J-20 is ready for "air combat": in China, a fighter maneuvered without Luneberg lenses

J-20 without Luneberg lens

Events are being held in China during which J-20 fighter pilots pay tribute to "the heroic Chinese pilots who fought in the Korean War." It is stated that the fighter is ready "for air battles."

This was reported by China Central Television (CCTV), having posted the relevant footage of the flights. At the same time, it is indicated that during the maneuvers, the aircraft were not equipped with Luneberg lenses - radar reflectors used to make the "stealth" visible when performing training or ferry flights.

In some military operations, it may also be necessary for fighters to reveal themselves in order to deter the enemy while hiding their true stealth characteristics. As experts explained to the Chinese media, earlier J-20 was constantly observed with Luneberg lenses located "under the belly" of the machines.

As indicated in the press, by removing the reflector, the country's Air Force showed determination to send the J-20 to the battlefields, which means the fighter's transition to a new level of combat readiness.

Air Force pilots in the new century will inherit the spirit of air combat and prepare for the coming battles, resolutely defending national sovereignty and dignity

- said the Chinese military.

Recall that in China, the J-20 is classified as a new generation fighter. At the same time, the PRC has not yet solved the problem of creating its own aircraft engine, which would be suitable in terms of its characteristics to the fifth generation fighters. That is why many experts do not consider the Chinese aircraft to be the fifth generation of combat aviation appropriate.

Comments

[Lech from Android.]

Forward Chinese comrades ... you are waiting for the victory on the world hegemon of the United States.
And we will see how your air battles with the F-35, F-22 will take place.

[Grandfather]

China hosts the Grave Sweeping Festival [Memorial Day], during which J-20 fighter pilots pay tribute to "the heroic Chinese pilots who fought in the Korean War."

well done ... and our Pilots were remembered?

[Malyuta]

Quote: Dead Day

during which the pilots of the J-20 fighters paid tribute to the "heroic Chinese pilots who fought in the Korean War." well done ... and remembered our Pilots?

I am very sorry, but it seems that the Chinese have gained such a pace of development that now they rarely remember their great northern neighbor.

[yehat2]

Quote: Malyuta

gained such a pace of development that now they rarely remember the great northern neighbor.

their development is at least a quarter directly dependent on the Russian Federation
so they cannot ignore

[tralflot1832]

You did not see what it was in the beginning. The title of the article has been changed. And for the better. Eternal memory to the Chinese pilots.

[tralflot1832]

And how do you do it, on a smartphone it is possible. You have a cover of the article in the beginning, now it is no less provocative.

[Free wind]

I'll tell you more. in Vietnam, no one remembers Russian aid. In the Museum of War Victims in Hanoi, there is not a single mention of Soviet aid, not at all. But there are stands that the Americans not only killed civilians and non-civilians, but there were cool guys among them who helped the locals a lot .. By the way, that girl from the photograph who was burned by napalms has been living in Canada since 90.

[Bad_gr]

Quote: Free Wind

in Vietnam, no one remembers Russian aid.

Everyone has a scanty memory of Russia's help. Starting with the Bulgarians, who, if not for our help, would not have existed as a nation, the Poles, who demolished the monument to Konev, who forbade the use of heavy artillery in the city, which saved the city, but it was paid for with the lives of our soldiers, etc., etc.

[Kaman]

I think that the J-20 also has problems with stealth (like the SU-57)

[Eugene-Eugene]

I think that honey is harmful, but I am the current thinking, where to think next

[Krasnoyarsk]

Quote: Lech from Android.

you are waiting for the victory on the world hegemon of the United States.

And they will leave us for a snack. There are no allies in the world, only fellow travelers. China is a fellow traveler today and an enemy tomorrow. impossible to predict.

[tralflot1832]

Administration of the site. A great holiday for the Chinese people Qing Ming is a great day of remembrance for the departed. People who gave their lives in the war in the DPRK 50 53 years will be remembered. And this is not a festival !!!

