Dualities in circular gyrotropic disks and waveguides

Longitudinally magnetized gyroelectric waveguide with circular electric wall boundaries exhibit split limit-TE cut-off numbers but degenerate limit-TM cut-off numbers for non-symmetric modes. The magnetic wall waveguide displays degenerate limit-TE and limit-TM cut-off numbers. These results have been deduced directly from the characteristic equations of the related planar circuits. The existence of dual characteristics between gyroelectric and gyromagnetic planar structures with electric and magnetic walls interchanged are con finned. Measured resonant frequencies are compared with theoretical models for some gyromagnetic devices.