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US 9,793,037 B2Granted
Apparatus and methods related to ferrite based circulators
AssigneeSkyworks Solutions, Inc.
InventorsDavid Bowie Cruickshank, Brian Murray
Life of this patent
Estimating the term…
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 (4PiMs) edge portion can reduce intermodulation distortion. Example configurations with such a reduced 4PiMs edge portions are disclosed.
Claims18
A passive circulator, comprising:
- a pair of ferrite plates, a center portion of each of the ferrite plates having a first saturation magnetization value and an edge portion of each of the ferrite plates having a second saturation magnetization value that is lower than the first saturation magnetization value;
- a pair of dielectric structures, each dielectric structure disposed along an outer perimeter of one of the ferrite plates;
- a pair of magnets that provide a static magnetic field to the ferrite plates to magnetize the ferrite plates, the ferrite plates disposed between the pair of magnets;
- and
- a housing that surrounds and encloses the pair of magnets, the pair of ferrite plates and the pair of dielectric structures, and which provides a return path for the magnetic field, the dielectric structures extending laterally from said outer perimeter of the ferrite plates to an inner surface of the housing.
2 more elements
A passive circulator module for isolating transmit and receive radio-frequency signals from each other, the module comprising:
- a pair of ferrite plates each defining a center portion and an edge portion, the center portion having a first saturation magnetization value and the edge portion having a second saturation magnetization value that is less than the first saturation magnetization value;
- a pair of dielectric rings, each dielectric ring disposed along an outer perimeter of the edge portion of one of the ferrite plates;
- a pair of magnets that provide a static magnetic field to the ferrite plates to magnetize the ferrite plates, the ferrite plates disposed between the pair of magnets;
- a housing that surrounds and encloses the pair of magnets, the pair of ferrite plates and the pair of dielectric rings, and which provides a return path for the magnetic field, the dielectric rings extending laterally from said edge portions of the ferrite plates to an inner surface of the housing;
- and
- signal ports coupled to a transmit radio-frequency signal, a receive radio-frequency signal, and an antenna.
3 more elements
A wireless device, comprising:
- a transmitter circuit;
- a receiver circuit;
- an antenna configured to transmit signals from the transmitter circuit and to receive signals for the receiver circuit;
- and
- a passive circulator for isolating transmit and receive signals between the transmitter and receiver circuits, including (a) a pair of ferrite plates each defining a center portion having a first saturation magnetization value and an edge portion having a second saturation magnetization value that is lower than the first saturation magnetization value;
- (b) a pair of dielectric structures, each dielectric structure disposed along an outer perimeter of one of the ferrite plates;
- (c) a pair of magnets that provide a static magnetic field to the ferrite plates to magnetize the ferrite plates, the ferrite plates disposed between the pair of magnets;
- (d) a housing that surrounds and encloses the pair of magnets, the pair of ferrite plates and the pair of dielectric structures, and which provides a return path for the magnetic field, the dielectric structures extending laterally from said outer perimeter of the ferrite plates to an inner surface of the housing;
- and (e) signal ports coupled to the transmitter circuit, the receiver circuit, and the antenna.
6 more elements
A method for reducing intermodulation distortion, the method comprising:
- providing a pair of ferrite plates having a ferrite medium, the ferrite plates having a center portion with a first saturation magnetization to allow passage of a transmit signal between first and second locations of the ferrite medium and passage of a receive signal between the second and a third location of the ferrite medium, the pair of ferrite plates having an edge portion with a second saturation magnetization that is lower than the first saturation magnetization to reduce intermodulation distortion occurring at the edge portion of the ferrite plates;
- disposing a pair of dielectric structures along an outer perimeter of the ferrite plates;
- applying a static magnetic field to the pair of ferrite plates with a pair of magnets, the pair of ferrite plates disposed between the pair of magnets;
- and
- providing a return path for the magnetic field with a housing that surrounds and encloses the pair of ferrite plates, the pair of dielectric structures and the pair of magnets, the dielectric structures extending laterally from said outer perimeter of the ferrite plates to an inner surface of the housing.
2 more elements
Dependencies are inferred from the claim text.