Talk:Active electronically scanned array

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Comments[edit]

i know i did not write this page in the simplest terms; soon i'll try to revise it to make it clearer for the layperson. i think it is reasonable to assume or require that the viewer has a basic understanding of radar technology (by reading of the radar page or otherwise). ✈ James C. 19:23, 2004 Jul 26 (UTC)

Chinese AESA?[edit]

There is a report in Strategy Pages defence news about the airborne AESA for the F16 class J10A indigenous fighter.

http://www.strategypage.com/htmw/htecm/articles/20070817.aspx

" Chinese Deploy Superior Avionics August 17, 2007: China is touting the advanced electronics in their new J10A fighter. The J10A is using an Active Electronically Scanned Array (AESA) radar. AESA systems consist of thousands of tiny radars that make it possible to track many different targets simultaneously. China claims the J10A radar can track ten targets at once, and attack four of them simultaneously (with long range missiles). China has revealed other military AESA radars recently, indicating years of intense research and development in this area.

"The J10 is also Chinese made. It looks something like the American F-16, and weighs about the same (19 tons). Like the F-16, and unlike the Su-27, the J10 has only one engine. Originally, the J10 used a Russian AL-31FN engine, but China has been working for a decade to manufacture their own version of this, the WS10A.

"It's no accident that the J10 resembles the F-16, because Israel apparently sold them technology for the Israeli Lavi jet fighter. Israel abandoned the Lavi project, because of the high cost and availability of cheaper alternatives (buying F-16s and F-15s from the United States.) But the Lavi was meant to be a super F-16, and incorporated a lot of design ideas from the F-16 (which the Israelis were very familiar with, as they used them, and had developed new components for them.) China has about a dozen J10As in service, and will probably increase production once their WS10A engine is operational (which may be in a year or two.) China's extensive espionage efforts in the U.S. has long sought jet engine and AESA technology.

81.86.144.210 11:36, 18 August 2007 (UTC)[reply] 

.....


Does the system *really* only activate 1 antenna at a time? Or is this really a Phased array radar? (I ask because "activate 1 antenna at a time" seems to be a popular oversimplification of how phased array radars work.) --DavidCary 23:39, 10 November 2005 (UTC)[reply]

  • I'm confused by your question; the quoted phrase "activate 1 antenna at a time" doesn't appear in this article or in the Phased array article. Engineer Bob 00:16, 11 November 2005 (UTC)[reply]

Active scanning with holes[edit]

Should the article not cover that this kind of radar is capable of being active even though ground based radar detectors is nearby. This can be done if the location of ground stations is known, and when turning active radar on, no radar ray will be sent in the direction of the known positions of those radar detection stations, in effect leaving holes of no rays. Sorry for explaining this so cumbersome, hope you get the point. -- A human 18:09, 17 January 2006 (UTC)[reply]

If I understand you correctly, you mean the feature to not scan each area with the same amount of energy (or some not at all), right? This is not restricted to AESAs, not even electronically scanned arrays. Mechanically scaning radars can also do this. 19:12, 17 January 2006 (UTC)
Oh, I didn't know that. Thanks for the clearification. -- A human 00:33, 18 January 2006 (UTC)[reply]


A Human: What you seem to be alluding to is the ability to steer a null (either on transmission or reception or, more likely, on both) in the direction of a known adversary. What is required is a radiation pattern which has exceptionally low sidelobes (i.e. a null) in a fixed direction even as the main beam is steered. This can be done only with an AESA antenna and cannot be done using conventional mechanical designs. In fact, an AESA can produce several such nulls and these nulls can be maintained even as the mainbeam is steered to within about 10 beamwidths away from the desired null (any closer and the null is not so deep and the mainbeam is too distorted). Nulls on reception can ensure that the radar does not receive jamming/interference from known direction(s). Nulls on transmission ensure that the transmitted radar signal cannot be intercepted. Clive

Merge Active Phased Array Radar[edit]

Probably needs to be merged in here. Any objections? CP/M comm |Wikipedia Neutrality Project| 18:04, 22 September 2006 (UTC)[reply]

