Dielectric filter, duplexer, and communications device

Patent metadata

Field	Value
Publication number	US-11909086-B2
Application number	US-202117359166-A
Country	US
Kind code	B2
Filing date	Jun 25, 2021
Priority date	Dec 26, 2018
Publication date	Feb 20, 2024
Grant date	Feb 20, 2024

Abstract

A dielectric filter, a duplexer, and a communications device are provided. The dielectric filter includes a dielectric body, and a wideband filtering structure and a narrowband filtering structure that are disposed in the dielectric body. The wideband filtering structure includes a groove disposed on a first surface of the dielectric body and configured to adjust a frequency position of a passband of the wideband filtering structure; and at least one first resonator including a through hole penetrating the bottom of the groove and a second surface of the dielectric body; and an open loop located on a bottom surface of the groove and is disposed around an opening of the through hole. The narrowband filtering structure includes at least one second resonator including a blind hole disposed on the second surface of the dielectric body. The first surface and the second surface of the dielectric body are disposed oppositely.

First claim

What is claimed is:

1. A dielectric filter comprising:
a dielectric body, wherein a surface of the dielectric body is covered with a conductive layer;
a wideband filtering structure comprising a groove and at least one first resonator, wherein:
the groove is disposed on a first surface of the dielectric body and is configured to adjust a frequency position of the passband of the wideband filtering structure;
the first resonator comprises a through hole and an open loop, the through hole penetrates the bottom of the groove and a second surface of the dielectric body, and a hole wall of the through hole is covered with the conductive layer;
the open loop is located on a bottom surface of the groove and is disposed around an opening of the through hole; and
a side surface of the groove and a part, other than the open loop, of the bottom surface of the groove are covered with the conductive layer;

a narrowband filtering structure comprising at least one second resonator, which comprises a blind hole disposed on the first surface or the second surface of the dielectric body, wherein a hole wall and a bottom surface of the blind hole are covered with the conductive layer; and the first surface and the second surface of the dielectric body are disposed oppositely;
wherein both the wideband filtering structure and the narrowband filtering structure are disposed in the dielectric body; a passband of the narrowband filtering structure is located within a passband of the wideband filter structure.

2. The dielectric filter according to claim 1 , wherein the dielectric body comprises a first dielectric block and a second dielectric block that are connected and are an integral structure, and a coupling adjustment structure is located between the first dielectric block and the second dielectric block, wherein:
the coupling adjustment structure is configured to adjust an amount of signal coupling between the first dielectric block and the second dielectric block; and
the wideband filtering structure is disposed in the first dielectric block, and the at least one second resonator in the narrowband filtering structure is disposed in the second dielectric block.

3. The dielectric filter according to claim 2 , wherein the dielectric body comprises a first side surface and a second side surface that are disposed oppositely;
the coupling adjustment structure comprises a first coupling blind hole disposed on the first side surface, and a second coupling blind hole disposed on the second side surface, wherein an orthographic projection of the first coupling blind hole on the second side surface overlaps at least a part of the second coupling blind hole; and
hole walls and bottom surfaces of the first coupling blind hole and the second coupling blind hole are covered with the conductive layer.

4. The dielectric filter according to claim 1 , wherein the dielectric body comprises a first dielectric block and a second dielectric block that are connected and are an integral structure, and a coupling adjustment structure is located between the first dielectric block and the second dielectric block, wherein:
the coupling adjustment structure is configured to adjust an amount of signal coupling between the first dielectric block and the second dielectric block;
the narrowband filtering structure, wherein the at least one second resonator comprises two second resonators, which are separately a first-order second resonator and a second-order second resonator that are coupled to each other;
the first-order second resonator and the wideband filtering structure are located in the first dielectric block, and the first-order second resonator is located on a side that is of the wideband filtering structure and that is close to the second dielectric block; and
the second-order second resonator is located in the second dielectric block.

5. The dielectric filter according to claim 1 , wherein the at least one first resonator of the wideband filtering structure comprises two first resonators, which are separately a first-order first resonator and a second-order first resonator that are coupled to each other, wherein:
the second-order first resonator is located between the first-order first resonator and the narrowband filtering structure.

6. The dielectric filter according to claim 1 , wherein the wideband filtering structure further comprises at least one adjustment through hole, wherein a hole wall of the adjustment through hole is covered with the conductive layer; and
the adjustment through hole penetrates the bottom of the groove and the second surface of the dielectric body, and the adjustment through hole is configured to adjust a harmonic suppression capability of the dielectric filter.

7. The dielectric filter according to claim 6 , wherein a plurality of adjustment through holes are arranged in a matrix form, and are evenly distributed at a position where the groove is located.

8. The dielectric filter according to claim 1 , wherein the wideband filtering structure further comprises a first signal hole and a second signal hole, wherein:
the first signal hole is configured to input a signal, and the second signal hole is configured to output a signal; or the second signal hole is configured to input a signal, and the first signal hole is configured to output a signal; and
the wideband filtering structure and the narrowband filtering structure are located between the first signal hole and the second signal hole.

9. The dielectric filter according to claim 8 , wherein the wideband filtering structure further comprises a third coupling blind hole, wherein a hole wall and a bottom surface of the third coupling blind hole are covered with the conductive layer;
the third coupling blind hole is located on a side surface of the groove, penetrates the groove, and is connected to one end of the first signal hole; and
a pore size of the third coupling blind hole is greater than a pore size of the first signal hole, and the third coupling blind hole is configured to adjust an amount of signal coupling between the first signal hole and the wideband filtering structure.

10. A duplexer, comprising a transmitter filter and a receiver filter, wherein
at least one of the transmitter filter or the receiver filter is a dielectric filter comprising:
a dielectric body, wherein a surface of the dielectric body is covered with a conductive layer;
a wideband filtering structure comprising a groove and at least one first resonator, wherein:
the groove is disposed on a first surface of the dielectric body and is configured to adjust a frequency position of the passband of the wideband filtering structure;
the first resonator comprises a through hole and an open loop, the through hole penetrates the bottom of the groove and a second surface of the dielectric body, and a hole wall of the through hole is covered with the conductive layer;
the open loop is located on a bottom surface of the groove and is disposed around an opening of the through hole; and
a side surface of the groove and a part, other than the open loop, of the bottom surface of the groove are covered with the conductive layer;

a narrowband filtering structure comprising at least one second resonator, which comprises a blind hole disposed on the first surface or the second surface of the dielectric body, wherein a hole wall and a bottom surface of the blind hole are covered with the conductive layer; and the first surface and the second surface of the dielectric body are disposed oppositely;
wherein both the wideband filtering structure and the narrowband filtering structure are disposed in the dielectric body; a passband of the narrowband filtering structure is located within a

Assignees

• Huawei Tech Co Ltd

Inventors

• Liang Dan
• Zhang Xiaofeng
• Cui Zheng

Classifications

• H01P1/2002 Primary

  Dielectric waveguide filters (H01P1/212, H01P1/213, H01P1/215, H01P1/219 take precedence) · CPC title

• H01P1/212

  suppressing or attenuating harmonic frequencies (H01P1/215 takes precedence) · CPC title

• H01P5/12

  Coupling devices having more than two ports (H01P5/04 takes precedence) · CPC title

• H04B1/40

  Circuits · CPC title

• H01P1/2056 Primary

  Comb filters or interdigital filters with metallised resonator holes in a dielectric block · CPC title