On aligning cascaded elements with the polarisation of the incident circularly polarised wave

Abstract

Abstract Given that the discrimination between the two senses of circular polarisation (CP) has been reported for cascades of progressively rotated wire‐grids, the author investigates whether or not the progressive rotation of the elements of a cascade would be the fundamental reason for the cascade to discriminate between the two senses of CP. The author also investigates whether or not the particular progressive rotation that consists in aligning each element of the cascade with the polarisation of a normally incident CP plane wave would necessarily provide the maximum discrimination between the two senses of CP. It is shown that neither progressive rotation nor alignment are fundamental or optimal for CP discrimination. CP discrimination is shown to be achieved even when the physical geometry of the CP antenna does not match the screw that is traced in space by the CP wave which is meant to be received/transmitted by the CP antenna. This observation is important to avoid misunderstanding the mechanism that underlies the phenomenon of CP discrimination.

Keywords

• electromagnetic wave polarisation
• microwave antenna arrays