Although the photos are the same, I think the referenced APAR article refers to a specific AESA system. Engineer Bob 23:44, 5 October 2006 (UTC)[reply]
Engineer Bob is correct, basically. While the term "active phased array radar" can be considered a generic term, AESA is an equivalent generic term whose usage has been in the ascendancy. The term "Active Phased Array Radar (APAR)" is the actual name of a specific active phased array radar (or AESA, if you prefer). Therefore, I think the page referring to APAR should remain as a reference to the APAR product, and should simply link to the generic page on AESAs. TheOriginalMagicMonkey 21:12, 7 October 2006 (UTC)[reply]
I've made some edits to the APAR page in order to add information but also to make it clear that it is a specific instance of an AESA. I feel strongly that the two pages should not be merged. TheOriginalMagicMonkey 22:32, 7 October 2006 (UTC)[reply]
(was edit conflict) While I for multiple times heard of APAR as a generic term, let it be this way, as it's better than redirect and dab title. Removed tags. I'll add dab into the (other) article. CP/M comm |Wikipedia Neutrality Project| 22:37, 7 October 2006 (UTC)[reply]
  • What other specific types of AESA are there? I have also encountered "Active Phased Array Radar" as a generic term, and the two as being equivalent. If there is a difference in specificity, please point it out. Şerban Alexandru Oprescu (talk) 15:37, 10 March 2016 (UTC)[reply]
    The MIMO implementations in high end wifi routers and significant mobile networks are effectively very small(less very small with the mobile systems) AESA setups. 159.196.76.184 (talk) 00:39, 15 May 2023 (UTC)[reply]

Increased gain[edit]

how is the gain higher for an aesa compared to a phased array? 59.92.156.36 13:46, 27 February 2007 (UTC)a pilot[reply]

It isn't. The fundamental limitation on antenna gain is the size of the antenna and the wavelength. This remains the case irrespective of whether the antenna is an AESA or conventional mechanical one. The only caveat to this is that antenna gain includes any losses within the antenna. It is possible that losses for an AESA are slightly lower than for conventional antennas but, in any case, this is a minor consideration. The possible confusion in your question may be that it is often said that an AESA antenna is capable of a higher output power than a conventional one. This is because, in practice, the sum of all the outputs from a multitude of medium power elements often exceeds that available from one high power transmitter/antenna combination. Clive — Preceding unsigned comment added by 62.63.61.10 (talk) 09:32, 18 October 2013 (UTC)[reply]

Sorting links to radars[edit]

If i where to sort the varius radars, should I sort by designation or, as seems more logical, by manufacturer. Johan G (talk) 02:45, 1 March 2009 (UTC)[reply]

Hi resolution image?[edit]

I suggest a higher resolution image. The link below contain pictures of an AESA radar on an Australian ship and are of a superior resolution.

http://images.navy.gov.au/fotoweb/Grid.fwx?archiveid=5000&columns=4&position=1&rows=2&search=HMAS%20Perth%20and%20Phased%20Array%20and%20%28FQYFD%20contains%2820101018~~20101122%29%29&sorting=ModifiedTimeAsc

Also noting that APAR actually stands for Active Electronically Scanned Array, this might remove some confusion from this article.

Cheers, — Preceding unsigned comment added by Streddy (talk • contribs) 06:34, 22 December 2010 (UTC)[reply]

Code injection[edit]

I call bullshit on the 'code injection' limitations of AESA radars. The article was clearly written by someone with little understanding of such techniques. Even if a buffer overflow vulnerability would exist (extremely unlikely), it would be a simple firmware fix. — Preceding unsigned comment added by 83.227.9.105 (talk) 11:05, 12 April 2012 (UTC)[reply]

This is untrue and 'code injection' does not always mean 'buffer overflow', code injection can be done in many ways, 'signature forging' ('packet forging' in computer networking) and exploitation of signature parsers is surely an option though in real time this is highly unlikely under combat conditions. 'firmware fix', lol'd. — Preceding unsigned comment added by 94.112.108.225 (talk) 17:19, 1 September 2012 (UTC)[reply]

Yeah, this is clearly bullshit by someone who has no knowledge of computer security. Packet forging is also bullshit - because there's nowhere to inject a package. Even if you'd have separate AESA radars communicating over an encrypted radio link you could not inject a packet, because it would have expired and you do not have the encryption keys to 'forge' a new packet. It is a myth, probably from the weakness of the old wireless encryption standard (WEP). The mention of this should be removed because it carries no relevance to the article. 212.16.163.66 (talk) 10:46, 5 April 2013 (UTC)[reply]

No one seems to object so I'm removing that from the article now. 213.112.224.31 (talk) 15:29, 5 May 2013 (UTC)[reply]

Receiver size?[edit]

"Receiver electronics were also large due to the high frequencies that they worked with."

There's nothing about high frequencies that requires large electronics. Clarification definitely needed. — Preceding unsigned comment added by 50.46.146.86 (talk) 23:45, 24 June 2012 (UTC)[reply]

Requested move[edit]

The following discussion is an archived discussion of the proposal. Please do not modify it. Subsequent comments should be made in a new section on the talk page. No further edits should be made to this section.

