Study on the influence of thin plasma thickness on electromagnetic wave attenuation

Plasma stealth technology has the advantage of real-time regulation of the absorbing band and does not affect the aerodynamic performance. The thin-layer cavity facilitates installation on special parts such as the surface of the aircraft body. However, the thickness of plasma directly determines the transmission distance of the radar wave in the plasma. When the thickness is decreased, the attenuation effect of the plasma on electromagnetic waves is reduced. In response to this problem, we studied the influence of thickness on electromagnetic wave scattering parameters, and established a fluid model of a planar transparent cavity ICP source using the multi-physics coupling method COMSOL in this paper. The accuracy of the fluid model is improved by adding the Boltzmann solver. COMSOL combined with ZT-FDTD method was used to establish the calculation model of ICP electromagnetic scattering parameter. The results of simulation show that the thickness has a significant influence on the ICP electromagnetic scattering parameters. When the thickness of plasma decreases, the central area of ne keeps deviating from the center of the cavity, the ring feature is enhanced, and the attenuation effect is generally in a downward trend. The main attenuation bandwidth in the frequency band also shows a shrinking trend. Through comparative experiments, the increase of pressure on the improvement of the main attenuation bandwidth compensates for the reduction of the main attenuation bandwidth caused by the decrease in thickness. •A fluid model of a planar ICP source is established using the multi-physics coupling method COMSOL.•COMSOL combined with ZT-FDTD method was used to calculate the electromagnetic scattering characteristic of ICP.•The problem of the inaccuracy of EEDF in fluid module is corrected by introducing Boltzmann equation solver.•The cavity thickness has a significant influence on the electromagnetic scattering characteristic of ICP.•When the plasma thickness decreases the attenuation effect is generally in a downward trend.