Abstract: Embodiments disclosed herein relate to using cobalt (Co) to fine tune the magnetic properties, such as permeability and magnetic loss, of nickel-zinc ferrites to improve the material performance in electronic applications. The method comprises replacing nickel (Ni) with sufficient Co+2 such that the relaxation peak associated with the Co+2 substitution and the relaxation peak associated with the nickel to zinc (Ni/Zn) ratio are into near coincidence. When the relaxation peaks overlap, the material permeability can be substantially maximized and magnetic loss substantially minimized. The resulting materials are useful and provide superior performance particularly for devices operating at the 13.56 MHz ISM band.

Abstract: Embodiments disclosed herein include methods of modifying synthetic garnets used in RF applications to reduce or eliminate Yttrium or other rare earth metals in the garnets without adversely affecting the magnetic properties of the material. Some embodiments include substituting Bismuth for some of the Yttrium on the dodecahedral sites and introducing one or more high valency ions to the octahedral and tetrahedral sites. Calcium may also be added to the dodecahedral sites for valency compensation induced by the high valency ions, which could effectively displace all or most of the Yttrium (Y) in microwave device garnets. The modified synthetic garnets with substituted Yttrium (Y) can be used in various microwave magnetic devices such as circulators, isolators and resonators.

Abstract: Embodiments disclosed herein include methods of modifying synthetic garnets used in RF applications to reduce or eliminate Yttrium or other rare earth metals in the garnets without adversely affecting the magnetic properties of the material. Some embodiments include substituting Bismuth for some of the Yttrium on the dodecahedral sites and introducing one or more high valency ions to the octahedral and tetrahedral sites. Calcium may also be added to the dodecahedral sites for valency compensation induced by the high valency ions, which could effectively displace all or most of the Yttrium (Y) in microwave device garnets. The modified synthetic garnets with substituted Yttrium (Y) can be used in various microwave magnetic devices such as circulators, isolators and resonators.

Abstract: Disclosed are apparatus and methods related to junction ferrite devices having improved insertion loss performance. In some implementations, a ferrite disk assembly can be configured for a radio-frequency (RF) circulator. The disk assembly can include a ferrite-based disk having a ferrite portion and a metalized layer formed on a grounding surface of the disk to improve electrical contact between the grounding surface of the disk with an external grounding surface. The ferrite-based disk can further include a dielectric portion disposed around the periphery of the ferrite center portion. In some embodiments, the metalized layer can be a silver layer formed on the grounding surface of the disk and having a desired thickness.

Abstract: Disclosed are synthetic garnets and related devices that can be used in radio-frequency (RF) applications. In some embodiments, such RF devices can include garnets having reduced or substantially nil Yttrium or other rare earth metals. Such garnets can be configured to yield high dielectric constants, and ferrite devices, such as TM-mode circulators/isolators, formed from such garnets can benefit from reduced dimensions. Further, reduced or nil rare earth content of such garnets can allow cost-effective fabrication of ferrite-based RF devices. In some embodiments, such ferrite devices can include other desirable properties such as low magnetic resonance linewidths. Examples of fabrication methods and RF-related properties are also disclosed.

Abstract: 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.

Abstract: Embodiments disclosed herein include methods of modifying synthetic garnets used in RF applications to reduce or eliminate Yttrium or other rare earth metals in the garnets without adversely affecting the magnetic properties of the material. Some embodiments include substituting Bismuth for some of the Yttrium on the dodecahedral sites and introducing one or more high valency ions to the octahedral and tetrahedral sites. Calcium may also be added to the dodecahedral sites for valency compensation induced by the high valency ions, which could effectively displace all or most of the Yttrium (Y) in microwave device garnets. The modified synthetic garnets with substituted Yttrium (Y) can be used in various microwave magnetic devices such as circulators, isolators and resonators.

Abstract: Embodiments disclosed herein relate to using cobalt (Co) to fine tune the magnetic properties, such as permeability and magnetic loss, of nickel-zinc ferrites to improve the material performance in electronic applications. The method comprises replacing nickel (Ni) with sufficient Co+2 such that the relaxation peak associated with the Co+2 substitution and the relaxation peak associated with the nickel to zinc (Ni/Zn) ratio are into near coincidence. When the relaxation peaks overlap, the material permeability can be substantially maximized and magnetic loss substantially minimized. The resulting materials are useful and provide superior performance particularly for devices operating at the 13.56 MHz ISM band.