L-Band AESA on Su-35

[Haavarla]

The Tikhomirov NIIP L-band AESA has considerable growth potential by virtue of the large size of the Flanker airframe, permitting additional antenna elements, cooling and power.

Growth options include:

Increasing the power rating of the existing TR modules, retaining conduction cooling.
Further increasing the power rating of the TR modules and introducing liquid cooling.
Improvements to antenna element design to increase element gain.
Extending the arrays further along the wings, to add an additional one or two subarrays.
Addition of receiver arrays in the leading edge of the vertical tails to provide dual plane monopulse precision angle tracking capability for fire control purposes.
For instance, increasing the array size to 16 elements improves power-aperture product for the existing design by almost 80%, by virtue of additional gain and transmit power. The use of more powerful TR modules provides for further improvements. The practical limit will be the available leading edge flap volume as the design progressively tapers toward the wingtips, and system constrains on liquid cooling capacity.

http://www.ausairpower.net/APA-2009-06.html

Ok, lets hear any toughts about this systems. Its growt potencial, etc etc?


Thanks

 

[Feanor]

The information is interesting but the source is questionable. I'm not an expert on radar performance, so I can't go through and check their work. But I'm hesitant to trust anything coming out of APA.

 

[Duffy]

Feanor is right. Carlo Kopp knows a lot about cell phones but is no radar expert. He is always doing computer modeling on the radar signature of the joint strike fighter but has no access to the air craft or any privileged information. Not mention he hates the thing.

 

[Haavarla]

The information is interesting but the source is questionable. I'm not an expert on radar performance, so I can't go through and check their work. But I'm hesitant to trust anything coming out of APA.

Well just ignore APA then, no big deal.

I believe this L-Band AESA was on display back at MAKS 2007 too.

What i want to find out is this, is this Radar on the current "901 or 902"?

If so, it could mean it's to stay on the Su-35S.
I mean, a couple of years down the road now, they would have figure out if this AESA will add anything to the capability on the Su-35S and in turn the PAK-FA.

Apperantly, the NPP Pulsar, the manufacturer of the TR modules and transistors employed in the modules, have made some most interesting disclosures which are very helpful in assessing performance:

1. TR module frequency band coverage between 1.0 and 1.5 GHz.
2. TR module volumetric power density of 2 kiloWatts/litre.
3. TR module nominal power rating of 200 Watts per TR channel, for a total of 2.4 kiloWatts per array, and 4.8 kiloWatts for a two array installation.


Thanks

 

[Aussie Digger]

Being an L-Band radar fitted into the leading edges of a tactical fighter it is not going to be especially powerful. It might be able to detect the F-35, but at what range? An X-Band fire control radar can detect an F-35 too but it is the range at which it can do so, which is the issue.

There are considerable technological challenges to be overcome, not least of which are power generation and cooling provisions in the fighter itself for this system, in addition to it's normal requirements.

This idea is again predicated upon the supposition that the F-35's signature management measures are only designed to address X band fire control radar capabilities.

Given the preponderance of radars that used other bands (S, I/J, Ku etc) it is unthinkable that L-M hasn't addressed these threats.

Another interesting point that occurred to me whilst reading APA's drivel on this subject.

For years they've told us how capable the Russian fighter radars IBIS, BARS etc are. The "bigger the antenna the bigger the power" theory of APA, that radar module count is all that matters in this debate.

They've shown us all sorts of pretty graphics which allegedly show us how superior the SU-35 and other modern Russian fighters are to the JSF (and anything else we might want, besides the F-22).

Now the Russians are thinking laterally about other ways they might try to defeat a 5th Gen VLO threat. A tacit admission perhaps that the big antenna alone, isn't enough???

 

[Bonza]

Ahhh, APA. Do they never give up?

It's been mentioned before, but their contention that the Russian air warfare industry has comprehensively countered every single piece of Western technology except for the F-22 has to be one of the greatest failures of logic I've ever seen.

I'm not even going to go into the legitimacy of their claims of impending existential threats to the F-35 (based only on open source material, of course) that the United States, with a full threat library and BILLIONS of dollars in research and development, somehow missed. Yeah, right...

They're utter clowns, and anything they have to say should be held up against their own agenda and the resulting bias, and evaluated accordingly.

