Communication device, narrow bandwidth dielectric waveguide filter and design method thereof

Abstract

The present invention relates to a communication device, a narrow-bandwidth dielectric waveguide filter and a design method thereof. The narrow-bandwidth dielectric waveguide filter includes a dielectric block and a metal layer coated on the outer surface of the dielectric block. A capacitive coupling hole and an inductive coupling structure are provided at the coupling window part of the dielectric block. The capacitive coupling hole is a metallized blind hole, and the inductive coupling structure is a metallized blind hole or a metallized blind groove. Since the capacitive coupling hole and the inductive coupling structure are provided at the coupling window part of the dielectric block, the thickness D of the dielectric block at the bottom wall part of the capacitive coupling hole can be designed to be large enough to make the capacitive coupling of the capacitive coupling hole large. However, since the inductive coupling of the inductive coupling structure can offset a part of the capacitive coupling of the capacitive coupling hole, the other part of the capacitive coupling of the capacitive coupling hole is equivalent to a narrow capacitive coupling, that is, a narrow-bandwidth design can be realized. At the same time, since the thickness D of the dielectric block at the bottom wall part of the capacitive coupling hole is large enough, the production and manufacturing are easy, and the sintering qualification rate of the product is improved.

Description

Technical Field

[0001] The present invention relates to the field of communication technology, and in particular to a communication device, a narrow-bandwidth dielectric waveguide filter and a design method thereof. Background Art

[0002] The filter is a frequency-selective device and an indispensable part of communication equipment. With the rapid development of communication systems entering the 5G era, the miniaturization of devices is the key to the development of communication equipment, and miniaturized, high-performance, and low-power filters are the key to the miniaturization of 5G equipment. Dielectric waveguide filters have all the characteristics of 5G equipment miniaturization, so they have broad application prospects in 5G communication equipment. The dielectric waveguide filter improves the air-filled form of the traditional waveguide filter into a high-dielectric constant ceramic material filling. The ceramic dielectric material is die-casted to play the role of transmitting signals and structural support. The metal material is attached to the surface of the ceramic dielectric material as an electric wall to play an electromagnetic shielding role. This structure can significantly reduce the size and weight of the filter.

[0003] In order to achieve the purpose of capacitive coupling, the traditional dielectric waveguide filter has the following two structural forms, and the capacitive coupling hole is a single blind hole form or a double blind hole form:

[0004] See also Figures 1 to 3 , Figure 1 The top view of the dielectric waveguide filter in the form of a single blind hole is shown. Figure 2 Indicated Figure 1 The cross-sectional view at AA, Figure 3 The bottom view of the dielectric waveguide filter in the form of a single blind hole is shown. The capacitive coupling hole is a single blind hole 11. By adjusting the distance H between the bottom wall of the single blind hole 11 and the surface of the dielectric waveguide filter 1 To control the coupling bandwidth, the spacing H 1 The smaller the size, the deeper the hole depth of the single blind hole 11, and the narrower the coupling bandwidth. Therefore, to realize a dielectric waveguide filter with a narrow coupling bandwidth, due to the spacing H 1 It will be quite small, even within 0.5mm, which makes the design and production more difficult and the qualified rate of product sintering is low.

[0005] Please refer to Figures 4 to 7 , Figure 4 The top view of the dielectric waveguide filter with double blind holes is shown. Figure 5 for Figure 4 The cross-sectional view at AA, Figure 6 The bottom view of the dielectric waveguide filter with double blind holes is shown. Figure 7 for Figure 6Cross-sectional view at BB. For a dielectric waveguide filter in the form of double blind holes, a blind hole 12 is provided on the upper surface of the dielectric waveguide filter and a blind hole 13 is provided on the lower surface. When the capacitive coupling bandwidth is to be adjusted, the distance W between the bottom wall of the upper blind hole 12 and the lower surface is adjusted. 1 , adjust the distance W between the bottom wall and the upper surface of the lower blind hole 13 2 , adjust the thickness W of the dielectric block between the upper blind hole 12 and the lower blind hole 13 3 , adjust the distance W between the side of the upper blind hole 12 away from the lower blind hole 13 and the side wall of the dielectric block adjacent to it 4 , and adjusting the distance W between the side of the hole wall of the lower blind hole 13 away from the upper blind hole 12 and the side wall of the dielectric block adjacent to it 5 , in W 1 ~W 5 Only when both are very small can a narrow bandwidth be achieved, which makes design and production more difficult and the qualified rate of product sintering is low. Summary of the invention

[0006] Based on this, it is necessary to overcome the defects of the prior art and provide a communication device, a narrow-bandwidth dielectric waveguide filter and a design method thereof, which can realize narrow bandwidth design, is easier to produce and manufacture, and improves the sintering qualification rate of the product.

