Patent ID: 7834717

Claim:
A nonreciprocal circuit device comprising: permanent magnets; a ferrite to which a direct-current magnetic field is applied by the permanent magnets; and a first center electrode and a second center electrode arranged so as to intersect each other on the ferrite in an insulation state in which the first and second center electrodes are electrically insulated from each other, each of the first and second center electrodes being made of a conductive film; wherein the ferrite and the permanent magnets define a ferrite-magnet assembly in which the ferrite is sandwiched between the permanent magnets in parallel or substantially in parallel with surfaces of the ferrite on which the first and second center electrodes are disposed; the ferrite includes a center layer and an outer layer, the outer layer is arranged to ensure an insulation state of the first center electrode and the second center electrode; saturation magnetization of the outer layer being smaller than saturation magnetization of the center layer.