Low-Profile Planar Dielectric Polarizer Using High-Dielectric-Constant Material and Anisotropic Antireflection Layers

A novel planar dielectric polarizer made of a low-profile high-dielectric-constant material is proposed. Two anisotropic antireflection layers are used on both sides to provide impedance transformation and anisotropy simultaneously. The proposed design uses a high-dielectric-constant material to reduce the overall thickness without severe reflections. The unit cells of the middle layer and the antireflection layer use separate periods for better adapting to the fabrication limitation. A polarizer prototype centered at 24 GHz is designed, fabricated, and measured. The prototype is 3-D-printed by commercial fused-deposition-modeling (FDM) technology using a material with a dielectric constant of 10. Experiments show that the prototype has a 25% operating bandwidth and a thickness of
$0.52\lambda _{0}$
(
$\lambda _{0}$
is the wavelength in the free space). The design methodology widens the choice for material selection and reduces the dimensions of the dielectric polarizer.