BRANCHING DEVICE

• US 20120081192A1
• Filed: 09/23/2011
• Published: 04/05/2012
• Est. Priority Date: 09/30/2010
• Status: Active Grant

• Current Assignee: Murata Manufacturing Co Limited
• Original Assignee: Murata Manufacturing Co Limited
• Inventors: HANAOKA, Kunitoshi
• Granted Patent: US 8,803,634 B2
• Time in Patent Office: Days
• US Class Current: 333/132
• CPC Class Codes: H03H 2001/0085 Multilayer, e.g. LTCC, HTCC, green sheets inside PCB filters H05K
• CPC Class Codes: H03H 7/0115 comprising only inductors and capacitors H03H7/075, H03H7/09, H03H7/12, H03H7/13 take precedence
• CPC Class Codes: H03H 7/175 Series LC in series path H03H7/1783 takes precedence
• CPC Class Codes: H03H 7/1758 Series LC in shunt or branch path H03H7/1791 takes precedence
• CPC Class Codes: H03H 7/465 having variable circuit topology, e.g. including switches
• CPC Class Codes: H04B 1/0057 using diplexing or multiplexing filters for selecting the desired band

Abstract

In a branching device, an LPF includes a first inductor arranged such that some conductor layers from among conductor layers are wound in a clockwise direction, and a second inductor arranged such that a conductor layer from among the conductor layers is wound in an counterclockwise direction. In addition, an HPF includes a third inductor arranged such that conductor layers are wound in the same clockwise direction as the first inductor. Therefore, when a high-frequency signal passes through the LPF, a winding direction is reversed. In addition, when a high-frequency signal passes through the HPF, a winding direction is reversed.

Claims

1. A branching device comprising:

an antenna terminal arranged to be connected to an antenna;

at least two signal terminals;

a first LC filter circuit connected between the antenna terminal and each of the at least two signal terminals and arranged to allow a signal in a first frequency band from among signals input from one of the terminals to pass therethrough; and

a second LC filter circuit connected between the antenna terminal and each of the at least two signal terminals and arranged to allow a signal in a second frequency band from among signals input from one of the terminals to pass therethrough;

wherein

the first LC filter circuit and the second LC filter circuit are provided in a laminated substrate in which a dielectric layer on which a conductor pattern is provided is laminated;

the first LC filter circuit includes a first inductor arranged such that a portion of a first coil conductor defined by the conductor pattern is wound in a predetermined direction, and a second inductor arranged such that a remaining portion of the first coil conductor defined by the conductor pattern is wound in a direction opposite to the predetermined direction; and

the second LC filter circuit includes a third inductor arranged such that a second coil conductor defined by the conductor pattern is wound in the predetermined direction.

2. The branching device according to claim 1, wherein at least a portion of the third inductor is disposed on the same dielectric layer as the second inductor.

3. The branching device according to claim 1, wherein an inductance of the second inductor is less than an inductance of the first inductor.

4. The branching device according to claim 1, wherein

the first LC filter circuit is a filter circuit arranged to allow the signal in the first frequency band from among signals input from the terminal to pass therethrough and output the signal to the antenna terminal;

and

the second LC filter circuit is a filter circuit arranged to allow the signal in the second frequency band from among signals received by the antenna terminal and input from the antenna terminal to pass therethrough and output the signal to the signal terminal.

5. The branching device according to claim 1, wherein

the first LC filter circuit is a filter circuit arranged to allow the signal in the first frequency band from among signals received by the antenna terminal and input from the antenna terminal to pass therethrough and output the signal to the signal terminal;

and

the second LC filter circuit is a filter circuit arranged to allow the signal in the second frequency band from among signals input from the terminal to pass therethrough and output the signal to the antenna terminal.

6. The branching device according to claim 1, wherein the first frequency band is the same as the second frequency band.