A dielectric waveguide filter with symmetrical cross-coupling zeros

Abstract

The invention relates to a dielectric waveguide filter with symmetrical cross-coupling zero points, comprising at least one dielectric body, wherein the outer sides of the dielectric body are all metallized to form a metal shielding layer, and the multiple dielectric bodies are connected by welding. The filter is also connected with a coaxial connector, and a plurality of dielectric resonant cavities are separated by a plurality of isolation through grooves penetrating the dielectric body. A first blind hole and a second blind hole symmetrical with respect to the center of the dielectric resonant cavity are arranged in a dielectric resonant cavity of at least one dielectric body. The dielectric waveguide filter with symmetrical cross-coupling zero points couples dielectric tuning cavities with each other by providing the first blind hole and the second blind hole symmetrical with respect to the center of the dielectric resonant cavity in the dielectric resonant cavity on the dielectric body, thereby generating a cross-coupling zero point, improving out-of-band suppression, and thus reducing the influence on other communication frequency bands.

Description

Technical Field

[0001] The invention relates to a dielectric waveguide filter or a MONO block dielectric filter, and in particular to a dielectric waveguide filter with symmetrical cross-coupling zero points. Background Art

[0002] In the 5G era, ceramic dielectric filters have become mainstream due to the requirements of Massive MIMO (large-scale antenna technology) for large-scale antenna integration. In the 5G era, filters need to be more miniaturized and integrated. Ceramic powder has an important influence on filter performance. High dielectric constant (εr) and low dielectric loss (Q×F value) are core performance indicators. Dielectric resonators are made of ceramic powder materials. Their advantages are small size, easy circuit miniaturization, high temperature stability, and no frequency restrictions (including millimeter wave bands). High dielectric constant, low dielectric loss and high Q value are core performance indicators. Due to the influence of the structure, dielectric waveguides cannot add cross-coupling zero-point structures as flexibly as traditional metal cavities. Summary of the invention

[0003] In view of the above shortcomings, the applicant has conducted research and improvement to provide a dielectric waveguide filter with symmetrical cross-coupling zeros that can effectively and flexibly add cross-coupling zeros to improve out-of-band suppression.

[0004] The technical solution adopted by the present invention is as follows:

[0005] A dielectric waveguide filter with symmetrical cross-coupling zero points comprises at least one dielectric body, the outer sides of the dielectric body are all metallized to form a metal shielding layer, the multiple dielectric bodies are connected by welding, the filter is also connected with a coaxial connector, a plurality of dielectric resonant cavities are separated on the dielectric body by a plurality of isolation through grooves penetrating the dielectric body, and a first blind hole and a second blind hole symmetrical with the center of the dielectric resonant cavity are arranged in a dielectric resonant cavity of at least one dielectric body.

[0006] As a further improvement of the above technical solution:

[0007] The dielectric body is made of a non-metallic dielectric with a dielectric constant ER in the range of 2 to 110.

[0008] A third blind hole whose center coincides with the center of the dielectric resonant cavity is arranged between the first blind hole and the second blind hole.

[0009] The first blind hole, the second blind hole and the third blind hole are waist-shaped blind holes.

[0010] The first blind hole, the second blind hole and the third blind hole are round blind holes.

[0011] The depths of the first blind hole, the second blind hole and the third blind hole are all greater than 1 / 2 of the thickness of the dielectric body.

[0012] A tuning frequency blind hole can be provided on the dielectric body in the dielectric resonance cavity.

[0013] The coaxial connector to which the filter is connected may be replaced by a surface mount pad.

[0014] The filter is connected to the coaxial connector and the surface mount pads.

[0015] The beneficial effects of the present invention are as follows: the dielectric waveguide filter with symmetrical cross-coupling zero points can realize cross-coupling zero points by opening a first blind hole and a second blind hole symmetrically around the center of the dielectric resonant cavity in the dielectric resonant cavity on the dielectric body, thereby improving out-of-band suppression and reducing the impact on other communication frequency bands. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is a front view of a dielectric waveguide filter with symmetrical cross-coupling zero points provided in the first embodiment.

[0017] Figure 2 for Figure 1 AA section view.

[0018] Figure 3 This is a front view of a dielectric waveguide filter with symmetrical cross-coupling zeros provided in the second embodiment.