 

[Salty Dog]

They dare to compare the L Band AESA to the APG-79 and APG-81. The "paper" expounds on the RF coverage and energy, antenna array layout and hardware, as well as detection and ECM modes. In simple terms the paper concentrates on RF and antenna only . What it lacks is all the other important essentials in what completes competent AESA radar systems such as processing capability, interleave modes (simultaneous air-to-air and air-to-ground), net centric capabilities (to share information with ground forces for battlefield support), SAR imaging, etc.

At least they had the good sense to include Skolnik´s "Radar Handbook", IMHO "The Radar Bible"

 

[tphuang]

NIIP seems to have like a lock on the Russian fighter radar contracts. Which is kind of sad since NIIR appears to be ahead of NIIP in AESA radar development (it actually has a working prototype in Zhuk-A). It kind of makes you wonder why they don't want to just build from Zhuk-A for a 2nd generation of AESA radar.

Considering that NIIP seems to be pretty good at producing PESA radar like Bars-M and Irbis, I kind of doubt this new AESA radar will turn out any better than Irbis. PLAAF conducted some tests on Irbis a while ago, it's actually a pretty good radar.

 

[Feanor]

The Zhuk-AE was recently reported in Russian press to have completed development, and has been chosen as the radar for the MiG-35. There are also rumors floating around that the Mig-35 will be fullfilling the LFI requirement, as opposed to the original plans for a second 5th-generation fighter jet. So I wouldn't count NIIR out yet.

processing capability, interleave modes (simultaneous air-to-air and air-to-ground), net centric capabilities (to share information with ground forces for battlefield support), SAR imaging,

Of course they left that out, because those tend to be a weakpoint of our current avionics industry. It wouldn't support their argument.

 

[SpudmanWP]

There are many problems with this usage as an anti-stealth radar.

1. The wing-root L-band AESA is that it is only 1 T/R module high. What this means is that it cannot scan in the vertical. Does anyone know what the vertical FOV is?

2. The two arrays do not significantly overlap in coverage, co their combined power as an overall rating is misleading.

3. It cannot inherently do a height finding mode.

4. The L-Band radar will light up the RwR in every fighter in the area and the F-22 &F-35 can launch based on this info alone, no need to go active with it's own APG-77/81.

 

[Salty Dog]

There are many problems with this usage as an anti-stealth radar.

1. The wing-root L-band AESA is that it is only 1 T/R module high. What this means is that it cannot scan in the vertical. Does anyone know what the vertical FOV is?

2. The two arrays do not significantly overlap in coverage, co their combined power as an overall rating is misleading.

3. It cannot inherently do a height finding mode.

4. The L-Band radar will light up the RwR in every fighter in the area and the F-22 &F-35 can launch based on this info alone, no need to go active with it's own APG-77/81.

Agreed this radar can not scan in vertical. However, even if the vertical azimuth is +/- 10 degrees, this should be sufficient for long range search. Also, I do not see any problem with the small overlap. Keep in mind that 1) this is a secondary search radar which should feed data to the main radar for tracking and 2) the pilot can maneuver the aircraft to point at the target. This radar does not need to determine target altitude, the main radar with do that.

After reading the article again, I feel it's important to point out that this L Band AESA is in fact a secondary search radar (SSR). This means that while we have pointed out some of it's shortcomings, it is not meant to operate alone, and should complement and enhance the primary radar system in the nose of the aircraft..

 

[SpudmanWP]

It's was not being touted as a SSR, but as the answer to the F-22 and F-35's VLO X-Band stealth.

 

[Salty Dog]

It's was not being touted as a SSR, but as the answer to the F-22 and F-35's VLO X-Band stealth.

I thought the same when read the paper the first time. However:

The simplest strategy for NIIP to pursue in designing a pulse Doppler radar RF and processing subsystem for the L-band AESA is to adapt an existing design, an evolutionary model frequently used by Russian designers. It is likely that the N035 Irbis E is being used for this purpose with the new X-band AESA design. Once such a radar exists, adapting it for use with an L-band AESA would involve only modest engineering effort.

Longer term an operational design would likely emulate the US “Dual Band Radar” design strategy employed in the DDG-1000 weapon system, with separate L-band and X-band AESAs, using separate optimised power supplies and RF components, but sharing common central digital signal processing and data processing subsystems. In an airborne application where weight and volume are real problems, this is arguably the optimal strategy.

