AESA (active electronically scanned array) systems have made a huge impact on radar technology and will play a vital role as they evolve in the future. Below we’ll look at what AESA radar is, how it works, its advantages, and its potential for the future.
What Is AESA Radar?
AESA (which stands for active electronically scanned array) radar, also sometimes referred to as active phased array radar (APAR), relies on a special type of phased antenna setup. An AESA consists of many individual antenna elements (100s to 1000s) each with its own amplitude and phase control.
These elements are arranged either in a linear or two-dimensional array and as each one emits individual wavefronts, they actually converge into one, also known as a plane wave.
Still want to understand how does AESA radar works in a practical sense for the end user and how this functionality impacts them? The biggest benefit of a phased array system is how easily operators can control the direction of surveillance.
Instead of manually needing to move the antennas, it can all be done electronically. By simply delaying the frequency of the individual antennas (which can operate at different individual frequencies), operators can change the direction of where those individual waves converge.
Prior to AESAs, radars used a mechanically scanned array (MSAs). This consisted of an antenna (typically a dish-style one) mounted on a gimbal that mechanically scans the antenna to send energy in different directions spatially.
In military applications, AESAs have become popular because they offer a noticeable speed improvement for radar beam scanning. (They’re able to digitally scan beams on the order of nanoseconds.)
Plus, warfighters have more precision in targeting the areas they want to monitor. And the ability to redirect the radar electronically is a lot safer than options that require manual movement.
The Advantages of AESA Radar Systems
AESA radar was developed from its predecessor PESA radar. And as the technology advanced it started becoming more prevalent for ground-, sea-, and air-based operations, especially during the 1990s. Broadly speaking, there are several advantages of AESA radar systems that make them a preferred choice for warfighters.
1. More Detailed Range of Detection
AESA radars are preferred when compared to PESA radars, their early predecessor. While a PESA radar can scan beams it’s limited by moving parts required to mechanically perform beam scanning. In contrast, AESA radars electronically scan with no moving parts, a single beam or multiple beams that more rapidly and provide warfighters with better situational awareness. (This is especially helpful in applications like detecting micro-UAVs.)
Because AESA radars don’t have moving parts they ultimately provide enhanced reliability around the data being provided to end users. Plus, unlike MSAs (which have 2 primary amplifiers to transmit energy and amplify received target echoes) there’s less loss in the signals, again leading to a better detection range from AESAs.
2. Better Resistance to Jamming
Jamming involves broadcasting a signal that confuses the receiver’s ability to differentiate between the pulse of the radar and the bad actor. And while it’s not impossible to jam an AESA radar system, it’s a lot more difficult to do.
Because AESAs are comprised of multiple individual antenna elements, they’re capable of advanced techniques made possible by array processing. This includes tactics like adaptive array nulling which automatically filters out jamming signals from a single or multiple location.
3. Less Risk of Complete System Failure
Since AESA radar relies on multiple transmit and receive modules (TRMs) and the antenna electronics are distributed, there isn’t a single point of failure. This improves the radar’s mean time between failure (MTBF) and mean time to repair (MTTR).
4. Offer Multi-Function Capabilities
Because the radar beam can be scanned electronically in nanoseconds, the radar timeline can be used to accomplish other functions. That includes things like track while scan (TWS), electronic support measures (ESM), electronic attack (EA), and communications.
The Challenges of AESA Radar Systems
While AESA systems offer a lot of perks, there are some challenges that go in hand with choosing to use them.
1. They’re More Difficult to Manufacture
Because of their complexity, AESAs are more of a challenge to construct than their predecessors. Building an AESA radar requires subject matter experts for antenna design, circuit design, digital control, thermal analysis, and power system.
2. A More Costly Alternative
While they provide more accuracy than the radars before them, AESA systems also cost more. That cost is proportional to the number of elements (TR modules), but that’s why manufacturers do their best to optimize the number of elements required.
3. Requires multiple AESAs for 360o coverage
For a flat phased standard AESA antenna, the nominal FOV is 120 degrees. However, to match the field of regard (FOR) of a gimbaled antenna multiple AESAs are required.
Looking At It In Action: Ways AESA Radar Is Being Incorporated
While AESA radar has been around for a while, it continues to advance and is still very much an important part of modern-day warfighting.
For example, it’s being incorporated into the navy to help detect inbound air threats. This can include anything from fighter jets and missiles to UAVs.
It’s also been playing a key role in a variety of ground combat scenarios. It’s been of note in the war between Ukraine and Russia. The U.S. has provided radars to help the Ukrainians survey and counteract artillery and other threats.
Ultimately RADA USA’s AESA systems are employed by the Army, Navy, Marines, and Air Force in various scenarios spanning the air, sea, and land. That includes use in the Marine Air Defense Integrated System (MADIS) and maneuver short-range air defense (MSHORAD).
The Future of AESA radar
One of the primary focuses in the future of AESA manufacturing is to create systems that offer better multi-function applications. Meaning they can offer more than just radar capability, but they can also be used for other functions like ESM and communication.
On the more technical side, professionals in this field are working to develop:
- Higher levels of digital beamforming, so the phase and amplitude control is done digitally with fewer TR modules needed.
- Wider instantaneous bandwidths.
- Multiple simultaneous beams on transmit and receive, to allow for an even better level of performance.
To truly dive into AESA and learn more about its functionality on a deeper level and explore its applications, we recommend reading this book by our in-house expert, Dr. Arik D. Brown.
At RADA, we feel it’s essential to always be improving and working towards new goals to help refine AESA technology. That’s why we offer cutting-edge systems that at the same time meet the highest SWaP-C criteria and offer a great price-to-performance ratio.