[0019] Figure 4 This is a front view of a dielectric waveguide filter with symmetrical cross-coupling zero points provided in Example 3.

[0020] Figure 5 This is a front view of a dielectric waveguide filter with symmetrical cross-coupling zeros provided in Example 4.

[0021] Figure 6 This is a front view of a dielectric waveguide filter with symmetrical cross-coupling zero points provided in Example 5.

[0022] Figure 7 This is a front view of a dielectric waveguide filter with symmetrical cross-coupling zeros provided in Example 6.

[0023] Figure 8 for Figure 7 BB cross-section view.

[0024] Fig. 9 This is an S parameter curve of the dielectric waveguide filter with symmetrical cross-coupling zero points provided in Example 6.

[0025] In the figure: 1. dielectric body; 11. coaxial connector; 12. surface mount pad; 2. isolation slot; 3. dielectric resonant cavity; 4. first blind hole; 5. second blind hole; 6. third blind hole; 7. tuning frequency blind hole. DETAILED DESCRIPTION

[0026] Embodiment 1

[0027] The specific implementation of this embodiment is described below in conjunction with the accompanying drawings.

[0028] like Figure 1 , Figure 2 As shown, the dielectric waveguide filter with symmetrical cross-coupling zero points of the present embodiment comprises two layers of dielectric bodies 1 made of ceramics, the outer sides of the dielectric bodies 1 are copper metallized to form a copper shielding layer, the two layers of dielectric bodies 1 are connected by welding, and the lower end of the dielectric body 1 of the lowest layer is connected to the coaxial connector 11, six dielectric resonant cavities 3 are separated by a "T"-shaped isolation through slot 2 and a "cross"-shaped isolation through slot 2 penetrating the dielectric bodies 1 on the two dielectric bodies 1, a first blind hole 4 and a second blind hole 5 symmetrical with the center of the dielectric resonant cavity 3 are provided in one dielectric resonant cavity 3 of the upper dielectric body 1, tuning frequency blind holes 7 are provided in the other dielectric resonant cavities 3, the first blind hole 4 and the second blind hole 5 are waist-shaped blind holes, and the cross-coupling zero point can be realized by the first blind hole 4 and the second blind hole 5 provided on the dielectric resonant cavity 3 on the upper side, thereby improving out-of-band suppression and reducing the influence on other communication frequency bands.

[0029] Embodiment 2

[0030] The specific implementation of this embodiment is described below in conjunction with the accompanying drawings.

[0031] like Figure 3 As shown, the dielectric waveguide filter with symmetrical cross-coupling zero points of the present embodiment includes a single-layer dielectric body 1 made of quartz, the outer side of the dielectric body 1 is copper-metallized to form a copper shielding layer, the lower end of the dielectric body 1 is connected to a coaxial connector 11, and four dielectric resonant cavities 3 are separated on the dielectric body 1 by a "cross"-shaped isolation through groove 2 that runs through the dielectric body 1. A first blind hole 4 and a second blind hole 5 symmetrical with the center of the dielectric resonant cavity 3 are arranged in one dielectric resonant cavity 3 of the dielectric body 1, and the first blind hole 4 and the second blind hole 5 are circular blind holes. By providing the first blind hole 4 and the second blind hole 5 on one dielectric resonant cavity 3, the four dielectric resonant cavities 3 can be coupled with each other, and two cross-coupling zero points can be generated, thereby improving out-of-band suppression and reducing the impact on other communication frequency bands.

[0032] Embodiment 3

[0033] The specific implementation of this embodiment is described below in conjunction with the accompanying drawings.

