Electromagnetic backscattering from thin conductive films

The radar backscattering from thin conductive films is examined and an expression which provides an indication of the loss in cross section as a function of layer thickness is derived. Experimental results are given for aluminum and nickel, as obtained from anechoic chamber measurements. It is indicated that a metallic film of only a few thousandths of a skin depth is all that is necessary to provide reflection coefficients of unity, and that the only material property of any significance is the dc conductivity. As a result, it is concluded that a ferromagnetic material does not allow for utilization of a thinner film as a reflective surface.