Filter

Abstract

The present application provides a filter, comprising a first resonator (11). The first resonator (11) comprises a resonator housing (111) and a dielectric resonator (112). The filter further comprises a first coupling structure (20) arranged in the resonator housing (111). Two opposite ends of the first coupling structure (20) are both grounded. The first coupling structure (20) comprises a first coupling portion (21) and a second coupling portion (22). One end of the second coupling portion (22) is connected to the end of the first coupling portion (21) away from the central axis of the dielectric resonator (112). The first coupling portion (21) intersects the dielectric resonator (112) in the circumferential direction, and the second coupling portion (22) intersects the dielectric resonator (112) in the radial direction. The filter can couple a TE mode and a TM mode of the first resonator (11) by means of the first coupling structure (20), and a better coupling effect is achieved, thereby facilitating the simulation design of the filter.

Description

filter

[0001] This application claims priority to Chinese Patent Application No. 202411555983.5, filed on October 31, 2024, with the State Intellectual Property Office of the People's Republic of China, entitled "Filter," the entire contents of which are incorporated herein by reference. This application also claims priority to two other Chinese Patent Applications Nos. 202411556005.2 and 202422671375.2, both filed on October 31, 2024, with the State Intellectual Property Office of the People's Republic of China, entitled "Filter and Communication Device," the entire contents of which are incorporated herein by reference. Technical Field

[0002] This application belongs to the field of communication technology, and in particular relates to a filter. Background Technology

[0003] In some cases, filters include dielectric cavity resonators capable of coupling at least two orthogonal high-Q resonant modes, TE and TM, within a single cavity. That is, the dielectric cavity resonator possesses at least two resonant modes, TE and TM, which facilitates better coupling with resonators such as metal coaxial resonators, thus improving the usability, applicability, and practicality of the dielectric cavity resonator. Such dielectric cavity resonators can achieve at least a second-order filtering effect, equivalent to the filtering effect of at least two single-mode resonators, i.e., equivalent to the filtering effect of at least two microwave resonators, thereby improving the performance and space utilization of the dielectric cavity resonator. Furthermore, the dielectric cavity resonator has a small size, which is beneficial for miniaturization and lightweight design. In this case, how to couple the TE and TM modes of the dielectric cavity resonator has become a problem to be solved in the industry.

[0004] Application content

[0005] This application provides a filter designed to address the problem of coupling the TE and TM modes of a dielectric cavity resonator when the filter includes at least two resonant modes: TE and TM.

[0006] To achieve the above objectives, the technical solution adopted in the embodiments of this application is as follows:

[0007] In a first aspect, a filter is provided, including a first resonator having at least two resonant modes: a TE mode and a TM mode. The first resonator includes a resonator housing and a dielectric resonator disposed within the resonator housing, the dielectric resonator being connected to a first wall of the resonator housing. The filter further includes a first coupling structure disposed within the resonator housing, with both opposite ends of the first coupling structure grounded. The first coupling structure includes a first coupling portion and a second coupling portion, one end of the second coupling portion being connected to the end of the first coupling portion away from the central axis of the dielectric resonator. The first coupling portion intersects the circumferential direction of the dielectric resonator, and the second coupling portion intersects the radial direction of the dielectric resonator, so that the TE mode and the TM mode of the first resonator are coupled.

[0008] The beneficial effects of the filter provided in this application are as follows:

[0009] The filter provided in this application embodiment has a first coupling structure disposed within a first resonator having at least two resonant modes: TE mode and TM mode. This first coupling structure couples the TE and TM modes of the first resonator. Specifically, the first coupling structure can couple the TM mode by cutting the magnetic field of the TM mode through a first coupling portion intersecting the circumference of the dielectric resonator; it can also couple the TE mode by cutting the magnetic field of the TE mode through a second coupling portion intersecting the radial direction of the dielectric resonator. Furthermore, based on the connection between the second coupling portion and the first coupling portion, the TE and TM modes of the first resonator can be coupled together on the first coupling structure. Thus, the filter can achieve coupling of the TE and TM modes of the first resonator through a simplified and optimized first coupling structure, resulting in better coupling performance. This optimizes the filter's structure and performance and facilitates filter simulation design. Attached Figure Description

[0010] To clearly illustrate the technical solutions in the embodiments of this application, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0011] Figure 1 is a top view of a filter provided in some embodiments of this application;

[0012] Figure 2 is a top view of the filter provided in Figure 1 with a hidden dielectric resonator.

[0013] Figure 3 is a three-dimensional schematic diagram of the filter provided in Figure 2;

[0014] Figure 4 is a magnetic field distribution diagram of the TM mode of the first resonator provided in the embodiment of this application when the TE mode and the TM mode are not coupled by the first coupling structure;

[0015] Figure 5 is a magnetic field distribution diagram of the TM mode of the first resonator provided in the embodiment of this application when the TE mode and the TM mode are coupled through the first coupling structure;

[0016] Figure 6 is a second magnetic field distribution diagram of the TM mode of the first resonator provided in the embodiment of this application when the TE mode and the TM mode are coupled through the first coupling structure. The magnetic field direction of the TM mode in Figure 6 is opposite to that of the TM mode in Figure 5.

[0017] Figure 7 is a magnetic field distribution diagram of the TE mode of the first resonator provided in the embodiment of this application when the TE mode and the TM mode are not coupled by the first coupling structure;

[0018] Figure 8 is a second magnetic field distribution diagram of the TE mode of the first resonator provided in the embodiment of this application when the TE mode and the TM mode are not coupled by the first coupling structure;

[0019] Figure 9 is a magnetic field distribution diagram of the TE mode of the first resonator provided in the embodiment of this application when the TE mode and the TM mode are coupled through the first coupling structure;

[0020] Figure 10 is a second magnetic field distribution diagram of the TE mode of the first resonator provided in the embodiment of this application when the TE mode and the TM mode are coupled through the first coupling structure. The magnetic field direction of the TE mode in Figure 10 is opposite to that of the TE mode in Figure 9.

[0021] Figure 11 is a top view of a first resonator provided in some other embodiments of this application. Compared with Figure 2, the first coupling structure changes the coupling polarity between the TE mode and the TM mode of the first resonator by relocating the second coupling part to one side of the first coupling part in a clockwise direction.

[0022] Figure 12 is a schematic diagram of the filter topology provided in Figure 1, where solid lines represent inductive coupling, dashed lines represent capacitive coupling, 10a-TEM represents the TEM mode of the first metal resonator, 10b-TE represents the TE mode of the first dual-mode resonator, 10b-TM represents the TM mode of the first dual-mode resonator, and so on.

[0023] Figure 13 is a top view of a second resonator and a third resonator provided in some other embodiments of this application, wherein a second coupling structure is disposed in the third resonator, the second coupling structure intersects the circumferential direction of the resonator of the third resonator, and one end of the second coupling structure extends to the first coupling window and intersects the radial direction of the resonator of the second resonator.

[0024] Figure 14 is a top view of a second resonator and a third resonator provided in some other embodiments of this application, wherein the second coupling structure is disposed in the first coupling window and intersects the center line connecting the second resonator and the third resonator;

[0025] Figure 15 is a top view of a second resonator and a third resonator provided in some other embodiments of this application. Compared with Figure 1, the second coupling structure is mirrored along the center line connecting the second resonator and the third resonator to reverse the coupling polarity between the TE mode of the second resonator and the TM mode or TEM mode of the third resonator.

[0026] Figure 16 is a partial structural schematic diagram of a filter provided in some other embodiments of this application, wherein two adjacent resonators are both TE-TM dual-mode resonators;

[0027] Figure 17 is a partial structural schematic diagram of a filter provided in some other embodiments of this application, wherein the fourth resonator is a TE single-mode resonator and the fifth resonator is a TE-TM dual-mode resonator.

[0028] Figure 18 shows the frequency simulation diagrams of each resonant mode provided in Figure 17. Line a represents the TE mode of the fourth resonator, line b represents the TM mode of the fifth resonator, and line c represents the TE mode of the fifth resonator.

[0029] Figure 19 shows the coupling simulation diagrams of each resonant mode provided in Figure 17. Line a represents the coupling amount between the TE mode of the fourth resonator and the TM mode of the fifth resonator, line b represents the coupling amount between the TE mode of the fourth resonator and the TE mode of the fifth resonator, and line c represents the coupling amount between the TE mode of the fifth resonator and the TM mode of the fifth resonator.

[0030] Figure 20 is a perspective view of a medium provided in some other embodiments of this application, wherein the medium is provided with an opening;

[0031] Figure 21 is a partial structural schematic diagram of a filter provided in some other embodiments of this application, wherein the fourth resonator is a TE single-mode resonator and the fifth resonator is a TE single-mode resonator;

[0032] Figure 22 shows the frequency simulation diagrams of each resonant mode provided in Figure 21, where line a represents the TE mode of the fourth resonator and line b represents the TE mode of the fifth resonator.

[0033] Figure 23 shows the coupling simulation diagrams of each resonant mode provided in Figure 21. Line a represents the coupling amount between the TE mode of the fourth resonator and the TE mode of the fifth resonator when no dielectric element is provided, and line b represents the coupling amount between the TE mode of the fourth resonator and the TE mode of the fifth resonator when a dielectric element is provided.

[0034] Figure 24 is a top view of a fourth resonator and a fifth resonator provided in some other embodiments of this application, wherein the fifth coupling portion and the sixth coupling portion of the third coupling structure are bent toward the same side of the connecting portion;

[0035] Figure 25 is a top view of a fourth resonator and a fifth resonator provided in some other embodiments of this application, wherein the fifth coupling part of the third coupling structure is bent toward the side of the connecting part, and the sixth coupling part is bent toward the other side of the connecting part;

[0036] Figure 26 is a top view of a sixth resonator and a seventh resonator provided in some other embodiments of this application, wherein two coupling windows are provided between the sixth resonator and the seventh resonator.

[0037] The following are the labeling elements in the figure:

[0038] 10-Resonator, 10a-First metal resonator, 10b-First dual-mode resonator, 10c-Second dual-mode resonator, 10d-Third dual-mode resonator, 10e-Fourth dual-mode resonator, 10f-Second metal resonator; 11-First resonator; 111-Resonator housing, 1111-First wall, 1112-Resonant cavity, 1113-Side wall; 112-Dielectric resonator, 1121-Outer peripheral surface of dielectric resonator; 12-Second resonator, 13-Third resonator, L-Center line connecting the second and third resonators; 14-Resonator; 15-Fourth resonator, 16 - Fifth resonator, 17-Sixth resonator, 18-Seventh resonator, 20-First coupling structure, 21-First coupling part, 22-Second coupling part, 30-Coupling window, 30a-First coupling window, 40-Second coupling structure, 41-Third coupling part, 42-Fourth coupling part, 50-Dielectric element, d1-Height of dielectric element, d2-Width of dielectric element, d3-Thickness of dielectric element, 51-Opening; 60-Third coupling structure, 61-Connecting part, 62-Fifth coupling part, 63-Sixth coupling part, 70-Fourth coupling structure, 80-Base platform, 90-Coupling adjustment screw. Detailed Implementation

[0039] To make the technical problems, technical solutions, and beneficial effects to be solved by this application clear, the application will be described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of this application and are not intended to limit this application. Unless otherwise specified, all embodiments and optional embodiments of this application can be combined to form new technical solutions. Unless otherwise specified, all technical features and optional technical features of this application can be combined to form new technical solutions.

[0040] In this application, "axial" refers to the direction of extension of the central axis of the corresponding structure, "radial" refers to any direction of the corresponding structure that passes through and is perpendicular to the central axis, and "circumferential" refers to the direction of circumference of the outer circumference of the corresponding structure.

[0041] A single-mode resonator is a resonator that supports only one resonant mode within its passband. This resonant mode can be a TE (Transverse Electric) mode, a TM (Transverse Magnetic) mode, a TEM (Transverse Electric and Magnetic Field) mode, etc. For example, a metal coaxial resonator is a single-mode resonator; it only supports the TEM mode within its passband, making it a TEM single-mode resonator.

[0042] A dual-mode resonator is a resonator capable of simultaneously generating two stable oscillating signals at different frequencies. A dual-mode resonator supports two resonant modes within its passband. For example, a TE-TM dual-mode resonator supports both TE and TM modes within its passband; a HE dual-mode resonator supports both degenerate HE modes within its passband.

[0043] A multimode resonator is a resonator capable of simultaneously generating two or more stable oscillation signals at different frequencies. A multimode resonator can support multiple resonance modes within its passband. Multimode resonators can be three-mode resonators, four-mode resonators, etc. For example, the HE-TE three-mode resonator supports three resonance modes—TE mode and HE degenerate mode—within its passband; the HE-TM three-mode resonator supports three resonance modes—TM mode and HE degenerate mode—within its passband; and the HE-TE-TM four-mode resonator supports four resonance modes—TE mode, TM mode, and HE degenerate mode—within its passband.

[0044] A dielectric cavity resonator possesses at least two resonance modes: TE mode and TM mode. That is, within its passband, the dielectric cavity resonator can support at least two resonance modes: TE mode and TM mode. The dielectric cavity resonator can be a dual-mode resonator or a multi-mode resonator. When the dielectric cavity resonator is a dual-mode resonator, it is a TE-TM dual-mode resonator; when the dielectric cavity resonator is a multi-mode resonator, it possesses TE mode, TM mode, and other resonance modes.

[0045] In some cases, the filter includes the aforementioned dielectric cavity resonator, which has at least two resonance modes: TE mode and TM mode. In this situation, how to couple the TE and TM modes of the dielectric cavity resonator becomes a problem that needs to be solved in the industry.

[0046] The embodiments provided in this application will solve the above problems.

[0047] The specific implementation of this application will be described in detail below with reference to specific embodiments:

[0048] Please refer to Figures 1, 2, and 3. Some embodiments of this application provide a filter, including a first resonator 11. The first resonator 11 has at least two resonant modes: TE mode and TM mode. The first resonator 11 includes a resonator housing 111 and a dielectric resonator 112 disposed within the resonator housing 111. The dielectric resonator 112 is connected to the first wall 1111 of the resonator housing 111. The filter also includes a first coupling structure 20 disposed within the resonator housing 111. Both ends of the first coupling structure 20 are grounded. The first coupling structure 20 includes a first coupling portion 21 and a second coupling portion 22. One end of the second coupling portion 22 is connected to the end of the first coupling portion 21 away from the central axis of the dielectric resonator 112. The first coupling portion 21 intersects the circumferential direction of the dielectric resonator 112, and the second coupling portion 22 intersects the radial direction of the dielectric resonator 112, so that the TE mode and TM mode of the first resonator 11 are coupled.

[0049] It should be noted that the filter has at least one resonator 10, and the at least one resonator 10 is a first resonator 11. The first resonator 11 is a dielectric cavity resonator with at least two resonance modes: TE mode and TM mode. It can be understood that the first resonator 11 has at least two resonance modes: TE mode and TM mode, that is, the first resonator 11 can support at least two resonance modes, TE mode and TM mode, within its passband range.

[0050] The resonator housing 111 has a resonant cavity 1112 inside. The resonant cavity 1112 can be, but is not limited to, a rectangular resonant cavity, a square resonant cavity, a polygonal cylindrical resonant cavity, a cylindrical resonant cavity, etc. The resonant cavity 1112 can accommodate a dielectric resonator 112. Optionally, the dielectric resonator 112 can be centrally arranged within the resonant cavity 1112. The resonator housing 111 can provide shielding to prevent signal leakage.

[0051] One of the walls of the resonator housing 111 is the first wall 1111. In practical applications, the first wall 1111 of the resonator housing 111 can be the wall located on the lower side, or it can be any wall located on the upper side, left side, right side, front side, or rear side. In addition, the shape, size, material, etc. of the resonator housing 111 can be flexibly set as needed.

