Originally posted by |-|05|:
i thought it was active stealth which the french,euro and US plane designers are trying to do also
No, the Russian Plasma Stealth is documented as something totally diferent from Active Stealth (also known as Active Radar Cancellation). In simple terms, Radar involves the emission of radio waves which will reflect off other aircraft back to the transmitting aircraft, thus giving a signal on the original aircraft's radar screen.
The various types of (known) stealth technologies are:
1) RAM (Radar Absorbing Materials): This is the most well known and comes in the form of paint or paneling found on the B-2 Spirit and F-117A Nighthawk. Basically, the materials used absorb the radar waves so less radar waves bounce back to the transmitting aircraft.
2) Active Radar Cancellation (what the French, European & US are experimenting): Active Radar Cancellation, to put this simply, an air defense radar is transmitting at a certain frequency; the signal is bouncing off the aircraft; a receiver aboard the aircraft picks up the signal and a computer analyses its base frequency and modulations and an out-of-phase signal is generated by onboard systems to cancel out the enemy radar signal. In other words, it uses new radar waves to cancel out the transmitting aircraft's radar waves.
3) Plasma Stealth: As mentioned, this uses electrically ionized gas as a radar absorbing layer, probably works like RAM.
Of the three methods, Active Radar Cancellation is probably the most complex as positioning the transmitting antennae aboard the aircraft to cover the entire aircraft (since the enemy radar signal is reflected from a multitude of points on the airframe and it's reflected differently from every one of them) is extremely difficult.
As the term Active Stealth is an informal name and is fairly broad in it's meaning. Many may confuse it to mean just Active Radar Cancellation.