Using an array lens as a circular polarization splitting prism

Abstract

Element rotation can be used to phase circular polarization (CP) reectarrays and array lenses. It is well known that the phase shift is proportional to the element's rotation, and this feature has been used in antenna designs [1], [2]. In this paper we focus on a lesser known attribute of the element rotation technique: the phase shift has opposite signs for each hand of CP. This feature can be used to build a at lens that splits an incident wave according to its CP components. The effect is similar to how a Wollaston prism separates unpolarized light into two linearly polarized beams. As shown in Fig. 1, the lens decomposes a randomly polarized incident wave into its CP components and redirects the power from each component into two separate beams. Surfaces that filter CP components have been generalized as circular-polarization-selective-surfaces [3]. These surfaces are not prisms as they reect one CP component and transmit the other.