US Patent 9214712 Apparatus and methods related to ferrite based circulators

Apparatus and methods related to ferrite based circulators are disclosed. A ferrite disk used in a circulator can be configured to reduce intermodulation distortion when routing radio-frequency signals having closely spaced frequencies. Such a reduction in intermodulation distortion can be achieved by adjusting magnetization at the edge portion of the ferrite disk. By way of an example, a ferrite disk with a reduced saturation magnetization (4 PiMs) edge portion can reduce intermodulation distortion. Example configurations with such a reduced 4 PiMs edge portions are disclosed.