Confined-flux ferrite structure for circulator/isolator

• US 6,518,851 B2
• Filed: 04/09/2001
• Issued: 02/11/2003
• Est. Priority Date: 05/12/2000
• Status: Expired due to Term

• Current Assignee: Renaissance Electronics & Communications LLC (AEM Components (USA), Inc.)
• Original Assignee: Renaissance Electronics Corporation
• Inventors: Kocharyan, Karen
• Primary Examiner(s): Bettendorf, Justin P.
• Application Number:
  US09/827,787
• Publication Number:
  US 20020039054A1
• Time in Patent Office: 673 Days
• Field of Search: H01/P.139, H01/P.1387, 333/1.1, 333/24.2
• US Class Current: 333/1.1
• CPC Class Codes: H01P 1/32 Non-reciprocal transmission devices H01P1/02 - H01P1/30 take precedence

Abstract

A ferrite structure for non-reciprocal microwave device such as circulator/isolator. The structure includes one or more composite ferrite bodies, each having at least one region of a soft ferrite material and at least one region of a hard ferrite material, and at least two ferrous/ferrite plates. The ferrous/ferrite plates are attached to the composite ferrites so as to contribute to the completion of the magnetic loop via hard and soft ferrite portions of the composite ferrites. The soft and hard ferrite regions are magnetized in the opposite directions. The range of operation is selected to be between the resonant frequencies of soft and hard ferrite materials. With such setting the hard and soft ferrite regions provide the circulation in the same direction. As compared to the state-of-the art devices, the circulators/isolators made according to the present invention incorporate the confined-flux self-magnetized ferrite structure thus eliminating the use of conventional magnets. These devices have extended bandwidth, are reliable in operation and inexpensive in production. The structure according to the present invention is very compact, lightweight and broadband.

Claims

1. A confined-flux ferrite structure for circulator/isolator comprising

a first composite body of a gyromagnetic material;

a second composite body of a gyromagnetic material;

at least two plates of ferromagnetic material;

a junction of electrically conductive material,

wherein said composite bodies having at least one region of soft ferrite material with a first resonant frequency and one region of hard ferrite material with a second resonant frequency, said hard ferrite material region is magnetized and disposed relative to the said soft ferrite material region so as to complete the magnetic loop in said structure, and operation bandwidth of said circulator/isolator is selected to be between said first and said second resonant frequencies and said junction is disposed between and against said first and said second composite bodies, said plates are disposed each outside and against said composite bodies.

2. A structure as recited in claim 1, wherein said first and said second composite bodies each having disk-like shape with one of said ferrite material regions is disposed centrally as a puck, and at least another one of said ferrite material regions is disposed as a ring concentrically around said puck.

3. A structure as recited in claim 1, wherein said first composite body of gyromagnetic material and said second composite body of gyromagnetic material and also said two plates of ferromagnetic material are symmetrically disposed about said junction in parallel relationship to and in contact with each other.

4. A structure as recited in claim 1, wherein said junction of electrically conductive material having Y-like shape with central portion and three branches, said central portion disposed concentrically to and basically within said composite body area, and said three branches outgoing 120 degrees apart from said central portion.

5. A structure as recited in claim 1, wherein said soft ferrite material region and said hard ferrite material region having opposite directions of magnetization.

6. A confined-flux ferrite structure for circulator/isolator, comprising

at least one composite body of a gyromagnetic material;

at least two plates of a ferromagnetic material,

wherein said composite body having at least one region of soft ferrite material with a first resonant frequency and at least one region of hard ferrite material with a second resonant frequency, said regions disposed concentrically in the same plane and in between said plates of ferromagnetic material, said hard ferrite material region is magnetized and disposed relative to said soft ferrite material region so as to complete the magnetic loop, said regions having opposite direction of magnetization, operation frequency is adapted to be between said first and said second resonant frequencies, and said structure is adapted to be used in devices with waveguide transmission lines.

7. A confined-flux ferrite structure for circulator/isolator, comprising

at least one composite body of a gyromagnetic material;

at least two plates of a ferrimagnetic material,

wherein said composite body having at least one region of soft ferrite material with a first resonant frequency and at least one region of hard ferrite material with a second resonant frequency, both said regions disposed in the same plane and in between said plates of ferrimagnetic material, said hard ferrite material region is magnetized and disposed relative to said soft ferrite material region so as to complete the magnetic loop, said regions having opposite direction of magnetization, operation frequency is adapted to be between said first and said second resonant frequencies, and said structure is adapted to be used in devices having quasi-optical transmission lines.