[0052] The dielectric resonator 112 is a resonator 14 made of dielectric material. The dielectric resonator 112 can be a ceramic dielectric resonator or a dielectric resonator made of other materials. One end of the dielectric resonator 112 along its axial direction is connected to the first wall 1111. The dielectric resonator 112 can be directly connected and fixed to the first wall 1111 by, but not limited to, welding, bonding, riveting, pressing, plugging, screw fastening, threaded connection, snap-fitting, etc., or it can be indirectly connected and fixed to the first wall 1111 by other structures connected to it (such as the base 80, ceramic base, coupling rib, etc.). The dielectric resonator 112 can be, but not limited to, columnar, block-shaped, rod-shaped, etc. The cross-sectional shape of the dielectric resonator 112 perpendicular to its axial direction can be, but not limited to, circular, rectangular, square, polygonal, petal-shaped, cross-shaped, etc. The cross-sectional shape of the dielectric resonator 112 parallel to its axial direction can also be, but not limited to, circular, rectangular, square, polygonal, petal-shaped, cross-shaped, etc. A central hole may or may not be provided at the central axis of the dielectric resonator 112.

[0053] Optionally, the filter may be configured with a tuning structure (not shown) to adjust the resonant frequencies of the TE and TM modes of the first resonator 11 via the tuning structure.

[0054] It should also be noted that, in order to couple the TE mode and TM mode of the first resonator 11, this embodiment provides at least one first coupling structure 20 within the resonant cavity 1112 of the resonator housing 111. The first coupling structure 20 is a metal component, or it is a non-metallic component with a metal layer on its surface. The specific location of the first coupling structure 20 is not limited and can be flexibly arranged.

[0055] Both ends of the first coupling structure 20 are grounded. The ends of the first coupling structure 20 can be directly connected to the first wall 1111, side wall 1113, top wall, etc., of the resonator housing 111, or indirectly connected to the resonator housing 111 via other metal components (e.g., base 80, steps, bridges, etc.) to achieve grounding. The ends of the first coupling structure 20 can be connected to only one wall of the resonator housing 111, or simultaneously to multiple walls of the resonator housing 111. For example, as shown in FIG3, in some embodiments, the first coupling part 21 can be connected to the first wall 1111 for grounding; the second coupling part 22 can be connected to both the first wall 1111 and the side wall 1113 of the resonator housing 111 for grounding. Of course, in other embodiments, when both ends of the first coupling structure 20 are grounded, other areas of the first coupling structure 20 can be hollowed out or not, can be suspended (e.g., the second coupling part 22 can be suspended relative to the first wall 1111) or not, and can be in the form of a sheet, rod, block, etc. In other embodiments, where the second coupling portion 22 is connected to the first wall 1111 of the resonator housing 111, the second coupling portion 22 may not be connected to the side wall 1113 of the resonator housing 111.

[0056] The first coupling structure 20 includes a first coupling portion 21 and a second coupling portion 22. The first coupling portion 21 intersects the circumferential direction of the dielectric resonator 112, that is, the first coupling portion 21 extends along the direction intersecting the circumferential direction of the dielectric resonator 112, such that the first coupling portion 21 has a radial component in the dielectric resonator 112. When the first coupling portion 21 intersects the circumferential direction of the dielectric resonator 112, the first coupling portion 21 can be arranged in a straight line or in a curve. As shown in Figures 4, 5, and 6, since the magnetic field of the TM mode is distributed in a horizontal (i.e., parallel to the orientation of the first wall 1111) ring shape and the electric field is distributed in a vertical (i.e., perpendicular to the orientation of the first wall 1111) ring shape, the first coupling portion 21, which is arranged to intersect the circumferential direction of the dielectric resonator 112, can cut the magnetic field of the TM mode and realize the coupling of the TM mode. Furthermore, the greater the amount of cutting of the magnetic field of the TM mode by the first coupling part 21, the stronger the coupling strength between the first coupling part 21 and the TM mode will be. Therefore, the setting position, extension path, size, etc. of the first coupling part 21 can be designed according to the requirements of the coupling strength.

[0057] The second coupling portion 22 intersects the radial direction of the dielectric resonator 112, that is, the second coupling portion 22 extends along the direction intersecting the radial direction of the dielectric resonator 112, so that the second coupling portion 22 has a circumferential component in the dielectric resonator 112. The second coupling portion 22 can be arranged in a straight line or in a curve (e.g., extended in an arc shape). As shown in Figures 7, 8, 9, and 10, since the electric field of the TE mode is distributed in a horizontal ring shape and the magnetic field is distributed in a vertical ring shape (corresponding to the distribution "along the radial direction of the dielectric resonator 112"), the second coupling portion 22, which is arranged radially to intersect the dielectric resonator 112, can cut the magnetic field of the TE mode and achieve coupling of the TE mode. Furthermore, the greater the amount of cutting of the magnetic field of the TE mode by the second coupling portion 22, the stronger the coupling strength between the second coupling portion 22 and the TE mode will be. Therefore, the setting position, extension path, and size of the second coupling portion 22 can be designed according to the requirements of the coupling strength.

[0058] One end of the second coupling portion 22 is connected to the end of the first coupling portion 21 away from the central axis of the dielectric resonator 112. This connection can be integral or separate. The distances from the two opposite ends of the first coupling portion 21 to the central axis of the dielectric resonator 112 cannot be equal to avoid failure to couple the TM mode. Specifically, one end of the first coupling portion 21 should be closer to the central axis of the dielectric resonator 112, and the other end should be farther away. The end of the first coupling portion 21 away from the central axis of the dielectric resonator 112 cannot be connected to a non-end portion (e.g., the middle portion) of the second coupling portion 22. This would cause the first coupling structure 20 to form a T-shaped structure, resulting in the two parts of the second coupling portion 22 located on either side of the first coupling portion 21 canceling out the coupling effect on the TE mode. Similarly, one end of the second coupling part 22 cannot be connected to a non-end portion (e.g., the middle portion) of the first coupling part 21, which would also cause the first coupling structure 20 to form a T-shaped structure. This would cause the two parts of the first coupling part 21 located on both sides of the second coupling part 22 to cancel each other out the coupling effect on the TM mode. That is, the first coupling part 21 and the second coupling part 22 need to be connected sequentially in an L-shaped or I-shaped manner, etc.

[0059] Based on the first coupling part 21 coupling the TM mode, the second coupling part 22 coupling the TE mode, and the second coupling part 22 being connected to the first coupling part 21 in sequence, the TE mode and TM mode of the first resonator 11 can be coupled on the first coupling structure 20.

[0060] Where the first coupling portion 21 intersects the circumferential direction of the dielectric resonator 112, and the second coupling portion 22 intersects the radial direction of the dielectric resonator 112, the angle between the first coupling portion 21 and the second coupling portion 22 can be set as needed. Where the first coupling portion 21 extends radially along the dielectric resonator 112, the angle between the first coupling portion 21 and the second coupling portion 22 is not allowed to be 0°, so that the second coupling portion 22 does not extend radially along the dielectric resonator 112. Where the first coupling portion 21 does not extend radially along the dielectric resonator 112, the angle between the first coupling portion 21 and the second coupling portion 22 is allowed to be 0°.

[0061] In summary, the filter provided in this application embodiment has a first coupling structure 20 disposed within a first resonator 11 having at least two resonant modes, TE mode and TM mode, to couple the TE mode and TM mode of the first resonator 11 through the first coupling structure 20. Specifically, the first coupling structure 20 can cut the magnetic field of the TM mode through a first coupling portion 21 intersecting the circumferential direction of the dielectric resonator 112 to couple the TM mode; it can also cut the magnetic field of the TE mode through a second coupling portion 22 intersecting the radial direction of the dielectric resonator 112 to couple the TE mode; and based on the connection between the second coupling portion 22 and the first coupling portion 21, the TE mode and TM mode of the first resonator 11 can be coupled on the first coupling structure 20. Thus, the filter can achieve coupling of the TE mode and TM mode of the first resonator 11 through the simplified and optimized first coupling structure 20, and the coupling effect is better, thereby optimizing the structure and performance of the filter and facilitating the simulation design of the filter.

[0062] Please refer to Figures 1, 2, and 3. In some embodiments of this application, the first coupling portion 21 is disposed close to the first wall 1111. Optionally, the first coupling portion 21 may be disposed between the dielectric resonator 112 and the first wall 1111.

[0063] Since the magnetic field and current of the TM mode are concentrated near the first wall 1111, meaning the magnetic field strength of the TM mode is stronger near the first wall 1111, by adopting the above-mentioned scheme, the first coupling part 21 can be positioned close to the first wall 1111, allowing the first coupling part 21 to cut more of the TM mode magnetic field, thereby increasing the coupling strength between the first coupling part 21 and the TM mode. Furthermore, the closer the first coupling part 21 is to the first wall 1111, the stronger the coupling strength and the better the coupling effect between the first coupling part 21 and the TM mode. This enhances the coupling effect of the first coupling part 21 on the TM mode, optimizes the coupling effect of the TE mode and TM mode of the first resonator 11 on the first coupling structure 20, and optimizes the performance of the filter.

[0064] Please refer to Figures 1, 2, and 3. In some embodiments of this application, the first coupling portion 21 abuts against the first wall 1111 on the side closest to the first wall 1111. That is, the distance between the first coupling portion 21 and the first wall 1111 is 0.

[0065] Since the magnetic field and current of the TM mode are concentrated near the first wall 1111, meaning the magnetic field strength of the TM mode is stronger near the first wall 1111, by adopting the above-mentioned scheme, the side of the first coupling part 21 closest to the first wall 1111 can be brought into contact with the first wall 1111, allowing the first coupling part 21 to cut more of the TM mode magnetic field. This results in a stronger coupling strength and better coupling effect between the first coupling part 21 and the TM mode. Therefore, the coupling effect of the TE mode and TM mode of the first resonator 11 on the first coupling structure 20 can be optimized, thereby improving the performance of the filter.

[0066] In particular, when the first coupling part 21 abuts against the first wall 1111 on the side close to the first wall 1111, the first coupling part 21 is not partially hollowed out, and the first coupling part 21 has a larger cross-sectional size in the longitudinal section perpendicular to the first wall 1111. This is beneficial to increasing the amount of magnetic field cut by the first coupling part 21 to the TM mode, and to optimizing the coupling strength and coupling effect between the first coupling part 21 and the TM mode.

[0067] When the first coupling part 21 abuts against the first wall 1111 on the side near the first wall 1111, the first coupling part 21 and the first wall 1111 can be integrally formed to achieve the "abutment" between the two, or they can be connected separately (e.g., by pressing, welding, abutment connection, etc.) to achieve the "abutment" between the two.

[0068] Of course, if the end of the first coupling part 21 that is far from the second coupling part 22 is grounded, the first coupling part 21 may be located close to the first wall 1111 and spaced apart from the first wall 1111.

[0069] Please refer to Figures 1, 2, and 3. In some embodiments of this application, the second coupling portion 22 is disposed near the outer peripheral surface 1121 of the dielectric resonator 112.

[0070] It should be noted that the second coupling portion 22 is disposed relatively close to the outer peripheral surface 1121 of the dielectric resonator 112, and relatively far from the central axis of the dielectric resonator 112. That is, the distance between the second coupling portion 22 and the outer peripheral surface 1121 of the dielectric resonator 112 is less than the distance between the second coupling portion 22 and the central axis of the dielectric resonator 112. The second coupling portion 22 may be close to the outer surface 1121 of the dielectric resonator 112, or it may be close to the inner surface 1121 of the dielectric resonator 112.

[0071] When the second coupling part 22 is positioned relatively close to the central axis of the dielectric resonator 112 and relatively far from the outer peripheral surface 1121 of the dielectric resonator 112, please refer to Figure 8. In this case, depending on the position of the second coupling part 22 and in combination with the magnetic field distribution of the TE mode, in order to enable the second coupling part 22 to cut a sufficient amount of the TE mode magnetic field, the second coupling part 22 is horizontally distributed (i.e., the second coupling part 22 is positioned basically parallel to the first wall 1111), or the second coupling part 22 is inclined at 0° to 45° relative to the horizontal state (i.e., the second coupling part 22 is inclined at angles of 5°, 10°, 15°, 30°, 40°, 45°, etc. relative to the first wall 1111, with the inclination angle within the range of 0° to 45°), so as to increase the amount of magnetic field cut by the second coupling part 22 to the TE mode. In this case, the second coupling part 22 is horizontally distributed or inclined at 0° to 45° relative to the horizontal state, which results in a large radial component of the second coupling part 22 in the dielectric resonator 112. Consequently, the second coupling part 22 will also cut the magnetic field of the TM mode and couple a certain amount of TM mode, thus affecting the overall coupling effect and coupling efficiency of the first coupling structure 21.

[0072] Referring to Figures 9 and 10, by positioning the second coupling portion 22 close to the outer peripheral surface 1121 of the dielectric resonator 112, and considering the magnetic field distribution of the TE mode, the second coupling portion 22 can be arranged vertically (i.e., vertically or substantially perpendicular to the first wall 1111) or tilted at 45°–90° relative to the horizontal state. This increases the amount of magnetic field cut by the second coupling portion 22 to the TE mode, thereby optimizing the coupling strength and effect between the second coupling portion 22 and the TE mode. In this case, with the second coupling portion 22 vertically positioned or tilted at 45°–90° relative to the horizontal state, the second coupling portion 22 has no radial component or only a small component in the radial direction of the dielectric resonator 112. This prevents the second coupling portion 22 from cutting the magnetic field of the TM mode or cuts only a small portion of the TM mode magnetic field. Consequently, the second coupling portion 22 may not couple the TM mode or may couple only a small portion of the TM mode, thus optimizing and improving the overall coupling effect and coupling efficiency of the first coupling structure 21.

[0073] By adopting the above scheme, the second coupling part 22 can be positioned close to the outer peripheral surface 1121 of the dielectric resonator 112, thereby increasing the magnetic field cut by the second coupling part 22 of the TE mode magnetic field and thus strengthening the coupling strength between the second coupling part 22 and the TE mode. Simultaneously, the cutting of the TM mode magnetic field by the second coupling part 22 can be minimized or even avoided, weakening or even eliminating the coupling of the second coupling part 22 to the TM mode. Therefore, the coupling effect of the second coupling part 22 to the TE mode can be enhanced, optimizing the coupling effect of the TE mode and TM mode of the first resonator 11 on the first coupling structure 20, and thus optimizing the filter performance.

[0074] Please refer to Figures 1, 2, and 3. In some embodiments of this application, the first coupling portion 21 extends radially along the dielectric resonator 112.

[0075] It should be noted that the first coupling portion 21 extends radially along the dielectric resonator 112. The end of the first coupling portion 21 near the dielectric resonator 112 can extend to the central axis of the dielectric resonator 112, or it can extend to a position spaced apart from the central axis of the dielectric resonator 112, for example, to the base 80. Wherein, when the first coupling portion 21 extends radially along the dielectric resonator 112, the closer the end of the first coupling portion 21 is to the central axis of the dielectric resonator 112, the greater the amount of magnetic field cut by the first coupling portion 21 to the TM mode, and the stronger the coupling strength between the first coupling portion 21 and the TM mode.

[0076] Since the magnetic field of the TM mode is distributed in a horizontal ring shape, by adopting the above-described scheme, the first coupling part 21 can be extended radially along the dielectric resonator 112, thereby increasing the amount of magnetic field cut by the first coupling part 21 to the TM mode, resulting in a stronger coupling strength between the first coupling part 21 and the TM mode. This enhances the coupling effect of the first coupling part 21 to the TM mode, optimizes the coupling effect of the TE mode and TM mode of the first resonator 11 on the first coupling structure 20, and improves the performance of the filter.

[0077] Of course, in other embodiments, when the first coupling portion 21 intersects the circumferential direction of the dielectric resonator 112, the first coupling portion 21 may not extend radially along the dielectric resonator 112. The first coupling portion 21 may extend in a straight line or in a curved line.

[0078] Please refer to Figures 1, 2, and 3. In some embodiments of this application, the second coupling portion 22 is perpendicular to the radial direction of the dielectric resonator 112. That is, the second coupling portion 22 is tangent to the circumferential direction of the dielectric resonator 112.

