Rotation of the Polarization Plane by Grooved Flanges in a Circular Waveguide

The polarization plane rotators located outside the volume of a transmission line are presented. Their work is based on the excitation of special ("dihedral") eigen-oscillations in a waveguide object formed by two grooved flanges with rotational symmetry. When one of the flanges rotates relative to the other, the composite object becomes 3D-chiral and rotates the plane of polarization by a certain angle in the band of several percent with minimal reverse loss. In circular and coaxial waveguides, mechanical or electronic tuning of the polarization plane is possible by mutual rotation of the flanges or by placing the controlled elements (media) into the object cavity.