A dielectric waveguide filter

Abstract

The present invention relates to a dielectric waveguide filter. On the one hand, the length of the negative coupling window is greater than 1 / 2 of the thicknesses of the first dielectric block and the second dielectric block, and the length of the negative coupling window is not less than 1 / 4 wavelength of the operating frequency of the dielectric waveguide filter. When applying the dielectric waveguide filter of the present application in electronic products, negative coupling is achieved between the resonant cavity on the first dielectric block and the resonant cavity on the second dielectric block through the negative coupling window, and in combination with the positive coupling window, two transmission zeros are generated in the dielectric waveguide filter, improving the out-of-band rejection ability. On the other hand, a negative coupling window and a positive coupling window are first opened on the outer wall surfaces where the first dielectric block and the second dielectric block are connected to each other, and then the first dielectric block and the second dielectric block are connected through the metal layer on the outer wall surface, improving the manufacturing efficiency and being suitable for mass production.

Description

Technical Field

[0001] The communication technology of the present invention relates to the field, and particularly relates to a dielectric waveguide filter. Background Art

[0002] As the requirements for miniaturization of base station equipment in 5G communication systems are getting higher and higher, the dielectric waveguide filter has become the mainstream application solution to replace traditional cavity filters in the future due to its advantages such as small volume, low insertion loss, high power handling capacity, and low cost. However, the commonly used dielectric waveguide filter in the industry at present is a single-layer structure solution, that is, each coupling window is made in the entire dielectric block. The dielectric waveguide filter made by this solution has the defect of poor out-of-band rejection ability, and the manufacturing efficiency is low, which is not conducive to mass production. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to provide a dielectric waveguide filter in view of the deficiencies of the prior art.

[0004] The technical solution of a dielectric waveguide filter of the present invention is as follows:

[0005] Through a first dielectric block and a second dielectric block whose outer wall surfaces are connected to each other, at least two resonators coupled in sequence are formed on the first dielectric block, and at least two resonators coupled in sequence are formed on the second dielectric block. Metal layers are covered on the outer wall surfaces of the first dielectric block and the second dielectric block;

[0006] On the mutually connected outer wall surface, a negative coupling window is opened to form negative coupling between the resonators of the first dielectric block and the resonators of the second dielectric block, and a positive coupling window is opened to form positive coupling between the resonators of the first dielectric block and the resonators of the second dielectric block;

[0007] The length of the negative coupling window is greater than 1 / 2 of the thickness of the first dielectric block and the second dielectric block, and the length of the negative coupling window is not less than 1 / 4 wavelength of the operating frequency of the dielectric waveguide filter.

[0008] The beneficial effects of a dielectric waveguide filter of the present invention are as follows:

[0009] On the one hand, the length of the negative coupling window is greater than 1 / 2 of the thicknesses of the first dielectric block and the second dielectric block, and the length of the negative coupling window is not less than 1 / 4 wavelength of the operating frequency of the dielectric waveguide filter. When applying a dielectric waveguide filter of this application in an electronic product, negative coupling is achieved between the resonators on the first dielectric block and the resonators on the second dielectric block through the negative coupling window, and in combination with the positive coupling window, two transmission zeros are generated in the dielectric waveguide filter, improving the out-of-band rejection ability. On the other hand, first, a negative coupling window and a positive coupling window are opened on the outer wall surfaces where the first dielectric block and the second dielectric block are connected to each other. Then, the first dielectric block and the second dielectric block are connected through the metal layer on the outer wall surface, improving the manufacturing efficiency and being suitable for mass production.

[0010] Based on the above technical solution, a dielectric waveguide filter of the present invention can be further improved as follows.

[0011] Further, the negative coupling window includes a first negative coupling window (51) provided on the first dielectric block (11) and a second negative coupling window (52) provided on the second dielectric block (12), and the first negative coupling window (51) and the second negative coupling window (52) are mirror images of each other.

[0012] Further, the positive coupling window includes a first positive coupling window (61) provided on the first dielectric block (11) and a second positive coupling window (62) provided on the second dielectric block (12), and the first positive coupling window (61) and the second positive coupling window (62) are mirror images of each other.

