Multilayer filter

• US 10,418,963 B2
• Filed: 11/02/2017
• Issued: 09/17/2019
• Est. Priority Date: 11/09/2016
• Status: Active Grant

• Current Assignee: TDK Corporation
• Original Assignee: TDK Corporation
• Inventors: Kitami, Manabu
• Primary Examiner(s): Patel, Rakesh B
• Application Number:
  US15/801,744
• Publication Number:
  US 20180145651A1
• Time in Patent Office: 684 Days
• Field of Search: 333175, 333185
• CPC Class Codes: H03H 1/00 Constructional details of impedance networks whose electrical mode of operation is not specified or applicable to more than one type of network constructional details of electromechanical transducers H03H9/00
• 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 7/1708 Comprising bridging elements, i.e. elements in a series path without own reference to ground and spanning branching nodes of another series path H03H7/07 takes precedence
• CPC Class Codes: H03H 7/1766 Parallel LC in series path H03H7/1783 takes precedence
• CPC Class Codes: H03H 7/1783 Combined LC in series path
• CPC Class Codes: H03H 7/1791 Combined LC in shunt or branch path

Abstract

A multilayer filter includes an element body formed by stacking a plurality of insulator layers, and an input terminal, a first output terminal, and a ground terminal arranged on outer surfaces of the element body, a first LC resonance circuit provided in a line connecting the input terminal to the first output terminal and including a first inductor and a first capacitor, and an open inductor having one end connected to the ground terminal and the other end open are provided in the element body, and the open inductor is arranged to face the first output terminal or the first inductor.

Claims

1. A multilayer filter comprising:

an element body formed by stacking a plurality of insulator layers; and

an input terminal, a first output terminal, and a ground terminal arranged on outer surfaces of the element body,

wherein a first LC resonance circuit provided in a line connecting the input terminal to the first output terminal and including a first inductor and a first capacitor, and an open inductor having one end connected to the ground terminal and another end open are provided in the element body,

the open inductor includes a plurality of coil conductors and is formed in a loop shape axially centered on a direction that is parallel to a direction in which the plurality of insulator layers are stacked,

the open inductor is arranged to face the first output terminal or the first inductor,

the one end of the open inductor includes one of the coil conductors arranged in one of the insulator layers and connected to the ground terminal, and

the other end of the open inductor includes another of the coil conductors arranged in another of the insulator layers different from the one of the insulator layers.

2. The multilayer filter according to claim 1, wherein the open inductor and the first inductor are adjacent to each other in the direction in which the plurality of insulator layers are stacked.

3. The multilayer filter according to claim 2,

wherein the first inductor is formed in a loop shape centered on a direction that follows the direction in which the plurality of insulator layers are stacked, which is an axial center, and

a width on the inner side of the first inductor and a width on the inner side of the open inductor are the same, when viewed in a direction that follows the axial center.

4. The multilayer filter according to claim 1,

wherein the first LC resonance circuit selectively passes a first signal at a frequency within a first frequency band among the first signal and a second signal at a frequency within a second frequency band that is a frequency band higher than the first frequency band, and

a second LC resonance circuit is provided in the element body, the second LC resonance circuit being provided in the line connecting the input terminal to the first output terminal, including a second inductor and a second capacitor, and selectively passing the second signal.

5. The multilayer filter according to claim 1,

wherein a second output terminal arranged on one of the outer surfaces of the element body is included, and

a third LC resonance circuit is provided in the element body, the third LC resonance circuit being provided in a line connecting the input terminal to the second output terminal and including a third inductor and a third capacitor.

6. A multilayer filter comprising:

an element body formed by stacking a plurality of insulator layers; and

an input terminal, a first output terminal, and a ground terminal arranged on outer surfaces of the element body,

wherein a first LC resonance circuit provided in a line connecting the input terminal to the first output terminal and including a first inductor and a first capacitor, and an open inductor having one end connected to the ground terminal and another end open are provided in the element body,

the open inductor is arranged to face the first output terminal or the first inductor, and

the open inductor and the first inductor are adjacent to each other in a direction in which the plurality of insulator layers are stacked.

7. A multilayer filter comprising:

an element body formed by stacking a plurality of insulator layers; and

an input terminal, a first output terminal, and a ground terminal arranged on outer surfaces of the element body,

wherein a first LC resonance circuit provided in a line connecting the input terminal to the first output terminal and including a first inductor and a first capacitor, and an open inductor having one end connected to the ground terminal and another end open are provided in the element body,

the open inductor is arranged to face the first output terminal or the first inductor,

the first LC resonance circuit selectively passes a first signal at a frequency within a first frequency band among the first signal and a second signal at a frequency within a second frequency band that is a frequency band higher than the first frequency band, and

a second LC resonance circuit is provided in the element body, the second LC resonance circuit being provided in the line connecting the input terminal to the first output terminal, including a second inductor and a second capacitor, and selectively passing the second signal.