[0079] Since the magnetic field of the TE mode is distributed in a vertical ring shape (corresponding to a radial distribution along the dielectric resonator 112), by adopting the above-described scheme, the second coupling portion 22 can be made perpendicular to the radial direction of the dielectric resonator 112, resulting in a larger cutting amount of the magnetic field of the TE mode by the second coupling portion 22, thereby strengthening the coupling strength between the second coupling portion 22 and the TE mode. This enhances the coupling effect of the second coupling portion 22 on the TE mode, optimizes the coupling effect of the TE and TM modes of the first resonator 11 on the first coupling structure 20, and optimizes the filter performance. Furthermore, compared to the embodiment where the second coupling portion 22 extends in an arc shape along the circumference of the dielectric resonator 112, the first coupling structure 20 in this embodiment has higher processing convenience.

[0080] Please refer to Figures 1, 2, and 3. In some embodiments of this application, the second coupling portion 22 extends in an arc shape along the circumference of the dielectric resonator 112. However, the second coupling portion 22 cannot extend in a closed loop along the circumference of the dielectric resonator 112; the closed loop is an axisymmetric structure and would cancel out the coupling effect on the TE mode.

[0081] Since the magnetic field of the TE mode is distributed in a vertical ring shape (corresponding to a radial distribution along the dielectric resonator 112), by adopting the above-described scheme, the second coupling portion 22 can extend in an arc shape along the circumference of the dielectric resonator 112, thereby increasing the amount of cutting off the magnetic field of the TE mode by the second coupling portion 22, resulting in a stronger coupling strength between the second coupling portion 22 and the TE mode. This enhances the coupling effect of the second coupling portion 22 on the TE mode, optimizes the coupling effect of the TE and TM modes of the first resonator 11 on the first coupling structure 20, and optimizes the filter performance. Furthermore, compared to the embodiment where the extension path of the second coupling portion 22 is perpendicular to the radial direction of the dielectric resonator 112, the second coupling portion 22 in this embodiment cuts off the magnetic field of the TE mode more significantly, resulting in a stronger coupling strength between the second coupling portion 22 and the TE mode.

[0082] Of course, in other embodiments, when the second coupling portion 22 intersects the radial direction of the dielectric resonator 112, the second coupling portion 22 may be extended in other directions, and the second coupling portion 22 may be extended in a straight line or in a curve.

[0083] Please refer to Figures 1, 2, and 3. In some embodiments of this application, the first coupling structure 20 is integrally connected to the resonator housing 111. That is, the first coupling structure 20 is integrally formed and integrally formed and connected to the resonator housing 111.

[0084] By adopting the above solution, the first coupling structure 20 can be integrally connected and molded with the resonator housing 111, which facilitates the processing and connection of the first coupling structure 20. Based on this, the processing convenience, structural strength, and assembly convenience of the first coupling structure 20 can be improved, the filter assembly process can be simplified, and the assembly convenience and efficiency of the filter can be improved.

[0085] Of course, in other embodiments, the first coupling structure 20 may be integrally formed and separately connected to the resonator housing 111. Alternatively, the first coupling portion 21 and the second coupling portion 22 of the first coupling structure 20 may be separately connected and separately connected to the resonator housing 111. Alternatively, the first coupling portion 21 of the first coupling structure 20 may be integrally formed with the resonator housing 111, while the second coupling portion 22 may be grounded and separately connected to the first coupling portion 21. Alternatively, the second coupling portion 22 of the first coupling structure 20 may be integrally formed with the resonator housing 111, while the first coupling portion 21 may be grounded and separately connected to the second coupling portion 22.

[0086] Please refer to Figures 1, 2, and 11. In some embodiments of this application, in the same first resonator 11, there are multiple first coupling structures 20. The second coupling part 22 of each first coupling structure 20 is disposed on the side of the first coupling part 21 along the counterclockwise direction (as shown in Figures 1 and 2), or the second coupling part 22 of each first coupling structure 20 is disposed on the side of the first coupling part 21 along the clockwise direction (as shown in Figure 11).

[0087] It should be noted that "counterclockwise" and "clockwise" are relative concepts, and can be determined (but not limited to) from the perspective of looking down at the first wall 1111.

[0088] The filter can be configured with multiple first coupling structures 20 as needed within the first resonator 11. Within the same first resonator 11, the specific construction (e.g., the location, extension path, and size of the first coupling part 21, and the location, extension path, and size of the second coupling part 22), shape, etc., of the multiple first coupling structures 20 can be the same or different.

[0089] In each of the first coupling structures 20 of the same first resonator 11, the second coupling part 22 of each first coupling structure 20 is uniformly located on one side of its first coupling part 21 in the counterclockwise direction (as shown in Figures 1 and 2), or the second coupling part 22 of each first coupling structure 20 is uniformly located on one side of its first coupling part 21 in the clockwise direction (as shown in Figure 11). Based on this, in the same first resonator 11, the current direction generated by the second coupling part 22 of each first coupling structure 20 cutting the TE mode magnetic field is the same, and the direction of the TE mode current (i.e. the current generated by cutting the TE mode magnetic field) of each first coupling structure 20 is similar. Since the direction of the TM mode current (i.e. the current generated by cutting the TM mode magnetic field) of each first coupling structure 20 is similar, each first coupling structure 20 can couple the TE mode and TM mode of the first resonator 11 to each other with the same coupling polarity (i.e., each first coupling structure 20 couples the TE mode and TM mode positively, or each first coupling structure 20 couples the TE mode and TM mode negatively). The effects of each first coupling structure 20 (i.e., the effect of "coupling the TE mode and TM mode of the first resonator 11") can be superimposed on each other and will not cancel each other out.

[0090] It should be noted that, in each of the first coupling structures 20 of the same first resonator 11, if the second coupling part 22 of one first coupling structure 20 is located on the side of its first coupling part 21 in a counterclockwise direction, and the second coupling part 22 of the other first coupling structure 20 is located on the side of its first coupling part 21 in a clockwise direction, then the coupling polarities of the two first coupling structures 20 will be opposite. This will cause the two first coupling structures 20 to cancel each other out, resulting in a redundant and complex filter structure, and causing the TE mode and TM mode of the first resonator 11 to be unable to couple or to have poor coupling effect. Of course, theoretically, as long as the effect of at least one of the first coupling structures 20 of the same first resonator 11 is not canceled out, the TE mode and TM mode of the first resonator 11 can be coupled through the first coupling structure 20 whose effect is not canceled out, but the structure is more redundant.

[0091] It should also be noted that the specific positions of each first coupling structure 20 in the same first resonator 11 can be flexibly arranged. For example, multiple first coupling structures 20 can be uniformly distributed on one side of the dielectric resonator 112, or distributed on both sides of the dielectric resonator 112, or arranged in equal-angle circles around the central axis of the dielectric resonator 112, or arranged in unequal-angle circles around the central axis of the dielectric resonator 112, and so on.

[0092] Multiple first coupling structures 20 of the same first resonator 11 need to be disconnected and spaced apart. For example, the second coupling parts 22 of any two first coupling structures 20 cannot be connected together. If the second coupling parts 22 of two first coupling structures 20 are connected together, the two second coupling parts 22 will cancel each other out the coupling effect on the TE mode.

[0093] For example, as shown in Figures 1 and 2, in some embodiments, the filter has two first coupling structures 20 within the first resonator 11. The second coupling portions 22 of the two first coupling structures 20 are uniformly located on one side of their first coupling portions 21 in a counterclockwise direction. The two first coupling structures 20 are distributed on opposite sides of the dielectric resonator 112. This arrangement not only enhances the coupling between the TE and TM modes of the first resonator 11 via the two first coupling structures 20, but also optimizes the number and location of the first coupling structures 20. This facilitates the arrangement design of the first coupling structures 20 and frees up space for setting other coupling structures (such as the second coupling structure 40, the third coupling structure 60, the fourth coupling structure 70, etc.), thereby facilitating filter planning and design, coupling construction, and improving filter performance and design flexibility.

[0094] By adopting the above scheme, the filter can be configured with multiple first coupling structures 20 as needed within the first resonator 11. The second coupling portion 22 of each first coupling structure 20 is uniformly located on one side of its first coupling portion 21 in a counter-clockwise direction, or uniformly located on one side of its first coupling portion 21 in a clockwise direction. This ensures that the multiple first coupling structures 20 can couple the TE and TM modes of the first resonator 11, and that the effects of the multiple first coupling structures 20 are superimposed without canceling each other out. Therefore, the coupling of the TE and TM modes of the first resonator 11 can be enhanced through the multiple first coupling structures 20, optimizing the coupling strength and effect, thereby improving the filter's performance.

[0095] Of course, in other embodiments, the filter may be provided with a first coupling structure 20 as needed within the first resonator 11.

[0096] Please refer to Figures 1, 2, and 11. In some embodiments of this application, each first coupling structure 20 is rotated and replicated around the central axis of the dielectric resonator 112.

[0097] It should be noted that the meaning of rotational replication is: in the same first resonator 11, each first coupling structure 20 can rotate around the central axis of the dielectric resonator 112 and coincide with other first coupling structures 20, that is, each first coupling structure 20 is a copy obtained by rotating other first coupling structures 20 around the central axis of the dielectric resonator 112 by a certain angle.

[0098] By adopting the above scheme, when multiple first coupling structures 20 are provided as needed within the first resonator 11, the specific structure, size, and shape of each first coupling structure 20 within the first resonator 11 can be set identically. Based on this, the structural design of each first coupling structure 20 within the same first resonator 11 can be standardized and unified, thereby improving the molding convenience of each first coupling structure 20.

[0099] Please refer to Figures 1, 2, and 11. In some embodiments of this application, the first coupling structure 20 changes the coupling polarity between the TE mode and the TM mode of the first resonator 11 by placing the second coupling part 22 on the side of the first coupling part 21 in the counterclockwise direction or placing the second coupling part 22 on the side of the first coupling part 21 in the clockwise direction.

[0100] It should be noted that in the first coupling structure 20 shown in Figures 1 and 2, the second coupling part 22 of the first coupling structure 20 is uniformly located on one side of the first coupling part 21 in the counterclockwise direction.

[0101] Compared with the first coupling structure 20 shown in Figures 1 and 2, in the first coupling structure 20 shown in Figure 11, the second coupling part 22 of the first coupling structure 20 is uniformly changed to one side of the first coupling part 21 in the clockwise direction.

[0102] Based on this, by reversing the orientation of the second coupling part 22 of the first coupling structure 20, the direction of the current generated by the second coupling part 22 of the first coupling structure 20 cutting the TE mode magnetic field can be reversed. This allows the TE mode current direction (i.e., the current generated by cutting the TE mode magnetic field) and the TM mode current direction (i.e., the current generated by cutting the TM mode magnetic field) of the first coupling structure 20 to switch between "flowing in the same direction" and "flowing in opposite directions". This reverses the coupling polarity of the coupling achieved by the first coupling structure 20, that is, reverses the coupling polarity between the TE mode and the TM mode of the first resonator 11.

[0103] The reversal of coupling polarity is the reversal of positive and negative coupling, not the reversal of inductive and capacitive coupling; the coupling relationship may remain unchanged. If the current direction of the TE mode (i.e., the current generated by cutting the TE mode magnetic field) and the current direction of the TM mode (i.e., the current generated by cutting the TM mode magnetic field) flow in the same direction on the first coupling structure 20, then the TE mode and the TM mode can form positive coupling on the first coupling structure 20. Conversely, if the current direction of the TE mode and the current direction of the TM mode flow in opposite directions on the first coupling structure 20, then the TE mode and the TM mode can form negative coupling on the first coupling structure 20.

[0104] By adopting the above scheme, the first coupling structure 20 can reverse the direction of the current generated by the second coupling part 22 cutting the TE mode magnetic field by changing its second coupling part 22 from the counterclockwise side of the first coupling part 21 to the clockwise side of the first coupling part 21, or vice versa. This reverses the coupling polarity between the TE mode and the TM mode of the first resonator 11. Therefore, the coupling polarity between the TE mode and the TM mode of the first resonator 11 can be reversed as needed, optimizing the filter performance and facilitating filter simulation design.

[0105] Please refer to Figures 1, 2, 3, and 12. In some embodiments of this application, the filter includes at least two resonators 10, and a coupling window 30 connecting the interior of each other is provided between two adjacent resonators 10.

[0106] It should be noted that the filter includes at least two resonators 10, and each resonator 10 is coupled as needed. The structure, type, and size of each resonator 10 can be the same or different. The type of resonator 10 can be a single-mode resonator, such as a TE single-mode resonator, a TM single-mode resonator, a TEM single-mode resonator (e.g., a metal coaxial resonator), etc.; the type of resonator 10 can also be a dual-mode resonator or a multi-mode resonator, such as a TE-TM dual-mode resonator, a TM dual-mode resonator, a HE-TE tri-mode resonator, a HE-TM tri-mode resonator, a HE-TE-TM quad-mode resonator, etc.

[0107] It can be understood that among the resonators 10 of the filter, at least one resonator 10 is the first resonator 11.

[0108] In the case where the resonator 10 is a dielectric cavity resonator having at least two resonance modes, TE mode and TM mode, the dielectric cavity resonator may be the first resonator 11 provided in any of the above embodiments of this application, or it may not be the first resonator 11 provided in any of the above embodiments of this application. When the dielectric cavity resonator is the first resonator 11 provided in any of the above embodiments of this application, the dielectric cavity resonator may, as needed, have the first coupling structure 20 mentioned above, so that its TE mode and TM mode are coupled via the first coupling structure 20; the dielectric cavity resonator may also not have the first coupling structure 20 mentioned above, so that its TE mode and TM mode are not coupled, or its TE mode and TM mode may be coupled via other coupling structures.

[0109] It should also be noted that a coupling window 30 is provided between two adjacent resonators 10 to connect their internal spaces. Two adjacent resonators 10 can establish a coupling relationship based on the coupling window 30. In particular, resonant modes of two adjacent resonators 10 with similar electromagnetic field distributions can be coupled to each other through the coupling window 30. For example, TE mode and TE mode can be coupled to each other through the coupling window 30, TM mode and TM mode can be coupled to each other through the coupling window 30, TM mode and TEM mode can be coupled to each other through the coupling window 30 (because the electromagnetic field distribution of TEM mode is similar to that of TM mode), TEM mode and TEM mode can be coupled to each other through the coupling window 30, and so on.

[0110] Specifically, when the coupling window 30 has a certain size (i.e., a relatively large size), the coupling between resonant modes with similar electromagnetic field distributions of two adjacent resonators 10 is better and more stable through the coupling window 30. Conversely, when the coupling window 30 is small, the coupling between resonant modes with similar electromagnetic field distributions of two adjacent resonators 10 is weaker, and may even be essentially suppressed. Based on this, the size of the coupling window 30 can be designed as needed to ensure that the coupling strength between resonant modes with similar electromagnetic field distributions of two adjacent resonators 10 reaches the required specifications.