[0007] The technical scheme is as follows: a narrow bandwidth dielectric waveguide filter, the narrow bandwidth dielectric waveguide filter comprises: a dielectric block and a metal layer coated on the outer surface of the dielectric block, a coupling window portion of the dielectric block is provided with a capacitive coupling hole and an inductive coupling structure, the capacitive coupling hole is a metalized blind hole, and the inductive coupling structure is a metalized blind hole or a metalized blind groove.

[0008] In the above narrow bandwidth dielectric waveguide filter, since the coupling window of the dielectric block is provided with a capacitive coupling hole and an inductive coupling structure, the thickness D of the dielectric block at the bottom wall of the capacitive coupling hole can be designed to be large enough, so that the capacitive coupling of the capacitive coupling hole is large. However, since the inductive coupling of the inductive coupling structure can offset a part of the capacitive coupling of the capacitive coupling hole, the other part of the capacitive coupling of the capacitive coupling hole is equivalent to a narrow capacitive coupling, that is, a narrow bandwidth design can be achieved. At the same time, since the thickness D of the dielectric block at the bottom wall of the capacitive coupling hole is large enough, the production is relatively easy, and the sintering qualification rate of the product is improved.

[0009] In one embodiment, the dielectric block is provided with two dielectric resonant cavities, and the coupling window portion is a portion between the two dielectric resonant cavities.

[0010] In one embodiment, the outer surface of the dielectric block includes a first surface and a second surface that are arranged opposite to each other; the capacitive coupling hole and the inductive coupling structure are both located on the first surface; or, the capacitive coupling hole and the inductive coupling structure are both located on the second surface; or, the inductive coupling hole and the capacitive coupling structure are respectively located on the first surface and the second surface.

[0011] In one of the embodiments, two spaced-apart frequency adjustment holes are arranged on the first surface, the coupling window is arranged between the two frequency adjustment holes, and the frequency adjustment holes are metalized blind holes.

[0012] In one of the embodiments, the inductive coupling structure is a metallized blind slot, and the two frequency adjustment holes are connected through the metallized blind slot.

[0013] In one embodiment, the inductive coupling structure is a metallized blind groove, the capacitive coupling hole and the metallized blind groove are both located on the first surface, and the capacitive coupling hole extends from the bottom wall of the metallized blind groove toward the second surface.

[0014] In one embodiment, the inductive coupling structure is a metallized blind groove, the capacitive coupling hole and the metallized blind groove are both located on the second surface, and the capacitive coupling hole extends from the bottom wall of the metallized blind groove toward the first surface.

[0015] In one embodiment, the distance between the first surface and the second surface is S, the depth of the inductive coupling structure is H, and the relationship between H and S satisfies H≤1 / 2S.

[0016] In one embodiment, the dielectric block is a ceramic dielectric block; the metal layer is a metal silver layer, a metal copper layer, a metal platinum layer or a metal gold layer plated, sprayed or adhered on the dielectric block.

[0017] A communication device comprises the narrow bandwidth dielectric waveguide filter.

[0018] In the communication device described above, since the coupling window of the dielectric block is provided with a capacitive coupling hole and an inductive coupling structure, the thickness D of the dielectric block at the bottom wall of the capacitive coupling hole can be designed to be large enough, so that the capacitive coupling of the capacitive coupling hole is large. However, since the inductive coupling of the inductive coupling structure can offset a part of the capacitive coupling of the capacitive coupling hole, the other part of the capacitive coupling of the capacitive coupling hole is equivalent to a narrow capacitive coupling, that is, a narrow bandwidth design can be achieved. At the same time, since the thickness D of the dielectric block at the bottom wall of the capacitive coupling hole is large enough, the production is relatively easy, and the sintering qualification rate of the product is improved.

