¶ Electronic Warfare – AN/ASQ-239 Barracuda

¶ What is Electronic Warfare?

Modern combat aircraft face threats from radar-guided air defence systems and guided missiles. These systems emit radar signals to detect, track, and guide missiles toward the aircraft. Electronic warfare (EW) has the task of detecting such threats and countering them — through warning, analysis, and active jamming.

The AN/ASQ-239 Barracuda by BAE Systems is the F-35's integrated electronic warfare system [47]. It is the aircraft's electronic shield: while the F-35's stealth design deflects enemy radar signals and thus makes detection difficult, the Barracuda system handles the active side of protection — it detects, analyses, and actively jams enemy sensors.

¶ How Does the System Support the Pilot?

The AN/ASQ-239 operates fully automatically in the background. The pilot does not need to search for threats. The system performs three tasks simultaneously:

Warning: It detects enemy radar signals and automatically displays all threats on the pilot's screens — showing type (e.g. surface-to-air missile, fighter aircraft), direction, and estimated distance.
Assessment: The system automatically distinguishes between harmless search radars and acute threats such as a fire-control radar that is actively guiding a missile toward the aircraft. Warnings are prioritised according to the threat level.
Protection: When a threat is detected, the system can autonomously initiate electronic countermeasures — for example, emitting jamming signals that blind an enemy radar or disrupting the guidance of an incoming missile.

¶ How Do the Components Work Together?

The AN/ASQ-239 consists of several components that function as an integrated system:

¶ The Antennas — the System's "Ears"

10 radio-frequency antennas (RF antennas) are embedded in the leading edges of the wings and tail surfaces. Their distribution across the entire aircraft allows them to detect radar signals from all directions — providing seamless 360-degree coverage. The system operates multi-spectrally: it monitors both the radio-frequency (RF) range and the infrared (IR) range, i.e. heat signatures.

¶ Signal Processing — the "Brain"

Received signals are analysed in real time. The system determines:

Which radar type is transmitting (surface-to-air missile, search radar, fire-control radar of a fighter aircraft)
Where the source is located — passively, without emitting any signals of its own that could reveal the aircraft's position (passive geolocation)
How acute the threat is (whether the radar is merely searching in general or has already locked onto the F-35)

¶ The Jammer — the "Sword"

When the system identifies an acute threat, it can respond with targeted electronic countermeasures:

Jamming signals blind enemy radars and make the aircraft invisible to them
Deception signals create a phantom target at a false position for the enemy radar

¶ Sensor Fusion — the Complete Picture

The Barracuda system does not operate in isolation. It is fully networked with the F-35's other sensors:

The aircraft's own radar (AN/APG-81) provides active tracking data
The infrared Distributed Aperture System (DAS) detects missiles and engine signatures
The Electro-Optical Targeting System (EOTS) identifies targets visually
Data links (Link 16, MADL) receive information from allied aircraft and ground stations

All this data is merged (fused) to create a combined situational picture that reveals more than any single sensor could detect alone. On the helmet-mounted display and cockpit screens, the pilot sees a single, clear threat picture — the complexity of the data processing remains in the background.

¶ System Architecture

10 RF antennas in the leading edges of wings and tail for 360-degree coverage
Multi-spectral capabilities: RF and IR spectrum
Heritage: Evolution of the F-22's AN/ALR-94 system

¶ Capabilities

Radar warning: Detection and classification of enemy radar emissions
Passive geolocation: Locating emitters across a broad EM spectrum without own emissions
Countermeasures: Electronic jamming and deception
Integration: Full fusion with APG-81/DAS/EOTS for a correlated threat picture

¶ Block 4 Upgrade: DTIP

BAE Systems is developing the Digital Channelized Receiver Techniques Generator (DTIP) [48]:

Smaller form factor
Reduced power consumption
Space for future upgrades
Development contract: USD 493 million, production contract: USD 491 million

¶ Fleet Status

Over 1,200 AN/ASQ-239 systems had been delivered by the end of 2024 [47]. BAE Systems is investing USD 100 million in a new manufacturing facility (7,400 m²) with AI-driven automation and a capacity of 11 systems per month [49].

¶ References

[47] BAE Systems: AN/ASQ-239 F-35 EW Countermeasure System
[48] Military Embedded Systems: Block 4 work for F-35 EW system gets BAE Systems update. 2023
[49] Microwaves & RF: Enhanced EW Upgrades AN/ASQ-239 System. 2024