[0111] For example, as shown in Figures 1, 2, and 12, in one example of a filter, the filter includes a first metal resonator 10a, a first dual-mode resonator 10b, a second dual-mode resonator 10c, a third dual-mode resonator 10d, a fourth dual-mode resonator 10e, and a second metal resonator 10f arranged sequentially. The first metal resonator 10a and the second metal resonator 10f are both TEM single-mode resonators, and the first dual-mode resonator 10b, the second dual-mode resonator 10c, the third dual-mode resonator 10d, and the fourth dual-mode resonator 10e are all first resonators 11 (i.e., all are TE-TM dual-mode resonators). A relatively large coupling window 30 is provided between adjacent first metal resonators 10a and first dual-mode resonators 10b, through which the TEM mode of the first metal resonator 10a and the TM mode of the first dual-mode resonator 10b are coupled to each other. A small coupling window 30 is provided between adjacent first dual-mode resonators 10b and second dual-mode resonators 10c. The TE mode of the first dual-mode resonator 10b and the TE mode of the second dual-mode resonator 10c are coupled to each other through the coupling window 30, while the TM mode of the first dual-mode resonator 10b and the TM mode of the second dual-mode resonator 10c are not coupled to each other through the coupling window 30. A larger coupling window 30 is provided between adjacent second dual-mode resonators 10c and third dual-mode resonators 10d. The TE mode of the second dual-mode resonator 10c and the TE mode of the third dual-mode resonator 10d are coupled to each other through the coupling window 30, while the TM mode of the second dual-mode resonator 10c and the TM mode of the third dual-mode resonator 10d are coupled to each other through the coupling window 30. A small coupling window 30 is provided between adjacent third dual-mode resonators 10d and fourth dual-mode resonators 10e. The TE mode of the third dual-mode resonator 10d and the TE mode of the fourth dual-mode resonator 10e are coupled to each other through the coupling window 30, while the TM mode of the third dual-mode resonator 10d and the TM mode of the fourth dual-mode resonator 10e are not coupled to each other through the coupling window 30. A larger coupling window 30 is provided between adjacent fourth dual-mode resonators 10e and second metal resonators 10f. The TM mode of the fourth dual-mode resonator 10e and the TEM mode of the second metal resonator 10f are coupled to each other through the coupling window 30.

[0112] By adopting the above scheme, coupling windows 30 connecting the interiors of adjacent resonators 10 can be set as needed between them. This allows resonant modes with similar electromagnetic field distributions of adjacent resonators 10 to couple with each other through the coupling windows 30. This facilitates the establishment of coupling relationships between adjacent resonators 10, the transfer of energy between them, and the transmission of energy along desired paths within each resonator 10. It also facilitates filter simulation design and optimizes filter performance. Furthermore, due to the simple structure of the coupling window 30, establishing coupling relationships through it simplifies and optimizes the coupling structure design between adjacent resonators 10, simplifies the filter structure, and promotes filter miniaturization, simplification, and weight reduction.

[0113] In particular, as shown in Figures 1 and 12, when two adjacent resonators 10 are both TE-TM dual-mode resonators, and the TE and TM modes of the TE-TM dual-mode resonators are coupled, by coupling the TE modes to each other through the coupling window 30, and by coupling the TM modes to each other through the coupling window 30, a main signal transmission path and a cross-coupling path can be formed between the two TM modes and the two TE modes. These two transmission paths will have a 180-degree phase difference in the filter passband, thus forming a transmission zero in the filter passband. This allows the filter to form a multi-zero scheme by combining the formed transmission zero with other zeros, effectively enhancing the out-of-band suppression and filtering effect of the filter, thereby enabling the filter to meet high selectivity requirements.

[0114] Please refer to Figures 1, 2, 3, and 12. In some embodiments of this application, at least one pair of adjacent resonators 10 are a second resonator 12 and a third resonator 13. The second resonator 12 has a TE mode resonance mode, and the third resonator 13 has a TM mode resonance mode or a TEM mode resonance mode. The coupling window 30 between the second resonator 12 and the third resonator 13 is a first coupling window 30a. The filter includes a second coupling structure 40 with both ends grounded. At least a portion of the second coupling structure 40 is disposed in the first coupling window 30a. The second coupling structure 40 couples the TE mode of the second resonator 12 with the TM mode or TEM mode of the third resonator 13.

[0115] It should be noted that at least one set of two adjacent resonators 10 uses a combination of the second resonator 12 and the third resonator 13. The second resonator 12 has a TE mode, meaning that the second resonator 12 can support at least the TE mode within its passband. For example, the second resonator 12 can be a TE single-mode resonator, a TE-TM dual-mode resonator, a HE-TE tri-mode resonator, a HE-TE-TM quad-mode resonator, or the first resonator 11 provided in any of the above embodiments of this application, etc. The third resonator 13 has a TM mode or a TEM mode, meaning that the third resonator 13 can support at least the TM mode or the TEM mode within its passband. The third resonator 13 can be a TM single-mode resonator, a TM dual-mode resonator, a TEM single-mode resonator, a TE-TM dual-mode resonator, a HE-TM tri-mode resonator, a HE-TE-TM quad-mode resonator, or the first resonator 11 provided in any of the above embodiments of this application, etc. The coupling window 30 between the second resonator 12 and the third resonator 13 is the first coupling window 30a.

[0116] The TE mode of the second resonator 12 and the TM or TEM mode of the third resonator 13 can be coupled via the second coupling structure 40. The second coupling structure 40 is a metal component, or a non-metallic component with a metal layer on its surface. Both ends of the second coupling structure 40 are grounded, making the coupling formed through the second coupling structure 40 inductive. The ends of the second coupling structure 40 can be directly connected to the housing component of the resonator 10, or indirectly connected to the housing component of the resonator 10 via other metal components (such as the base 80), thereby achieving grounding.

[0117] At least a portion of the second coupling structure 40 is disposed within the first coupling window 30a, so that the second coupling structure 40 can couple the TE mode of the second resonator 12 with the TM mode or TEM mode of the third resonator 13. The specific construction, extension path, shape, size, etc. of the second coupling structure 40 are not limited for the time being.

[0118] For example, as shown in Figures 1, 2, and 12, in one example of a filter, a first metal resonator 10a and a first dual-mode resonator 10b are two adjacent resonators 10. The first metal resonator 10a can be used as a third resonator 13 with a TEM mode, and the first dual-mode resonator 10b can be used as a second resonator 12 with a TE mode. The TEM mode of the first metal resonator 10a and the TE mode of the first dual-mode resonator 10b are coupled via a second coupling structure 40. Based on this, the TEM mode of the first metal resonator 10a can be coupled with the TM mode and the TE mode of the first dual-mode resonator 10b, respectively. This facilitates the design of cross-coupling paths between the TEM mode of the first metal resonator 10a, the TM mode of the first dual-mode resonator 10b, and the TE mode of the first dual-mode resonator 10b, thereby forming transmission zeros in the filter passband, improving the out-of-band suppression and filtering effect of the filter, and enabling the filter to meet high selectivity requirements. Similarly, the fourth dual-mode resonator 10e and the second metal resonator 10f are two adjacent resonators 10. The fourth dual-mode resonator 10e can be used as the second resonator 12 with the TE mode, and the second metal resonator 10f can be used as the third resonator 13 with the TEM mode. The TE mode of the fourth dual-mode resonator 10e and the TEM mode of the second metal resonator 10f are coupled through the second coupling structure 40. Based on this, the TE mode and the TM mode of the fourth dual-mode resonator 10e can be coupled with the TEM mode of the second metal resonator 10f, respectively. This facilitates the design of cross-coupling paths between the TE mode, the TM mode, and the TEM mode of the fourth dual-mode resonator 10e, thereby forming a transmission zero in the passband of the filter, improving the out-of-band rejection and filtering effect of the filter, and enabling the filter to meet the high selectivity requirements.

[0119] By adopting the above scheme, the TE mode of the second resonator 12 and the TM or TEM mode of the third resonator 13 can be coupled through the second coupling structure 40, thereby achieving coupling between the TE mode of the second resonator 12 and the TM or TEM mode of the third resonator 13. This facilitates the construction of desired coupling relationships between adjacent second resonators 12 and third resonators 13 via the second coupling structure 40; it even allows cross-coupling between the TE mode of the second resonator 12 and the TM or TEM mode of the third resonator 13 via the second coupling structure 40, enabling the generation of transmission zeros or balanced transmission zeros in the passband as needed. This facilitates filter simulation design and performance optimization.

[0120] Of course, in other embodiments, the second coupling structure 40 may be omitted.

[0121] Please refer to Figures 1, 2, and 3. In some embodiments of this application, the second coupling structure 40 includes a third coupling portion 41 and a fourth coupling portion 42 that are bent and connected in sequence. The third coupling portion 41 is disposed in the first coupling window 30a or extends from the first coupling window 30a into the second resonator 12. The third coupling portion 41 intersects the radial direction of the resonator element 14 of the second resonator 12 to couple the TE mode of the second resonator 12. The fourth coupling portion 42 is disposed in the third resonator 13 and intersects the circumferential direction of the resonator element 14 of the third resonator 13 to couple the TM mode or TEM mode of the third resonator 13.

[0122] It should be noted that each resonator 10 has a resonant element 14 (the resonant element 14 of the first resonator 11 is the dielectric resonant element 112). Depending on the needs of the resonator 10, the resonant element 14 can be a metal resonant element, a ceramic dielectric resonant element, or a dielectric resonant element of other materials; the resonant element 14 can be a hollow resonant element or a solid resonant element; the resonant element 14 can have a resonant disk or not; the resonant disk can have a flange or not; the resonant element can be a coaxial cylindrical resonant element, a coaxial cylindrical resonant element, or a sheet metal plate resonant element; the cross-sectional shape of the resonant element 14 perpendicular to its axial direction can be, but is not limited to, circular, rectangular, square, polygonal, petal-shaped, cross-shaped, etc., and the cross-sectional shape of the resonant element 14 parallel to its axial direction can also be, but is not limited to, circular, rectangular, square, polygonal, petal-shaped, cross-shaped, etc.

[0123] It should be noted that the fourth coupling part 42 is located within the third resonator 13 and intersects the circumference of the resonator element 14 of the third resonator 13. Since the magnetic field of the TM mode is distributed in a horizontal ring and the electric field in a vertical ring, and since the electromagnetic field distribution of the TEM mode is similar to that of the TM mode, the fourth coupling part 42 can cut the magnetic field of the TM mode (or TEM mode) of the third resonator 13, thus coupling the TM mode (or TEM mode) of the third resonator 13. Furthermore, as the amount of cutting of the magnetic field of the TM mode (or TEM mode) of the third resonator 13 by the fourth coupling part 42 increases, the coupling strength between the fourth coupling part 42 and the TM mode (or TEM mode) of the third resonator 13 gradually increases. Therefore, the specific position, extension path, and extension direction of the fourth coupling part 42 can be designed according to the required coupling strength between the fourth coupling part 42 and the TM mode (or TEM mode) of the third resonator 13. The fourth coupling part 42 can be arranged in a straight line or in a curved line. The fourth coupling portion 42 may coincide with the center line L connecting the second resonator 12 and the third resonator 13, or it may not coincide with the center line L connecting the second resonator 12 and the third resonator 13. In some embodiments, the fourth coupling portion 42 may be arranged to extend radially along the resonator element 14 of the third resonator 13 and close to the central axis of the resonator element 14 of the third resonator 13. This arrangement can increase the amount of cutting off the magnetic field of the TM mode (or TEM mode) of the third resonator 13 by the fourth coupling portion 42, and can enhance the coupling strength between the fourth coupling portion 42 and the TM mode (or TEM mode) of the third resonator 13.

[0124] One end of the third coupling part 41 is integrally or separately connected to one end of the fourth coupling part 42 (the resonant element 14 away from the third resonator 13). The third coupling part 41 is bent relative to the fourth coupling part 42, that is, the third coupling part 41 and the fourth coupling part 42 are arranged at an angle. The angle between the third coupling part 41 and the fourth coupling part 42 can be set as needed, and the specific angle is not limited.

[0125] The third coupling part 41 is integrally disposed within the first coupling window 30a; or, the third coupling part 41 passes through the first coupling window 30a and extends into the second resonator 12. The third coupling part 41 intersects the radial direction of the resonant element 14 of the second resonator 12. Since the electric field of the TE mode is distributed in a horizontal ring and the magnetic field is distributed in a vertical ring, the third coupling part 41 can cut the magnetic field of the TE mode of the second resonator 12 and couple the TE mode of the second resonator 12. Furthermore, as the amount of cutting of the magnetic field of the TE mode of the second resonator 12 by the third coupling part 41 increases, the coupling strength between the third coupling part 41 and the TE mode of the second resonator 12 gradually increases. Therefore, the specific position, extension path, and extension direction of the third coupling part 41 can be designed according to the required coupling strength between the third coupling part 41 and the TE mode of the second resonator 12. The third coupling part 41 can be arranged in a straight line or in a curve. In some embodiments, the third coupling portion 41 is perpendicular to the radial direction of the resonator 14 of the second resonator 12. This arrangement increases the amount of cutting off the TE mode magnetic field of the second resonator 12 by the third coupling portion 41, thereby enhancing the coupling strength between the third coupling portion 41 and the TE mode of the second resonator 12. In some embodiments, the third coupling portion 41 extends circumferentially along the second resonator 12. This arrangement also increases the amount of cutting off the TE mode magnetic field of the second resonator 12 by the third coupling portion 41, thereby enhancing the coupling strength between the third coupling portion 41 and the TE mode of the second resonator 12.

[0126] Since the fourth coupling part 42 couples the TM mode (or TEM mode) of the third resonator 13, and since the third coupling part 41 couples the TE mode of the second resonator 12, and based on the sequential connection of the third coupling part 41 and the fourth coupling part 42, the TE mode of the second resonator 12 and the TM mode (or TEM mode) of the third resonator 13 can be mutually coupled on the second coupling structure 40.

[0127] By adopting the above scheme, the second coupling structure 40 can cut the magnetic field of the TE mode of the second resonator 12 through the third coupling part 41 and couple the TE mode of the second resonator 12. It can also cut the magnetic field of the TM mode (or TEM mode) of the third resonator 13 through the fourth coupling part 42, which is bent and connected to the third coupling part 41, and couple the TM mode (or TEM mode) of the third resonator 13. Based on this, and based on the sequential connection relationship of the third coupling part 41 and the fourth coupling part 42, the TE mode of the second resonator 12 and the TM mode (or TEM mode) of the third resonator 13 can be mutually coupled on the second coupling structure 40. Thus, the second coupling structure 40 can achieve coupling between the TE mode of the second resonator 12 and the TM mode (or TEM mode) of the third resonator 13 with a modular and simplified structural design. Furthermore, compared to other solutions, it is easier to design the coupling strength of the "TE mode of the third coupling part 41 and the second resonator 12" and the "TM mode (or TEM mode) of the fourth coupling part 42 and the third resonator 13" separately, thereby optimizing the coupling effect achieved by the second coupling structure 40 and optimizing the performance of the filter.

[0128] Furthermore, since the fourth coupling part 42 intersects the circumferential direction of the resonator 14 of the third resonator 13, the fourth coupling part 42 can basically not occupy the circumferential space of the third resonator 13. When the third resonator 13 is the first resonator 11 and the third resonator 13 is provided with a corresponding first coupling structure 20, it can provide sufficient arrangement space for the first coupling structure 20 of the third resonator 13 (i.e., the first resonator 11). Since the third coupling part 41 is disposed entirely in the first coupling window 30a or penetrates into the second resonator 12, the third coupling part 41 can basically not occupy the internal space of the second resonator 12. When the second resonator 12 is the first resonator 11 and the second resonator 12 is provided with a corresponding first coupling structure 20, it can provide sufficient arrangement space for the first coupling structure 20 of the second resonator 12 (i.e., the first resonator 11).

[0129] Referring to Figure 13, in some embodiments of this application, the second coupling structure 40 is disposed within the third resonator 13, and the second coupling structure 40 intersects the circumferential direction of the resonator 14 of the third resonator 13 to couple the TM mode or TEM mode of the third resonator 13; one end of the second coupling structure 40 extends to the first coupling window 30a and intersects the radial direction of the resonator 14 of the second resonator 12 to couple the TE mode of the second resonator 12.

[0130] It should be noted that the second coupling structure 40 is located within the third resonator 13. Since the magnetic field of the TM mode is distributed in a horizontal ring and the electric field is distributed in a vertical ring (the electromagnetic field distribution of the TEM mode is similar to that of the TM mode), the second coupling structure 40 intersects the circumferential direction of the resonator 14 of the third resonator 13. This allows the second coupling structure 40 as a whole to cut the magnetic field of the TM mode (or TEM mode) of the third resonator 13, thereby coupling the TM mode (or TEM mode) of the third resonator 13. Furthermore, this results in a stronger coupling strength between the second coupling structure 40 and the TM mode (or TEM mode) of the third resonator 13.