[0019] A design method for a narrow bandwidth dielectric waveguide filter includes the following steps: when the narrow bandwidth remains unchanged and the thickness D of the dielectric block at the bottom wall of the capacitive coupling hole needs to be adjusted, the size of the inductive coupling structure is adjusted.

[0020] In the design method of the narrow bandwidth dielectric waveguide filter, since the inductive coupling of the inductive coupling structure can offset a part of the capacitive coupling of the capacitive coupling hole, the other part of the capacitive coupling of the capacitive coupling hole is equivalent to the narrow capacitive coupling, that is, the narrow bandwidth design can be achieved. At the same time, since the thickness D of the dielectric block at the bottom wall of the capacitive coupling hole is large enough, the production is relatively easy, and the sintering qualification rate of the product is improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The drawings constituting a part of this application are used to provide a further understanding of the present invention. The illustrative embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0022] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0023] Figure 1 A top view of a narrow bandwidth dielectric waveguide filter in the form of a conventional single blind hole;

[0024] Figure 2 for Figure 1 Sectional view at AA;

[0025] Figure 3 A bottom view of a conventional single blind hole narrow bandwidth dielectric waveguide filter;

[0026] Figure 4 A top view of a conventional narrow bandwidth dielectric waveguide filter in the form of double blind holes;

[0027] Figure 5 for Figure 4 Sectional view at AA;

[0028] Figure 6 A bottom view of a conventional narrow bandwidth dielectric waveguide filter in the form of double blind holes;

[0029] Figure 7 for Figure 6 Cross-sectional view at BB;

[0030] Figure 8 A top view of the narrow bandwidth dielectric waveguide filter according to the first embodiment of the present invention;

[0031] Fig. 9 for Figure 8 Sectional view at AA;

[0032] Fig.10 A bottom view of the narrow bandwidth dielectric waveguide filter according to the first embodiment of the present invention;

[0033] Fig.11 A top view of a narrow bandwidth dielectric waveguide filter according to a second embodiment of the present invention;

[0034] Fig.12 for Fig.11 Sectional view at AA;

[0035] Fig.13 A bottom view of a narrow bandwidth dielectric waveguide filter according to a second embodiment of the present invention;

[0036] Fig.14 A top view of a narrow bandwidth dielectric waveguide filter according to a third embodiment of the present invention;

[0037] Fig.15 for Fig.14 Sectional view at AA;

[0038] Fig.16 A bottom view of a narrow bandwidth dielectric waveguide filter according to a third embodiment of the present invention;

[0039] Fig.17 A top view of a narrow-bandwidth dielectric waveguide filter according to a fourth embodiment of the present invention;

[0040] Fig.18 for Fig.17 Sectional view at AA;

[0041] Fig.19 A bottom view of a narrow bandwidth dielectric waveguide filter according to a fourth embodiment of the present invention;

[0042] Fig. 20 A top view of a narrow bandwidth dielectric waveguide filter according to a fifth embodiment of the present invention;

[0043] Fig.21 for Fig. 20 Sectional view at AA;

[0044] Fig. 22 A bottom view of a narrow bandwidth dielectric waveguide filter according to a fifth embodiment of the present invention;

[0045] Fig.23 A top view of a narrow-bandwidth dielectric waveguide filter according to a sixth embodiment of the present invention;

[0046] Fig.24 for Fig.23 Sectional view at AA;

[0047] Fig.25 A bottom view of a narrow bandwidth dielectric waveguide filter according to a sixth embodiment of the present invention;

[0048] Fig.26 FIG. 4 is an S-parameter diagram of a narrow-bandwidth dielectric waveguide filter according to an embodiment of the present invention.

[0049] 20. Dielectric block; 21. Coupling window part; 22. Capacitive coupling hole; 23. Inductive coupling structure; 24. Dielectric resonant cavity; 25. Frequency adjustment hole; 30. Metal layer. DETAILED DESCRIPTION

[0050] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific embodiments of the present invention are described in detail below in conjunction with the accompanying drawings. In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without violating the connotation of the present invention, so the present invention is not limited by the specific embodiments disclosed below.

