ANALYSIS OF NONRECIPROCAL MODE PROPAGATION IN MAGNETOOPTIC RIB-WAVE-GUIDE STRUCTURE WITH THE SPECTRAL-INDEX METHOD

Passive linear nonreciprocal devices, such as isolators or circulators , require gyrotropic media. If there is a contribution to the dielectr ic permittivity tensor of odd order in the magnetization, the modes pr opagate differently in the forward and the backward directions. We inv estigate dielectric waveguides that are formed by a rib of rectangular cross section on top of a planar structure. The rib or planar structu re may consist of layers, each of which may be gyrotropic. We extend t he spectral-index method for calculating differences between forward- and backward-propagation constants. A new design for an efficient nonr eciprocal phase shifter is proposed.