SAAB unveils the worlds first operational Gallium-Nitride AESA radar

**Adar** · May 14, 2014, 04:18 AM

Full article

Summary of why it is interesting
Gallium Nitride is a semiconductor used to emit electromagnetic radiation and can be used in traditional "X-band" radar as well as other wavelengths. For military purposes X-band radar has been dominating the market as it offer the best compromise between range and precision. But low-observability aircraft such as the F-117 and F-22 have increased the value of radars utilizing longer wavelengths with less precision. To increase the precision and reduce clutter it is therefore necessary to make larger and more powerful radars which make the radars less mobile and vulnerable to suppression efforts by the enemy.

Gallium Nitride can carry a higher voltage and work under higher temperatures than Gallium Arsenide (the currently favored material) which allow manufacturers to build smaller and more powerful radars than before. The downside is that the production process for Gallium Nitride is far more complex and expensive which have restricted it's usage to small size high value applications such as satellite communication. But thanks to a collaboration between SAAB and Chalmers Technical University SAAB is now able to produce the first operational GaN based AESA radar to support SAABs WISCOM concept for future air combat (read more about that here).

So what it means is that

Instead of using one large array such as this to detect stealth aircraft:

An integrated air defense could combine two or more mobile vehicles like this:

To provide detection of currently stealthy aircraft.

Originally Posted by Ares on defense

Meanwhile, Saab's electro-tomtens in Gothenburg were quietly working in the moonlit farmyard, as tomtens do, and now have a customer (not named) for the GaN-based. 2,000-module Giraffe 4A, with delivery due in 2016.

That was the industry-news bit. However, the way they showed it off was quietly spectacular. We media reptiles first saw it outside the assembly hangar, antenna up and open to the sky. While we had lunch (fish was present, need you ask?) they folded the antenna down into its container, loaded the radar on to a truck and drove it up a short, steep dirt track into the woods. They hooked it up to a generator, in the rain, popped the antenna up again and proceeded to run a series of live demos for the media, powering down between each group to avoid microwaving our brains.

They did this with a near-brand-new development article. Moreover, none of the Swedish engineers saw anything unusual about this, at all.

The USAF issued a request for proposals in the autumn of 2013 for a similar radar after successful prototype testing by Raytheon (more info) to replace it's current long range radar AN-TPS-75 .

The different bands of radar.

More information:
http://www.advantechwireless.com/wp-...um-Nitride.pdf
http://electronicdesign.com/communic...wer-amplifiers

**Condottiere 40K** · May 14, 2014, 04:36 AM

So if they make it Gripen portable, Lockheed Martin might find itself in somewhat of a pickle.

**Adar** · May 14, 2014, 07:10 AM

Originally Posted by Condottiere 40K

So if they make it Gripen portable, Lockheed Martin might find itself in somewhat of a pickle.

I do not think that this is a significant change when it comes to air-to-air. Gripen E already got an AESA radar and the new thing in this article is that the sender/receiver elements are made out of Gallium Nitride instead of Gallium Arsenide. Miniaturizing an L-band radar got other constraints apart from power so I am not sure on how much it would help.

But what we need to remember is that the F-35:s primary mission is air-to-ground missions and integrated air defenses using AESA radars with GaN elements could very well turn out to problematic here as they outrange the weapons available for the F-35 to carry within it's internal weapons bay.

Internal:
106 km AGM-88 HARM
20+ km Brimstone
28 km JAGM
130 km JSOW (joint stand off weapon)
290 + km JSM (Joint Strike Missile)

External:
370 km JASSM
1000 km JASSM-ER
500 km Storm Shadow
300/500 km SOM
370 + km LRASM (Long Range Anti-ship Missile) - I am not sure on if this is planned for the F-35 as well.

Which mean that only external weapons got sufficient stand off to safely deal with this generation of radars. Unlike older VHF systems (such as the Russian on the picture) the Giraffe 8A is fully mobile so a networked defence of Giraffe 8As would be able to continuously switch positions in order to make SEAD (Suppression of Enemy Air Defenses) missions harder.

It is unlikely that USA would have to go to war against an enemy with Giraffe 8As in the near future. But it is unlikely that China and Russia are far behind in the development of these technologies so I expect the EA-18 Growler to become a very valuable asset to secure US air supremacy in the 21st century.