A device for unidirectional propagation of microwaves comprises a resonant microwave structure arranged to transmit microwaves between two ports and a magnetic source arranged to provide a generally static magnetic field and to have a resonant frequency distinct from that of the microwave structure, which is disposed adjacent the microwave structure so as to be located in presence of electromagnetic fields emanating from the transmitted microwaves such that the magnetic field interacts with the electromagnetic fields of the microwaves so as to form a set of hybridized resonant frequencies at which zero intrinsic damping exists, one of the set of hybridized resonant frequencies being a real eigenvalue providing the unidirectional propagation from one of the first and second ports to the other. A related method comprises arranging the magnetic source at a prescribed position where the real eigenvalue matches the frequency of an input signal applied at a selected port.

Disclosed are embodiments of synthetic garnet materials for use in radiofrequency applications. In some embodiments, increased amounts of gadolinium can be added into specific sites in the crystal structure of the synthetic garnet by incorporating indium, a trivalent element. By including both indium and increased amounts of gadolinium, the dielectric constant can be improved. Thus, embodiments of the disclosed material can be advantageous in both above and below resonance applications, such as for isolators and circulators.

Disclosed herein are ceramic materials, such as bismuth substituted garnets, which can have high curie temperatures and high dielectric constants. In certain implementations, indium can be incorporated into the ceramic to improve certain properties and to avoid calcium compensation. The ceramic materials disclosed herein can be particular advantageous for below resonance applications.

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.

Disclosed are methods of forming a single-piece magnetically tunable ferrite rods that can be used for radio-frequency (RF) applications, including using synthetic garnets. This can include methods of forming cellular towers and antennas. In some embodiments, a separate tuner need not be used in the resonator during magnetic tuning. Examples of fabrication methods and RF-related properties are disclosed.

A composite magnetic material has a plurality of grains having a magnetic ferrite phase, grain boundaries surrounding the grains, and a plurality of nanoparticles disposed at the grain boundaries. The nanoparticles of the composite material are both magnetic and electrically insulating, having a magnetic flux density of greater than about 100 mT and an electrical resistivity of at least about 10.sup.8 Ohm-cm. Also provided is a method of making the composite material. The material is useful for making inductor cores of electronic devices.

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.

Provided is a new magnetic material with high magnetic stability, as well as a manufacturing method therefor, said magnetic material having a higher saturation magnetization than ferrite-based magnetic materials, and having a higher electrical resistivity than existing metal-based magnetic materials, thus solving problems such as that of eddy current loss. Ti-ferrite nanoparticles obtained through wet synthesis are reduced within hydrogen, and grains are allowed to grow while simultaneously using a phase separation phenomenon due to a disproportionation reaction to produce a magnetic material powder in which an -(Fe, Ti) phase and a Ti-enriched phase are nano-dispersed. This powder is then sintered to produce a solid magnetic material.

Disclosed are single-piece magnetically tunable ferrite rods that can be used for radio-frequency (RF) applications, and methods of manufacturing the resonators using synthetic garnets. In some embodiments, a separate tuner need not be used in the resonator during magnetic tuning. Examples of fabrication methods and RF-related properties are also disclosed.

Disclosed are embodiments of synthetic garnet materials for use in radiofrequency applications. In some embodiments, increased amounts of gadolinium can be added into specific sites in the crystal structure of the synthetic garnet by incorporating indium, a trivalent element. By including both indium and increased amounts of gadolinium, the dielectric constant can be improved. Thus, embodiments of the disclosed material can be advantageous in both above and below resonance applications, such as for isolators and circulators.