Abstract:

Structured radar absorbing materials play an important role in the stealth technology of military air-vehicles for their omnidirectional effectiveness without the need to change the original aerodynamical shape configuration. But experimental study of stealth efficiency and parametric effects for full scale structures requires considerable financial support and testing space, which limits the application of experimental tests. Therefore,it is of significant value to find the electromagnetic dispersion laws of the scale-down medium and the modification method between scale-down and full scale vehicle configurations.This paper makes a numerical study of the electromagnetic dispersion law of a scale-down model for an airfoil-like complicated medium configuration by means of the 2-D electromagnetic finite element method.The numerical computation leads to the following conclusion: the radar cross section(RCS) test result of electromagnetic dispersion of a scale-down model cannot be directly converted into that of the real-world medium prototype under conductor modification principle if the medium impedance ratio is greater than 0.5,and necessary modification must be done.This conclusion is of practical significance for the stealth test of minifying large-scale medium configuration for military air-vehicles.

Key words: electromagnetic , dispersion,  , finite , element , numerical , method,  , airfoil-like , medium , configuration,  , scale-down , model,  , RCS , modification,  , largescale , structure