What is AESA Radar? How It’s Revolutionizing Modern Warfare

Recently, the deployment of AESA radar has gained significant attention with its increasing use in cutting-edge fighter jets like the F-35 and the Su-57. These aircraft, equipped with AESA radar technology, are reshaping the dynamics of modern warfare by providing unparalleled detection and tracking capabilities.

But why was this technology developed in the first place? The evolution of radar systems from older technologies like PESA to AESA was driven by the need for more efficient, adaptable, and resilient radar systems to counter growing threats in modern military conflicts. With AESA’s ability to simultaneously track multiple targets with high precision and superior range, it’s clear why it’s become indispensable for military forces around the world.

But how did AESA radar go from a mere concept to a critical component of military strategy, and how does it work to give fighter jets a significant edge in the skies?

What is AESA Radar?

To understand AESA radar, it’s important to first grasp the basics of how radar works. AESA radar (Active Electronically Scanned Array) is an advanced radar technology that uses an array of small, solid-state transmitters and receivers to scan and track targets.

Unlike older radar systems, such as PESA (Passive Electronically Scanned Array), which rely on mechanical rotation or a single large transmitter, AESA operates by electronically steering its radar beam. This allows it to scan faster, track multiple targets simultaneously, and resist jamming more effectively than older radar types like PESA or mechanically scanned arrays.

The development of AESA radar technology began as a response to the growing need for more powerful and adaptable radar systems in military applications. Early radar systems struggled with limitations like slow scan rates, vulnerability to jamming, and difficulty in tracking multiple targets at once. AESA was designed to overcome these issues, offering higher resolution, faster scanning capabilities, and improved resistance to electronic countermeasures.

The first widespread use of AESA radar in fighter jets was seen in the late 1980s and early 1990s, notably in systems like the AN/APG-77, which was integrated into the U.S. F-22 Raptor. Since then, AESA radar has become a critical component in modern military aviation, allowing for better targeting, improved situational awareness, and greater range.

How AESA Radar Works

To understand how AESA radar works, it’s helpful to first consider what it’s trying to solve. In high-stakes military operations—especially in the air—speed, accuracy, and adaptability are everything. Traditional radar systems, which rely on mechanical steering, fall short in these areas. Imagine trying to scan the sky with a flashlight you have to physically swivel. That’s essentially how older radars work—slow, predictable, and vulnerable.

AESA radar technology, by contrast, is like replacing that flashlight with a high-speed spotlight controlled by your mind. Its core innovation is electronic beam steering, which lets it direct radar energy anywhere in its field of view without moving a single part. This is achieved through an array of miniaturized transmit/receive modules. Each module emits its own signal, and by adjusting the timing of these signals, the radar can shift its beam almost instantly. This results in near-instant scanning and tracking, no mechanical delay, and fewer moving parts to fail in combat.

But speed alone isn’t what makes AESA radar revolutionary. It’s also about frequency agility—the radar’s ability to hop between frequencies at will. In modern warfare, where electronic countermeasures are widespread, being able to shift frequencies rapidly makes AESA radar systems harder to detect, track, or jam. Think of it as a conversation where the speaker keeps changing languages mid-sentence—enemy systems can’t keep up.

Another major breakthrough is multi-target tracking. Unlike older systems that focus on one task at a time—like scanning or targeting—AESA radar in fighter jets can perform several simultaneously. One beam can be used to track an enemy aircraft, another to scan for new threats, and yet another to guide a missile, all at the same time. This multitasking ability gives pilots more data, more quickly, and with greater reliability.

So when we ask, how does AESA radar work, the answer is about what that technology allows militaries to do. It provides faster reactions, better situational awareness, and greater survivability in contested airspace.

AESA vs PESA Radar

When comparing AESA vs PESA, the key differences come down to architecture, performance, and adaptability on the battlefield. Both fall under the category of phased array radar systems, meaning they steer their beams electronically—but the way they do it makes all the difference.

PESA radar was the stepping stone to modern systems. It uses a single central transmitter that sends a signal to multiple passive antenna elements. These elements can adjust the phase of the signal to steer the beam, but the signal originates from just one source. This makes PESA more limited in speed and flexibility.

In contrast, AESA radar consists of multiple individual transmit/receive modules. Each module generates its own signal, allowing AESA radar systems to operate with greater control, faster beam steering, and more resilience. Because each element is active and independent, AESA radar technology can perform multiple tasks simultaneously—such as scanning, tracking, and jamming resistance—without performance trade-offs.

