Edge-guided mode non-reciprocal circuit element for microwave energy

A non-reciprocal circuit element for microwave energy comprising:

• a ferrimagnetic slab;
• a strip-line conductor formed on one main surface of the ferrimagnetic slab and having first and second spaced edge portions of different lengths aligned parallel to the direction in which microwave energy is chiefly propagated;
• said conductor having a generally trapezoidal shape in which the ends of said conductor taper from said first edge portion to said second edge portion;
• the ends of said second edge portion defining the end portions of said conductor;
• a grounding conductor held in contact with the other main surface of the ferrimagnetic slab and kept at a ground potential;
• a first means for applying a DC magnetic field to the ferrimagnetic slab in a direction perpendicular to the plane of said ferrimagnetic slab, wherein a non-reciprocal propagation characteristic is exhibited at opposing edge portions of the strip-line conductor, characterized in that a second means is provided for developing a non-uniform DC magnetic field distribution at least along one edge portion of the strip-line conductor in cooperation with said first means for applying a DC magnetic field to the ferrimagnetic slab;
• said second means being comprised of means for supplying a magnetic field to one of said edges of said stripline conductor, the strength of the magnetic field being sufficient to cause said ferrimagnetic slab to bring about a magnetic resonance.