Why AESA for the JF-17?
The revolutionary radar…AESA
Radar has moved on in leaps and bounds since it was first established as an integral
part of military communications. Today, Active Electronically Scanned Array radar is the
most flexible and advanced available.
The AESA
Developments since the 1960s have now culminated in the development of the Active Electronically Scanned Array or AESA radar, which is a type of phased array radar system.
The AESA has much greater versatility and speed, greater range and resolution making it easier for applications such as
searching, mapping and targeting. AESAs are also used for other purposes such as communications, detection and jamming.
The AESA radars are being widely used in for airborne applications, and is especially well-suited for unmanned aerial
vehicles.
AESA antennas comprise hundreds or even thousands of transmit/receive modules and each of these modules acts
as an individual radar. It truly is a case of strength in numbers.
The AESA is solid state – there are no moving parts, and this increases the overall reliability of the system as there
are basically less things that can go wrong. An AESA radar can steer its beams electronically – nearly at the speed of
light – and can re-direct them instantly from one target to another making them extremely versatile and agile. The modules
can work together or in groups enabling them to perform multiple tasks at the same time.
The AESA’s composition and solid state means that it is easy to repair and upgrade, equalling lower lifecycle costs. In fact, AESA radars can boast up to twice the life expectancy of their counterpart PESA radar systems. The other major advantage
that AESA radar has over its rivals is that it can operate in different frequency bands and can switch in between them. This means that the radar is able to track more targets at any one time as the AESA can switch frequencies and produce beams in a variety of different frequencies simultaneously, giving excellent situational awareness.
The AESA can produce strong signals whilst still remaining stealthy.
The AESA is also a good deal more compact than their predecessors. Signals were previously produced in a TWT or Klystron device but the introduction of gallium arsenide has changed this, enabling manufacturers to shrink their devices.Today, the entire AESA system can be as small as a milk carton.
Another great benefit of the use of AESA radar systems is the fact that they are much more difficult to intercept due to the fact that the AESA can change its frequency with every pulse it sends out. There is also no fixed pulse repetition for the AESA and so therefore traditional Radar Warning Receivers are not useful against AESA radars.
Jamming is also difficult to achieve. Jammers usually work by establishing the operating frequency of the radar and then
broadcasting a signal over it which then confuses the receiver. As the AESA can change its frequency, they are extremely
difficult to jam. The AESA can also be switched to a receive only mode to enable jammers to be tracked.
AESAs are also a great deal more difficult to detect. They can also continually broadcast, meaning that a great deal more
data can be generated by them than by traditional radar systems, creating much greater situational awareness.
http://www.satellite-evolution.com/issues-2011/gmc-oct-2011/radar.pdf
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