Stealth jets are about to get a little stealthier. That is, if Chinese engineers have anything to say about it. And, presumably, they do.
A group of researchers at Huazhong University of Science and Technology have published details on a chameleon-like stealth material that reactively tunes itself to absorb radar signals at different frequencies. The AFSS material - "active frequency selecting surface" -- can be used to coat the exterior of stealth aircraft so that it is rendered invisible to specific detection techniques.
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According to this interesting report at Ars Technica, current stealth technology only works against radars in a particular range - the SHF, or super high frequency range, if you're keeping score at home. But stealth craft are vulnerable to radar detection and targeting systems operating in the UHF range, or ultra high frequency.
The AFSS material would actually adjust itself to match and absorb longer-length frequencies when those wavelengths are detected, facilitating a kind of shapeshifting on the fly - literally. The technology incorporates several different systems using radically miniaturized diodes that act as resistors to electromagnetic radiation.
When combined with other stealth technologies, like those weird geometric designs that deflect radar waves, the AFSS technology could be the next big step in stealth aircraft development.
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The material is ultra thin, too, measuring only 7.8 mm when applied as a coating to metal and other surfaces. It consists of two layers supported by a third honeycombed layer provides separation from the underlying surface. The prototype AFSS system has been shown to absorb radio frequencies ranging from 0.7 to 1.9GHz, reducing reflectivity by anywhere from 10 to 40dB, researchers say.
"As radar detection equipment continues to improve, our thin absorbers with broad bandwidth and working in the UHF band will be widely useful," the researchers conclude. The study was published in the latest edition of the Journal of Applied Physics.
via Ars Technica