I what's the secret of Stelth Technology?
here's an intersting aricle about plasma witch is an ionise gas that will help Stealth Technology to work (besids anglw witch can reflect back to the radar waves. Oh yah I Saw the construction of F117 on history channel. Looks v nice from the top but if you think from the buttom, who will that angle reflect back to flat surface?
Here's the stuff about plasma and you will understand better once you read evrything all the way to the bootom. I alos posted a link to a pic regarding the angle of radar waves
Here is another interesting opinion about plasma stealth system descibed in ITAR/TASS article. This is from sci.physics.electromag:
"A while ago, there was an interesting post about putting a lighted candle in a microwave oven. while I did not actually do this myself (wife would kill me), apparently the flame, which is, of course plasma, absorbs the microwaves, and becomes self-sustaining, absorbing the microwave energy, and actually spreading. It may be that the Russian plasma generator works the same way, but of course, keeping the plasma going with EXPOSED R.F. generators would certainly be counter-productive from a STEALTH viewpoint, the plane would stand out like a beacon. The generators would have to be shielded, which would present significant difficulties in letting the plasma out quick enough to still be plasma.
A good old electrical discharge would also create plasma, but again, the EMI would be horrific.
The trick to STEALTH with plasma is quite straightforward. STEALTH consists mainly of absorbing the RADAR signals instead of reflecting them back to the RADAR set. This is done by matching the wave impedance (about 377 Ohm) with something resistive. The plasma is conductive, and in the correct quantities, i.e., mixture with air, will do the job very well. The 20 dB improvement they mention (1/100th reflected power) is probably very obtainable.
Very Interesting article.
And here's another message from sci.physics.electromagnetism on the same topic:
"Keep in mind that the following words are uttered from someone who maintains an interest in physics ... not a dedicated understanding. If it were possible to surround a plane with plasma, or anything else that claims radar reducing capability, you are probably dealing with a chemical application of the two basic signature reducing methods --- dispersion and dissipation. Plasma is ionized gas, which means that it's atoms have so much kinetic energy that valence electrons have been freed through atomic-level collisions. I suppose a radio signal encountering a plasma stream would easily be subject to dispersion. The electromagnetic radio wave encountering the plasma would become highly energized and change directions. This would cause it not to be reflected back to the radar station, and thus the radar station would have no knowledge of the aircraft's presence. It could be possible (and this is complete speculation on my part) that plasma could also entrap and dissipate the energy of the radio wave. This is what radar-absorbent materials currently do, like "IronBall," which is the nickname for the radar-absorbent paint used on planes like the F-22. They use ferro-magnetic (permanently magnetized) materials to try bounce the signal around until it dies, so that it can't reflect back to the radar station. Having a plasma stream do this would increase stealthiness without sacrificing aerodynamics and it may be more weight-effective."
Here's the pic and more info from howthingswork.com
The article How Radar Works talks about the basic principles of a radar system. The idea is for the radar antenna to send out a burst of radio energy, which is then reflected back by any object it happens to encounter. The radar antenna measures the time it takes for the reflection to arrive, and with that information can tell how far away the object is.
The metal body of an airplane is very good at reflecting radar signals, and this makes it easy to find and track airplanes with radar equipment.
The goal of stealth technology is to make an airplane invisible to radar. There are two different ways to create invisibility:
The airplane can be shaped so that any radar signals it reflects are reflected away from the radar equipment.
The airplane can be covered in materials that absorb radar signals.