[rotmistr60]

By removing the reflector, the country's air force showed determination to send the J-20 to the battlefields

There is indeed enough resolve, but "battlefields" have not yet been observed (we will leave Taiwan and the disputed islands aside for now). Well, of course, it is necessary to pay tribute to the victims.

[Papapg]

In our time, a corner reflector was used to increase the reflecting surface, a rather inexpensive device.

[Ka-52]

In our time, a corner reflector was used to increase the reflecting surface, a rather inexpensive device.

do not confuse the corner reflector and the Luneberg design. The Luneberg lens is primarily an emitter antenna - an actively transmitting element. A corner reflector is a passive device, a reflector in which the reflective planes are selected so as to directionally reflect the incident wave. They are each used for their own tasks. Lenses are used on airplanes and target missiles. And for ground (water) targets, imitators of objects such as a tank or a ship, corner reflectors are installed.

[Errr]

Quote: Ka-52

The Luneberg lens is primarily an emitter antenna - an actively transmitting element.

The Luneberg lens is in the first and all subsequent stages, including the last, just ... a lens. Without any "stuffing" of active elements.

They are now made multilayer - each layer has its own dielectric constant. The more layers (up to 10-15), the more accurately you can observe the required square-law dependence of the refractive index on the radius.

The photo below shows very clearly the multilayer structure of the lens exposed to missiles.

Absolutely without any antenna, the Luneberg lens, covered on one side with radio-reflective material, sends all the incoming radio waves back :

Luneberg lenses are now used as an effective reflector of radio waves. If one of its hemisphere is covered with a radio-reflecting material, then a lens with very little power loss reflects the incident signal in exactly the same direction it came from... For example, they are put on stealth planes in peacetime to mislead spies and saboteurs.

https://otrageniya.livejournal.com/1829843.html

[Ka-52]

Luneberg lens, lens antenna with a controllable position of the radiation pattern maximum in a wide sector of angles.

Lens antenna - an antenna with a lens similar to an optical one. Consists of an irradiator, lens, KVP and fasteners

[Errr]

You gave an example of a special case application of the Luneberg lens in the American ship radar AN / SPG-59... This is not at all what is under the belly of an airplane.

[Ka-52]

in the American ship radar AN / SPG-59

do not like mattresses - please visit our Orthodox radar station on Balkhash

This is not at all what is under the belly of an airplane

Would you like to go by car? )) they say it is useful for stabilizing a television signal over a satellite radio channel

[Errr]

I'm with Thomas, and you are with Yarema.
Luneberg lens, which is ONLY LENS special design, can be used in various products. In the American AN / SPG-59, for example, it was used in a phase-shifting device, which is now achieved in a more efficient way.

There are quite non-standard options for implementation and use. ANTENN based on Luneberg lens... An example is the antenna of the "Neman-P" radar.

Receiving position of the radar "Neman" at the Balkhash training ground.

And today the most promising area of ​​application of Luneberg lenses is the organization of communication in arbitrary directions in space. Figure 7 shows a variant of the possible application of LL when working in multichannel communication systems.

Multichannel satellite communication terminal with LL.

Currently, the world market presents options for civilian use of Luneberg lenses installed on the roofs of cars to organize a stable television signal via a satellite radio channel. An example is KVH's TracVision systems.

Luneberg lens for civil use.

Source: https://nag.ru/articles/article/30272/vyisokonapravlennyie-linzovyie-antennyi-lyuneberga.html
And so on and so forth.
Only all of the above has to do with highly directional lens Luneberg antennasIe devices that have the above lens in their composition.
Not so complex installations are suspended under the plane, but just a set of 2 Luneberg lenses working in diametrically opposite hemispheres, nothing more. Voila!

The photo above shows the Luneberg lens on the F-22, and the bottom photo on the J-20 (top right corner).

For some reason, only on the F-35 there are 4 of them.

[Ka-52]

no need to strain so much, it is harmful :))
In the idea of ​​Lumberg himself, the lens works together with the source (horn).

[Errr]

Quote: Ka-52

no need to strain so much, it is harmful :))

Suddenly I remembered:

- Dad, what are the dogs doing?
- Look, sonny, one dog relaxed, and the other tensed. Got it?
- Got it ...
- What do you understand?
- No need to relax.