[0034] like Figure 4As shown, the dielectric waveguide filter with symmetrical cross-coupling zero points of the present embodiment comprises a single-layer dielectric body 1 made of glass, the outer side of the dielectric body 1 is copper-metallized to form a copper shielding layer, the lower end of the dielectric body 1 is connected to a coaxial connector 11, and six dielectric resonant cavities 3 are separated on the dielectric body 1 by a "T"-shaped isolation through slot 2 and a "cross"-shaped isolation through slot 2 penetrating the dielectric body 1, and a first blind hole 4 and a second blind hole 5 are arranged in one dielectric resonant cavity 3 of the dielectric body 1, and the first blind hole 4 and the second blind hole 5 are waist-shaped blind holes, and the dielectric resonant cavity 3 is located between the first blind hole 4 and the second blind hole 5. A third blind hole 6 is provided between the blind holes 5, and the third blind hole 6 is also a waist-shaped blind hole. The center of the third blind hole 6 coincides with the center of the dielectric resonant cavity 3 in which it is located, and the third blind hole 6 is arranged in parallel with the first blind hole 4 and the second blind hole 5. Except for a single dielectric resonant cavity 3 provided with the first blind hole 4, the second blind hole 5 and the third blind hole 6, tuning frequency blind holes 7 are provided in other dielectric resonant cavities 3. By providing the first blind hole 4, the second blind hole 5 and the third blind hole 6 in a single dielectric resonant cavity 3, the six dielectric resonant cavities 3 can be coupled to each other, and four cross-coupling zero points can be generated, thereby improving out-of-band suppression and reducing the impact on other communication frequency bands.

[0035] Embodiment 4

[0036] The specific implementation of this embodiment is described below in conjunction with the accompanying drawings.

[0037] like Figure 5 As shown, the dielectric waveguide filter with symmetrical cross-coupling zero points of the present embodiment comprises a single-layer dielectric body 1 made of a PCB board, the outer side of the dielectric body 1 is copper-metallized to form a copper shielding layer, the lower end of the dielectric body 1 is connected to a coaxial connector 11, and six dielectric resonant cavities 3 are separated on the dielectric body 1 by a "T"-shaped isolation through slot 2 and a "cross"-shaped isolation through slot 2 penetrating the dielectric body 1, and a first blind hole 4 and a second blind hole 5 are arranged in one dielectric resonant cavity 3 of the dielectric body 1, and the first blind hole 4 and the second blind hole 5 are waist-shaped blind holes, and the dielectric resonant cavity 3 is symmetrical to the center of the dielectric resonant cavity 3. The resonant cavity 3 is located between the first blind hole 4 and the second blind hole 5, and a third blind hole 6 is provided. The third blind hole 6 is a circular blind hole. The center of the third blind hole 6 coincides with the center of the dielectric resonant cavity 3 in which it is located. Except for the single dielectric resonant cavity 3 having the first blind hole 4, the second blind hole 5 and the third blind hole 6, tuning frequency blind holes 7 are provided in other dielectric resonant cavities 3. By providing the first blind hole 4, the second blind hole 5 and the third blind hole 6 on the single dielectric resonant cavity 3, the six dielectric resonant cavities 3 can be coupled to each other, and four cross-coupling zero points can be generated, thereby improving out-of-band suppression and reducing the impact on other communication frequency bands.

[0038] Embodiment 5

[0039] The specific implementation of this embodiment is described below in conjunction with the accompanying drawings.

[0040] like Figure 6 As shown, the dielectric waveguide filter with symmetrical cross-coupling zero points of this embodiment includes a single-layer dielectric body 1 made of sapphire, the outer side of the dielectric body 1 is formed by silver metallization to form a silver shielding layer, the lower end of the dielectric body 1 is connected to a coaxial connector 11, and six dielectric resonant cavities 3 are separated on the dielectric body 1 by a "T"-shaped isolation through groove 2 and a "cross"-shaped isolation through groove 2 that penetrate the dielectric body 1. A first blind hole 4 and a second blind hole 5 are arranged in a dielectric resonant cavity 3 of the dielectric body 1, and the first blind hole 4 and the second blind hole 5 are circular blind holes, and the dielectric resonant cavity 3 is symmetrical to the center of the dielectric resonant cavity 3. The cavity 3 is located between the first blind hole 4 and the second blind hole 5, and a third blind hole 6 is provided. The third blind hole 6 is also a circular blind hole. The center of the third blind hole 6 coincides with the center of the dielectric resonant cavity 3 in which it is located. Except for the single dielectric resonant cavity 3 having the first blind hole 4, the second blind hole 5 and the third blind hole 6, tuning frequency blind holes 7 are provided in other dielectric resonant cavities 3. By providing the first blind hole 4, the second blind hole 5 and the third blind hole 6 on the single dielectric resonant cavity 3, the six dielectric resonant cavities 3 can be coupled to each other, and four cross-coupling zero points can be generated, thereby improving out-of-band suppression and reducing the impact on other communication frequency bands.