This architecture shift transforms battlefield performance. For instance, AESA radar in fighter jets enables near-instant target acquisition, simultaneous multi-target tracking, and far better resistance to electronic countermeasures than PESA. In modern air combat or surveillance missions, milliseconds matter—and AESA wins those margins.

Comparative Table: AESA vs PESA

What Are the Advantages of AESA Radar?

The shift toward AESA radar technology in modern air forces is seen as a response to real operational needs. When compared to older systems, AESA radar brings a series of tactical and logistical advantages that directly impact mission effectiveness and survivability.

Increased Reliability and Lower Maintenance

One of the most overlooked but critical advantages of AESA radar systems is their reliability. Traditional radars with mechanical components or centralized transmitters (like PESA) are prone to wear and single-point failures. In contrast, AESA radar uses hundreds—or even thousands—of solid-state transmit/receive modules. If one module fails, the rest continue operating, often with barely any performance loss.

This decentralized design dramatically reduces downtime and maintenance. For example, the AN/APG-81 AESA radar on the F-35 fighter has demonstrated extremely high operational availability compared to legacy systems. In combat situations, this means jets spend less time in the hangar and more time where they matter—on mission.

Faster Target Acquisition and Tracking

AESA radar in fighter jets is designed for speed—both in scanning airspace and locking onto threats. Because it steers its beam electronically, AESA can switch its focus in microseconds. This allows it to acquire and track fast-moving targets with minimal delay, giving pilots a decisive advantage in air-to-air engagements.

Take the F-22 Raptor, equipped with the AN/APG-77 AESA radar. It can track multiple targets, scan vast areas, and support missile guidance—all in parallel. That kind of performance is game-changing when reaction time is the difference between kill or be killed.

Low Probability of Intercept (LPI)

Another major strength of AESA radar is its stealth—yes, even the radar itself can be stealthy. Thanks to frequency agility, low power side-lobes, and the ability to use different frequencies for each pulse, AESA radar has a low probability of intercept (LPI).

That means enemy sensors have a much harder time detecting that your radar is active. This is crucial in modern warfare, where detection often leads to destruction. A fighter jet using AESA radar technology can track or engage targets without immediately revealing its own position—an advantage that fits perfectly into stealth-based combat strategies.

Resistance to Jamming

Electronic warfare is a major part of 21st-century conflicts, and radars are frequent targets. Here, AESA radar again outclasses older systems. Because it operates with multiple, independently controlled modules, it can resist jamming in several ways—by rapidly changing frequencies, nulling interference, or even focusing energy in specific directions to punch through jamming signals.

For example, during exercises, AESA-equipped aircraft like the Eurofighter Typhoon or F/A-18 Super Hornet have shown the ability to maintain radar functionality in contested, jammed environments—while non-AESA systems often become blind.

AESA Radar Military Applications

So, where is AESA radar actually used—and why is it considered one of the most important sensor technologies in modern defense? The answer lies in its versatility. It can be mounted on a stealth fighter, a naval destroyer, or part of a ground-based missile defense network.

AESA Radar in Fighter Jets

Perhaps the most well-known and impactful use of AESA radar in fighter jets is in fifth-generation aircraft. These jets operate in highly contested environments, often relying on stealth and electronic warfare capabilities. Unlike older radar systems, AESA radar in fighter jets provides a multi-functional capability—scanning the skies, tracking threats, guiding weapons, and resisting jamming—all at once.

The American F-22 Raptor, for example, employs the AN/APG-77 AESA radar, allowing it to detect enemy aircraft at long ranges, lock onto multiple targets simultaneously, and remain hard to detect due to its low probability of intercept (LPI) emissions.

The F-35 Lightning II takes this further with its AN/APG-81 radar, which integrates real-time electronic warfare, ground mapping, and air-to-air tracking. The radar is deeply embedded into the aircraft’s sensor fusion system, enabling pilots to maintain unmatched situational awareness without compromising stealth.

In Europe, the Dassault Rafale uses the RBE2-AA AESA radar, delivering high-resolution ground imaging and simultaneous multi-target tracking, even in dense electronic environments. Meanwhile, Russia’s Sukhoi Su-57 is expected to carry the N036 Byelka AESA radar system, which uses multiple arrays positioned around the aircraft to provide 360-degree coverage. This setup enhances the Su-57’s situational awareness and supports its design philosophy of combining stealth with supermaneuverability.

