A dielectric resonator

Abstract

The application provides a dielectric resonator, comprising: a dielectric resonant cavity, the dielectric resonant cavity comprising a solid dielectric body and a metal plating layer wrapping an outer surface of the dielectric body; a capacitively loaded structure embedded in the dielectric body, and an end surface of the capacitively loaded structure being in contact with the metal plating layer of a surface of the dielectric resonant cavity, the capacitively loaded structure having a cross section with an area greater than that of the end surface; and a quality factor of the dielectric resonator being related to a volume-surface ratio of the capacitively loaded structure.

Description

Technical Field

[0001] This invention relates to the field of filters, and in particular to a dielectric resonator. Background Technology

[0002] In existing dielectric waveguide filters, to push out higher-order modes and reduce frequencies, rectangular waveguide resonators are used, with a semi-blind aperture at the center of the resonator. This semi-blind aperture has a cross-section consistent with the shape and area of ​​the aperture on the resonator surface, and its depth is close to half the resonator's diameter. However, as the depth of the semi-blind aperture increases, the resonator's quality factor (Q value) deteriorates sharply.

[0003] Alternatively, existing technologies may employ a stepped via at the center of the resonator to form the TM mode, thereby optimizing higher-order modes. However, similar to the semi-blind via loading structure, it also suffers from an unsatisfactory Q value. Summary of the Invention

[0004] To address the above technical problems, this invention provides a dielectric resonator that improves the quality factor of the resonator by forming a capacitor loading structure inside the resonator with a cross-sectional area larger than the area of ​​the opening, thereby increasing the distributed parameter capacitance.

[0005] One embodiment provides a dielectric resonator, comprising:

[0006] A dielectric resonant cavity, comprising a solid dielectric body and a metal plating layer covering the outer surface of the dielectric body;

[0007] A capacitor loading structure is embedded in the dielectric body, and its end face is in contact with the metal plating layer on the surface of the dielectric resonant cavity to form an opening on the surface of the dielectric resonant cavity. The capacitor loading structure has a cross-section with an area larger than the area of ​​the end face.

[0008] The quality factor of the dielectric resonator is related to the volume-to-surface ratio of the capacitively loaded structure.

[0009] In one embodiment, the cross-sectional area of ​​the capacitor-loaded structure gradually increases in its height direction.

[0010] In one embodiment, the cross-sectional area of ​​the capacitor-loaded structure increases in a stepwise manner along its height.

[0011] In one embodiment, the capacitor loading structure has a first capacitor loading structure and a second capacitor loading structure arranged sequentially along the height direction.

[0012] One end of the first capacitor loading structure is the end face, and the second capacitor loading structure is connected to the other end of the first capacitor loading structure. The cross-sectional area of ​​the second capacitor loading structure is larger than that of the first capacitor loading structure.

[0013] In one embodiment, both the first capacitor loading structure and the second capacitor loading structure are cylindrical in shape, and the height direction of the first capacitor loading structure is consistent with the height direction of the capacitor loading structure.

[0014] In one embodiment, the axial directions of the first capacitor loading structure and the second capacitor loading structure are aligned, and the cross-sectional area of ​​the second capacitor loading structure is larger than the cross-sectional area of ​​the first capacitor loading structure.

[0015] In one embodiment, the axes of the first capacitor loading structure and the second capacitor loading structure are perpendicular, and the area of ​​the longitudinal section of the second capacitor loading structure is greater than the area of ​​the cross section of the first capacitor loading structure.

[0016] In one embodiment, the capacitor loading structure is a solid metal structure.

[0017] In one embodiment, the capacitor loading structure is a hollow structure with a metal layer covering its surface, and the capacitor loading structure is filled with a dielectric.

[0018] As can be seen from the above technical solutions, in this embodiment, the capacitor loading structure is disposed within the dielectric body, and it is only connected to the metal plating layer on the surface of the dielectric body through one end face, thereby forming a blind hole in the dielectric resonant cavity. However, unlike the traditional blind hole with a constant diameter, the portion of the capacitor loading structure located inside the resonator in this embodiment has a cross-sectional area larger than that of the end face (i.e., the opening on the surface of the resonant cavity). That is, the capacitor loading structure tends to increase in volume along its height direction from the end face towards the interior of the dielectric resonant cavity, and correspondingly, the capacitor loading structure also tends to increase in surface area along its height direction from the end face towards the interior of the dielectric resonant cavity.

[0019] Compared to traditional capacitive coupling structures, the capacitor-loaded structure 20 in this embodiment increases the distributed parameter capacitance, thereby improving the quality factor (Q value) and reducing losses. In this way, the volume of the dielectric resonator can be reduced while achieving the same unloaded Q value and the same frequency; or, with the same volume and frequency of the dielectric resonator, the unloaded Q value of the dielectric resonator can be increased. Attached Figure Description

[0020] The following figures are for illustrative purposes only and do not limit the scope of the invention.

