Reflection and transmission of radio waves at a dielectric slab with variable permittivity

Expressions for the reflection and the transmission power coefficients are derived for the case where a plane wave is obliquely incident on a dielectric slab in which the relative permittivity decreases symmetrically according to a
1/z^{2}
law from a given maximum value at the plane of symmetry and tends towards unity at the two faces of the slab. The effect of the curvature and other parameters governing the inverse square profile on the transparency property of the material at radar frequencies has been studied within a large
d/\lambda
range where
d
is the half-slab thickness and
\lambda
the wavelength of the incident wave.