[0013] Further, both the first negative coupling window and the second negative coupling window are in a concave shape, and the positions of the two sides of the concave shape near the bottom are recessed to form concave openings, and both of the concave openings communicate with the concave part of the concave shape.

[0014] The beneficial effects of adopting the above further solution are: the structures of the first negative coupling window and the second negative coupling window are simple, further improving the manufacturing efficiency and being suitable for mass production.

[0015] Further, starting from the top surface of the concave opening, a metal layer of a preset shape is removed within the concave opening to change the magnitude of the coupling amount between the resonator on the first dielectric block corresponding to the first negative coupling window and the resonator on the second dielectric block corresponding to the second negative coupling window.

[0016] The beneficial effects of adopting the above further solution are as follows: when it is necessary to change the coupling amount between the resonator on the first dielectric block corresponding to the first negative coupling window and the resonator on the second dielectric block corresponding to the second negative coupling window, it is only necessary to remove the metal layer of a preset shape in the concave notch, without expanding the height and width of the concave shapes of the first negative coupling window and the second negative coupling window, making its structure more compact.

[0017] Further, a first resonator and a second resonator that are sequentially coupled are formed on the first dielectric block, and a third resonator and a fourth resonator that are sequentially coupled are formed on the second dielectric block;

[0018] The first negative coupling window is located on the outer surface of the first resonator, the second negative coupling window is located on the outer surface of the third resonator, and the first negative coupling window and the second negative coupling window are used to couple the first resonator and the third resonator;

[0019] The first positive coupling window is located on the outer surface of the second resonator, the second positive coupling window is located on the outer surface of the fourth resonator, and the first positive coupling window and the second positive coupling window are used to couple the second resonator and the fourth resonator.

[0020] Further, a fifth resonator that is coupled to the second resonator is further formed on the first dielectric block, and a sixth resonator that is coupled to the fourth resonator is further formed on the second dielectric block;

[0021] A first input / output coupling blind hole is further provided on the first dielectric block, and the first input / output coupling blind hole is located on the outer surface of the fifth resonator;

[0022] A second input / output coupling blind hole is further provided on the second dielectric block, and the second input / output coupling blind hole is located on the outer surface of the sixth resonator.

[0023] Further, a tuning blind hole is respectively provided for each of the first resonator, the second resonator, the third resonator, the fourth resonator, the fifth resonator, and the sixth resonator.

[0024] Further, a coupling blind hole is respectively provided between the first resonator and the second resonator, between the second resonator and the fifth resonator, between the third resonator and the fourth resonator, and between the fourth resonator and the sixth resonator.

[0025] Further, both the first positive coupling window and the second positive coupling window are rectangular or elliptical.

[0026] Further, the first dielectric block and the second dielectric block are ceramic dielectric blocks.

[0027] Further, the metal layer is a silver-plated metal layer or a copper-plated metal. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It is a structural diagram of a dielectric waveguide filter according to an embodiment of the present invention;

[0029] Figure 2 It is a schematic structural diagram of a first negative coupling window;

[0030] The realization, functional features and advantages of the object of the present invention will be further described with reference to the embodiments and the accompanying drawings. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0031] It should be understood that the specific embodiments described herein are only used to explain the present invention, and are not used to limit the embodiments of the present invention.

[0032] As Figure 1 shown, a dielectric waveguide filter according to an embodiment of the present invention includes a first dielectric block 11 and a second dielectric block 12 whose outer wall surfaces are connected to each other. At least two sequentially coupled resonant cavities are formed on the first dielectric block 11, and at least two sequentially coupled resonant cavities are formed on the second dielectric block 12. Metal layers are provided on the outer wall surfaces of the first dielectric block 11 and the second dielectric block 12;

[0033] On the mutually connected outer wall surfaces, a negative coupling window is provided to form negative coupling between the resonant cavities of the first dielectric block 11 and the resonant cavities of the second dielectric block 12, and a positive coupling window is provided to form positive coupling between the resonant cavities of the first dielectric block 11 and the resonant cavities of the second dielectric block 12;

[0034] The length of the negative coupling window is greater than 1 / 2 of the thickness of the first dielectric block 11 and the second dielectric block 12, and the length of the negative coupling window is not less than 1 / 4 wavelength of the operating frequency of the dielectric waveguide filter.

