produce directional or omnidirectional beam patterns.

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The system can direct its RF energy to any target of interest located at any point on the horizon within microseconds. Operators can also quickly scan the antenna output over a designated area of ​​interest. During normal surveillance operations, the antenna array scans the horizon at 90 rotations per second.

The OE-120’s CV-3372/UPX antenna positioner receives commands from the C-10063/UPX controller, distributes RF power to the radiators, and digitally controls the output mode and aiming direction of the system. The system’s C-10063/UPX antenna controller, meanwhile, is located below decks and continuously translates data synchronized from the ship’s environmental sensors.

On this order, BAE Systems engineers will perform the work in Nashua, NH, and is expected to be complete by November 2024. For more information, contact BAE Systems Electronic Systems online at, or Naval Air Systems Command at www.navair.