Quote: Ka-52

In the idea of ​​Lumberg himself, the lens works together with the source (horn).

Is it possible from this place in more detail?

[voyaka uh]

"Not so complicated installations are suspended under the plane" ///
---
This is no longer the case.

[Errr]

If you're talking about the F-35, then I'm already intrigued.

[Mountain shooter]

Oh, how curious it is to look on the J-20 radar without Luneberg lenses. And put the F-35 side by side.
It's like an engineer. The fact that the fighters "put on camouflage coats" speaks of the extreme point of tension and that the Chinese comrades leave very little time before the "bayonet battle". Considering that the enemy will not have time to use and "adjust" their radars ... Although, on the demonstration, where is the enemy with the radars from?

[Vita vko]

Quote: Mountain Shooter

curious to look at the J-20 radar without Luneberg lenses. And put the F-35 side by side.

Radiopaque coating that one that another aircraft is known for, the exact dimensions too. Nothing prevents us from building a reduced model of the aircraft and taking a full radar portrait from it in all ranges. Then all that remains is to verify and calibrate it during short-term detections with real radars. The technique is relatively simple and has been used for a long time. I think that the parameters of both the thermal and radar portrait of the J-20, F-35 and F-22 have been crammed into the memory of the onboard computers of Russian fighters for 10 years, including the algorithms for using weapons for these purposes.
As far as I understand, now a promising direction is the development of the capabilities of fighters to destroy ballistic and hypersonic targets.

[Alex_Bora]

You are so naive ... Especially about 10 years))) ... In 10 years ... Maybe ...
And the reduced copy will only help for the optical port. For a radar portrait, you need a full-size model + appropriate materials + corresponding equipment models under radio-transparent surfaces or, at worst, a mathematical model.
Scaling the linear dimensions of the target will not scale the transmitter wavelength. And this will already be a different picture, nothing to do with reality.

[Vitaly.17]

Quote: Alex_Bora

Scaling the linear dimensions of the target will not scale the transmitter wavelength. And this will already be a different picture, nothing to do with reality.

How is it, but our scientists at NII-2 did not even think about it
Thank you for prompting

[tralflot1832]

Are you talking about NII 2 near Tver?

[vic02]

you will not scale the transmitter wavelength

It is possible to scale the wavelength, but the fact that the model, made from the estimated data, will not allow obtaining the real characteristics of the target is for sure.

[vic02]

Radio absorbing coating that one knows that another aircraft, exact dimensions too

Do you know the exact dimensions, reflection characteristics and characteristics of the F-22 and J-20 RPMs that even allies are not allowed to get close to? Verify objects hung with Luneberg lenses by short-term detections? All models provide only rough estimates.

[Grognag]

And the lens was probably bright red? And if it is invisible, why is it in the photo? Maybe it is less noticeable for radars?

[Errr]

Quote: Grognag

And the lens was probably bright red?

Actually yellow-orange.
In the photo below, it is under the belly near the left main landing gear.

[Alexey Stepanov]

What about the J-20 with meter invisibility?

[voyaka uh]

In meter it is noticeable. As well as F-22 and F-35.
Only the B-2 is hardly noticeable in the meter range too.

[Pavel57]

Quote: yehat2

their development is at least a quarter directly dependent on the Russian Federation
so they cannot ignore

Their development so far directly depends on the sales market - the USA and Europe.

[avt77]

The J-20 is visually similar to the 5th generation, but in fact it is not.

[Dzafdet]

Quote: Alex_Bora

You are so naive ... Especially about 10 years))) ... In 10 years ... Maybe ...
And the reduced copy will only help for the optical port. For a radar portrait, you need a full-size model + appropriate materials + corresponding equipment models under radio-transparent surfaces or, at worst, a mathematical model.
Scaling the linear dimensions of the target will not scale the transmitter wavelength. And this will already be a different picture, nothing to do with reality.

We stole a couple of F-xx in Syria and brought them to Moscow for study. So both the planes and the models are all right ...