Russian Fifth-Generation Fighter to Exceed Rivals

[Chinaownseverything]

Dude, enough

the F22 and the F35 have as much to do with metamaterials as they have with metaphysics ....

the excellent F22 design is down to the key understanding and computer aided design of and on the theories developed by Pyotr Ya. Ufimtsev.

Designers have a much better understanding and can simulate far better the difraction and absorbtion of em waves far better now than they could in the 70's .

Fundamentals of the Physical Theory of Diffraction
Pyotr Ya. Ufimtsev

I suggest you buy the book if you have any doubts ...
oh by the way , the guy was russian and he wrote the book in the 60's ...

oh .. and the ENTIRE stealth tech is based on it.

Explain then why recently developed stealth ships look more like the F-117 than the F-22?

Creating a stealth fighter is not as easy as stealing an airframe and filling it up with electronics and slapping on an engine.

The only reason why the F-22 is possible is because of advances in metamaterials

See here

http://ieeexplore.ieee.org/search/f...ft&openedRefinements=*&searchField=Search+All

This paper shows the drastic effect that generic RAM paint, obviously in a real situation militaries will be using RAM paint thats not for sale, and not all parts of the plane are painted (As some parts of the plane will face particularly nasty heat+ pressure that will erode it), the parts that aren't painted are constructed from radar absorbing metamaterials

http://ieeexplore.ieee.org/search/f...ts&openedRefinements=*&searchField=Search+All

And as you can see from this paper they compare the radar cross section of the F-117 to the F-22 simply based on the shape


Clearly the F-117 has the superior stealth design since the F-117 is almost 3 times as big as the F-22 yet the RCS does not differ significantly, if the F-22 was optimized for stealth the design would look similar to the F-117 as it would have an even smaller cross section.

I have IEEE login so if you are unable to login I can post pics even though they will take awhile

 

[gambit]

I have read enough of this metamaterials nonsense.

Explain then why recently developed stealth ships look more like the F-117 than the F-22?

Because of the 2D environment. Radar signals do not penetrate well into and under water. Realistically...Any radar signal that impact water surface will deflect back up, therefore it make sense to have faceted angles on the ship. The effect is called 'multipath propagation' and is most prominent when the approaching signal is parallel to the surface, even land. For water, temperature layers can create additional deflective surfaces for any radar signal that did penetrate the surface.

Assuming a parallel to the surface approaching signal, we have:

1) Direct-direct
This is where the signal and echo have their direct paths.

2) Direct-indirect
This is where the signal is direct, from seeker to target, but a portion of the echo deflects off the water surface before going back to the seeker radar.

3) Indirect-direct
This is where a portion of the signal deflects off the water surface, create an echo off the body, and a portion of the echo took the direct path back to the seeker radar.

4) Indirect-indirect
This is where portions of both signal and echo deflects off the water surface before reaching their destinations.

All four types have delays with each other. Ironically...The more sophisticated the seeking radar, the greater the negative effects from multipath propagation as this sophisticated radar is trying to process what it believes to be four targets or four ghosts, depending on the humidity level and temperature layers of the body of water.

So for ship, angling its side surfaces to deflect any echo signals upward make sense. Where else can we deflect but up anyway since this is a 2D environment?

The only reason why the F-22 is possible is because of advances in metamaterials

There are no 'metamaterials' on the F-22.

See here

This paper shows the drastic effect that generic RAM paint, obviously in a real situation militaries will be using RAM paint thats not for sale, and not all parts of the plane are painted (As some parts of the plane will face particularly nasty heat+ pressure that will erode it), the parts that aren't painted are constructed from radar absorbing metamaterials

IEEE Xplore - Abstract Page

And as you can see from this paper they compare the radar cross section of the F-117 to the F-22 simply based on the shape


Clearly the F-117 has the superior stealth design since the F-117 is almost 3 times as big as the F-22 yet the RCS does not differ significantly, if the F-22 was optimized for stealth the design would look similar to the F-117 as it would have an even smaller cross section.

