Branching filter

Patent metadata

Field	Value
Publication number	US-2022294411-A1
Application number	US-202217686186-A
Country	US
Kind code	A1
Filing date	Mar 3, 2022
Priority date	Mar 9, 2021
Publication date	Sep 15, 2022
Grant date	—

Abstract

A branching filter includes a common port, a first signal port, a second signal port, a first filter, which is provided between the common port and the first signal port, that selectively passes a signal of a frequency within a first passband, a second filter, which is provided between the common port and the second signal port, that selectively passes a signal of a frequency within a second passband different from the first passband, and a capacitor that has a first end and a second end and connects the first filter and the second filter.

First claim

What is claimed is:

1 . A branching filter comprising:
a common port; a first signal port; a second signal port; a first filter, which is provided between the common port and the first signal port, that selectively passes a signal of a frequency within a first passband; a second filter, which is provided between the common port and the second signal port, that selectively passes a signal of a frequency within a second passband different from the first passband; and a capacitor, which has a first end and a second end, that connects the first filter and the second filter.

2 . The branching filter according to claim 1 , wherein the second passband is a frequency band higher than the first passband.

3 . The branching filter according to claim 2 , further comprising a first path that connects the common port and the first signal port, wherein:
the first filter includes a first inductor provided in the first path; and the first end of the capacitor is connected to the first path between the first inductor and the first signal port.

4 . The branching filter according to claim 2 , further comprising a second path that connects the common port and the second signal port, wherein:
the second filter includes a second inductor provided between the second path and a ground; and the second end of the capacitor is connected to a third path that connects the second path and the second inductor.

5 . The branching filter according to claim 2 , wherein the capacitor forms an attenuation pole on a high frequency side of the second passband in a pass characteristic of the second filter.

6 . The branching filter according to claim 1 , wherein the first filter and the second filter constitute a diplexer.

7 . The branching filter according to claim 1 , further comprising:
a third signal port; and a third filter, which is provided between the common port and the third signal port, that selectively passes a signal of a frequency within a third passband different from the first and second passbands.

8 . The branching filter according to claim 7 , wherein the third passband is a frequency band higher than the first and second passbands.

9 . The branching filter according to claim 7 , wherein the first filter, the second filter, and the third filter constitute a triplexer.

Assignees

• Tdk Corp

Inventors

• Sato Takuya
• Tsukamoto Kazuhiro
• Tsutsumi Masanori

Classifications

• H03H7/0115

  comprising only inductors and capacitors (H03H7/075, H03H7/09, H03H7/12, H03H7/13 take precedence) · CPC title

• H03H7/24

  Frequency- independent attenuators · CPC title

• H03H7/46 Primary

  Networks for connecting several sources or loads, working on different frequencies or frequency bands, to a common load or source · CPC title

• H03H7/1766

  Parallel LC in series path (H03H7/1783 takes precedence) · CPC title

• H03H7/463 Primary

  Duplexers · CPC title