[0051] In the description of the present invention, it is to be understood that the terms “center”, “longitudinal”, “lateral”, “length”, “width”, “thickness”, “up”, “down”, “front”, “back”, “left”, “right”, “vertical”, “horizontal”, “top”, “bottom”, “inside”, “outside”, “clockwise”, “counterclockwise”, “axial”, “radial”, “circumferential”, etc., indicating orientations or positional relationships are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0052] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0053] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0054] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0055] It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it may be directly on the other element or there may be a central element. When an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be a central element at the same time. The terms "vertical", "horizontal", "upper", "lower", "left", "right" and similar expressions used herein are for illustrative purposes only and are not intended to be the only implementation method.

[0056] See also Figures 8 to 10 , Figure 8 FIG. 4 is a schematic diagram showing a top view of a narrow bandwidth dielectric waveguide filter in a first embodiment of the present invention. Fig. 9 Shows Figure 8 The cross-sectional view at AA, Fig.10 The bottom view of the structure of the narrow bandwidth dielectric waveguide filter in the first embodiment of the present invention is shown. A narrow bandwidth dielectric waveguide filter provided by an embodiment of the present invention comprises a dielectric block 20 and a metal layer 30 coated on the outer surface of the dielectric block 20. A capacitive coupling hole 22 and an inductive coupling structure 23 are provided at the coupling window portion 21 of the dielectric block 20. The capacitive coupling hole 22 is a metalized blind hole, and the inductive coupling structure 23 is a metalized blind hole or a metalized blind groove.

[0057] It should be noted that, for the capacitive coupling hole 22, the greater the thickness D of the dielectric block 20 at the bottom wall of the capacitive coupling hole 22, the greater the capacitive coupling and the wider the capacitive coupling bandwidth; conversely, the smaller the thickness D of the dielectric block 20 at the bottom wall of the capacitive coupling hole 22, the smaller the capacitive coupling and the narrower the capacitive coupling bandwidth. In addition, when the inductive coupling structure 23 is, for example, a metallized blind hole, the size of the inductive coupling structure 23 is characterized by the hole depth and the hole diameter. The larger the hole depth and / or the hole diameter of the inductive coupling structure 23, the larger the inductive coupling. Conversely, the smaller the hole depth and / or the hole diameter of the inductive coupling structure 23, the smaller the inductive coupling. When the inductive coupling structure 23 is, for example, a metallized blind groove, the size of the inductive coupling structure 23 is characterized by the groove length, groove width and groove depth H. When any one of the groove length, groove width and groove depth H of the inductive coupling structure 23 increases, the inductive coupling increases. Conversely, when any one of the groove length, groove width and groove depth H of the inductive coupling structure 23 decreases, the inductive coupling decreases.

[0058] In the above narrow bandwidth dielectric waveguide filter, since the coupling window portion 21 of the dielectric block 20 is provided with a capacitive coupling hole 22 and an inductive coupling structure 23, the thickness D of the dielectric block 20 at the bottom wall portion of the capacitive coupling hole 22 can be designed to be large enough, so that the capacitive coupling of the capacitive coupling hole 22 is large. However, since the inductive coupling of the inductive coupling structure 23 can offset a part of the capacitive coupling of the capacitive coupling hole 22, the other part of the capacitive coupling of the capacitive coupling hole 22 is equivalent to a narrow capacitive coupling, that is, a narrow bandwidth design can be achieved. At the same time, since the thickness D of the dielectric block 20 at the bottom wall portion of the capacitive coupling hole 22 is large enough, the production is relatively easy, and the sintering qualification rate of the product is improved.

[0059] Please refer to Figures 8 to 10 It should be noted that the dielectric block 20 is provided with two dielectric resonant cavities 24 , and the coupling window portion 21 is a portion between the two dielectric resonant cavities 24 .

[0060] Please refer to Figures 8 to 10 In one embodiment, the outer surface of the dielectric block 20 includes a first surface and a second surface that are disposed opposite to each other. The first surface corresponds to Figure 8 The surface shown, and Fig. 9 The upper surface shown; the second surface corresponds to Fig.10 The surface shown, and Fig. 9 The capacitive coupling hole 22 and the inductive coupling structure 23 are both located on the first surface. At this time, the thickness D of the dielectric block 20 at the bottom wall of the capacitive coupling hole 22 refers to the distance between the bottom wall of the capacitive coupling hole 22 and the bottom surface.