I have IEEE login so if you are unable to login I can post pics even though they will take awhile

The F-117 uses angled facetings while the F-22 uses curves. Both fall under body shaping to effect radar surface behavior controls. The negative side to angled faceting is reduce aerodynamic performance and increase use of absorbers. The positive side of curves are superior aerodynamic performance and far less demand for absorbers. So for the 3D environment curves are better.

News for you, buddy. Radar absorber, solid or liquid, are commercially available. They are known for radome application. It is only the ferrite particle formulation in size and distribution that is secret to these 'stealth' aircrafts.

 

[amalakas]

Finaly Gambit

you popped in when and where you were needed. !


also ..

It is only the ferrite particle formulation in size and distribution that is secret to these 'stealth' aircrafts.

I was under the impression that the method of application for RAM coatings is also a "secret" as their performace varies depending on how they are applied on surfaces.

 

[gambit]

I was under the impression that the method of application for RAM coatings is also a "secret" as their performace varies depending on how they are applied on surfaces.

Not really. The 'paint' is just like any other paint that we use to color our houses or aircrafts. Except that it is slightly heavier. Then we moved to adhesive panels. For gaps between panels, we have 'zip strips', essentially sticky strings that are thicker and heavier to get between the gaps.

Clarifications...

For 'gaps between panels', I meant aircraft hard panels, not the adhesive panels or sheets. It is the frequently access maintenance hard panels that are problematic for RCS controls.

 

[amalakas]

Not really. The 'paint' is just like any other paint that we use to color our houses or aircrafts. Except that it is slightly heavier. Then we moved to adhesive panels. For gaps between panels, we have 'zip strips', essentially sticky strings that are thicker and heavier to get between the gaps.

fair enough

 

[Thomas]

Not really. The 'paint' is just like any other paint that we use to color our houses or aircrafts. Except that it is slightly heavier. Then we moved to adhesive panels. For gaps between panels, we have 'zip strips', essentially sticky strings that are thicker and heavier to get between the gaps.

It is also incorporated into carbon fiber now as well.

 

[Devianz]

Clearly the Antenna used for communications is different from the Antenna used used in radars.

RESOLUTION RADAR USING METAMATERIALS

A radar system includes at least one transmit array comprising a plurality of metamaterial elements. The radar system further includes at least one near-field stimulator for inputting electromagnetic signal to the transmit array so that a sub-wavelength target is illuminated with an electromagnetic wave.

Phased array metamaterial antenna system

An efficient, low-loss, low sidelobe, high dynamic range phased-array radar antenna system is disclosed that uses metamaterials, which are manmade composite materials having a negative index of refraction, to create a biconcave lens architecture (instead of the aforementioned biconvex lens) for focusing the microwaves transmitted by the antenna. Accordingly, the sidelobes of the antenna are reduced. Attenuation across microstrip transmission lines may be reduced by using low loss transmission lines that are suspended above a ground plane a predetermined distance in a way such they are not in contact with a solid substrate. By suspending the microstrip transmission lines in this manner, dielectric signal loss is reduced significantly, thus resulting in a less-attenuated signal at its destination.

Left-Handed Metamaterial Technologies Significant for Information and Communication Devices

Wide-Range Beam Scan of Radar Antenna
A radar is a system that performs a wide range scanning detection across a certain angle by rotating its antenna havinig a directional narrow beamradiation pattern. The phase of the electromagnetic wave inside the antenna is so controlled as to implement the antenna's beam scan without using a rotation mechanism. A backward wave from a lefthanded metamaterial can be used effectively to widen the range of beam scanning. Sweeping the frequency of the radar electromagnetic wave from the righthanded frequency band to the left-handed frequency band, both the ordinary forward wave (electromagnetic wave in a right-handed medium) and the backward wave can be used. The doubled range in phase shift can double the scanning range by the antenna beam

METAMATERIAL MEDIATED INVERSE CHERENKOV ACCELERATION

In this paper we consider the application of metamaterials to Traveling Wave Tubes (TWT). The TWT proposed in the 1940's by Kompfner [1] remains the driving technology for many applications ranging from communications to radar. The interaction between
electron beam and EM field results in an energy transfer from beam to wave. To date four papers [2][3][4][5] have considered metamaterials in TWTs, first three of them used metamaterials to line the side of the structure to minimise losses and increase efficiency, while the 4th paper [5] used metamaterial along the waveguide mode propagation path.

