Optimal Design and Implementation of Inhomogeneous Planar Radome by Perforating the Host Material

An analytical expression for the reflection and transmission coefficients (TE and TM) for inhomogeneous planar layer (IPL) with variable inverse square relative permittivity is achieved. The correctness of derived expression is shown by comparison with Comsol numerical simulation. After choosing an appropriate material as the host medium, the transmission coefficient of inhomogeneous layer is calculated versus d/λ
₀
. Then, the optimum profile of relative dielectric constant is obtained based on desired requirements. As an experimental prototype, IPL is discretized to seven different homogeneous layers. Equivalent medium theory (EMT) is used to realize necessary dielectric constant of each layer by using asymmetric Brugemans's (ABG) formula. The radome layers are fabricated by perforating numerous holes in the host material with diameters sufficiently smaller than the wavelength. Properly sticking different layers together forms the final radome geometry. The designed radome is verified with free-space measurement setup. The measurement results are in good agreement with simulations and shows low insertion loss and high stability in wide aspect angle range for both TE and TM polarizations.