[0061] It should be noted that the specific arrangement positions of the capacitive coupling hole 22 and the inductive coupling structure 23 on the first surface are not limited. The capacitive coupling hole 22 and the inductive coupling structure 23 can overlap each other, that is, the capacitive coupling hole 22 is formed by extending the bottom wall of the inductive coupling structure 23 toward the second surface (e.g., Figures 8 to 10 The capacitive coupling hole 22 and the inductive coupling structure 23 may also be provided independently of each other, that is, the capacitive coupling hole 22 and the inductive coupling structure 23 are located at two different positions on the first surface (such as Figures 11 to 13 shown).

[0062] See also Figures 11 to 13 , Fig.11 FIG. 4 is a schematic diagram showing a top view of a narrow bandwidth dielectric waveguide filter in a second embodiment of the present invention. Fig.12 Shows Fig.11 The cross-sectional view at AA, Fig.13 FIG. 4 is a bottom view schematic diagram of the narrow bandwidth dielectric waveguide filter in the second embodiment of the present invention. Figures 11 to 13 Schematic diagram of a narrow bandwidth dielectric waveguide filter and Figures 8 to 10 Compared with the narrow bandwidth dielectric waveguide filter shown in the figure, the difference is that Figures 11 to 13 The capacitive coupling hole 22 and the inductive coupling structure 23 are shown at two different positions on the first surface. At this time, the thickness D of the dielectric block 20 at the bottom wall of the capacitive coupling hole 22 refers to the distance between the bottom wall of the capacitive coupling hole 22 and the lower surface of the dielectric block 20.

[0063] It should also be noted that the capacitive coupling hole 22 and the inductive coupling structure 23 may not be disposed on the first surface, but may be disposed on the second surface, which is not limited here.

[0064] See also Figures 14 to 16 , and see Figures 17 to 19 , Fig.14 FIG. 4 is a schematic diagram showing a top view of a narrow bandwidth dielectric waveguide filter in a third embodiment of the present invention. Fig.15 Shows Fig.14 The cross-sectional view at AA, Fig.16 FIG. 4 is a bottom view schematic diagram of the narrow bandwidth dielectric waveguide filter in the third embodiment of the present invention. Fig.17 FIG. 4 is a schematic diagram showing a top view of a narrow bandwidth dielectric waveguide filter in a fourth embodiment of the present invention. Fig.18 Shows Fig.17 The cross-sectional view at AA, Fig.19 FIG. 2 shows a bottom view of a narrow bandwidth dielectric waveguide filter in a fourth embodiment of the present invention. In another embodiment, the capacitive coupling hole 22 and the inductive coupling structure 23 are both located on the second surface. Fig.15 or Fig.18 The thickness D of the dielectric block 20 at the bottom wall of the capacitive coupling hole 22 refers to the distance between the bottom wall of the capacitive coupling hole 22 and the upper surface of the dielectric block 20.

[0065] See also Figure 20 to Figure 22 , Figure 20 to Figure 22 FIG. 4 is a schematic diagram showing the structure of a narrow bandwidth dielectric waveguide filter in a fifth embodiment of the present invention. Figure 23 to Figure 25 FIG. 1 is a schematic diagram of the structure of a narrow bandwidth dielectric waveguide filter in a sixth embodiment of the present invention. In one embodiment, the inductive coupling hole and the capacitive coupling structure are located on the first surface and the second surface, respectively. It should be noted that the inductive coupling hole and the capacitive coupling structure are located on the first surface and the second surface, respectively, means that when the inductive coupling hole is located on the first surface, the capacitive coupling structure is located on the second surface (e.g., Figure 23 to Figure 25 When the inductive coupling hole is located on the second surface, the capacitive coupling structure is located on the first surface (as shown in FIG. Figure 20 to Figure 22 shown).

[0066] See also Fig.21 or Fig.24 The thickness D of the dielectric block 20 at the bottom wall of the capacitive coupling hole 22 refers to the distance between the bottom wall of the capacitive coupling hole 22 and the bottom wall of the inductive coupling structure 23.