[0041] Embodiment 6

[0042] The specific implementation of this embodiment is described below in conjunction with the accompanying drawings.

[0043] like Figures 7 to 9 As shown, the dielectric waveguide filter with symmetrical cross-coupling zero points of the present embodiment comprises a single-layer dielectric body 1 made of ceramic, the outer side of the dielectric body 1 is silver-metallized to form a silver shielding layer, the lower end of the dielectric body 1 is connected to a surface-mount pad 12, and six dielectric resonant cavities 3 are separated on the dielectric body 1 by a "T"-shaped isolation through groove 2 and a "cross"-shaped isolation through groove 2 penetrating the dielectric body 1, a first blind hole 4 and a second blind hole 5 are arranged in a dielectric resonant cavity 3 of the dielectric body 1, the first blind hole 4 and the second blind hole 5 are waist-shaped grooves, and the dielectric resonant cavity 3 is provided with a third blind hole 6 between the first blind hole 4 and the second blind hole 5, and the third blind hole 6 The center of is coincident with the center of the dielectric resonant cavity 3, and the third blind hole 6 is arranged vertically to the first blind hole 4 and the second blind hole 5, and the first blind hole 4 and the second blind hole 5 are connected, so that the dielectric resonant cavity 3 forms an "I"-shaped blind hole. Except for the single dielectric resonant cavity 3 provided with the first blind hole 4, the second blind hole 5 and the third blind hole 6, the other dielectric resonant cavities 3 are provided with tuning frequency blind holes 7. Through the "I"-shaped blind holes composed of the first blind hole 4, the second blind hole 5 and the third blind hole 6 provided on the dielectric resonant cavity 3, the six dielectric resonant cavities 3 can be coupled with each other, four cross-coupling zeros can be generated, and the out-of-band suppression is improved, thereby reducing the influence on other communication frequency bands.

[0044] The dielectric body 1 in the first to sixth embodiments can be made of any non-metallic medium having a dielectric constant ER in the range of 2 to 110.

[0045] The depths of the first blind hole 4 , the second blind hole 5 and the third blind hole 6 in the first to sixth embodiments all exceed 1 / 2 of the thickness of the dielectric body 1 , but do not exceed the thickness of the dielectric body 1 , that is, they are not through.

[0046] The above description is an explanation of the present invention, not a limitation of the present invention. The scope of the present invention is defined in the claims. The present invention may be modified in any form without violating the basic structure of the present invention.

Claims

1. A dielectric waveguide filter with a symmetrical cross-coupling zero point, comprising two layers of dielectric bodies (1), the outer sides of the dielectric bodies (1) are metallized to form a metal shielding layer, the dielectric bodies (1) are connected by welding, the filter is also connected to a coaxial connector (11), and the dielectric body (1) is separated into a plurality of dielectric resonant cavities (3) by a plurality of isolation slots (2) penetrating the dielectric body (1), characterized in that: A first blind hole (4) and a second blind hole (5) are arranged in a dielectric resonant cavity (3) of at least one dielectric body (1) and are symmetrical about the center of the dielectric resonant cavity (3); a third blind hole (6) whose center coincides with the center of the dielectric resonant cavity (3) is arranged between the first blind hole (4) and the second blind hole (5); the depths of the first blind hole (4), the second blind hole (5) and the third blind hole (6) are all greater than 1 / 2 of the thickness of the dielectric body (1); and a tuning frequency blind hole (7) is arranged in other dielectric resonant cavities (3) on the dielectric body (1).

2. The dielectric waveguide filter with symmetrical cross-coupling zeros according to claim 1, characterized in that: The dielectric body (1) is made of a non-metallic dielectric with a dielectric constant ER in the range of 2 to 110.

3. The dielectric waveguide filter with symmetrical cross-coupling zeros according to claim 1, characterized in that: The first blind hole (4), the second blind hole (5) and the third blind hole (6) are waist-shaped blind holes.

4. The dielectric waveguide filter with symmetrical cross-coupling zeros according to claim 1, characterized in that: The first blind hole (4), the second blind hole (5) and the third blind hole (6) are round blind holes.

5. The dielectric waveguide filter with symmetrical cross-coupling zeros according to claim 1, characterized in that: The coaxial connector (11) connected to the filter is replaced by a surface mount pad (12).

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