[0035] On the one hand, the length of the negative coupling window is greater than 1 / 2 of the thickness of the first dielectric block 11 and the second dielectric block 12, and the length of the negative coupling window is not less than 1 / 4 wavelength of the operating frequency of the dielectric waveguide filter. When applying a dielectric waveguide filter of the present application in an electronic product, negative coupling is realized between the resonant cavities on the first dielectric block 11 and the resonant cavities on the second dielectric block 12 through the negative coupling window, and combined with the positive coupling window, two transmission zeros are generated in the dielectric waveguide filter, improving the out-of-band rejection ability; on the other hand, first, a negative coupling window and a positive coupling window are provided on the mutually connected outer wall surfaces of the first dielectric block 11 and the second dielectric block 12, and then, the first dielectric block 11 and the second dielectric block 12 are connected through the metal layer on the outer wall surface, improving the production efficiency and being suitable for mass production.

[0036] Preferably, in the above technical solution, the negative coupling window includes a first negative coupling window 51 provided in the first dielectric block 11 and a second negative coupling window 52 provided in the second dielectric block 12, and the first negative coupling window 51 and the second negative coupling window 52 are mirror images of each other; the positive coupling window includes a first positive coupling window 61 provided in the first dielectric block 11 and a second positive coupling window 62 provided in the second dielectric block 12, and the first positive coupling window 61 and the second positive coupling window 62 are mirror images of each other. Specifically:

[0037] The first dielectric block 11 includes a first outer wall surface, the second dielectric block 12 includes a second outer wall surface, and the first dielectric block 11 and the second dielectric block 12 are connected by a metal layer on the first outer wall surface and the second outer wall surface, that is, the mutually connected outer wall surfaces are the first outer wall surface and the second outer wall surface;

[0038] The metal layer on the first outer wall surface is provided with a first negative coupling window 51 and a first positive coupling window 61, and the metal layer on the second outer wall surface is provided with a second negative coupling window 52 and a second positive coupling window 62;

[0039] Among them, the first negative coupling window 51 and the second negative coupling window 52 have the same structure, and the first negative coupling window 51 and the second negative coupling window 52 are oppositely arranged, that is, the first negative coupling window (51) and the second negative coupling window (52) are mirror images of each other, and are used for coupling the resonator on the first dielectric block 11 corresponding to the first negative coupling window 51 and the resonator on the second dielectric block 12 corresponding to the second negative coupling window 52;

[0040] The first positive coupling window 61 and the second positive coupling window 62 are oppositely arranged, and are used for coupling the resonator on the first dielectric block 11 corresponding to the first positive coupling window 61 and the resonator on the second dielectric block 12 corresponding to the second positive coupling window 62;

[0041] The length of the first negative coupling window 51 is greater than 1 / 2 of the thickness of the first dielectric block 11, the length of the second negative coupling window 52 is greater than 1 / 2 of the thickness of the second dielectric block 12, and the lengths of the first negative coupling window 51 and the second negative coupling window 52 are not less than 1 / 4 wavelength of the operating frequency of the dielectric waveguide filter.