[0067] In one embodiment, please refer to Figures 8 to 10 The first surface is provided with two spaced apart frequency adjustment holes 25 , the frequency adjustment holes 25 being metalized blind holes. Specifically, the coupling window portion 21 is provided between the two frequency adjustment holes 25 .

[0068] Specifically, the frequency adjustment hole 25 can be a round hole, a square hole or a special-shaped hole. The frequency adjustment hole 25 can affect the frequency of the dielectric filter. The smaller the size of the frequency adjustment hole 25 (for example, reducing the hole depth h of the frequency adjustment hole 25), the smaller the frequency adjustment hole 25. 2 ) the higher the frequency of the dielectric waveguide filter. Therefore, by changing the size of the frequency adjustment hole 25, the frequency of the dielectric waveguide filter can be adjusted.

[0069] It should be noted that, in other embodiments, when the frequency meets the set value, the frequency does not need to be adjusted, and the frequency adjustment hole 25 is not necessary.

[0070] Furthermore, the frequency adjustment hole 25 is a circular blind hole or a regular polygonal blind hole. The circular and regular polygonal blind holes are regular in shape and easy to process, so the production process of the dielectric waveguide filter can be more convenient. Moreover, since the size of the circular blind hole can be accurately characterized by the hole diameter and hole depth, the size of the regular polygonal blind hole can be represented by the side length and hole depth. Therefore, when the frequency adjustment is realized by using the frequency adjustment hole 25, the size of the frequency adjustment hole 25 is easier to determine and process.

[0071] See also Fig. 9 or Fig.21 In one embodiment, the inductive coupling structure 23 is a metallized blind groove, and the two frequency adjustment holes 25 are connected through the metallized blind groove. It should be noted that the shape of the metallized blind groove is not limited, for example, it can be a long strip, S-shaped, Z-shaped, etc. It is a feasible solution that the metallized blind groove can connect the two frequency adjustment holes 25. Of course, it is also a feasible solution that the metallized blind groove is not connected to the two frequency adjustment holes 25, which is not limited here. In this embodiment, the shape of the metallized blind groove is a long strip, and the long side direction of the long strip is consistent with the direction of the center line connecting the two frequency adjustment holes 25. In this way, the dielectric block 20 can be easily manufactured.

[0072] See also Figures 8 to 10 , or, see Figures 14 to 16 , see Figure 20 to Figure 22 ,or Fig.23 and Fig.24 Specifically, the capacitive coupling hole 22 and the metallized blind slot are located on the center line of the two frequency adjustment holes 25, that is, the capacitive coupling hole 22 and the metallized blind slot are arranged in the middle of the coupling window part 21. Specifically, the center of the capacitive coupling hole 22 and the center of the metallized blind slot are both located on the center line of the two frequency adjustment holes 25. In this way, the wall thickness of the capacitive coupling hole 22 and the metallized blind slot are thicker, the structure is more stable, and the production quality is higher. In addition, the product performance is better. Figures 11 to 13 ,or, Figures 17 to 19 Of course, it is also a feasible solution that the capacitive coupling hole 22 and the metallized blind slot deviate from the position of the center line of the two frequency adjustment holes 25, which is not limited here.

[0073] See also Fig. 9 In one embodiment, the inductive coupling structure 23 is a metallized blind groove, the capacitive coupling hole 22 and the metallized blind groove are both located on the first surface, and the capacitive coupling hole 22 extends from the bottom wall of the metallized blind groove toward the second surface.

[0074] See also Fig.15In one embodiment, the inductive coupling structure 23 is a metallized blind groove, the capacitive coupling hole 22 and the metallized blind groove are both located on the second surface, and the capacitive coupling hole 22 extends from the bottom wall of the metallized blind groove toward the first surface.

[0075] Please refer to Fig. 9 In one embodiment, the distance between the first surface and the second surface is S, the depth of the inductive coupling structure 23 is H, and the relationship between H and S is H≤1 / 2S.

[0076] It should be noted that, when the inductive coupling structure 23 is a metallized blind groove, the depth H is the groove depth H of the metallized blind groove; when the inductive coupling structure 23 is an inductive coupling hole, the depth H is the hole depth of the inductive coupling hole.