[0021] Figure 1 This is a schematic diagram of the structure of the first embodiment of the dielectric resonator of the present invention.

[0022] Figure 2 yes Figure 1 A schematic diagram of the capacitor loading structure in the diagram.

[0023] Figure 3 This is a schematic diagram of the structure of the second embodiment of the dielectric resonator of the present invention.

[0024] Figure 4 yes Figure 3 A schematic diagram of the capacitor loading structure in the diagram. Detailed Implementation

[0025] To provide a clearer understanding of the technical features, objectives, and effects of the invention, specific embodiments of the invention are now described with reference to the accompanying drawings, in which the same reference numerals denote the same parts.

[0026] In this document, “illustrative” means “serving as an example, illustration or description”, and any illustration or implementation described herein as “illustrative” should not be construed as a more preferred or advantageous technical solution.

[0027] To keep the drawings concise, only the parts relevant to the invention are shown in each figure, and do not represent the actual structure of the product. Furthermore, to facilitate understanding, in some figures, only one of the components with the same structure or function is shown schematically, or only one is labeled.

[0028] In this article, terms such as "up," "down," "front," "back," "left," and "right" are used only to indicate the relative positional relationship between related parts, rather than to define the absolute position of these related parts.

[0029] In this article, "first," "second," etc., are used only to distinguish one another, and not to indicate degree of importance, order, or prerequisite for each other.

[0030] In this document, terms such as "equal" and "same" are not strict mathematical and / or geometric limitations, but also include errors that are understandable to those skilled in the art and permissible in manufacturing or use. Unless otherwise stated, numerical ranges in this document include not only the entire range within its two endpoints, but also several subranges contained therein.

[0031] The exemplary embodiments will now be described more fully with reference to the accompanying drawings.

[0032] To address the problems in the prior art, the present invention provides a dielectric resonator that improves the quality factor of the resonator by forming a capacitor loading structure inside the resonator with a cross-sectional area larger than the area of ​​the opening, thereby increasing the distributed parameter capacitance.

[0033] like Figure 1 As shown, one embodiment of the present invention provides a dielectric resonator 1, comprising:

[0034] The dielectric resonant cavity 10 includes a solid dielectric body and a metal plating layer that surrounds the outer surface of the dielectric body.

[0035] The capacitor loading structure 20 is embedded in the dielectric body, and its end face 21 is in contact with the metal plating on the surface of the dielectric resonant cavity 10 to form an opening on the surface of the dielectric resonant cavity 10. The capacitor loading structure 20 has a cross-section with an area larger than that of the end face 21.

[0036] In this embodiment, the height direction of the capacitor loading structure 20 is perpendicular to the end face 21, and the end face 21 can serve as either the bottom or top surface of the capacitor loading structure 20. The cross-section of the capacitor loading structure referred to herein can also be any cross-section parallel to the end face 21.

[0037] In this embodiment, the capacitor loading structure 20 is disposed within the dielectric body, and it is only connected to the metal plating on the surface of the dielectric body through one end face 21, thereby forming a blind hole in the dielectric resonant cavity 10. However, unlike the conventional blind hole with a constant diameter, the portion of the capacitor loading structure 20 located inside the resonator in this embodiment has a cross-sectional area larger than that of the end face 21 (i.e., the opening on the surface of the resonant cavity 10). That is, the capacitor loading structure 20 tends to increase in volume along its height direction from the end face 21 toward the interior of the dielectric resonant cavity 10, and correspondingly, the capacitor loading structure 20 also tends to increase in surface area along its height direction from the end face 21 toward the interior of the dielectric resonant cavity 10.

[0038] Compared to traditional capacitive coupling structures, the capacitor-loaded structure 20 in this embodiment increases the distributed parameter capacitance, thereby improving the quality factor (Q value) and reducing losses. In this way, the volume of the dielectric resonator can be reduced while achieving the same unloaded Q value and the same frequency; or, with the same volume and frequency of the dielectric resonator, the unloaded Q value of the dielectric resonator can be increased.

[0039] The capacitor loading structure 20 is only connected to the surface of the dielectric resonant cavity with one end face, and the whole structure is embedded in the dielectric body, with no other position connected to the surface of the dielectric resonant cavity or other structures in the dielectric body.

[0040] For example, in such Figure 1 In the illustrated embodiment, the dielectric body further includes a recessed adjustment hole 30. Preferably, the adjustment hole 30 and the end face 21 are respectively disposed on a pair of opposite surfaces of the dielectric body, and the other end of the capacitor loading structure 20 opposite to the end face 21 is connected to the adjustment hole 30, but with a certain distance.