[0131] One end of the second coupling structure 40 (the resonator 14 away from the third resonator 13) extends to the first coupling window 30a to facilitate coupling with the second resonator 12. Since the electric field of the TE mode is distributed in a horizontal ring and the magnetic field is distributed in a vertical ring, the end of the second coupling structure 40 extending to the first coupling window 30a intersects the radial direction of the resonator 14 of the second resonator 12 (in particular, the second coupling structure 40 cannot be extended along the center line L connecting the second resonator 12 and the third resonator 13). This allows the end of the second coupling structure 40 to cut the magnetic field of the TE mode of the second resonator 12 and couple the TE mode of the second resonator 12.

[0132] Since the second coupling structure 40 couples both the TM mode (or TEM mode) of the third resonator 13 and the TE mode of the second resonator 12, the TE mode of the second resonator 12 and the TM mode (or TEM mode) of the third resonator 13 can be mutually coupled on the second coupling structure 40.

[0133] The second coupling structure 40 can be extended in a straight line or in a curved line.

[0134] By adopting the above scheme, the second coupling structure 40 as a whole can cut the magnetic field of the TM mode (or TEM mode) of the third resonator 13, thus enabling the second coupling structure 40 to couple the TM mode (or TEM mode) of the third resonator 13 with a strong coupling strength. Furthermore, the end of the second coupling structure 40 extending to the first coupling window 30a can cut the magnetic field of the TE mode of the second resonator 12, thus enabling the second coupling structure 40 to couple the TE mode of the second resonator 12. Based on this, the second coupling structure 40 can achieve a simplified and optimized structural design, allowing the TE mode of the second resonator 12 to couple with the TM mode (or TEM mode) of the third resonator 13, with a better coupling effect. Moreover, compared to other schemes, the main space occupied by the second coupling structure 40 is within the third resonator 13, and it does not occupy much space in the first coupling window 30a. This facilitates the optimization of the size of the first coupling window 30a and also allows for the placement of other coupling structures (such as the third coupling structure 60 or the fourth coupling structure 70 mentioned later) or the dielectric component 50 in the first coupling window 30a. This facilitates the design of the coupling structure between adjacent second resonators 12 and third resonators 13, facilitates the simulation design of filters, and optimizes the performance of filters.

[0135] Furthermore, since the second coupling structure 40 intersects the circumferential direction of the resonator 14 of the third resonator 13, the second coupling structure 40 can basically not occupy the circumferential space of the third resonator 13. When the third resonator 13 is the first resonator 11 and the third resonator 13 is provided with the first coupling structure 20, it can provide sufficient space for the first coupling structure 20 of the third resonator 13 (i.e., the first resonator 11). Since one end of the second coupling structure 40 (the resonator 14 away from the third resonator 13) extends to the first coupling window 30a, the second coupling structure 40 can basically not occupy the internal space of the second resonator 12. When the second resonator 12 is the first resonator 11 and the second resonator 12 is provided with the first coupling structure 20, it can provide sufficient space for the first coupling structure 20 of the second resonator 12 (i.e., the first resonator 11).

[0136] Please refer to Figure 14. In some embodiments of this application, the second coupling structure 40 is disposed in the first coupling window 30a and intersects the center line L connecting the second resonator 12 and the third resonator 13; along the axial direction of the resonator 14 of the third resonator 13, the second coupling structure 40 is disposed on the same side as the connection end of the resonator 14 of the third resonator 13.

[0137] It should be noted that, since the electric field of the TE mode is distributed in a horizontal ring and the magnetic field is distributed in a vertical ring, by placing the second coupling structure 40 in the first coupling window 30a and making the second coupling structure 40 intersect (for example, perpendicular to) the center line L connecting the second resonator 12 and the third resonator 13, the second coupling structure 40 can cut the magnetic field of the TE mode of the second resonator 12 to couple the TE mode of the second resonator 12.

[0138] The connection end of the resonator 14 of the third resonator 13 refers to the end of the resonator 14 of the third resonator 13 that is connected and fixed to the housing of the third resonator 13. Along the axial direction of the resonator 14 of the third resonator 13 (that is, the direction corresponding to the axial direction of the resonator 14 of the third resonator 13, which is also the height direction of the first coupling window 30a), the second coupling structure 40 is disposed on the same side as the connection end of the resonator 14 of the third resonator 13. That is, the second coupling structure 40 is disposed close to the housing wall to which the connection end of the resonator 14 of the third resonator 13 is connected and fixed. For example, if the connection end of the resonator 14 of the third resonator 13 is connected and fixed to the bottom wall of the filter housing, then the second coupling structure 40 is disposed close to the bottom wall of the filter housing; or, for example, if the connection end of the resonator 14 of the third resonator 13 is connected and fixed to the top wall of the filter housing, then the second coupling structure 40 is disposed close to the top wall of the filter housing.

[0139] Because the current of the TM mode (or TEM mode) of the third resonator 13 diverges towards the housing wall connected to the "connection end of the resonator 14 of the third resonator 13," meaning the current of the TM mode (or TEM mode) is concentrated near the housing wall connected to the "connection end of the resonator 14 of the third resonator 13," by setting the second coupling structure 40 on the same side as the connection end of the resonator 14 of the third resonator 13, the second coupling structure 40 can directly conduct the current of the TM mode (or TEM mode) from the housing wall connected to the "connection end of the resonator 14 of the third resonator 13," thereby achieving coupling of the TM mode (or TEM mode) of the third resonator 13. In this case, the amount of magnetic field cut-off between the second coupling structure 40 and the TM mode (or TEM mode) is less.

[0140] Since the second coupling structure 40 couples both the TM mode (or TEM mode) of the third resonator 13 and the TE mode of the second resonator 12, the TE mode of the second resonator 12 and the TM mode (or TEM mode) of the third resonator 13 can be coupled to each other on the second coupling structure 40.

[0141] The second coupling structure 40 can be extended in a straight line or in a curved line.

[0142] By adopting the above scheme, the second coupling structure 40 can conduct current of the TM mode (or TEM mode) from the housing wall connected to the "connection end of the resonator 14 of the third resonator 13" in the first coupling window 30a, thereby achieving coupling of the TM mode (or TEM mode) of the third resonator 13. The second coupling structure 40 can also cut the magnetic field of the TE mode of the second resonator 12 in the first coupling window 30a, thus enabling the second coupling structure 40 to couple the TE mode of the second resonator 12. Based on this, the second coupling structure 40 can achieve a simplified and optimized structural design to couple the TE mode of the second resonator 12 with the TM mode (or TEM mode) of the third resonator 13. Furthermore, compared to other solutions, the second coupling structure 40 occupies primarily within the first coupling window 30a, essentially not occupying the internal space of the resonator 10, thus facilitating the structural design of the resonator 10 itself. When the third resonator 13 is the first resonator 11 and the third resonator 13 is correspondingly provided with the first coupling structure 20, sufficient space can be provided for the first coupling structure 20 of the third resonator 13 (i.e., the first resonator 11). Similarly, when the second resonator 12 is the first resonator 11 and the second resonator 12 is correspondingly provided with the first coupling structure 20, sufficient space can be provided for the first coupling structure 20 of the second resonator 12 (i.e., the first resonator 11). Therefore, the coupling structure design of adjacent second resonators 12 and third resonators 13 is facilitated, as is the simulation design of the filter, and the performance of the filter can be optimized. Since the second coupling structure 40 has a small cutting amount with the TM mode (or TEM mode) magnetic field, this embodiment is mainly applicable to situations requiring a small coupling amount.

[0143] Of course, in other embodiments, the second coupling structure 40 may adopt other structural designs.

[0144] Please refer to Figures 1, 2, and 15. In some embodiments of this application, the second coupling structure 40 is mirror-flipped along the center line L connecting the second resonator 12 and the third resonator 13, so that the coupling polarity between the TE mode of the second resonator 12 and the TM or TEM mode of the third resonator 13 is reversed.

[0145] It should be noted that, compared with the second coupling structure 40 shown in Figures 1 and 2, the second coupling structure 40 shown in Figure 15 reverses its orientation by mirroring along the center line L connecting the second resonator 12 and the third resonator 13. This reverses the direction of the current generated by the second coupling structure 40 cutting the magnetic field, thereby reversing the coupling polarity achieved by the second coupling structure 40. That is, the coupling polarity between the TE mode of the second resonator 12 and the TM mode (or TEM mode) of the third resonator 13 is reversed. Note that this polarity reversal is a reversal of positive and negative coupling, not a reversal of inductive and capacitive coupling; the coupling relationship may remain unchanged.

[0146] By adopting the above scheme, the second coupling structure 40 can be mirror-flipped along the center line L connecting the second resonator 12 and the third resonator 13, thereby reversing the direction of the current generated by the second coupling structure 40 cutting the magnetic field. This reverses the coupling polarity between the TE mode of the second resonator 12 and the TM mode (or TEM mode) of the third resonator 13. This facilitates the on-demand change of the coupling polarity between the TE mode of the second resonator 12 and the TM mode (or TEM mode) of the third resonator 13, facilitates the design of coupling structures between adjacent second resonators 12 and third resonators 13, facilitates filter simulation design, and optimizes filter performance.

[0147] Please refer to Figures 1, 2, 12, and 16. In some embodiments of this application, the filter includes a medium 50 disposed in the coupling window 30.

[0148] It should be noted that at least one coupling window 30 is provided with a dielectric element 50. The dielectric element 50 can be made of a dielectric material with a high dielectric constant, and the material of the dielectric element 50 can be, but is not limited to, ceramic. The dielectric element 50 can be a regular structure (e.g., columnar structure, block structure, conical structure, etc.) or an irregular structure.

[0149] Since the dielectric element 50 mainly changes the propagation medium of electromagnetic waves in the coupling window 30, the dielectric element 50 can affect the coupling effect and coupling strength between resonant modes with similar electromagnetic field distributions of two adjacent resonators 10. The dielectric element 50 can affect the coupling effect and coupling strength between TE modes and TE modes, and can also affect the coupling effect and coupling strength between TM modes (or, TM mode and TEM mode; or, TEM mode and TEM mode).

[0150] The dielectric element 50 primarily enhances capacitive coupling, which is equivalent to weakening inductive coupling. If two adjacent resonators 10 have resonant modes with similar electromagnetic field distributions capacitively coupled through the coupling window 30, the coupling strength of this capacitive coupling can be enhanced by placing the dielectric element 50 in the coupling window 30. For example, TE modes can capacitively couple with each other through the coupling window 30, and the capacitive coupling strength between TE modes can be enhanced through the dielectric element 50.

[0151] If two adjacent resonators 10 have resonant modes with similar electromagnetic field distributions that are inductively coupled through the coupling window 30, then by placing a dielectric element 50 in the coupling window 30, the capacitive coupling can be enhanced through the dielectric element 50, which is equivalent to weakening the inductive coupling. Specifically, if the enhancement effect of the dielectric element 50 on the capacitive coupling is weaker than the strength of the inductive coupling formed by the two resonant modes through the coupling window 30, then the two resonant modes are still inductively coupled through the coupling window 30 and the dielectric element 50, with the dielectric element 50 mainly weakening the strength of the inductive coupling between the two resonant modes. If the enhancement effect of the dielectric element 50 on the capacitive coupling is equal to the strength of the inductive coupling formed by the two resonant modes through the coupling window 30, then the capacitive coupling enhanced by the dielectric element 50 is equivalent to canceling the inductive coupling formed by the two resonant modes through the coupling window 30, making the two resonant modes essentially uncoupled through the coupling window 30 and the dielectric element 50. If the enhancement effect of the dielectric 50 on capacitive coupling is stronger than the strength of the inductive coupling formed by the two resonant modes through the coupling window 30, then the inductive coupling formed by the two resonant modes through the coupling window 30 is completely canceled out, and the inductive coupling between the two resonant modes is reversed to capacitive coupling through the dielectric 50. For example, TM mode and TM mode (or TM mode and TEM mode; or TEM mode and TEM mode) were originally inductively coupled to each other through the coupling window 30. On this basis, the capacitive coupling can be enhanced through the dielectric 50. Depending on the enhancement effect of the dielectric 50 on capacitive coupling, TM mode and TM mode (or TM mode and TEM mode; or TEM mode and TEM mode) may still be inductively coupled but the inductive coupling strength is weakened, or they may be basically uncoupled, or they may be reversed from inductive coupling to capacitive coupling.

[0152] If there is both TE-mode coupling and TM-mode coupling (or TM-mode and TEM-mode; or TEM-mode and TEM-mode) between two adjacent resonators 10, then the dielectric 50 can both enhance the coupling strength of the capacitive coupling between TE-mode and TE-mode and weaken the coupling strength of the inductive coupling between TM-mode and TM-mode (or TM-mode and TEM-mode; or TEM-mode and TEM-mode). When the enhancement effect of the dielectric 50 on capacitive coupling is weaker than or equal to the strength of the inductive coupling formed between TM mode and TM mode (or, TM mode and TEM mode; or, TEM mode and TEM mode) through coupling window 30, the dielectric 50 can enhance the coupling between TE mode and TE mode and weaken the coupling between TM mode and TM mode (or, TM mode and TEM mode; or, TEM mode and TEM mode). In particular, if the size of coupling window 30 is small, the dielectric 50 can cooperate with coupling window 30 to suppress inductive coupling, so that the coupling between TM mode and TM mode (or, TM mode and TEM mode; or, TEM mode and TEM mode) is weaker or even basically non-coupled. When the enhancement effect of the dielectric 50 on capacitive coupling is stronger than the strength of the inductive coupling formed between TM mode and TM mode (or, TM mode and TEM mode; or, TEM mode and TEM mode) through coupling window 30, the dielectric 50 can enhance the coupling between TE mode and TE mode and reverse the inductive coupling between TM mode and TM mode (or, TM mode and TEM mode; or, TEM mode and TEM mode) to capacitive coupling.

[0153] For example, as shown in Figures 1, 2, and 12, in one example of the filter, the coupling window 30 between the first dual-mode resonator 10b and the second dual-mode resonator 10c is small in size. The coupling window 30 is provided with a dielectric element 50. The TE mode of the first dual-mode resonator 10b and the TE mode of the second dual-mode resonator 10c enhance capacitive coupling through the coupling window 30 and the dielectric element 50. The dielectric element 50 cooperates with the coupling window 30 to suppress inductive coupling, so that the TM mode of the first dual-mode resonator 10b and the TM mode of the second dual-mode resonator 10c do not couple with each other. Similarly, the coupling window 30 between the third dual-mode resonator 10d and the fourth dual-mode resonator 10e is smaller in size. A dielectric element 50 is provided in the coupling window 30. The TE mode of the third dual-mode resonator 10d and the TE mode of the fourth dual-mode resonator 10e enhance capacitive coupling through the coupling window 30 and the dielectric element 50. The dielectric element 50 cooperates with the coupling window 30 to suppress inductive coupling, so that the TM mode of the third dual-mode resonator 10d and the TM mode of the fourth dual-mode resonator 10e do not couple with each other.

[0154] It should be noted that resonant modes with dissimilar electromagnetic field distributions between two adjacent resonators 10 will not be coupled through the coupling window 30 and the dielectric 50. For example, the TE mode and the TM mode will not be coupled through the coupling window 30 and the dielectric 50, and the TE mode and the TEM mode will not be coupled through the coupling window 30 and the dielectric 50. Resonant modes with dissimilar electromagnetic field distributions need to be coupled through other coupling structures (such as the second coupling structure 40, etc.).