Read also: Dassault Rafale: France’s Most Advanced Fighter Jet

Across all these platforms, the advantages of AESA radar—including rapid beam steering, frequency agility, high resistance to jamming, and operational reliability—give pilots the tools they need to dominate complex and rapidly changing airspace. It’s no exaggeration to say that modern AESA radar systems have redefined what air superiority means in the 21st century.

AESA Radar in Naval Systems

The integration of AESA radar systems into modern naval platforms has revolutionized how warships detect and respond to threats at sea. In maritime warfare, where seconds can mean the difference between survival and destruction, the speed and precision offered by AESA technology are invaluable.

Unlike older mechanical or PESA systems, AESA radar in military naval applications enables ships to perform simultaneous air and surface surveillance, missile tracking, and engagement—often while operating under intense electronic warfare conditions.

The U.S. Navy’s next-generation SPY-6 radar, for instance, exemplifies the shift toward AESA-based naval sensors. Designed for advanced destroyers and future guided-missile ships, SPY-6 provides significantly enhanced sensitivity, range, and target discrimination. It can track stealth aircraft, cruise missiles, and even ballistic missile threats simultaneously. Thanks to its modular AESA radar architecture, the system can be scaled and adapted for different classes of warships, from large surface combatants to smaller frigates.

European navies have also embraced AESA radar technology. The French Navy’s Thales Sea Fire radar, mounted on the new FDI-class frigates, offers all-weather, multi-mission capabilities with high resistance to jamming and clutter.

Similarly, Israel’s EL/M-2248 MF-STAR AESA radar, deployed on Sa’ar 5 and Sa’ar 6 corvettes, provides simultaneous tracking of aerial, surface, and even low-signature threats like UAVs and sea-skimming missiles. These systems are active combat enablers, coordinating with onboard missile systems for real-time threat engagement.

In all these cases, the use of AESA radar in naval systems enhances reaction time, improves reliability under harsh maritime conditions, and ensures a vessel’s survivability in multi-threat environments.

AESA in Air Defense Systems

On the ground, AESA radar systems play a crucial role in modern air defense networks, providing early warning, threat tracking, and fire-control functions with unmatched speed and resilience.

One of the most prominent examples is the PATRIOT PAC-3 system, which has been upgraded with an AESA-based radar to enhance performance against ballistic and cruise missiles. This upgraded radar offers extended detection range, faster response time, and higher resolution—essential when dealing with maneuvering or low-altitude threats. The frequency agility and multi-target tracking capabilities of AESA also mean the system can maintain a lock on multiple incoming threats even in the presence of electronic interference.

European systems have also adopted AESA technology. The SAMP/T air defense system, developed by France and Italy, incorporates AESA radar to support its Aster missiles. This system is designed to protect high-value assets and population centers from a range of aerial threats, including fast jets, UAVs, and short-range ballistic missiles. The AESA radar’s low probability of intercept (LPI) properties also enhance the system’s survivability by making it more difficult for enemy forces to detect or jam the radar.

What makes AESA radar in air defense particularly valuable is mostly related to its adaptability. It can be deployed as part of fixed air defense installations, mobile units, or even integrated into broader missile shield architectures. Whether defending a battlefield, a city, or an entire region, AESA-equipped air defense systems bring a new level of precision, reliability, and resilience to the fight.

So, Why Is AESA Radar a Game-Changer in Modern Warfare?

Because it fundamentally redefines what radar can do on the battlefield. AESA radar, or Active Electronically Scanned Array is a leap forward in speed, precision, and survivability. It gives fighter jets like the F-35 and Rafale the ability to track multiple targets without revealing their position, enabling naval ships to defend against missile swarms in contested waters, or anchoring ground-based air defense systems in hostile electronic environments.

Its key advantages—such as electronic beam steering, multi-target tracking, low probability of intercept, and resistance to jamming—make it indispensable across domains. The shift from PESA to AESA was more about transforming radar from a single-purpose tool into a multi-role, highly adaptive weapon system.

In today’s high-threat, data-driven battlespace, the side with the better radar often sees first, acts first—and wins. And in that equation, AESA radar systems are no longer optional—they’re essential.