Comparative Analysis of Tunable Compact Rotators

Three versions of two-layer polarization plane rotators in a circular waveguide based on the internal fringing field interaction are considered. They work on the excitation of unusual eigen-oscillations within the gap between a pair of peculiar four-slot metal irises. The subjects for comparison were the range of rotation angles, the possibility to provide good matching, and the ability of rotators to be tuned by mutual iris-to-iris rotation. The best properties were found in the case of the conjugated planar-chiral irises.