[0155] For example, as shown in Figures 17, 18, and 19, in a specific embodiment of the filter, the fourth resonator 15 is a TE single-mode resonator, and the fifth resonator 16 is a TE-TM dual-mode resonator. According to Figure 18, the center frequencies of the three resonant modes—the TE mode of the fourth resonator 15, the TM mode of the fifth resonator 16, and the TE mode of the fifth resonator 16—are approximately around 2.6 GHz. According to Figure 19, when a dielectric element 50 is provided in the coupling window 30 between the fourth resonator 15 and the fifth resonator 16, the TE mode of the fourth resonator 15 and the TE mode of the fifth resonator 16 can be capacitively coupled to each other. The coupling amount between the TE mode of the fourth resonator 15 and the TE mode of the fifth resonator 16 (around the 2.6 GHz resonant frequency) is approximately 48 GHz. The coupling amount between the TE mode of the fourth resonator 15 and the TM mode of the fifth resonator 16 (around the 2.6 GHz resonant frequency) is approximately 0 GHz, which is equivalent to no coupling and requires other coupling structures for coupling. The coupling amount between the TE mode of the fifth resonator 16 and the TM mode of the fifth resonator 16 (around the 2.6 GHz resonant frequency) is approximately 0 GHz, which is equivalent to no coupling and requires other coupling structures for coupling. Therefore, the dielectric element 50 can affect the coupling effect, coupling strength, and coupling polarity between resonant modes of two adjacent resonators 10 with similar electromagnetic field distributions. For example, it can affect the coupling between TE modes, TM modes, TM and TEM modes, and TEM modes. The dielectric element 50 cannot affect the coupling between resonant modes of two adjacent resonators 10 with dissimilar electromagnetic field distributions. For example, it cannot affect the coupling between TE and TM modes, or between TE and TEM modes. The dielectric element 50 cannot affect the coupling between multiple resonant modes of a dual-mode resonator or multi-mode resonator itself. For example, it cannot affect the coupling between the TE and TM modes of a TE-TM dual-mode resonator itself.

[0156] It should also be noted that the enhancement effect of the dielectric component 50 on capacitive coupling can be adjusted based on parameters such as the size and dielectric constant of the dielectric component 50, thereby affecting the coupling effect and coupling strength between resonant modes with similar electromagnetic field distributions of two adjacent resonators 10. That is, the size, dielectric constant, and other parameters of the dielectric component 50 can be set as needed.

[0157] In this design, the height d1 of the dielectric element 50 is its dimension along the height direction of the coupling window 30, which corresponds to the axial direction of the resonator 14 and is perpendicular to the through direction of the coupling window 30. The width d2 of the dielectric element 50 is its dimension along the width direction of the coupling window 30, which is perpendicular to both the through direction and the height direction of the coupling window 30. The height d1 and width d2 of the dielectric element 50 primarily affect the coupling strength between TE modes, while having little effect on the coupling strength between TM modes (or, TM mode and TEM mode; or, TEM mode and TEM mode). Generally, the higher the height d1 and the wider the width d2 of the dielectric element 50, the stronger the coupling strength between TE modes.

[0158] Wherein, the thickness d3 of the dielectric element 50 is the dimension of the dielectric element 50 in the direction through which the coupling window 30 passes, and is also the dimension on the line connecting the centers of two adjacent resonators 10. The thickness d3 of the dielectric element 50 mainly affects the coupling strength between TM modes (or, TM mode and TEM mode; or, TEM mode and TEM mode), while having little effect on the coupling strength between TE modes. As the thickness d3 of the dielectric element 50 increases, it is equivalent to gradually strengthening the capacitive coupling between TM modes (or, TM mode and TEM mode; or, TEM mode and TEM mode). Depending on the enhancement effect of the dielectric element 50 on capacitive coupling, the TM modes (or, TM mode and TEM mode; or, TEM mode and TEM mode) may still be inductively coupled but the inductive coupling strength is weakened, they may be basically uncoupled, or they may reverse from inductive coupling to capacitive coupling.

[0159] By adopting the above scheme, not only can the size of the coupling window 30 be adjusted, but also the dielectric element 50 used to enhance capacitive coupling can be set in the coupling window 30 as needed. This allows for convenient and reliable precise adjustment of the coupling effect and coupling strength between resonant modes with similar electromagnetic field distributions of two adjacent resonators 10. This facilitates adjusting the coupling between multiple sets of resonant modes of two adjacent resonators 10 to the required strength, or reversing it to the desired coupling relationship (i.e., capacitive or inductive coupling). Therefore, it is convenient to construct coupling relationships between two adjacent resonators 10 as needed via the coupling window 30 and the dielectric element 50, achieving the required coupling strength, coupling relationship, and coupling polarity. Furthermore, the dielectric element 50 can achieve superior coupling adjustment effects with a relatively small size. This simplifies and optimizes the coupling structure design between two adjacent resonators 10, facilitates filter simulation design, optimizes filter performance, and expands the coupling bandwidth range.

[0160] Furthermore, compared to existing technologies that use flying rods to establish coupling relationships, the dielectric component 50 is a non-metallic component, which will not form a floating arm and will not generate additional resonances with frequencies near the passband range. Therefore, the performance of the filter can be optimized and improved, especially the filtering performance and out-of-band rejection performance of the filter.

[0161] Furthermore, in existing technologies, the fly rod needs to be installed on the coupling window via an insulating bracket. The fly rod and the insulating bracket require assembly, as does the insulating bracket and the coupling window, making the assembly process cumbersome. In addition, due to these two assembly steps, it is difficult to maintain a stable installation position and state of the fly rod at the coupling window. However, the dielectric component 50 provided in this embodiment can be directly installed onto the coupling window 30, simplifying installation, reducing assembly steps, and improving filter assembly efficiency. Moreover, since the dielectric component 50 is directly installed onto the coupling window 30, its installation accuracy, positional accuracy, installation stability, and positional stability within the coupling window 30 are improved, ensuring stable filter performance.

[0162] Furthermore, compared to existing technologies that use flying rods to construct coupling relationships, the dielectric element 50 is not limited to affecting only the coupling effect and coupling strength of one set of resonant modes. The dielectric element 50 can affect the coupling effect and coupling strength between TE modes, as well as between TM modes (or, TM mode and TEM mode; or, TEM mode and TEM mode). Therefore, the dielectric element 50 has better applicability and a wider range of applications. The dielectric element 50 is particularly suitable for situations where "there is both TE mode coupling and TM mode coupling (or, TM mode and TEM mode; or, TEM mode and TEM mode) between two adjacent resonators 10". In this case, the dielectric element 50 can simultaneously affect the coupling effect and coupling strength between TE modes and between TM modes, and can simultaneously control the "TE mode coupling" and "TM mode coupling" between two adjacent resonators 10.

[0163] Furthermore, compared to existing technologies that use flying rods to establish coupling relationships, the dielectric element 50 can achieve superior coupling adjustment effects with a smaller size. Therefore, while improving filter performance, the space required by the dielectric element 50 can be reduced, which is beneficial to the miniaturization and weight reduction of the filter.

[0164] Of course, in other embodiments, the medium element 50 may be omitted from the coupling window 30.

[0165] Please refer to Figures 3 and 16. In some embodiments of this application, the dielectric element 50 is a columnar structure. For example, the dielectric element 50 may be a polygonal prism structure or a cylindrical structure.

[0166] By adopting the above scheme and making the dielectric component 50 a columnar structure, on the one hand, the structure and shape of the dielectric component 50 can be made more regular and modular. Based on this, it is convenient to process the columnar dielectric component 50 by methods such as machining, injection molding, dry pressing, and sintering, which can improve the processing convenience, processing accuracy, and processing efficiency of the dielectric component 50. It can also make the formed dielectric component 50 have better structural stability and strength, and facilitate the connection, fixation, and assembly of the dielectric component 50. On the other hand, it is convenient to accurately control the dimensions (e.g., height, width, and thickness) of the columnar dielectric component 50. Based on this, it is convenient to accurately adjust the coupling effect and coupling strength between TE modes, and to accurately adjust the coupling effect, coupling strength, and coupling polarity between TM modes (or, TM mode and TEM mode; or, TEM mode and TEM mode). This facilitates the coupling design between two adjacent resonators 10, facilitates the simulation design of the filter, and optimizes the performance of the filter.

[0167] Of course, in other embodiments, the medium 50 can be a regular structure of other forms (e.g., a conical structure, a frustum structure, etc.) or an irregular structure.

[0168] Please refer to Figure 16. In some embodiments of this application, the medium 50 is a cuboid structure (including a cube structure).

[0169] Compared to other columnar structures, making the dielectric element 50 a cuboid structure allows for more standardized and defined dimensions and shape. This facilitates precise determination and control of the height d1, width d2, and thickness d3 of the dielectric element 50 using the length, width, and height of the cuboid. This allows for precise adjustment of the coupling effect and strength between TE modes, and between TM modes (or TM and TEM modes; or TEM and TEM modes). Consequently, it facilitates precise coupling design between adjacent resonators 10, enables filter simulation design, and optimizes filter performance.

[0170] Please refer to Figures 3 and 20. In some embodiments of this application, the dielectric element 50 has a cylindrical structure. Since the cylindrical shape is more regular, it is more conducive to the processing, shaping, and assembly of the dielectric element 50.

[0171] Of course, in other embodiments, the medium 50 may be other columnar structures, such as triangular prism structures, etc.

[0172] Referring to Figure 16, in some embodiments of this application, the medium 50 is a solid structure. That is, the interior of the medium 50 has no voids or gaps (e.g., holes, slots).

[0173] Compared to a hollow structure of the same volume, making the dielectric component 50 a solid structure allows for a greater amount of dielectric material to serve as the propagation medium for electromagnetic waves. This eliminates internal voids or gaps (since voids or gaps use air as the propagation medium for electromagnetic waves). Consequently, the dielectric component 50 can more effectively influence the coupling effect and coupling strength between resonant modes with similar electromagnetic field distributions of two adjacent resonators 10. This optimizes the utility of the dielectric component 50, facilitating coupling design and energy propagation between adjacent resonators 10, simplifying filter simulation design, and optimizing filter performance. Furthermore, the processing and manufacturing of a solid dielectric component 50 is relatively simple, eliminating the need for drilling, grooving, and demolding. Therefore, it improves the ease of processing, accuracy, and efficiency of the dielectric component 50, resulting in a more stable and stronger structure.

[0174] Of course, in other embodiments, the medium element 50 can be a hollow structure, that is, the medium element 50 can be provided with holes, gaps, hole structures, groove structures, etc.

[0175] Please refer to Figure 16. In some embodiments of this application, the filter includes a coupling adjustment screw 90 disposed on one side of the dielectric 50 along its own height direction.

[0176] It should be noted that the filter can be equipped with a coupling adjustment screw 90 on one side of the dielectric element 50 along the height direction of the dielectric element 50 as needed. That is, the coupling adjustment screw 90 is also provided in the coupling window 30 and is set corresponding to the dielectric element 50 along the height direction of the dielectric element 50.

[0177] The coupling adjustment screw 90 can be directly threaded into the threaded hole of the corresponding wall of the filter housing; alternatively, a mounting part (not shown in the figure) can be embedded in the corresponding wall of the filter housing, and the coupling adjustment screw 90 can be threaded into the threaded hole of the mounting part. Based on this, the coupling adjustment screw 90 can be screwed in or out relative to the corresponding wall of the filter housing to adjust the length of the portion of the coupling adjustment screw 90 extending into the filter housing, thereby adjusting the coupling strength between two adjacent resonators 10.

[0178] By adopting the above scheme, when two adjacent resonators 10 with similar electromagnetic field distributions are coupled through the coupling window 30 and the dielectric 50, by setting a coupling adjustment screw 90 on one side of the dielectric 50 along its own height direction, the length of the part of the coupling adjustment screw 90 extending into the filter can be easily and quickly adjusted by screwing it in or out. This allows for fine adjustment of the coupling strength between the two adjacent resonators 10 with similar electromagnetic field distributions, making the adjustment convenient, fast, and accurate.

[0179] Of course, in other embodiments, the coupling adjustment screw 90 can be replaced with a coupling adjustment structure of other structural types. Alternatively, if it is not necessary to adjust the coupling strength between resonant modes with similar electromagnetic field distributions of two adjacent resonators 10, the coupling adjustment screw 90 and other coupling adjustment structures can be omitted.

[0180] Please refer to Figures 3, 16, and 20. In some embodiments of this application, when a coupling adjustment screw 90 is provided on one side of the medium element 50 along its own height direction, an opening 51 is provided on the side of the medium element 50 facing the coupling adjustment screw 90. The opening 51 is correspondingly provided with the coupling adjustment screw 90, and the opening 51 allows the coupling adjustment screw 90 to pass through it.

[0181] It should be noted that when the dielectric element 50 has a coupling adjustment screw 90 on one side along its height direction, an opening 51 can be provided on the side of the dielectric element 50 facing the coupling adjustment screw 90. The opening 51 can be a blind hole or a through hole. The opening 51 can be a circular hole, a rectangular hole, etc. The opening 51 corresponds to the coupling adjustment screw 90 along its axial direction, the extension direction of the opening 51 corresponds to the extension direction of the coupling adjustment screw 90, and the cross-sectional dimension of the opening 51 is greater than or equal to the cross-sectional dimension of the coupling adjustment screw 90. When the length of the portion of the coupling adjustment screw 90 extending into the filter is relatively long, the coupling adjustment screw 90 is allowed to extend into the opening 51.

[0182] By adopting the above scheme, even when the length of the part of the coupling adjustment screw 90 extending into the filter is relatively long, the coupling adjustment screw 90 can be allowed to extend into the opening 51 of the dielectric component 50. Based on this, the adjustment range of the coupling adjustment screw 90 can be expanded accordingly, and the adjustable range of the coupling strength between the resonant modes with similar electromagnetic field distributions of two adjacent resonators 10 can be expanded accordingly, thereby improving the performance index of the filter.

[0183] Of course, in other embodiments, if the medium 50 is provided with a coupling adjustment screw 90 on one side along its own height direction, the opening 51 may not be provided on the side of the medium 50 facing the coupling adjustment screw 90. For example, the medium 50 may be a solid structure.

[0184] Please refer to Figures 3 and 16. In some embodiments of this application, the dielectric element 50 is formed independently. That is, the dielectric element 50 is first formed independently and then assembled into the coupling window 30.

[0185] By adopting the above scheme and making the dielectric component 50 independently molded, on the one hand, it is convenient to independently mold the dielectric component 50 through methods such as machining, injection molding, dry pressing, and sintering. It is also convenient to select different materials for independently molding the dielectric component 50, which can improve the processing convenience, processing accuracy, processing efficiency, material selectivity, and design flexibility of the dielectric component 50. It also facilitates the connection, fixation, and assembly of the dielectric component 50. On the other hand, it is convenient to accurately control the size of the dielectric component 50 during the independent molding of the dielectric component 50, so that the dielectric component 50 can accurately affect the coupling effect, coupling strength, and coupling polarity between two adjacent resonators 10, thereby optimizing the performance of the filter.

[0186] Please refer to Figures 3 and 16. In some embodiments of this application, the dielectric constant of the dielectric element 50 is 30 to 40. Optionally, the material of the dielectric element 50 may be, but is not limited to, ceramic.

[0187] By adopting the above scheme, and by making the dielectric constant of dielectric element 50 30 to 40, dielectric element 50 can have a high dielectric constant. Based on this, the capacitance effect of dielectric element 50 can be significantly enhanced, enabling dielectric element 50 to provide a strong capacitive coupling enhancement effect between adjacent resonators 10. This allows dielectric element 50 to more significantly affect the coupling effect and coupling strength between resonant modes with similar electromagnetic field distributions of two adjacent resonators 10, thus optimizing the utility of dielectric element 50. This facilitates the coupling design and energy propagation between two adjacent resonators 10, facilitates the simulation design of filters, and optimizes the performance of filters.

[0188] Of course, in other embodiments, the dielectric element 50 may be made of a dielectric material, and the dielectric constant of the dielectric element 50 is not limited to the range of 30 to 40.

[0189] Please refer to Figures 16, 17, and 21. In some embodiments of this application, at least one set of two adjacent resonators 10 are a fourth resonator 15 and a fifth resonator 16. The fourth resonator 15 has a TE mode resonance mode, and the fifth resonator 16 has a TE mode resonance mode. The TE mode of the fourth resonator 15 and the TE mode of the fifth resonator 16 are capacitively coupled through a coupling window 30 and a dielectric 50.

