Single layer anisotropic impedance surface for linear to circular polarization conversion in Reflect mode

Anisotropic impedance surfaces are proposed as low-profile and broadband linear to circular polarization reflectors. By virtue of anisotropy it is possible to independently control the reflection characteristics of two orthogonal linearly polarized incident plane waves and therefore achieve polarization conversion. By means of an example involving a dipole array, the operation principle is demonstrated. A prototype is designed and its performance characteristics are evaluated. The 3 dB relative axial ratio bandwidth exceeds 60%, while low loss and better than previously reported angular stability are also demonstrated. Numerical and experimental results on a fabricated prototype are presented to validate the design and the performance.