A perforated medium (PM) combined with an ultra-wideband frequency selective surface (FSS) is proposed for the antenna radome design, which provides more flexibility in the radome materials selection and processing. The dielectric constant performance of the PM can be improved by perforating air holes through the medium, thus the restrictions of the FSS medium material parameters can be released. A multiscale homogenization method is utilized to calculate the dielectric constant of this PM, and the transmission coefficients of the planar FSS structure at different incidence angles are computed. The PM FSS is then applied in the curved antenna radome. The physical optic method serves to analyze the transmission performance of the curved antenna radome. In order to reduce the computational difficulties and meet the requirements of physical optic computing, the transmission coefficients are obtained as a function of the frequency by the vector fitting method, and the incidence angle dependence is deduced by B spline interpolation. The simulated and experimental radiation patterns with and without the radome are compared and the results show good agreement.

The electromagnetic parameters of the dispersion material and metamaterial are vital in the engineering. The phase unwrapping method is proposed to deal with the phase ambiguity of the transmission and reflection method in electromagnetic (EM) parameters extraction. The computed results demonstrate that the proposed method can give the correct effective parameters. In dealing with scattering parameters with noise, the wavelet transform method is utilized to remove the noise added to the scattering parameters. The simulated results show that the correct material parameters can be obtained by wavelet denoising method. Finally, the proposed method is used to extract the parameters of the photonic crystal. The effective parameter gives a different aspect in explanation to the function for the photonic crystal.

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