Metamaterials based steerable antennas for millimeter wave radar applications

Enjoy

 

[Thomas]

There a lots of different applications for meta materials, some of it having to do with stealth. However the entire field of meta materials is in it's infancy. And to ascribe currently fielded stealth aircraft as benefiting from meta materials is incorrect.

A Duke university team that is at the vanguard of Meta Material research give an example of meta material usages.

Duke Magazine-The Magic of Metamaterials By Ker Than-March/April 2007

" In the future, the Duke team’s metamaterials could be used to conceal military aircraft from radar better than current stealth technology, protect people and electronics against harmful electromagnetic radiation, create super-sensitive solar cells, or focus light rays into tight beams, enabling a satellite orbiting Mars, for example, to transmit power to a rover on the planet’s surface.

Two other classes of metamaterials, being developed by other researchers, have the potential to create “super lenses” that could be fitted onto microscopes and allow scientists to peer into the mysterious inner workings of living cells, or to shepherd electrons more precisely and efficiently for the construction of smaller electronics and faster computers."

 

[Chinaownseverything]

Because of the 2D environment. Radar signals do not penetrate well into and under water. Realistically...Any radar signal that impact water surface will deflect back up, therefore it make sense to have faceted angles on the ship. The effect is called 'multipath propagation' and is most prominent when the approaching signal is parallel to the surface, even land. For water, temperature layers can create additional deflective surfaces for any radar signal that did penetrate the surface.

Assuming a parallel to the surface approaching signal, we have:

1) Direct-direct
This is where the signal and echo have their direct paths.

2) Direct-indirect
This is where the signal is direct, from seeker to target, but a portion of the echo deflects off the water surface before going back to the seeker radar.

3) Indirect-direct
This is where a portion of the signal deflects off the water surface, create an echo off the body, and a portion of the echo took the direct path back to the seeker radar.

4) Indirect-indirect
This is where portions of both signal and echo deflects off the water surface before reaching their destinations.

All four types have delays with each other. Ironically...The more sophisticated the seeking radar, the greater the negative effects from multipath propagation as this sophisticated radar is trying to process what it believes to be four targets or four ghosts, depending on the humidity level and temperature layers of the body of water.

So for ship, angling its side surfaces to deflect any echo signals upward make sense. Where else can we deflect but up anyway since this is a 2D environment?

Nope the basic rule is that the more spherical the more easily you show up on radar. Without a doubt it has been proven that a flat angled plate has the best deflection.

RCS of bent rectangular shape



Compared to RCS of curved rectangular shape



Adaptive grid method to show deflection of a angled plate

There are no 'metamaterials' on the F-22.

The F-117 uses angled facetings while the F-22 uses curves. Both fall under body shaping to effect radar surface behavior controls. The negative side to angled faceting is reduce aerodynamic performance and increase use of absorbers. The positive side of curves are superior aerodynamic performance and far less demand for absorbers. So for the 3D environment curves are better.

News for you, buddy. Radar absorber, solid or liquid, are commercially available. They are known for radome application. It is only the ferrite particle formulation in size and distribution that is secret to these 'stealth' aircrafts.

Here you go RCS comparisons between the F-22 and F-117









The design of the F-117 is obviously better for stealth as the F-117 is much larger than the F-22 yet the RCS cross sections are almost equivalent.

The F-22 was built more for aerodynamics rather than pure stealth as a shrunken F-117 to the size of the F-22 would have a smaller cross section.

However the F-22 gets a smaller RCS because of metamaterials and better RAM paint.

And please learn what metamaterial is before making claims about it

History of metamaterials - Wikipedia, the free encyclopedia

Invention of the metamaterial

Historically, and conventionally, the function or behavior of materials can be altered through their chemistry. This has long been known. For example, adding lead changes the color or hardness of glass. However, at the end of the 20th century this definition was about to be expanded.[9]

In the 1990s Sir John Pendry, a physicist from Imperial College in London who was consulting for a British company, Marconi Materials Technology, as a condensed matter physics expert. The company manufactured a stealth technology, a radiation-absorbing carbon, for naval vessels. However, the company did not understand the physics of the material. The company asked Pendry if he could figure it out.