The result of the proposal was move per request.--Fuhghettaboutit (talk) 12:24, 8 September 2012 (UTC)[reply]

Active Electronically Scanned Array → Active electronically scanned array –

The article says it's a type of equipment, which strongly suggests that this is a generic term. Per WP:MOSCAPS ("Wikipedia avoids unnecessary capitalization") and WP:TITLE, this is a generic, common term, not a propriety or commercial term, so the article title should be downcased. In addition, WP:MOSCAPS says that a compound item should not be upper-cased just because it is abbreviated with caps. Lowercase will match the formatting of related article titles. Tony (talk) 00:30, 1 September 2012 (UTC)[reply]

The above discussion is preserved as an archive of the proposal. Please do not modify it. Subsequent comments should be made in a new section on this talk page. No further edits should be made to this section.

Poor understanding of basic math.[edit]

In the section under 'Advantages' titled 'Low Probability of Intercept', the claim is made that the return signal follows the inverse square law, after which the author suggests this means the return signal drops with four times the square of the distance. This did not sit right with me, so I checked the reference provided. The reference says that the return signal drops with the 4th power of the distance. The reference then gives an example comparing twice the distance yielding 1/16th the return signal....which is most likely where the 'four times the square of the distance' figure was generated. The 4th power is not the same as 4 times the square unless the change being discussed is doubling. This should be corrected and the remainder of what this writer has added to Wikipedia checked for basic math errors. 70.185.104.164 (talk) 07:11, 7 June 2013 (UTC) BGriffin[reply]


BGriffin: You are correct. The two-way detection process of radar yields a returning echo power which decays as 1/range^4 (which is not the same a 4xrange^2). However, interception is a one-way detection process and so gives a received power which decays as 1/range^2. Despite this advantage that interception has over radar detection, almost all the other issues stack in favour of the radar (and there are many such issues). By careful design the radar can build up many advantages it has over the interceptor in order to make up for or even surpass its 1/R^4 law. There are many things a radar can do to engineer an advantage and these are collectively known as Low Probability of Intercept (LPI) radars. These are too numerous and involved to elaborate on here, sorry. Clive — Preceding unsigned comment added by 62.63.61.10 (talk) 09:54, 18 October 2013 (UTC)[reply]

Some clarification please[edit]

"They improve on the older passive electronically scanned radars by spreading their signal emissions out across a band of frequencies, which makes it very difficult to detect over background noise." I know there are radars that exist that transmit over a very wide bandwidth, to make them hard to detect, but I don't believe this in an inherent feature of an AESA radar, and that it's just something you can put into an advanced radar system to improve it. The way the article is written at the moment, it seems to indicate that all AESA radars operate like this, which I don't believe is the case. But, I am no radar expert and could be wrong. Does anyone who actually knows about radars, know whether the article is right or wrong? Hammerfrog (talk) 16:43, 28 August 2013 (UTC)[reply]


Hammerfrog: I am an expert on radar and you are quite correct. There's nothing inherently wideband about AESA radars, other radars can also be wideband. In ALL radars, the technology obviously has to support the desired bandwidth. AESA antennas are not especially wideband; the radiating/transmitting elements they use are often not wideband and the spacings between elements is also a function of the wavelength and hence frequency at which they operate. To be honest, this is just one of many shortcomings in this article. There are several misleading claims and many glaring omissions about the advantages and disadvantages of AESA over conventional designs. Get a good book. Clive — Preceding unsigned comment added by 62.63.61.10 (talk) 09:45, 18 October 2013 (UTC)[reply]

AESA TR module and capabilities[edit]

This phrase is unclear: "Unlike the PESA, where the signal is generated at single frequencies by a small number of transmitters, in the AESA each module generates and radiates its own independent signal." Specifically, is the statement meant to imply that the signal source (oscillator plus modulator or DREX) is in the AESA TR module? If so, does it not lose the phase coherency that is required to reconstruct the return signals? Can you provide a reference for this as the ones I found do not make this implication, see http://www.globalsecurity.org/military/systems/aircraft/systems/an-apg-aesa.htm. At best, this seems to be an evolving technique and not definitional to AESA, see: http://www.dodsbir.net/sitis/archives_display_topic.asp?Bookmark=43314. (Additional comment removed as redundant to one above) Dave 204.186.81.254 (talk) 15:30, 5 January 2015 (UTC)[reply]

AESA is an antenna technology, not a type of radar[edit]

An AESA is not a "type of phased array radar", it is a type of antenna that is commonly used in radar systems but which may be used for other applications. I suggest the article would probably be better if it described the antenna technology in more generic terms and then discussed its application to radar, communications, EW, etc. NickNak (talk) 16:45, 5 April 2015 (UTC)[reply]

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