Perforated Medium Applied in Frequency Selective Surfaces and Curved Antenna Radome

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.

Electromagnetic Mathematical Modeling of 3D Supershaped Dielectric Lens Antennas

The electromagnetic analysis of a special class of 3D dielectric lens antennas is described in detail. This new class of lens antennas has a geometrical shape defined by the three-dimensional extension of Gielis’ formula. The analytical description of the lens shape allows the development of a dedicated semianalytical hybrid modeling approach based on geometrical tube tracing and physical optic. In order to increase the accuracy of the model, the multiple reflections occurring within the lens are also taken into account.