CN-224232904-U - Low-pass structure and filter

Abstract

The application relates to the field of communication, and provides a low-pass structure and a filter. The low-pass structure is arranged in a low-pass cavity of the filter housing, and the low-pass cavity is provided with a first cavity wall. The low-pass structure comprises a low-pass member, the low-pass member comprises a high-impedance branch which is a rod-shaped structure and at least one low-impedance branch, the low-impedance branch comprises a low-impedance part and a connecting part, the low-impedance part is positioned on one side of the high-impedance branch, which is close to the first cavity wall, and is insulated from the first cavity wall to form a capacitor between the low-impedance part and the high-impedance branch, and the connecting part is connected between the low-impedance part and the high-impedance branch. Based on the structure, the low-pass structure can generate transmission zero points equivalent to low-impedance branches, so that the out-of-band signal attenuation speed near the edge of a pass band can be remarkably improved, and the out-of-band rejection performance of a near end can be improved. In addition, the low-pass structure can flexibly adjust the number of generated transmission zero points by increasing or decreasing the number of low-impedance branches, and flexibly adjust out-of-band rejection characteristics, so that the design flexibility and applicability of the low-pass structure can be improved.

Inventors

• LIU WANG
• ZHANG HAIFENG

Assignees

• 大富科技(安徽)股份有限公司

Dates

Publication Date

20260512

Application Date

20250428

Claims (10)

1. 1. A low pass structure disposed in a low pass cavity of a filter housing, the low pass cavity having a first cavity wall, the low pass structure comprising: The low-pass piece comprises a high-impedance branch and at least one low-impedance branch, wherein the high-impedance branch is of a rod-shaped structure, the low-impedance branch comprises a low-impedance part and a connecting part, the low-impedance part is positioned on one side, close to the first cavity wall, of the high-impedance branch, and is insulated from the first cavity wall to form a capacitor between the low-impedance part and the high-impedance branch, and the connecting part is connected between the low-impedance part and the high-impedance branch.
2. 2. The low pass structure of claim 1, wherein said connection is angled.
3. 3. The low-pass structure according to claim 2, wherein the connecting portion includes a first connecting section, a second connecting section, a third connecting section and a fourth connecting section which are connected in turn by bending, the first connecting section is connected to the high-impedance branch and extends to a side close to the low-impedance portion, the third connecting section extends from the second connecting section to a side close to the low-impedance portion, the third connecting section is arranged at an interval from the outer periphery of the low-impedance portion, and one end of the fourth connecting section far away from the third connecting section is connected to the periphery of the low-impedance portion.
4. 4. The low-pass structure of claim 1, wherein a plurality of said low-impedance branches are provided, each of said low-impedance branches being spaced along an extended path of said high-impedance branch.
5. 5. The low pass structure of claim 1, further comprising an insulating pad disposed between the low impedance portion and the first cavity wall.
6. 6. The low pass structure of claim 5, wherein all of said low impedance portions share one of said insulating pads.
7. 7. The low-pass structure according to claim 1, wherein the low-impedance portion is penetrated by a fastening hole, and the low-impedance portion is connected and fixed to the first cavity wall by a fastener penetrating the fastening hole.
8. 8. The low pass structure of any of claims 1-7, wherein the low impedance portion is spaced parallel to the first cavity wall; and/or the low impedance part is of a plate-shaped structure; And/or the high-impedance branches are arranged in a linear extending mode.
9. 9. The low pass structure of any of claims 1-7, wherein the low pass member is integrally formed from a sheet metal substrate.
10. 10. A filter comprising a filter housing, and a low-pass structure according to any of claims 1-9, the filter housing being provided with a low-pass cavity, the low-pass structure being provided in the low-pass cavity.

Description

Low-pass structure and filter Technical Field The application belongs to the technical field of communication, and particularly relates to a low-pass structure and a filter. Background In some cases, the filter includes a cavity provided with a low-pass slot, a cover plate covering the cavity and compressing the low-pass structure to urge the low-pass structure into a tight fit with the low-pass slot, and a low-pass structure mounted in the low-pass slot. The low-pass structure comprises a low-pass part and an insulating sleeve, wherein the low-pass part comprises a high-impedance section with a small diameter and a low-impedance section with a large diameter, the high-impedance section and the low-impedance section are alternately connected to form a sugar-gourd-string type low-pass part, the insulating sleeve is sleeved on the periphery of the low-pass part so as to be insulated between the low-pass part and the wall of the low-pass groove, and an equivalent capacitance is formed between the low-impedance section and the wall of the low-pass groove. However, in this way, the sugar-gourd serial low-pass element forms a serial distributed LC filter network only through an equivalent inductance (L) formed by the high-impedance section and an equivalent capacitance (C) formed by the low-impedance section, but only generates a pole through LC resonance, so that a transmission zero is difficult to generate, and the out-of-band suppression of the near-end band is poor. Disclosure of utility model The embodiment of the application provides a low-pass structure and a filter, which aim to solve the problem that a transmission zero is difficult to generate for a sugar-gourd-string low-pass part, so that the out-of-band suppression of a near end is poor. In order to achieve the above purpose, the technical scheme adopted by the embodiment of the application is as follows: In a first aspect, a low-pass structure is provided, provided in a low-pass cavity of a filter housing, the low-pass cavity having a first cavity wall, the low-pass structure comprising: The low-pass piece comprises a high-impedance branch and at least one low-impedance branch, wherein the high-impedance branch is of a rod-shaped structure, the low-impedance branch comprises a low-impedance part and a connecting part, the low-impedance part is positioned on one side, close to the first cavity wall, of the high-impedance branch, and is insulated from the first cavity wall to form a capacitor between the low-impedance part and the high-impedance branch, and the connecting part is connected between the low-impedance part and the high-impedance branch. In some embodiments, the connection is provided in a bent configuration. In some embodiments, the connecting portion includes a first connecting section, a second connecting section, a third connecting section and a fourth connecting section that are sequentially bent and connected, the first connecting section is connected to the high-impedance branch and extends to a side close to the low-impedance portion, the third connecting section extends from the second connecting section to a side close to the low-impedance portion, the third connecting section and the periphery of the low-impedance portion are arranged at intervals, and one end of the fourth connecting section, which is far away from the third connecting section, is connected to the periphery of the low-impedance portion. In some embodiments, the low impedance branch is provided in plurality, each of the low impedance branches being spaced along the path of extension of the high impedance branch. In some embodiments, the low pass structure further comprises an insulating pad disposed between the low impedance portion and the first cavity wall. In some embodiments, all of the low impedance portions share one of the insulating pads. In some embodiments, the low-impedance portion is penetrated by a fastening hole, and the low-impedance portion is fixedly connected with the first cavity wall through a fastener penetrating through the fastening hole. In some embodiments, the low impedance portion is spaced parallel to the first cavity wall. In some embodiments, the low impedance portion is a plate-like structure. In some embodiments, the high impedance stub is disposed in a straight line extension. In some embodiments, the low pass is integrally formed from a sheet metal substrate. In a second aspect, a filter is provided, including a filter housing, and a low-pass structure provided in an embodiment of the present application, where the filter housing is provided with a low-pass cavity, and the low-pass structure is disposed in the low-pass cavity. The low-pass structure provided by the application has the beneficial effects that: In the low-pass structure provided by the embodiment of the application, the low-pass piece can form an equivalent inductance through the high-impedance branch, can be connected between the low-impedance part and the high-