[0077] In one embodiment, the dielectric block 20 is a ceramic dielectric block. In addition, the metal layer 30 is a metal silver layer, a metal copper layer, a metal platinum layer or a metal gold layer plated, sprayed or bonded on the dielectric block 20 .

[0078] In one embodiment, a communication device includes the narrow bandwidth dielectric waveguide filter of any one of the above embodiments.

[0079] In the communication device described above, since the coupling window portion 21 of the dielectric block 20 is provided with a capacitive coupling hole 22 and an inductive coupling structure 23, the thickness D of the dielectric block 20 at the bottom wall portion of the capacitive coupling hole 22 can be designed to be large enough, so that the capacitive coupling of the capacitive coupling hole 22 is large. However, since the inductive coupling of the inductive coupling structure 23 can offset a part of the capacitive coupling of the capacitive coupling hole 22, the other part of the capacitive coupling of the capacitive coupling hole 22 is equivalent to a narrow capacitive coupling, that is, a narrow bandwidth design can be achieved. At the same time, since the thickness D of the dielectric block 20 at the bottom wall portion of the capacitive coupling hole 22 is large enough, the production is relatively easy, and the sintering qualification rate of the product is improved.

[0080] In one embodiment, a design method of a narrow bandwidth dielectric waveguide filter of any of the above embodiments comprises the following steps: when the size of the narrow bandwidth remains unchanged and the thickness D of the dielectric block 20 at the bottom wall of the capacitive coupling hole 22 needs to be adjusted, the size of the inductive coupling structure 23 is adjusted.

[0081] Specifically, the greater the thickness D of the dielectric block 20 at the bottom wall of the capacitive coupling hole 22, the greater the capacitive coupling and the wider the capacitive coupling bandwidth; conversely, the smaller the thickness D of the dielectric block 20 at the bottom wall of the capacitive coupling hole 22, the smaller the capacitive coupling and the narrower the capacitive coupling bandwidth.

[0082] In addition, when the inductive coupling structure 23 is, for example, a metallized blind hole, the size of the inductive coupling structure 23 is characterized by the hole depth and the hole diameter. The larger the hole depth and / or the hole diameter of the inductive coupling structure 23, the larger the inductive coupling. Conversely, the smaller the hole depth and / or the hole diameter of the inductive coupling structure 23, the smaller the inductive coupling. When the inductive coupling structure 23 is, for example, a metallized blind groove, the size of the inductive coupling structure 23 is characterized by the groove length, groove width and groove depth H. When any one of the groove length, groove width and groove depth H of the inductive coupling structure 23 increases, the inductive coupling increases. Conversely, when any one of the groove length, groove width and groove depth H of the inductive coupling structure 23 decreases, the inductive coupling decreases.

[0083] In the design method of the narrow bandwidth dielectric waveguide filter, since the inductive coupling of the inductive coupling structure 23 can offset a part of the capacitive coupling of the capacitive coupling hole 22, the other part of the capacitive coupling of the capacitive coupling hole 22 is equivalent to a narrow capacitive coupling, that is, a narrow bandwidth design can be achieved. At the same time, since the thickness D of the dielectric block 20 at the bottom wall of the capacitive coupling hole 22 is large enough, the production is relatively easy, and the sintering qualification rate of the product is improved.

[0084] Furthermore, when it is necessary to increase the thickness D of the dielectric block 20 at the bottom wall of the capacitive coupling hole 22, any one of the slot length, slot width and slot depth H of the inductive coupling structure 23 is increased. In this way, the increased capacitive coupling is offset by increasing the inductive coupling, so that the narrow bandwidth is maintained within the preset range.

[0085] See also Fig.26 , Fig.26 The S parameter diagram of a narrow bandwidth dielectric waveguide filter according to an embodiment of the present invention is shown. Specifically, the dielectric waveguide filter is, for example, an eight-cavity two-zero-point dielectric waveguide filter, and the capacitive coupling bandwidth is specifically required to be 81 MHZ.

[0086] In order to ensure that the capacitive coupling bandwidth meets the preset requirements, the design requirements of the dielectric waveguide filter are as follows:

[0087] The inductive coupling structure 23 is specifically a metalized blind groove. When the groove depth H of the metalized blind groove is 1 mm, the thickness D of the dielectric block 20 at the bottom wall of the capacitive coupling hole 22 is 0.96 mm.