[0042] On the one hand, by providing a first negative coupling window 51 and a second negative coupling window 52 with the same structure, wherein the length of the first negative coupling window 51 is greater than 1 / 2 of the thickness of the first dielectric block 11, the length of the second negative coupling window 52 is greater than 1 / 2 of the thickness of the second dielectric block 12, and the lengths of the first negative coupling window 51 and the second negative coupling window 52 are not less than 1 / 4 wavelength of the operating frequency of the dielectric waveguide filter, negative coupling is achieved between the resonant cavity on the first dielectric block 11 corresponding to the first negative coupling window 51 and the resonant cavity on the second dielectric block 12 corresponding to the second negative coupling window 52, ​​and combined with the first negative coupling window 51, the resonant cavity on the first dielectric block 11 corresponding to the first negative coupling window 51 and the resonant cavity on the second dielectric block 12 corresponding to the second negative coupling window 52 are connected to the first dielectric block 12. The positive coupling, i.e., inductive coupling, between the resonant cavity on the first dielectric block 11 corresponding to the positive coupling window 61 and the resonant cavity on the second dielectric block 12 corresponding to the second positive coupling window 62 causes the dielectric waveguide filter to produce two transmission zeros, thereby improving the out-of-band suppression capability. On the other hand, first, a first negative coupling window 51 and a first positive coupling window 61 are arranged on the first dielectric block 11, and a second negative coupling window 52 and a second positive coupling window 62 are arranged on the second dielectric block 12. Then, the first dielectric block 11 and the second dielectric block 12 are connected through the metal layers of the first outer wall surface and the second outer wall surface, thereby improving the manufacturing efficiency and being suitable for mass production.

[0043] The number of resonant cavities coupled in sequence formed on the first dielectric block 11 may be 2, 3, 4, etc., and correspondingly, the number of resonant cavities coupled in sequence formed on the second dielectric block 12 may also be 2, 3, 4, etc.;

[0044] Specifically, the first dielectric block 11 and the second dielectric block 12 are connected through the metal layers of the first outer wall surface and the second outer wall surface by printing silver paste and sintering at high temperature, so that the first dielectric block 11 and the second dielectric block 12 are spliced ​​into a complete dielectric waveguide filter, eliminating the through-hole partition between non-adjacent resonant cavities, thereby improving the isolation between the first dielectric block 11 and the second dielectric block 12 and the structural reliability of the dielectric waveguide filter, and also greatly improving the yield rate of the manufactured dielectric waveguide filter. Specifically, the coupling window of the lithography needs to be avoided when printing the silver paste.

[0045] It can be understood that since the length of the first negative coupling window 51 is greater than 1 / 2 of the thickness of the first dielectric block 11, the length of the second negative coupling window 52 is greater than 1 / 2 of the thickness of the second dielectric block 12, and the lengths of the first negative coupling window 51 and the second negative coupling window 52 are both not less than 1 / 4 wavelength of the operating frequency of the dielectric waveguide filter, negative coupling is achieved between the resonator on the first dielectric block 11 corresponding to the first negative coupling window 51 and the resonator on the second dielectric block 12 corresponding to the second negative coupling window 52, thereby forming a transmission zero. Moreover, by combining the positive coupling, i.e., inductive coupling, between the resonator on the first dielectric block 11 corresponding to the first positive coupling window 61 and the resonator on the second dielectric block 12 corresponding to the second positive coupling window 62, two transmission zeros are generated in the dielectric waveguide filter, further improving the out-of-band rejection ability. Among them, the structures of the first positive coupling window 61 and the second cross-coupling window can be the same or different.

[0046] It can be understood that the first negative coupling window 51, the second negative coupling window 52, the first positive coupling window 61, and the second positive coupling window 62 are formed by removing the metal layer on the first outer wall through techniques such as printing etching or photolithography. The manufacturing is simple, and it is easier to manufacture the first negative coupling window 51, the second negative coupling window 52, the first positive coupling window 61, and the second positive coupling window 62 with high precision compared to the dry pressing scheme in the single-layer structure solution. Especially for the first negative coupling window 51 and the second negative coupling window 52, the precision requirement cannot exceed ±0.03 mm. It is difficult to guarantee this if using the dry pressing scheme. If CNC (Computerized Numerical Control precision machining) engraving is used for secondary processing to ensure this precision, the cost will increase. In this application, it is very easy to achieve the precision requirement of ±0.03 mm through printing etching or photolithography, and the manufacturing is simple and the cost is low.

[0047] Preferably, as Figure 2 shown, in the above technical solution, both the first negative coupling window 51 and the second negative coupling window 52 are in a concave shape, and the positions of the two side edges 510 of the concave shape near the bottom are recessed to form recessed openings 530, and the two recessed openings 530 are both communicated with the concave part 520 of the concave shape.

