A Way to Realize a Multi-Frequency Polarization Plane Rotator

In this paper, we propose a simple design of a planar-chiral screen based polarization plane rotator that enables a polarization conversion at two assigned frequency bands simultaneously. The rotator is composed of a pair of conjugated double periodic perforated screens separated by a short distance. Two groups of four rectangular slots are cut along a perimeter of the screen periodical cell. Polarization rotation frequencies are controlled by choosing appropriated dimensions and placements of the slots' groups. At the same time, we report that even a rotator with equal slots belonging to different (outer or internal) quadruples enables a dual-frequency operation as well.