[0041] Furthermore, the volume of the capacitor loading structure 20 is not infinitely large, because the surface area of ​​the capacitor loading structure 20 is the main factor affecting the distributed parameter capacitance, and the setting of the capacitor loading structure reduces the volume of the dielectric body, which will also increase the loss of the dielectric resonator.

[0042] Thus, in one embodiment, the quality factor of the dielectric resonator 1 is related to the volume surface ratio of the capacitively loaded structure 20.

[0043] Specifically, the smaller the volume surface area of ​​the capacitor-loaded structure 20, the larger its unloaded Q value. Therefore, the shape of the capacitor-loaded structure 20 should be chosen with a smaller volume surface area to achieve a balance between increasing losses and improving the distributed parameter capacitance.

[0044] In one embodiment, the cross-sectional area of ​​the capacitor loading structure 20 gradually increases in its height direction. Taking the capacitor loading structure 20 being in contact with the bottom surface of the dielectric resonant cavity 10 as an example, the capacitor loading structure 20 is formed into an inverted conical structure.

[0045] Optionally, the increasing trend of the cross-sectional area of ​​the capacitor loading structure 20 in its height direction can be continuous or stepped.

[0046] For example, such as Figure 1 and Figure 2 As shown, the capacitor loading structure 20 has a first capacitor loading structure 22 and a second capacitor loading structure 23 arranged sequentially along the height direction.

[0047] In this structure, one end of the first capacitor loading structure 22 is an end face 21, and the second capacitor loading structure 23 is connected to the other end of the first capacitor loading structure 22. The cross-sectional area of ​​the second capacitor loading structure 23 is larger than the cross-sectional area of ​​the first capacitor loading structure 22.

[0048] In this embodiment, the first capacitor loading structure 22 may have a consistent cross-sectional shape in the height direction of the entire capacitor loading structure 20. Similarly, the second capacitor loading structure 23 may have a consistent cross-sectional shape in the height direction of the entire capacitor loading structure 20, and the cross-sectional area of ​​the second capacitor loading structure 23 is greater than the cross-sectional area of ​​the first capacitor loading structure 22.

[0049] Therefore, in this embodiment, the second capacitor loading structure 23 is used to increase the volume-to-surface ratio of the capacitor loading structure 20. This two-stage combined structure can both increase the distributed parameter capacitance and facilitate processing and manufacturing.

[0050] Among commonly used object shapes, the cylinder is a structure that is easy to manufacture and has a relatively small surface area. Therefore, in one embodiment, such as Figure 1 and Figure 2 As shown, both the first capacitor loading structure 22 and the second capacitor loading structure 23 are cylindrical in shape, and the height direction of the first capacitor loading structure 22 is consistent with the height direction of the capacitor loading structure 20.

[0051] Among them, in such Figure 1 and Figure 2 In the embodiment shown, the axial directions of the first capacitor loading structure 22 and the second capacitor loading structure 23 are aligned, and the cross-sectional area of ​​the second capacitor loading structure 23 is larger than the cross-sectional area of ​​the first capacitor loading structure 22.

[0052] The cross-section of a cylinder is perpendicular to its height direction (axial direction). In this case, Figure 1 and Figure 2 In the illustrated embodiment, the first capacitor loading structure 22 and the second capacitor loading structure 23 can be coaxial or non-coaxial, as long as they are connected to form an integral structure.

[0053] Optionally, since the second capacitor loading structure 23 is used to provide an increased volume surface area ratio of the capacitor loading structure 20, the shape of the capacitor loading structure can be selected such that only the second capacitor loading structure 23 is cylindrical.

[0054] In one specific embodiment, the performance parameters of the dielectric resonator with the increased cross-sectional area capacitive loading structure of this embodiment, compared with the existing semi-blind hole resonator with the same cross-sectional area and aperture area, are shown in the table below:

[0055] Table 1

[0056]

[0057] As can be seen from Table 1, under the same unloaded Q value and frequency conditions, the dielectric resonator with the capacitor-loaded structure of this embodiment, which has an increased cross-sectional area, can reduce the overall volume of the resonator by nearly 36% and push out higher-order modes, which has a significant impact on improving the performance of the resonator in all aspects.

[0058] In such Figure 3 and Figure 4In one embodiment shown, the axes of the first capacitor loading structure 22 and the second capacitor loading structure 23 are perpendicular, and the area of ​​the longitudinal section of the second capacitor loading structure 23 is greater than the area of ​​the cross section of the first capacitor loading structure 22.

[0059] The longitudinal section of the cylinder is a section passing through the central axis of the cylinder. Similarly, the axis of the second capacitor loading structure 23 may not intersect with the axis of the first capacitor loading structure 22, and the cylinder of the second capacitor loading structure does not need to be tangent to the cylinder of the first capacitor loading structure.

