A three-port Ferrite resonator circuit using coplanar waveguide

A three-port magnetically-tunable ferrite resonator circuit is proposed, which uses a ferrite resonator and coplanar waveguide on a dielectric substrate. This circuit has both resonator and isolator properties, and is applicable to a magnetically-tunable oscillator using with an active component. It is not necessary to use an additional isolator for reducing the influence of the reflected power on the oscillation. Experiments are done with YIG and CaVG ferrite. The existence of an optimum position for placing ferrite to obtaining the maximum non-reciprocity, is ascertained by the theoretical and experimental results. This circuit is simple in construction , and suitable for wide-band operation.