[0048] The structures of the first negative coupling window 51 and the second negative coupling window 52 are simple, further improving the manufacturing efficiency and being suitable for mass production. Among them, the length of the first negative coupling window 51 and the second negative coupling window 52 refers to the sum of the lengths of the two side edges 510 and the bottom edge 550 of the concave shape. It can be understood that the length of the first negative coupling window 51 can be understood as the total length of each part of the first negative coupling window 51, or the length confirmed according to the center of gravity positions of each part. Moreover, the process of obtaining the length of the negative coupling window in the dielectric waveguide filter is well-known to those skilled in the art and will not be elaborated here.

[0049] Preferably, in the above technical solution, as Figure 2 shown, starting from the top surface of the concave opening 530, a metal layer of a preset shape is removed within the concave opening 530, i.e., the removed portion 540, so as to change the magnitude of the negative coupling amount between the resonant cavity on the first dielectric block 11 corresponding to the first negative coupling window 51 and the resonant cavity on the second dielectric block 12 corresponding to the second negative coupling window -52.

[0050] When it is necessary to change the coupling amount between the resonant cavity on the first dielectric block 11 corresponding to the first negative coupling window 51 and the resonant cavity on the second dielectric block 12 corresponding to the second negative coupling window 52, it is only necessary to remove the metal layer of a preset shape within the concave opening 530, without expanding the height and width of the concave-shaped of the first negative coupling window 51 and the second negative coupling window 52, making its structure more compact. Among them, the preset shape can be a rectangle, a semicircle, etc. Among them, etching process, engraving process or grinding process can be used for removal.

[0051] It can be understood that: the metal layer of a preset shape, i.e., the removed portion 540, can be removed only within one of the concave openings 530 of the first negative coupling window 51. Correspondingly, the metal layer of a preset shape, i.e., the removed portion 540, is also removed only within one of the concave openings 530 of the second negative coupling window 52. At this time, the length of the first negative coupling window 51 and the second negative coupling window 52 refers to: the sum of the lengths of the two side edges 510 of the concave shape, the length of the bottom edge 550, and the length of one removed portion 540;

[0052] The metal layer of a preset shape, i.e., the removed portion 540, can be removed within both of the concave openings 530 of the first negative coupling window 51. Correspondingly, the metal layer of a preset shape, i.e., the removed portion 540, is removed within both of the concave openings 530 of the second negative coupling window 52. At this time, the length of the first negative coupling window 51 and the second negative coupling window 52 refers to: the sum of the lengths of the two side edges 510 of the concave shape, the length of the bottom edge 550, and the lengths of two removed portions 540.

[0053] A dielectric waveguide filter according to this embodiment increases the negative coupling amount between the resonant cavity on the first dielectric block 11 corresponding to the first negative coupling window 51 and the resonant cavity on the second dielectric block 12 corresponding to the second negative coupling window 52 by removing the metal layer of a preset shape within the concave openings 530, shortening the longitudinal dimension of the etched pattern, i.e., shortening the lengths of the first negative coupling window 51 and the second negative coupling window 52. Originally, the length of the pattern that needs to be longitudinally etched, i.e., the length of the negative coupling window, is 1 / 2 wavelength of the operating frequency of the dielectric waveguide filter to achieve negative coupling. Now, the length of the longitudinally etched pattern is less than 1 / 2 wavelength and negative coupling can be achieved.

[0054] Preferably, in the above technical solution, a first resonant cavity 21 and a second resonant cavity 22 are sequentially coupled on the first dielectric block 11, and a third resonant cavity 23 and a fourth resonant cavity 24 are sequentially coupled on the second dielectric block 12;

[0055] The first negative coupling window 51 is located on the outer surface of the first resonant cavity 21, the second negative coupling window 52 is located on the outer surface of the third resonant cavity 23, and the first negative coupling window 51 and the second negative coupling window 52 are used to couple the first resonant cavity 21 and the third resonant cavity 23;

[0056] The first positive coupling window 61 is located on the outer surface of the second resonant cavity 22, the second positive coupling window 62 is located on the outer surface of the fourth resonant cavity 24, and the first positive coupling window 61 and the second positive coupling window 62 are used to couple the second resonant cavity 22 and the fourth resonant cavity 24.

