# US 11,909,086 B2 · Dielectric filter, duplexer, and communications device

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- Number: US 11,909,086 B2
- Document ID: US11909086B2
- Status: Granted
- Kind: B2
- Application number: 17/359,166
- Filed: 2021-06-25
- Published: 2021-10-21
- Granted: 2024-02-20
- Earliest claimed: 2018-12-26
- Assignees: Huawei Technologies Co., Ltd.
- Applicants: Huawei Technologies Co., Ltd.
- Inventors: Dan Liang; Xiaofeng Zhang; Zheng Cui
- Web page: https://patentgrep.com/patent/US11909086B2

## CPC

- H01P 1/2002: {Dielectric waveguide filters (H01P1/212, H01P1/213, H01P1/215, H01P1/219 take precedence)}
- H01P 1/2056: {Comb filters or interdigital filters with metallised resonator holes in a dielectric block}
- H01P 1/212: suppressing or attenuating harmonic frequencies (H01P1/215 takes precedence)
- H01P 5/12: Coupling devices having more than two ports (H01P5/04 takes precedence)
- H01P 1/2136: {using comb or interdigital filters; using cascaded coaxial cavities (H01P1/2131, H01P1/2135 take precedence)}
- H04B 1/40: Circuits
- H01P: WAVEGUIDES; RESONATORS, LINES, OR OTHER DEVICES OF THE WAVEGUIDE TYPE (operating at optical frequencies G02B)
- H04B: TRANSMISSION

## 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.

## Claims

### Claim 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.

### Claim 2 (depends on 1)

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.

### Claim 3 (depends on 2)

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.

### Claim 4 (depends on 1)

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.

### Claim 5 (depends on 1)

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.

### Claim 6 (depends on 1)

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.

### Claim 7 (depends on 6)

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.

### Claim 8 (depends on 1)

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.

### Claim 9 (depends on 8)

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.

### Claim 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 passband of the wideband filter structure.

### Claim 11 (depends on 10)

The duplexer according to claim 10, 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.

### Claim 12 (depends on 11)

The duplexer according to claim 11, 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.

### Claim 13 (depends on 10)

The duplexer according to claim 10, 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.

### Claim 14 (depends on 10)

The duplexer according to claim 10, 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.

### Claim 15 (depends on 10)

The duplexer according to claim 10, 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.

### Claim 16

A communications device, comprising a duplexer which comprises 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 passband of the wideband filter structure.

### Claim 17 (depends on 16)

The communications device according to claim 16, 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.

### Claim 18 (depends on 17)

The communications device according to claim 17, 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.

### Claim 19 (depends on 16)

The communications device according to claim 16, 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.

### Claim 20 (depends on 16)

The communications device according to claim 16, 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.