 

[SpudmanWP]

But that does not apply to the "wing root" kit which is being prophesied by Kopp as the answer to LO aircraft.

 

[Salty Dog]

But that does not apply to the "wing root" kit which is being prophesied by Kopp as the answer to LO aircraft.

From the paper Abstract:

The design has clear potential to provide a genuine “shared multifunction aperture” with applications including:

1. Search, track and missile midcourse guidance against low signature aircraft.
2. Identification Friend Foe / Secondary Surveillance Radar.

Well, the paper is about the SSR function of the "leading edge flap" L Band AESA radar. AFAIK the author is not saying it is "the" solution to counter VLO aircraft, but this could be an enhancement or complementary solution to the Su-35 AESA
.

This is nothing less than the “shared multifunction aperture” model now very popular in the design of Western X-band fighter radars, examples including the Raytheon APG-79 and NG APG-81.

I personally do not care for some of Kopp's material, however in this particular case, I do not see where this paper is "out in left field".

 

[SpudmanWP]

From: F-35 Joint Strike Fighter vs Russia's New Airborne Counter-Stealth Radars

The new Tikhomirov NIIP L-band AESA is the first example of a technology which negates the intended X-band stealth advantage well before the F-35 Joint Strike Fighter achieves even limited operational capability.

What's with "negates"? I will admit degrades, diminishes, and even complicates... but negates?

So if its not wing root L-Band AESA, what is the "new technology"?

For years everyone has said it's all about the number of T&R modules. If you start replacing X-Band modules with L-Band ones in a "shared multifunction aperture", then you will lose range in the X-band and be easier to jam.

Ships can do a "shared multifunction aperture" because they have all te realestate they can handle. A fighter does not have that luxery.

 

[Salty Dog]

From: F-35 Joint Strike Fighter vs Russia's New Airborne Counter-Stealth Radars

What's with "negates"? I will admit degrades, diminishes, and even complicates... but negates?

Looks to me like a poor choice of words. Looks like you "switched articles".

So if its not wing root L-Band AESA, what is the "new technology"?

For years everyone has said it's all about the number of T&R modules. If you start replacing X-Band modules with L-Band ones in a "shared multifunction aperture", then you will lose range in the X-band and be easier to jam.

Ships can do a "shared multifunction aperture" because they have all te realestate they can handle. A fighter does not have that luxery.

I'm not sure what "new technology" you are referring to. The articles do not refer to any new technologies.

Where do you see L-band modules replacing X-band modules? The X-band modules are in the nose cone radar and the L-band modules are in the leading edge flaps. These are physically different modules in different locations. So how will there be range loss in the X-band spectrum? Where is the "real estate" issue?

BTW, the "wing root" is where the wing physically attaches to or joins the fuselage. I believe you mean to say "leading edge flap".

 

[SpudmanWP]

I was not trying to switch articles, just get supporting information from the same source.

I was confused about your use of the term "shared multifunction aperture" as it infers T&R modules located together in the same array.

If they stay in the flap area, then they will never solve the output power and scanning issues to be an effective anti-stealth radar. btw, If the main radar cannot acquire the VLO fighter, the L-band's inability to find the height is a true issue.

 

[Salty Dog]

I was not trying to switch articles, just get supporting information from the same source.

I was confused about your use of the term "shared multifunction aperture" as it infers T&R modules located together in the same array.

If they stay in the flap area, then they will never solve the output power and scanning issues to be an effective anti-stealth radar. btw, If the main radar cannot acquire the VLO fighter, the L-band's inability to find the height is a true issue.

No worries mate. The L-band leading edge flap radar is simply a 2-D radar (horizontal azimuth only for bearing and range) vice a 3-D radar (which adds a vertical azimuth and height). The paper gave two solutions to this height finding problem. The first is to "roll' the fighter which is a cheap way to get a 3-D effect (same principle used by the Rolling Airframe Missile), or secondly to add another L-band array on the leading edge vertical stabilizer which will give a another 2-D radar with a vertical azimuth. This latter solution will combine the horizontal and vertical scan azimuths of both L-band arrays to give a 3-D presentation and therefore height. Some early Soviet era air search/tracking radars worked in much the same way.

 

[south]

Rolling the aircraft, is the most absurd claim that I have ever heard, and shows how far detached these guys are from reality.