[0057] Preferably, in the above technical solution, the first dielectric block 11 further forms a fifth resonant cavity 25 coupled to the second resonant cavity 22, and the second dielectric block 12 further forms a sixth resonant cavity 26 coupled to the fourth resonant cavity 24;

[0058] The first dielectric block 11 is further provided with a first input / output coupling blind hole 71, and the first input / output coupling blind hole 71 is located on the outer surface of the fifth resonant cavity 25;

[0059] The second dielectric block 12 is further provided with a second input / output coupling blind hole 72, and the second input / output coupling blind hole 72 is located on the outer surface of the sixth resonant cavity 26.

[0060] Wherein, when the first input / output coupling blind hole 71 is used as a signal input interface, the corresponding second input / output coupling blind hole 72 is used as a signal output interface, and vice versa.

[0061] Next, a dielectric waveguide filter of the present application will be described by taking the signal transmission path as an example. Specifically:

[0062] 1) The first negative coupling window 51 is located on the outer surface of the first resonant cavity 21, the second negative coupling window 52 is located on the outer surface of the third resonant cavity 23, the first positive coupling window 61 is located on the outer surface of the second resonant cavity 22, and the second positive coupling window 62 is located on the outer surface of the fourth resonant cavity 24. At this time, the resonant cavity of the first dielectric block 11 corresponding to the first negative coupling window 51 is the first resonant cavity 21, the resonant cavity of the second dielectric block 12 corresponding to the second negative coupling window 52 is the third resonant cavity 23, the resonant cavity of the first dielectric block 11 corresponding to the first positive coupling window 61 is the second resonant cavity 22, and the resonant cavity of the second dielectric block 12 corresponding to the second positive coupling window 62 is the fourth resonant cavity 24. Then:

[0063] The signal transmission path is: the second input / output coupling blind hole 72 → the sixth resonant cavity 26 → the fourth resonant cavity 24 → the third resonant cavity 23 → the first resonant cavity 21 → the second resonant cavity 22 → the fifth resonant cavity 25 → the first input / output coupling blind hole 71. Among them, since there is negative coupling between the second negative coupling window 52 of the third resonant cavity 23 and the first negative coupling window 51 of the first resonant cavity 21, the phase of the electromagnetic wave is inverted when it is transmitted from the first negative coupling window 51 to the second negative coupling window 52, thus forming a transmission zero point. And because there is also positive coupling between the second positive coupling window 62 of the fourth resonant cavity 24 and the first positive coupling window 61 of the third resonant cavity 23, two transmission zero points are generated in the dielectric waveguide filter, further improving the out-of-band rejection ability.

[0064] 2) The first negative coupling window 51 can be located on the outer surface of the second resonant cavity 22, the second negative coupling window 52 is located on the outer surface of the fourth resonant cavity 24, the first positive coupling window 61 is located on the outer surface of the first resonant cavity 21, and the second positive coupling window 62 is located on the outer surface of the third resonant cavity 23. At this time, the resonant cavity of the first dielectric block 11 corresponding to the first negative coupling window 51 is the second resonant cavity 22, the resonant cavity of the second dielectric block 12 corresponding to the second negative coupling window 52 is the fourth resonant cavity 24, the resonant cavity of the first dielectric block 11 corresponding to the first positive coupling window 61 is the first resonant cavity 21, and the resonant cavity of the second dielectric block 12 corresponding to the second positive coupling window 62 is the third resonant cavity 23. Then:

[0065] The signal transmission path is: the second input / output coupling blind hole 72 → the sixth resonant cavity 26 → the fourth resonant cavity 24 → the third resonant cavity 23 → the first resonant cavity 21 → the second resonant cavity 22 → the fifth resonant cavity 25 → the first input / output coupling blind hole 71,

[0066] Among them, since there is negative coupling between the second negative coupling window 52 of the fourth resonator 24 and the first negative coupling window 51 of the second resonator 22, the electromagnetic wave is phase-inverted when transmitted from the first negative coupling window 51 to the second negative coupling window 52, thus forming a transmission zero point. And since there is also positive coupling between the second positive coupling window 62 of the third resonator 23 and the first positive coupling window 61 of the second resonator 22, the dielectric waveguide filter generates two transmission zero points, further improving the out-of-band rejection ability.

