Design of thin circular polarizers

A circular polarizer is a surface or a cascade of surfaces that converts linearly polarized waves into circularly polarized waves. In this paper, a simple method is proposed to model and design these surfaces using transmission line circuit theory. This technique also permits to reduce spacing between surfaces as desired. In this way, thinner circular polarizers can be made. A conventional meander-line circular polarizer (spacing of λ/4 between its surfaces) made of three surfaces is designed and compared with a new “hybrid” circular polarizer having half the thickness. Results are shown and compared.