[0060] exist Figures 1 to 4 In any of the embodiments shown, the capacitor loading structure 20 can be a solid metal structure. When its end face 21 is in contact with the surface of the dielectric resonant cavity 10, a surface overlapping with it is also formed on the surface of the dielectric resonant cavity 10. Furthermore, the metal of the capacitor loading structure 20 can be the same as or different from the metal layer on the surface of the dielectric resonant cavity 10.

[0061] Optionally, the capacitor loading structure 20 can be a hollow structure with a metal layer covering its surface, and the cavity of the capacitor loading structure 20 can be filled with a dielectric, such as air or other media. When its end face 21 is in contact with the surface of the dielectric resonant cavity 10, there is an opening on the surface of the dielectric resonant cavity 10.

[0062] As can be seen from the above technical solutions, in this embodiment, the capacitor loading structure is disposed within the dielectric body, and it is only connected to the metal plating layer on the surface of the dielectric body through one end face, thereby forming a blind hole in the dielectric resonant cavity. However, unlike the traditional blind hole with a constant diameter, the portion of the capacitor loading structure located inside the resonator in this embodiment has a cross-sectional area larger than that of the end face (i.e., the opening on the surface of the resonant cavity). That is, the capacitor loading structure tends to increase in volume along its height direction from the end face towards the interior of the dielectric resonant cavity, and correspondingly, the capacitor loading structure also tends to increase in surface area along its height direction from the end face towards the interior of the dielectric resonant cavity.

[0063] Compared to traditional capacitive coupling structures, the capacitor-loaded structure 20 in this embodiment increases the distributed parameter capacitance, thereby improving the quality factor (Q value) and reducing losses. In this way, the volume of the dielectric resonator can be reduced while achieving the same unloaded Q value and the same frequency; or, with the same volume and frequency of the dielectric resonator, the unloaded Q value of the dielectric resonator can be increased.

[0064] Under the same unloaded Q value and frequency conditions, the dielectric resonator with the capacitor-loaded structure of this embodiment, which has an increased cross-sectional area, can reduce the overall volume of the resonator by nearly 36% and push out higher-order modes, which has a significant impact on improving the performance of the resonator in all aspects.

[0065] The detailed descriptions listed above are merely specific descriptions of feasible embodiments of the present invention and are not intended to limit the scope of protection of the present invention. All equivalent implementation schemes or modifications made without departing from the spirit of the present invention, such as combinations, divisions or repetitions of features, should be included within the scope of protection of the present invention.

Claims

1. A dielectric resonator (1), characterized in that, include: The dielectric resonant cavity (10) includes a solid dielectric body and a metal plating layer that surrounds the outer surface of the dielectric body; A capacitor loading structure (20) is embedded in the dielectric body, and its end face (21) is in contact with the metal plating on the surface of the dielectric resonant cavity (10) to form an opening on the surface of the dielectric resonant cavity (10). The capacitor loading structure (20) has a cross-section with an area larger than that of the end face (21). The capacitor loading structure (20) has a first capacitor loading structure (22) and a second capacitor loading structure (23) arranged sequentially along the height direction. One end of the first capacitor loading structure (22) is the end face (21), and the second capacitor loading structure (23) is connected to the other end of the first capacitor loading structure (22). The cross-sectional area of ​​the second capacitor loading structure (23) is greater than the cross-sectional area of ​​the first capacitor loading structure (22). The first capacitor loading structure (22) and the second capacitor loading structure (23) are both cylindrical in shape, and the height direction of the first capacitor loading structure (22) is consistent with the height direction of the capacitor loading structure (20). The axes of the first capacitor loading structure (22) and the second capacitor loading structure (23) are perpendicular, and the area of ​​the longitudinal section of the second capacitor loading structure (23) is greater than the area of ​​the cross section of the first capacitor loading structure (22). The quality factor of the dielectric resonator (1) is related to the volume-to-surface ratio of the capacitor-loaded structure (20).

2. The dielectric resonator (1) according to claim 1, characterized in that, The cross-sectional area of ​​the capacitor-loaded structure (20) gradually increases in its height direction.

3. The dielectric resonator (1) according to claim 1, characterized in that, The cross-sectional area of ​​the capacitor loading structure (20) increases in a stepwise manner in its height direction.

4. The dielectric resonator (1) according to claim 1, characterized in that, The first capacitor loading structure (22) and the second capacitor loading structure (23) are aligned in the same direction, and the cross-sectional area of ​​the second capacitor loading structure (23) is greater than the cross-sectional area of ​​the first capacitor loading structure (22).

5. The dielectric resonator (1) according to any one of claims 1 to 4, characterized in that, The capacitor loading structure (20) is a solid metal structure.

6. The dielectric resonator (1) according to any one of claims 1 to 4, characterized in that, The capacitor loading structure (20) is a hollow structure with a metal layer on its surface, and the capacitor loading structure (20) is filled with a dielectric.

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