MAGNETIC RESONANCE TYPE ISOLATOR

• US 20120056691A1
• Filed: 08/31/2011
• Published: 03/08/2012
• Est. Priority Date: 09/03/2010
• Status: Active Grant

• Current Assignee: Murata Manufacturing Co Limited
• Original Assignee: Murata Manufacturing Co Limited
• Inventors: HASEGAWA, Takashi
• Granted Patent: US 8,319,575 B2
• Time in Patent Office: Days
• US Class Current: 333/24.2
• CPC Class Codes: H01P 1/365 Resonance absorption isolators
• CPC Class Codes: H01P 1/387 Strip line circulators

Abstract

A magnetic resonance type isolator includes a ferrite; a connection conductor that is arranged on the ferrite and includes first, second and third ports; a permanent magnet that applies a direct current magnetic field to the ferrite; a capacitor (or an inductor) that defines a first reactance element; and a capacitor (or an inductor) that defines a second reactance element. A main line arranged between the first port and the second port of the connection conductor does not resonate, an end portion of a sub-line that branches off from the main line serves as the third port, and a wave reflected from the sub-line is modulated so that its phase is shifted by 90° or about 90° at an intersection of the connection conductor. One of the capacitors is connected to the third port and the other capacitor is connected between the first port and the second port.

Claims

1. A magnetic resonance type isolator comprising:

a ferrite;

a connection conductor that is arranged on the ferrite and includes a first port, a second port and a third port; and

a permanent magnet that applies a direct current magnetic field to the ferrite;

wherein

a main line arranged between the first port and the second port of the connection conductor does not resonate, an end portion of a sub-line that branches off from the main line serves as the third port, a first reactance element is connected to the third port and the first reactance element is connected to the ground; and

a second reactance element is connected between the first port and the second port.

5. The magnetic resonance type isolator according to claim 1, wherein an impedance matching element is connected to each of the first and second ports.

6. The magnetic resonance type isolator according to claim 1, wherein the first reactance element is an inductance element.

7. The magnetic resonance type isolator according to claim 1, wherein the first reactance element is a capacitance element.

8. The magnetic resonance type isolator according to claim 1, wherein the first reactance element is an inductance element, and a capacitance element connected to the ground is connected between the first port and an input port, and a capacitance element connected to the ground is connected between the second port and an output port.

9. The magnetic resonance type isolator according to claim 1, wherein the first reactance element is an inductance element, and a capacitance element connected to the ground is connected in series between the first port and an input port, and a capacitance element connected to the ground is connected in series between the second port and an output port.

10. The magnetic resonance type isolator according to claim 1, wherein the second reactance element is a capacitance element.

11. The magnetic resonance type isolator according to claim 1, wherein the second reactance element is an inductance element.

2. A magnetic resonance type isolator comprising:

a ferrite including a first main surface and a second main surface that oppose each other;

a connection conductor that is arranged on the first main surface of the ferrite and includes a first port, a second port and a third port; and

a permanent magnet that applies a direct current magnetic field to the ferrite;

wherein

a main line arranged between the first port and the second port of the connection conductor does not resonate, a sub-line that branches off from the main line serves as an opposing conductor that extends in a direction perpendicular or substantially perpendicular to the main line onto the second main surface, an end portion of the opposing conductor serves as the third port, a first reactance element is connected to the third port and the first reactance element is connected to the ground; and

a second reactance element is connected between the first port and the second port.

3. A magnetic resonance type isolator comprising:

a ferrite including a first main surface and a second main surface that oppose each other;

a connection conductor that is arranged on the first main surface of the ferrite and includes a first port, a second port and a third port;

a permanent magnet that applies a direct current magnetic field to the ferrite; and

a mounting substrate;

wherein

a main line arranged between the first port and the second port of the connection conductor does not resonate, an end portion of a sub-line that branches off from the main line serves as the third port, a first reactance element is connected to the third port and the first reactance element is connected to the ground;

a second reactance element is connected between the first port and the second port; and

the ferrite is sandwiched between a pair of permanent magnets, which respectively oppose the first and second main surfaces of the ferrite, and the ferrite is mounted on the mounting substrate such that the first and second main surfaces thereof are perpendicular or substantially perpendicular to a surface of the mounting substrate.

4. The magnetic resonance type isolator according to claim 3, wherein the sub-line serves as an opposing conductor, which extends in a direction perpendicular or substantially perpendicular to the main line onto the second main surface, and an end portion of the opposing conductor serves as the third port.