Your arguments are mostly irrelevant, your jargon impresses nobody. You can't understand simple mathematical proofs. You don't seem to understand propagation of electromagnetic radiation.

Stick to your area of expertise washing toilets for the USA navy instead of trying to talk physics when you probably don't have a high school degree.

 

[Chinaownseverything]

There a lots of different applications for meta materials, some of it having to do with stealth. However the entire field of meta materials is in it's infancy. And to ascribe currently fielded stealth aircraft as benefiting from meta materials is incorrect.

A Duke university team that is at the vanguard of Meta Material research give an example of meta material usages.

Duke Magazine-The Magic of Metamaterials By Ker Than-March/April 2007

" In the future, the Duke team’s metamaterials could be used to conceal military aircraft from radar better than current stealth technology, protect people and electronics against harmful electromagnetic radiation, create super-sensitive solar cells, or focus light rays into tight beams, enabling a satellite orbiting Mars, for example, to transmit power to a rover on the planet’s surface.

Two other classes of metamaterials, being developed by other researchers, have the potential to create “super lenses” that could be fitted onto microscopes and allow scientists to peer into the mysterious inner workings of living cells, or to shepherd electrons more precisely and efficiently for the construction of smaller electronics and faster computers."

There are many types of metamaterials, literally thousands all of them have potential military applications. More are being discovered everyday.

We have had plenty of these at hand when the F-22 was being conceived

History of metamaterials - Wikipedia, the free encyclopedia

Invention of the metamaterial

Historically, and conventionally, the function or behavior of materials can be altered through their chemistry. This has long been known. For example, adding lead changes the color or hardness of glass. However, at the end of the 20th century this definition was about to be expanded.[9]

In the 1990s Sir John Pendry, a physicist from Imperial College in London who was consulting for a British company, Marconi Materials Technology, as a condensed matter physics expert. The company manufactured a stealth technology, a radiation-absorbing carbon, for naval vessels. However, the company did not understand the physics of the material. The company asked Pendry if he could figure it out.[9]

 

[Chinaownseverything]

RESOLUTION RADAR USING METAMATERIALS




Phased array metamaterial antenna system


Left-Handed Metamaterial Technologies Significant for Information and Communication Devices


METAMATERIAL MEDIATED INVERSE CHERENKOV ACCELERATION


Metamaterials based steerable antennas for millimeter wave radar applications

Enjoy

What is your point? I have already acknowledged that metamaterials could be used to improve radar.

Russian guy used USA replacing the antenna of a router with metamaterial and claimed that they were using them in AESA radars NOW using the assumption that if they did it to a router they can do it to a radar.

We might be able to improve radar in the future, but the radar we use right now does not incorporate

 

[Devianz]

I would love to see Gambit's reply.....

 

[Devianz]

What is your point? I have already acknowledged that metamaterials could be used to improve radar.

Russian guy used USA replacing the antenna of a router with metamaterial and claimed that they were using them in AESA radars NOW using the assumption that if they did it to a router they can do it to a radar.

We might be able to improve radar in the future, but the radar we use right now does not incorporate

That's the whole point.... In future many things would be possible.

 

[Thomas]

We have had plenty of these at hand when the F-22 was being conceived

Not true the concept of the F-22 dates to the 80's, with the first YF-22 flight in 1990. The first experimental demonstration of Meta Materials was in 2000. Prior to that meta materials were theoretical only. The field really is only in it's early stages of development. 20 - 30+ years from now you may start to see meta materials applied to the field of stealth. but for now the technology simply is not there.

Metamaterial - Wikipedia, the free encyclopedia

Lockheed Martin F-22 Raptor - Wikipedia, the free encyclopedia

 

[dbc]

Stick to your area of expertise washing toilets for the USA navy instead of trying to talk physics when you probably don't have a high school degree.

..and what do you do at NYU-Poly