Retrodirective array immune to incident waves with arbitrary polarizations

A retrodirective array (RDA) capable of retransmitting predictable polarization with respect to any received polarization state is presented. RDAs have the unique ability to scatter the received signal back to the interrogator without prior knowledge of the source location. In addition to this unique feature, the proposed system can receive any polarization and always retransmits the signal that is orthogonally polarized with respect to the received polarization state. This added feature helps to maintain a more stable communication link between the RDA and the interrogator by mitigating the polarization mismatch loss. The proposed system shows excellent retrodirectivity for various received linear and circular polarizations.