[0067] Preferably, in the above technical solution, the first resonator 21, the second resonator 22, the third resonator 23, the fourth resonator 24, the fifth resonator 25 and the sixth resonator 26 are each provided with a tuning blind hole. Specifically:

[0068] A first tuning blind hole 31 is provided on the first resonator 21, a second tuning blind hole 32 is provided on the second resonator 22, a third tuning blind hole 33 is provided on the third resonator 23, a fourth tuning blind hole 34 is provided on the fourth resonator 24, a fifth tuning blind hole 35 is provided on the fifth resonator 25, and a sixth tuning blind hole 36 is provided on the sixth resonator 26. For example, the first resonator 21 can be tuned by removing the metal layer in the first tuning blind hole 31.

[0069] Preferably, in the above technical solution, a coupling blind hole is respectively provided between the first resonator 21 and the second resonator 22, between the second resonator 22 and the fifth resonator 25, between the third resonator 23 and the fourth resonator 24, and between the fourth resonator 24 and the sixth resonator 26. Specifically:

[0070] A first coupling blind hole 41 is provided on the first dielectric block 11 and between the first resonator 21 and the second resonator 22, and the first coupling blind hole 41 is used for coupling the first resonator 21 and the second resonator 22;

[0071] A third coupling blind hole 43 is provided on the first dielectric block 11 and between the second resonator 22 and the fifth resonator 25, and the third coupling blind hole 43 is used for coupling the second resonator 22 and the fifth resonator 25;

[0072] A second coupling blind hole 42 is provided on the second dielectric block 12 and between the third resonator 23 and the fourth resonator 24, and the second coupling blind hole 42 is used for coupling the third resonator 23 and the third resonator 23;

[0073] A fourth coupling blind hole 44 is provided on the second dielectric block 12 and between the fourth resonator cavity 24 and the sixth resonator cavity 26. The fourth coupling blind hole 44 is used to couple the fourth resonator cavity 24 and the sixth resonator cavity 26.

[0074] Among them, the inductive coupling amount, that is, the magnitude of the positive coupling amount, between two mutually coupled resonator cavities is controlled by the size of the coupling blind hole that couples the two.

[0075] Preferably, in the above technical solution, both the first positive coupling window 61 and the second positive coupling window 62 are rectangular or elliptical.

[0076] Preferably, in the above technical solution, the first dielectric block 11 and the second dielectric block 12 are ceramic dielectric blocks.

[0077] Preferably, in the above technical solution, the metal layer is a silver-plated metal layer or copper plating.

[0078] In addition, to improve the metallization yield of the metal layer, chamfers with R or C need to be provided on the edges of all tuning blind holes, all coupling blind holes, all input / output coupling blind holes, the first dielectric block 11 and the second dielectric block 12. The chamfer size can be any value, but considering the suitability for production, the recommended value is between 0.1 and 0.5.

[0079] The above are only the preferred embodiments of the present invention, and do not limit the patent scope of the present invention accordingly. Any equivalent structural transformation made by using the content of the specification and drawings of the present invention, or directly or indirectly applied in other related technical fields, shall be included in the patent protection scope of the present invention by the same token.

