Radar absorption by plasma
Publish date: 2001-01-01
Report number: FOI-R--0027--SE
Pages: 18
Written in: Swedish
Abstract
The possibility of reducing the radar cross section of aircraft by means of collisional plasmas is discussed. Electromagnetic theory shows that this is feasible, provided the plasma layer is sufficiently thick and has sufficient electron and neutral gas densities. For instance, a 2 cm thick plasma layer with electron density 10(18 in upper index) m(-3 in upper index) in a background of inert gas at atmospheric pressure gives at least about 10 dB reduction for frequencies from 4 to 15 GHz. Possible ways to generate such plasmas with moderate power consumption are discussed and references to experimental results published in the literature are given. Plasmas similar to those required for RCS reduction can be generated in inert gases using kV voltages at kHz frequencies across electrodes, at least one of which is covered by a dielectric. The published experimental results demonstrate all the required parameters, with the exception of layer thickness.