[0088] When the groove depth H of the metallized blind groove is 1.5 mm, the thickness D of the dielectric block 20 at the bottom wall of the capacitive coupling hole 22 is 1.23 mm;

[0089] When the groove depth H of the metallized blind groove is 1.8 mm, the thickness D of the dielectric block 20 at the bottom wall of the capacitive coupling hole 22 is 1.86 mm.

[0090] Thus, by increasing the groove depth H of the metallized blind groove, the thickness D of the dielectric block 20 at the bottom wall of the capacitive coupling hole 22 can be increased accordingly, making the production easier, improving the sintering qualification rate of the product, and realizing mass production of the product.

[0091] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0092] The above-mentioned embodiments only express several implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for ordinary technicians in this field, appropriate deformations and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be based on the attached claims.

Claims

1. A narrow bandwidth dielectric waveguide filter, It is characterized in that The narrow bandwidth dielectric waveguide filter comprises: a dielectric block and a metal layer coated on the outer surface of the dielectric block, the outer surface of the dielectric block comprises a first surface, two frequency adjustment holes are arranged at intervals on the first surface, a coupling window portion of the dielectric block is arranged between the two frequency adjustment holes, a capacitive coupling hole and an inductive coupling structure are arranged at the coupling window portion of the dielectric block, the capacitive coupling hole is a metallized blind hole, the inductive coupling structure is a metallized blind groove, the metallized blind groove is in the shape of a long strip, the long side direction of the long strip is consistent with the direction of the center line connecting the two frequency adjustment holes, and the capacitive coupling hole and the metallized blind groove are both located at the position of the center line connecting the two frequency adjustment holes.

2. The narrow bandwidth dielectric waveguide filter according to claim 1, It is characterized in that The dielectric block is provided with two dielectric resonant cavities, and the coupling window portion is a portion between the two dielectric resonant cavities.

3. The narrow bandwidth dielectric waveguide filter according to claim 1, It is characterized in that The outer surface of the dielectric block also includes a second surface arranged opposite to the first surface; the capacitive coupling hole and the inductive coupling structure are both located on the first surface; or, the capacitive coupling hole and the inductive coupling structure are both located on the second surface; or, the capacitive coupling hole and the inductive coupling structure are respectively located on the first surface and the second surface.

4. The narrow bandwidth dielectric waveguide filter according to claim 3, It is characterized in that The frequency adjustment hole is a metalized blind hole.

5. The narrow bandwidth dielectric waveguide filter according to claim 4, It is characterized in that The two frequency adjustment holes are connected through the metallized blind groove.

6. The narrow bandwidth dielectric waveguide filter according to claim 3, It is characterized in that The capacitive coupling hole and the metallized blind groove are both located on the first surface, and the capacitive coupling hole extends from the bottom wall of the metallized blind groove toward the second surface.

7. The narrow bandwidth dielectric waveguide filter according to claim 3, It is characterized in that The capacitive coupling hole and the metallized blind groove are both located on the second surface, and the capacitive coupling hole extends from the bottom wall of the metallized blind groove toward the first surface.

8. The narrow bandwidth dielectric waveguide filter according to any one of claims 3 to 7, It is characterized in that The distance between the first surface and the second surface is S, the depth of the inductive coupling structure is H, and the relationship between H and S satisfies H≤1 / 2S.

9. The narrow bandwidth dielectric waveguide filter according to any one of claims 3 to 7, It is characterized in that The dielectric block is a ceramic dielectric block; the metal layer is a metal silver layer, a metal copper layer, a metal platinum layer or a metal gold layer plated, sprayed or adhered on the dielectric block.

10. A communication device, It is characterized in that A narrow bandwidth dielectric waveguide filter comprising the dielectric waveguide filter according to any one of claims 1 to 9.

11. A method for designing a narrow bandwidth dielectric waveguide filter according to any one of claims 1 to 9, It is characterized in that The method comprises the following steps: when the narrow bandwidth remains unchanged and the thickness D of the dielectric block at the bottom wall of the capacitive coupling hole needs to be adjusted, the size of the inductive coupling structure is adjusted.

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