Low-pass filter

• US 10,187,028 B2
• Filed: 03/29/2017
• Issued: 01/22/2019
• Est. Priority Date: 03/30/2016
• Status: Active Grant

• Current Assignee: Taiyo Yuden Company Limited (Taiyo Yuden Co)
• Original Assignee: Taiyo Yuden Company Limited (Taiyo Yuden Co)
• Inventors: Takeuchi, Hirotaka
• Primary Examiner(s): Patel, Rakesh
• Application Number:
  US15/472,588
• Publication Number:
  US 20170288630A1
• Time in Patent Office: 664 Days
• Field of Search: 333175, 333185
• CPC Class Codes: H03H 2001/0085 Multilayer, e.g. LTCC, HTCC, green sheets
• 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 7/1758 Series LC in shunt or branch path H03H7/1791 takes precedence
• CPC Class Codes: H03H 7/1766 Parallel LC in series path H03H7/1783 takes precedence

Abstract

In one aspect, the present disclosure provides a surface-mounted low-pass filter, including: a mounting surface having an input terminal electrode, an output terminal electrode, and a ground terminal electrode; a parallel resonant circuit between the input terminal electrode and the output terminal electrode; and a series resonant circuit between one end of the parallel resonant circuit and the ground terminal electrode, wherein the series resonant circuit has a first capacitor and a first inductor, and wherein, when the low-pass filter is viewed from above in a direction perpendicular to the mounting surface with the mounting surface on the bottom, the first inductor of the series resonant circuit is above the first capacitor.

Claims

1. A surface-mounted low-pass filter, comprising:

a mounting surface having an input terminal electrode, an output terminal electrode, and a ground terminal electrode;

a parallel resonant circuit between the input terminal electrode and the output terminal electrode; and

a series resonant circuit between one end of the parallel resonant circuit and the ground terminal electrode,

wherein the series resonant circuit has a first capacitor and a first inductor,

wherein, when the low-pass filter is viewed from above in a direction perpendicular to the mounting surface with the mounting surface on the bottom, the first inductor of the series resonant circuit is above the first capacitor

wherein the parallel resonant circuit has a second capacitor and a second inductor, and

wherein, when the low-pass filter is viewed from above in the direction perpendicular to the mounting surface, the first inductor of the series resonant circuit does not overlap the second inductor of the parallel resonant circuit.

2. The low-pass filter according to claim 1, wherein, when the low-pass filter is viewed from above in the direction perpendicular to the mounting surface, the first inductor does not overlap the input terminal electrode or the output terminal electrode.

3. A low-pass filter, comprising:

a mounting surface having an input terminal electrode, an output terminal electrode, and a ground terminal electrode;

a parallel resonant circuit between the input terminal electrode and the output terminal electrode; and

a series resonant circuit between one end of the parallel resonant circuit and the ground terminal electrode,

wherein the series resonant circuit has a first capacitor and a first inductor,

wherein, when the low-pass filter is viewed from above in a direction perpendicular to the mounting surface with the mounting surface on the bottom, the first inductor of the series resonant circuit is above the first capacitor, and

wherein two or more of the parallel resonant circuit are provided and connected in series between the input terminal electrode and the output terminal electrode, and the series resonant circuit is provided between the ground terminal electrode and a connection node at which two of said two or more parallel resonant circuits connect in series.

4. The low-pass filter according to claim 3,

wherein the two or more parallel resonant circuits each have a capacitor and an inductor, and

wherein, when the low-pass filter is viewed from above in the direction perpendicular to the mounting surface, the first inductor of the series resonant circuit does not overlap any of the inductors of the parallel resonant circuits.

5. A low-pass filter, comprising:

a mounting surface having an input terminal electrode, an output terminal electrode, and a ground terminal electrode;

a parallel resonant circuit between the input terminal electrode and the output terminal electrode; and

a series resonant circuit between one end of the parallel resonant circuit and the ground terminal electrode,

wherein the series resonant circuit has a first capacitor and a first inductor,

wherein, when the low-pass filter is viewed from above in a direction perpendicular to the mounting surface with the mounting surface on the bottom, the first inductor of the series resonant circuit is above the first capacitor, and

wherein N number of said parallel resonant circuit is provided and connected in series between the input terminal electrode and the output terminal electrode, and 1 to (N+1) number of said series resonant circuit is provided and each connected between said ground terminal or a separate ground terminal and one end of one of the (N+1) series resonance circuits, where N is an integer greater than or equal to 1.