[0190] It should be noted that at least one set of two adjacent resonators 10 uses a combination of a fourth resonator 15 and a fifth resonator 16. The fourth resonator 15 has a TE mode, meaning that the fourth resonator 15 can support at least the TE mode within its passband. For example, the fourth resonator 15 can be a TE single-mode resonator, a TE-TM dual-mode resonator, a HE-TE tri-mode resonator, a HE-TE-TM quad-mode resonator, or the first resonator 11 provided in any of the above embodiments of this application, etc. The fifth resonator 16 has a TE mode, meaning that the fifth resonator 16 can support at least the TE mode within its passband. For example, the fifth resonator 16 can be a TE single-mode resonator, a TE-TM dual-mode resonator, a HE-TE tri-mode resonator, a HE-TE-TM quad-mode resonator, or the first resonator 11 provided in any of the above embodiments of this application, etc.

[0191] When the coupling window 30 has a certain size (i.e., the size of the coupling window 30 is relatively large), the TE mode of the fourth resonator 15 and the TE mode of the fifth resonator 16 can be capacitively coupled to each other through the coupling window 30, and the dielectric element 50 in the coupling window 30 can enhance the capacitive coupling strength between the TE mode of the fourth resonator 15 and the TE mode of the fifth resonator 16.

[0192] When the coupling window 30 is small, the TE mode of the fourth resonator 15 and the TE mode of the fifth resonator 16 are mainly capacitively coupled based on the dielectric 50. The main function of the coupling window 30 is to accommodate the dielectric 50.

[0193] The capacitive coupling strength between the TE mode of the fourth resonator 15 and the TE mode of the fifth resonator 16 can be adjusted mainly by adjusting the height d1, width d2, and dielectric constant of the dielectric component 50.

[0194] By adopting the above scheme, the TE mode of the fourth resonator 15 and the fifth resonator 16 can be capacitively coupled through the coupling window 30 and the dielectric element 50 disposed in the coupling window 30, and the coupling effect is better. Based on this, two adjacent resonators 10 with TE mode resonance can be adapted to use the coupling window 30 and the dielectric element 50 to construct the required capacitive coupling relationship as needed and achieve the required coupling strength, thereby improving the design flexibility of the filter, facilitating the simulation design of the filter, and optimizing the performance of the filter.

[0195] For example, as shown in Figures 21, 22, and 23, in one specific embodiment of the filter, the fourth resonator 15 is a TE single-mode resonator, and the fifth resonator 16 is a TE single-mode resonator. According to Figure 22, the resonant frequency of the fourth resonator 15 is approximately 2.4 GHz, and the resonant frequency of the fifth resonator 16 is approximately 2.4 GHz. According to Figure 23, when the TE mode of the fourth resonator 15 and the TE mode of the fifth resonator 16 are capacitively coupled only through the coupling window 30 (i.e., without the dielectric 50), the coupling amount between the TE modes of the fourth resonator 15 and the fifth resonator 16 (around the 2.4 GHz resonant frequency) is approximately 37 GHz; while when the TE modes of the fourth resonator 15 and the fifth resonator 16 are capacitively coupled through both the coupling window 30 and the dielectric 50 (i.e., with the dielectric 50), the coupling amount between the TE modes of the fourth resonator 15 and the fifth resonator 16 (around the 2.4 GHz resonant frequency) is approximately 46 GHz, and the coupling effect is significantly better than that without the dielectric 50.

[0196] Referring to Figure 16, in some embodiments of this application, at least one pair of adjacent resonators 10 are a sixth resonator 17 and a seventh resonator 18. The sixth resonator 17 has a TM mode or a TEM mode resonant mode, and the seventh resonator 18 has a TM mode or a TEM mode resonant mode. The TM mode or TEM mode of the sixth resonator 17 is inductively coupled to the TM mode or TEM mode of the seventh resonator 18 through a coupling window 30, and the coupling strength between them is adjusted by a dielectric 50; or, the TM mode or TEM mode of the sixth resonator 17 is capacitively coupled to the TM mode or TEM mode of the seventh resonator 18 through a dielectric 50.

[0197] It should be noted that at least one set of two adjacent resonators 10 uses a combination of the sixth resonator 17 and the seventh resonator 18. The sixth resonator 17 has a TM mode or a TEM mode, that is, the sixth resonator 17 can support at least the TM mode or the TEM mode within its passband. The sixth resonator 17 can be a TM single-mode resonator, a TEM single-mode resonator, a TM dual-mode resonator, a TE-TM dual-mode resonator, a HE-TM tri-mode resonator, a HE-TE-TM quad-mode resonator, or the first resonator 11 provided in any of the above embodiments of this application, etc. The seventh resonator 18 has a TM mode or a TEM mode, that is, the seventh resonator 18 can support at least the TM mode or the TEM mode within its passband. The seventh resonator 18 can be a TM single-mode resonator, a TEM single-mode resonator, a TM dual-mode resonator, a TE-TM dual-mode resonator, a HE-TM tri-mode resonator, a HE-TE-TM quad-mode resonator, or the first resonator 11 provided in any of the above embodiments of this application, etc.

[0198] The TM or TEM mode of the sixth resonator 17 and the TM or TEM mode of the seventh resonator 18 can be inductively coupled to each other through the coupling window 30. On this basis, the dielectric element 50 in the coupling window 30 can enhance the capacitance between the sixth resonator 17 and the seventh resonator 18, which is equivalent to weakening the inductive coupling strength between the TM or TEM mode of the sixth resonator 17 and the TM or TEM mode of the seventh resonator 18.

[0199] Based on this, when the enhancement effect of the dielectric 50 on capacitive coupling is weaker than the strength of the inductive coupling formed by the TM mode and the TM mode (or, the TM mode and the TEM mode; or, the TEM mode and the TEM mode) through the coupling window 30, the TM mode or TEM mode of the sixth resonator 17 and the TM mode or TEM mode of the seventh resonator 18 achieve inductive coupling through the coupling window 30 and the dielectric 50. The effect of the dielectric 50 is to weaken the inductive coupling strength (i.e., adjust the inductive coupling strength).

[0200] When the enhancement effect of the dielectric 50 on capacitive coupling is stronger than the strength of the inductive coupling formed by the TM mode and the TM mode (or, the TM mode and the TEM mode; or, the TEM mode and the TEM mode) through the coupling window 30, the TM mode or TEM mode of the sixth resonator 17 and the TM mode or TEM mode of the seventh resonator 18 achieve capacitive coupling through the coupling window 30 and the dielectric 50. The function of the dielectric 50 is to cancel the "inductive coupling formed through the coupling window 30" and reverse the coupling relationship from inductive coupling to capacitive coupling.

[0201] When the enhancement effect of dielectric 50 on capacitive coupling is equal to the strength of inductive coupling formed by TM mode and TM mode (or, TM mode and TEM mode; or, TEM mode and TEM mode) through coupling window 30, the coupling between the TM mode or TEM mode of the sixth resonator 17 and the TM mode or TEM mode of the seventh resonator 18 through coupling window 30 and dielectric 50 is weak, basically non-coupled. The effect of dielectric 50 is to effectively cancel out the "inductive coupling formed through coupling window 30".

[0202] The coupling relationship, coupling strength, and coupling polarity between the TM mode or TEM mode of the sixth resonator 17 and the TM mode or TEM mode of the seventh resonator 18 can be adjusted mainly by adjusting the thickness d3 and the dielectric constant of the dielectric component 50.

[0203] By adopting the above scheme, the adjacent sixth resonator 17 and seventh resonator 18 can be inductively or capacitively coupled to each other through the coupling window 30 and the dielectric element 50 disposed in the coupling window 30, and the coupling effect is better. Based on this, two adjacent resonators 10 with TM mode or TEM mode respectively can be adapted to use the coupling window 30 and the dielectric element 50 to construct the required coupling relationship (which can be inductive coupling relationship, capacitive coupling relationship, or no coupling relationship) as needed, and achieve the required coupling strength, thereby improving the design flexibility of the filter, facilitating the simulation design of the filter, and optimizing the performance of the filter.

[0204] Please refer to Figures 24 and 25. In some embodiments of this application, at least one pair of adjacent resonators 10 are a fourth resonator 15 and a fifth resonator 16. The fourth resonator 15 has a TE mode resonance mode, and the fifth resonator 16 has a TE mode resonance mode. The filter includes a third coupling structure 60, which is disposed in the coupling window 30 between the fourth resonator 15 and the fifth resonator 16, and couples the TE mode of the fourth resonator 15 with the TE mode of the fifth resonator 16.

[0205] It should be noted that at least one set of two adjacent resonators 10 uses a combination of a fourth resonator 15 and a fifth resonator 16. The fourth resonator 15 has a TE mode, meaning that the fourth resonator 15 can support at least the TE mode within its passband. For example, the fourth resonator 15 can be a TE single-mode resonator, a TE-TM dual-mode resonator, a HE-TE tri-mode resonator, a HE-TE-TM quad-mode resonator, or the first resonator 11 provided in any of the above embodiments of this application, etc. The fifth resonator 16 has a TE mode, meaning that the fifth resonator 16 can support at least the TE mode within its passband. For example, the fifth resonator 16 can be a TE single-mode resonator, a TE-TM dual-mode resonator, a HE-TE tri-mode resonator, a HE-TE-TM quad-mode resonator, or the first resonator 11 provided in any of the above embodiments of this application, etc.

[0206] The TE mode of the fourth resonator 15 and the TE mode of the fifth resonator 16 can be coupled via a third coupling structure 60. At least a portion of the third coupling structure 60 is disposed in the coupling window 30 between the fourth resonator 15 and the fifth resonator 16.

[0207] The third coupling structure 60 can be a metal component, a non-metallic component with a metal layer on its surface, or a non-metallic component. The specific construction, extension path, shape, and size of the third coupling structure 60 are not currently limited. The third coupling structure 60 can be insulated and installed in the coupling window 30 between the fourth resonator 15 and the fifth resonator 16 via an insulating component, or it can be insulated and installed on the housing of the fourth resonator 15 and / or the housing of the fifth resonator 16 via an insulating component.

[0208] It should be noted that the third coupling structure 60 enables coupling between TE modes, but due to the different electromagnetic field distributions of the TE and TM modes, the third coupling structure 60 may or may not enable coupling between TM modes (or TM mode and TEM mode; or TEM mode and TEM mode). Whether or not the third coupling structure 60 can achieve coupling between TM modes (or TM mode and TEM mode; or TEM mode and TEM mode) can be determined according to the specific design requirements of the filter, and the specific structure of the third coupling structure 60 can be designed as needed.

[0209] By adopting the above scheme, the TE mode of the fourth resonator 15 and the TE mode of the fifth resonator 16 can be coupled through the third coupling structure 60, thereby achieving coupling between the TE modes of the fourth resonator 15 and the fifth resonator 16. This facilitates the construction of the required coupling relationship between the adjacent fourth resonator 15 and fifth resonator 16 via the third coupling structure 60, achieving the desired coupling strength and relationship. This simplifies filter simulation design and facilitates the optimization of filter performance.

[0210] Of course, in other embodiments, the TE mode of the fourth resonator 15 and the TE mode of the fifth resonator 16 can be coupled directly through the larger coupling window 30, or through the coupling window 30 and the dielectric 50, thus omitting the third coupling structure 60.

[0211] Referring to Figures 24 and 25, in some embodiments of this application, the third coupling structure 60 includes a connecting portion 61, a fifth coupling portion 62 bent and connected to one end of the connecting portion 61, and a sixth coupling portion 63 bent and connected to the other end of the connecting portion 61. The fifth coupling portion 62 and the sixth coupling portion 63 are bent toward the same side of the connecting portion 61 (as shown in Figure 24); or, the fifth coupling portion 62 is bent toward one side of the connecting portion 61 and the sixth coupling portion 63 is bent toward the other side of the connecting portion 61 (as shown in Figure 25).

[0212] It should be noted that the connecting portion 61 passes through the coupling window 30 between the fourth resonator 15 and the fifth resonator 16. The connecting portion 61 can connect between the fifth coupling portion 62 and the sixth coupling portion 63 to support them. The extending direction of the connecting portion 61 can be parallel to or not parallel to the through direction of the coupling window 30. The connecting portion 61 can extend in a straight line or a curve.

[0213] The fifth coupling portion 62 is bent and connected to one end of the connecting portion 61. The fifth coupling portion 62 and the connecting portion 61 can be integrally connected or separately connected. The fifth coupling portion 62 is used to couple the TE mode of the fourth resonator 15. Specifically, the fifth coupling portion 62 may intersect the radial direction of the resonator element 14 of the fourth resonator 15 to cut the magnetic field of the TE mode of the fourth resonator 15, thereby coupling the TE mode of the fourth resonator 15. As shown in Figures 24 and 25, in some embodiments, the fifth coupling portion 62 may extend in an arc shape along the circumference of the resonator element 14 of the fourth resonator 15 to couple the TE mode of the fourth resonator 15 and achieve a better coupling effect.

[0214] The sixth coupling portion 63 is bent and connected to the end of the connecting portion 61 away from the fifth coupling portion 62. The sixth coupling portion 63 and the connecting portion 61 can be integrally connected or separately connected. The sixth coupling portion 63 is used to couple the TE mode of the fifth resonator 16. Specifically, the sixth coupling portion 63 may intersect the radial direction of the resonator element 14 of the fifth resonator 16 to cut the magnetic field of the TE mode of the fifth resonator 16, thereby coupling the TE mode of the fifth resonator 16. As shown in Figures 24 and 25, in some embodiments, the sixth coupling portion 63 may extend in an arc shape along the circumference of the resonator element 14 of the fifth resonator 16 to couple the TE mode of the fifth resonator 16 and achieve a better coupling effect.

[0215] By adopting the above scheme, the third coupling structure 60 can be connected between the fifth coupling section 62 and the sixth coupling section 63 via the connecting part 61 to support the fifth coupling section 62 and the sixth coupling section 63. The TE mode of the fourth resonator 15 can also be coupled via the fifth coupling section 62, and the TE mode of the fifth resonator 16 can be coupled via the sixth coupling section 63, so that the TE modes of the fourth resonator 15 and the fifth resonator 16 can be coupled on the third coupling structure 60. Thus, the filter can achieve coupling of the TE modes of the fourth resonator 15 and the fifth resonator 16 through the simplified and optimized third coupling structure 60, with better coupling effect, thereby optimizing the filter's structure and performance and facilitating filter simulation design.

[0216] It should also be noted that in the third coupling structure 60 shown in FIG. 24, the fifth coupling portion 62 and the sixth coupling portion 63 are bent toward the same side of the connecting portion 61, that is, the fifth coupling portion 62 and the sixth coupling portion 63 are located on the same side of the connecting portion 61, making the third coupling structure 60 in a shape similar to the Chinese character "ji".

[0217] In the third coupling structure 60 shown in FIG. 25, the fifth coupling portion 62 is bent toward one side of the connecting portion 61, while the sixth coupling portion 63 is bent toward the other side of the connecting portion 61, that is, the fifth coupling portion 62 and the sixth coupling portion 63 are respectively arranged on opposite sides of the connecting portion 61.

[0218] Based on this, by adopting the above solution, the third coupling structure 60 can transform between the structural forms of "the fifth coupling portion 62 and the sixth coupling portion 63 are bent toward the same side of the connecting portion 61" and "the fifth coupling portion 62 is bent toward one side of the connecting portion 61, while the sixth coupling portion 63 is bent toward the other side of the connecting portion 61", so as to reverse the coupling relationship realized by the third coupling structure 60, that is, to reverse the coupling relationship between the TE mode of the fourth resonator 15 and the TE mode of the fifth resonator 16 between a capacitive coupling relationship and an inductive coupling relationship. Thus, it is convenient to achieve the required coupling relationship between the TE mode of the fourth resonator 15 and the TE mode of the fifth resonator 16, convenient for the coupling design between the fourth resonator 15 and the fifth resonator 16, convenient for the simulation design of the filter, and optimize the performance of the filter. Among them, for the structural forms of "the fifth coupling portion 62 and the sixth coupling portion 63 are bent toward the same side of the connecting portion 61" and "the fifth coupling portion 62 is bent toward one side of the connecting portion 61, while the sixth coupling portion 63 is bent toward the other side of the connecting portion 61", which specific structural form realizes inductive coupling and which realizes capacitive coupling need to be determined by considering other specific settings (such as the settings of ports).