Claims

1. A dielectric waveguide filter, characterized in that, comprising: a first dielectric block (11) and a second dielectric block (12) connected to each other through an outer wall surface, at least two resonators coupled in sequence are formed on the first dielectric block (11), at least two resonators coupled in sequence are formed on the second dielectric block (12), and metal layers are covered on the outer wall surfaces of the first dielectric block (11) and the second dielectric block (12); on the mutually connected outer wall surface, a negative coupling window for forming negative coupling between the resonators of the first dielectric block (11) and the resonators of the second dielectric block (12) is provided, and a positive coupling window for forming positive coupling between the resonators of the first dielectric block (11) and the resonators of the second dielectric block (12) is provided; the length of the negative coupling window is greater than 1 / 2 of the thickness of the first dielectric block (11) and the second dielectric block (12), and the length of the negative coupling window is not less than 1 / 4 wavelength of the operating frequency of the dielectric waveguide filter; the negative coupling window includes a first negative coupling window (51) provided on the first dielectric block (11) and a second negative coupling window (52) provided on the second dielectric block (12), and the first negative coupling window (51) and the second negative coupling window (52) are mirror images of each other; the positive coupling window includes a first positive coupling window (61) provided on the first dielectric block (11) and a second positive coupling window (62) provided on the second dielectric block (12), and the first positive coupling window (61) and the second positive coupling window (62) are mirror images of each other; the first dielectric block (11) includes a first outer wall surface, the second dielectric block (12) includes a second outer wall surface, and the first dielectric block (11) and the second dielectric block (12) are connected through the metal layers on the first outer wall surface and the second outer wall surface; the metal layer on the first outer wall surface is provided with the first negative coupling window (51) and the first positive coupling window (61), and the metal layer on the second outer wall surface is provided with a second negative coupling window (52) and a second positive coupling window (62).

2. The dielectric waveguide filter according to claim 1, characterized in that, both the first negative coupling window (51) and the second negative coupling window (52) are in a concave shape, and the positions of the two sides (510) of the concave shape close to the bottom are concave to form concave openings (530), and the two concave openings (530) are both communicated with the concave part (520) of the concave shape.

3. The dielectric waveguide filter according to claim 2, characterized in that, further comprising: starting from the top surface of the concave opening (530), removing a metal layer of a preset shape in the concave opening (530) to change the magnitude of the negative coupling amount between the resonator on the first dielectric block (11) corresponding to the first negative coupling window (51) and the resonator on the second dielectric block (12) corresponding to the second negative coupling window (52).

4. The dielectric waveguide filter according to claim 2 or 3, characterized in that, A first resonant cavity (21) and a second resonant cavity (22) which are sequentially coupled are formed on the first dielectric block (11), and a third resonant cavity (23) and a fourth resonant cavity (24) which are sequentially coupled are formed on the second dielectric block (12); the first negative coupling window (51) is located on the outer surface of the first resonant cavity (21), and the second negative coupling window (52) is located on the outer surface of the third resonant cavity (23); the first positive coupling window (61) is located on the outer surface of the second resonant cavity (22), and the second positive coupling window (62) is located on the outer surface of the fourth resonant cavity (24).

5. A dielectric waveguide filter according to claim 4, wherein, a fifth resonant cavity (25) for coupling with the second resonant cavity (22) is further formed on the first dielectric block (11), and a sixth resonant cavity (26) for coupling with the fourth resonant cavity (24) is further formed on the second dielectric block (12); a first input / output coupling blind hole (71) is further provided on the first dielectric block (11), and the first input / output coupling blind hole (71) is located on the outer surface of the fifth resonant cavity (25); a second input / output coupling blind hole (72) is further provided on the second dielectric block (12), and the second input / output coupling blind hole (72) is located on the outer surface of the sixth resonant cavity (26).

6. A dielectric waveguide filter according to claim 5, wherein, a tuning blind hole is respectively provided in each of the first resonant cavity (21), the second resonant cavity (22), the third resonant cavity (23), the fourth resonant cavity (24), the fifth resonant cavity (25) and the sixth resonant cavity (26).

7. A dielectric waveguide filter according to claim 5 or 6, wherein, a coupling blind hole is respectively provided between the first resonant cavity (21) and the second resonant cavity (22), between the second resonant cavity (22) and the fifth resonant cavity (25), between the third resonant cavity (23) and the fourth resonant cavity (24), and between the fourth resonant cavity (24) and the sixth resonant cavity (26).

8. A dielectric waveguide filter according to claim 1, wherein, both the first positive coupling window (61) and the second positive coupling window (62) are rectangular or elliptical.

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