[0219] Of course, in other embodiments, the third coupling structure 60 can adopt other structural designs.

[0220] Please refer to FIGS. 1, 3, and 26. In some embodiments of the present application, at least one group of two adjacent resonators 10 are the sixth resonator 17 and the seventh resonator 18. The sixth resonator 17 has a TM mode resonance mode or a TEM mode resonance mode, and the seventh resonator 18 has a TM mode resonance mode or a TEM mode resonance mode; the filter includes a fourth coupling structure 70, and the fourth coupling structure 70 is arranged in the coupling window 30 between the sixth resonator 17 and the seventh resonator 18, and couples the TM mode or TEM mode of the sixth resonator 17 with the TM mode or TEM mode of the seventh resonator 18.

[0221] It should be noted that at least one set of two adjacent resonators 10 uses a combination of the sixth resonator 17 and the seventh resonator 18. The sixth resonator 17 has a TM mode or a TEM mode, that is, the sixth resonator 17 can support at least the TM mode or the TEM mode within its passband. The sixth resonator 17 can be a TM single-mode resonator, a TEM single-mode resonator, a TM dual-mode resonator, a TE-TM dual-mode resonator, a HE-TM tri-mode resonator, a HE-TE-TM quad-mode resonator, or the first resonator 11 provided in any of the above embodiments of this application, etc. The seventh resonator 18 has a TM mode or a TEM mode, that is, the seventh resonator 18 can support at least the TM mode or the TEM mode within its passband. The seventh resonator 18 can be a TM single-mode resonator, a TEM single-mode resonator, a TM dual-mode resonator, a TE-TM dual-mode resonator, a HE-TM tri-mode resonator, a HE-TE-TM quad-mode resonator, or the first resonator 11 provided in any of the above embodiments of this application, etc.

[0222] The TM or TEM mode of the sixth resonator 17 and the TM or TEM mode of the seventh resonator 18 can be coupled via a fourth coupling structure 70. At least a portion of the fourth coupling structure 70 is disposed in the coupling window 30 between the sixth resonator 17 and the seventh resonator 18.

[0223] The fourth coupling structure 70 may be a metal component, a non-metallic component with a metal layer on its surface, or a non-metallic component. The specific construction, extension path, shape, and dimensions of the fourth coupling structure 70 are not currently limited.

[0224] It should be noted that the fourth coupling structure 70 can couple TM modes with TM modes (or TM modes with TEM modes; or TEM modes with TEM modes). However, due to the different electromagnetic field distributions of the TE and TM modes, the fourth coupling structure 70 may or may not couple TE modes. Whether the fourth coupling structure 70 can achieve coupling between TE modes depends on the specific design requirements of the filter, and the specific structure of the fourth coupling structure 70 can be designed as needed.

[0225] By adopting the above scheme, the adjacent sixth resonator 17 and seventh resonator 18 can be coupled through the fourth coupling structure 70, thereby achieving coupling between the TM or TEM mode of the sixth resonator 17 and the TM or TEM mode of the seventh resonator 18. This facilitates the construction of the required coupling relationship between the adjacent sixth resonator 17 and seventh resonator 18 via the fourth coupling structure 70, achieving the desired coupling strength and relationship. This simplifies filter simulation design and performance optimization.

[0226] Of course, in other embodiments, the TM mode or TEM mode of the sixth resonator 17 and the TM mode or TEM mode of the seventh resonator 18 can be coupled directly through the larger coupling window 30, or through the coupling window 30 and the dielectric 50, thus omitting the fourth coupling structure 70.

[0227] Please refer to Figures 1 and 3. In some embodiments of this application, the fourth coupling structure 70 is a coupling rib with both ends grounded, so that the TM mode or TEM mode of the sixth resonator 17 is inductively coupled to the TM mode or TEM mode of the seventh resonator 18.

[0228] It should be noted that the fourth coupling structure 70 is a coupling rib, which is a metal component. Both ends of the coupling rib are grounded, enabling inductive coupling. The ends of the coupling rib can be directly connected to the housing component of the resonator 10, or indirectly connected to the housing component of the resonator 10 via other metal components (such as the base 80), thus achieving grounding. When the resonator element 14 of the resonator 10 is a metal resonator element, the coupling rib can also be directly connected to the resonator element 14.

[0229] For example, as shown in Figures 1, 3, and 12, in one example of the filter, the coupling window 30 of the second dual-mode resonator 10c and the third dual-mode resonator 10d is relatively large. A fourth coupling structure 70, which serves as a coupling rib, is inserted through the coupling window 30. The fourth coupling structure 70, together with the coupling window 30, enables the inductive coupling of the TM mode of the second dual-mode resonator 10c and the TM mode of the third dual-mode resonator 10d, which is equivalent to enhancing the inductive coupling strength between the TM mode of the second dual-mode resonator 10c and the TM mode of the third dual-mode resonator 10d.

[0230] By adopting the above scheme, the fourth coupling structure 70 can be made into a coupling rib with both ends grounded, so that the TM or TEM mode of the sixth resonator 17 and the TM or TEM mode of the seventh resonator 18 can establish the required inductive coupling relationship through the coupling rib. Compared with other structural types of the fourth coupling structure 70, the coupling rib has a simplified and optimized structure, is easy to process and assemble, and can easily achieve the required inductive coupling relationship, thus achieving better coupling effect. Therefore, the structural design of the fourth coupling structure 70 can be simplified and optimized, which can facilitate the simulation design of the filter and optimize the performance of the filter.

[0231] As shown in Figures 1 and 3, in some embodiments, only one coupling window 30 may be provided between the sixth resonator 17 and the seventh resonator 18. This coupling window 30 facilitates the establishment of a coupling relationship between the resonant modes of the sixth resonator 17 and the seventh resonator 18, whose electromagnetic field distributions are similar. The coupling window 30 can also be used to pass through the fourth coupling structure 70.

[0232] As shown in Figure 26, in some embodiments, two coupling windows 30 can be provided between the sixth resonator 17 and the seventh resonator 18. One coupling window 30 facilitates the establishment of a coupling relationship between the resonant modes of the sixth resonator 17 and the seventh resonator 18, whose electromagnetic field distributions are similar. The other coupling window 30 is dedicated to the passage of the fourth coupling structure 70. This arrangement facilitates the optimization of the position of the coupling window 30 dedicated to the passage of the fourth coupling structure 70, thereby optimizing the layout of the fourth coupling structure 70. It is particularly beneficial in cases where the fourth coupling structure 70 is a coupling rib, thus shortening the extension length of the coupling rib, which facilitates the molding and assembly of the fourth coupling structure 70 and reduces the material consumption and cost of the fourth coupling structure 70.

[0233] Please refer to Figures 1, 3, and 26. In some embodiments of this application, the fourth coupling structure 70 is a flying rod, which capacitively couples the TM mode or TEM mode of the sixth resonator 17 with the TM mode or TEM mode of the seventh resonator 18.

[0234] It should be noted that the fourth coupling structure 70 is a fly rod. The fly rod achieves capacitive coupling, meaning it allows the TM or TEM mode of the sixth resonator 17 to be capacitively coupled with the TM or TEM mode of the seventh resonator 18. The fly rod is a metal component, insulated and mounted on the coupling window 30, or insulated and mounted on the housing of the sixth resonator 17 and / or the seventh resonator 18. The specific construction, extension path, shape, and size of the fly rod are not limited.

[0235] By adopting the above scheme, the fourth coupling structure 70 can be made into a flybar, facilitating the establishment of the required capacitive coupling relationship between the TM or TEM mode of the sixth resonator 17 and the TM or TEM mode of the seventh resonator 18 via the flybar. This simplifies and optimizes the structural design of the fourth coupling structure 70, making it easier for the TM or TEM mode of the sixth resonator 17 and the TM or TEM mode of the seventh resonator 18 to achieve the required capacitive coupling relationship and achieve better coupling effect. This, in turn, facilitates the simulation design of the filter and optimizes its performance.

[0236] It should be noted that, for the second coupling structure 40, the third coupling structure 60, the fourth coupling structure 70 and the medium 50 provided in the above embodiments of this application, only one of them can be set in the same coupling window 30 according to specific coupling requirements, or any few or all of them can be set in the same coupling window 30.

[0237] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A filter, comprising a first resonator, wherein the first resonator has at least two resonant modes: a TE mode and a TM mode, wherein, The first resonator includes a resonator housing and a dielectric resonator disposed within the resonator housing, the dielectric resonator being connected to a first wall of the resonator housing; the filter further includes a first coupling structure disposed within the resonator housing, both ends of the first coupling structure being grounded, the first coupling structure including a first coupling portion and a second coupling portion, one end of the second coupling portion being connected to the end of the first coupling portion away from the central axis of the dielectric resonator, the first coupling portion intersecting the circumferential direction of the dielectric resonator, and the second coupling portion intersecting the radial direction of the dielectric resonator, so that the TE mode and TM mode of the first resonator are coupled together.

2. The filter as claimed in claim 1, wherein, The first coupling part is disposed close to the first wall.

3. The filter as described in claim 2, wherein, The first coupling portion abuts against the first wall on the side closest to the first wall.

4. The filter as described in claim 1, wherein, The second coupling portion is disposed near the outer peripheral surface of the dielectric resonator.

5. The filter as claimed in claim 1, wherein, The first coupling portion extends radially along the dielectric resonator.

6. The filter as claimed in claim 1, wherein, The second coupling portion is perpendicular to the radial direction of the dielectric resonator; Alternatively, the second coupling portion extends in an arc shape along the circumference of the dielectric resonator.

7. The filter as claimed in claim 1, wherein, The first coupling structure is integrally connected to the resonator housing.

8. The filter as claimed in any one of claims 1-7, wherein, In the same first resonator, there are multiple first coupling structures, and the second coupling part of each first coupling structure is disposed on one side of the first coupling part along the counterclockwise direction, or the second coupling part of each first coupling structure is disposed on one side of the first coupling part along the clockwise direction.

9. The filter as claimed in claim 8, wherein, Each of the first coupling structures is replicated by rotating around the central axis of the dielectric resonator.

10. The filter as claimed in any one of claims 1-7, wherein, The first coupling structure changes the coupling polarity between the TE mode and the TM mode of the first resonator by placing the second coupling part on one side of the first coupling part in a counterclockwise direction or on one side of the first coupling part in a clockwise direction.

11. The filter as claimed in any one of claims 1-7, wherein, The filter includes at least two resonators, and a coupling window connecting the interior of each other is provided between two adjacent resonators.

12. The filter as claimed in claim 11, wherein, At least one pair of adjacent resonators are a second resonator and a third resonator, the second resonator has a TE mode resonant mode, the third resonator has a TM mode resonant mode or a TEM mode resonant mode, and the coupling window between the second resonator and the third resonator is a first coupling window; The filter includes a second coupling structure with both ends grounded, at least a portion of which is located within the first coupling window. The second coupling structure couples the TE mode of the second resonator with the TM mode or TEM mode of the third resonator.

13. The filter as claimed in claim 12, wherein, The second coupling structure includes a third coupling part and a fourth coupling part that are bent and connected in sequence; The third coupling part is disposed in the first coupling window, or extends from the first coupling window into the second resonator. The third coupling part intersects the radial direction of the resonant element of the second resonator to couple the TE mode of the second resonator. The fourth coupling part is disposed inside the third resonator and intersects with the circumferential direction of the resonator element of the third resonator to couple the TM mode or TEM mode of the third resonator.

14. The filter of claim 12, wherein, The second coupling structure is disposed within the third resonator, and the second coupling structure intersects the circumferential direction of the resonator element of the third resonator to couple the TM mode or TEM mode of the third resonator; One end of the second coupling structure extends to the first coupling window and intersects the radial direction of the resonator of the second resonator to couple the TE mode of the second resonator.

15. The filter as claimed in claim 12, wherein, The second coupling structure is disposed in the first coupling window and intersects the center line connecting the second resonator and the third resonator; along the axial direction of the resonator of the third resonator, the second coupling structure is disposed on the same side as the connection end of the resonator of the third resonator.

16. The filter of claim 12, wherein, The second coupling structure is mirrored along the center line connecting the second resonator and the third resonator to reverse the coupling polarity between the TE mode of the second resonator and the TM or TEM mode of the third resonator.

17. The filter of claim 11, wherein, The filter includes a dielectric element disposed in the coupling window.

18. The filter of claim 17, wherein, The medium component has a columnar structure.

19. The filter of claim 18, wherein, The medium is a cuboid structure; Alternatively, the medium may be a cylindrical structure.

20. The filter of claim 17, wherein, The medium is a solid structure; Alternatively, the filter includes a coupling adjustment screw disposed on one side of the dielectric element along its own height direction, and the dielectric element has an opening on the side facing the coupling adjustment screw, the opening being corresponding to the coupling adjustment screw, and the opening allowing the coupling adjustment screw to pass through.

21. The filter of claim 17, wherein, The medium component is formed independently; And / or, the dielectric constant of the dielectric element is 30 to 40.

22. The filter of claim 17, wherein, At least one pair of adjacent resonators are a fourth resonator and a fifth resonator, the fourth resonator having a TE mode resonance mode, the fifth resonator having a TE mode resonance mode, and the TE modes of the fourth resonator and the fifth resonator being capacitively coupled to the dielectric through the coupling window.

23. The filter of claim 17, wherein, At least one pair of adjacent resonators are a sixth resonator and a seventh resonator, wherein the sixth resonator has a TM mode resonant mode or a TEM mode resonant mode, and the seventh resonator has a TM mode resonant mode or a TEM mode resonant mode. The TM or TEM mode of the sixth resonator is inductively coupled to the TM or TEM mode of the seventh resonator through the coupling window, and the coupling strength between them is adjusted by the dielectric material; or, the TM or TEM mode of the sixth resonator is capacitively coupled to the TM or TEM mode of the seventh resonator through the dielectric material.

24. The filter of claim 11, wherein, At least one pair of adjacent resonators are a fourth resonator and a fifth resonator, wherein the fourth resonator has a TE mode resonant mode and the fifth resonator has a TE mode resonant mode; The filter includes a third coupling structure disposed in the coupling window between the fourth resonator and the fifth resonator, and couples the TE mode of the fourth resonator with the TE mode of the fifth resonator.

25. The filter of claim 24, wherein, The third coupling structure includes a connecting part, a fifth coupling part bent and connected to one end of the connecting part, and a sixth coupling part bent and connected to the other end of the connecting part. The fifth coupling portion and the sixth coupling portion are bent toward the same side of the connecting portion; Alternatively, the fifth coupling portion may be bent toward one side of the connecting portion, and the sixth coupling portion may be bent toward the other side of the connecting portion.

26. The filter of claim 11, wherein, At least one pair of adjacent resonators are a sixth resonator and a seventh resonator, wherein the sixth resonator has a TM mode resonant mode or a TEM mode resonant mode, and the seventh resonator has a TM mode resonant mode or a TEM mode resonant mode. The filter includes a fourth coupling structure disposed in the coupling window between the sixth resonator and the seventh resonator, and couples the TM mode or TEM mode of the sixth resonator with the TM mode or TEM mode of the seventh resonator.

27. The filter of claim 26, wherein, The fourth coupling structure is a coupling rib with both ends grounded, which enables the TM mode or TEM mode of the sixth resonator to be inductively coupled to the TM mode or TEM mode of the seventh resonator.

28. The filter of claim 26, wherein, The fourth coupling structure is a flying rod, which capacitively couples the TM mode or TEM mode of the sixth resonator with the TM mode or TEM mode of the seventh resonator.

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