A resonator and a combined filter
The resonator, designed with a double-ended open-circuit structure, solves the problem of excessively short resonator length at high frequencies, thereby reducing processing difficulty and improving product quality stability, making it suitable for industrial mass production.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- SUZHOU JAPIN TECH CO LTD
- Filing Date
- 2025-06-26
- Publication Date
- 2026-07-17
AI Technical Summary
In existing technologies, as the resonant frequency increases, the dielectric constant of the ceramic powder cannot be further reduced, resulting in a resonator that is too short, difficult to manufacture, and unsuitable for industrial mass production.
The resonator with a double-ended open-circuit structure can achieve a resonant frequency of half the wavelength. Increasing the length and thickness of the through-hole of the resonator reduces the difficulty of processing and facilitates processing and control accuracy.
Under the premise of the same resonant frequency, the length and thickness of the through hole of the resonator have been increased, the processing difficulty has been reduced, the product quality has been ensured to meet the requirements, and it is suitable for industrial mass production.
Smart Images
Figure CN224520168U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of filter technology, and in particular to a resonator and a combined filter. Background Technology
[0002] Ceramic resonators are widely used in filters, oscillators, sensors, and other fields. Length control is a key parameter in the design and manufacturing of ceramic resonators, directly affecting their resonant frequency, temperature stability, and performance. When the length of a ceramic resonator decreases, the resonant frequency increases; conversely, the frequency decreases. Therefore, precisely controlling the resonator length is the core method for tuning the target frequency. Traditionally, this involves precisely cutting the ceramic blank to ensure length tolerances; compensation for shrinkage during sintering: ceramic materials shrink during sintering, requiring pre-designing the blank dimensions to compensate for the length change after sintering (adjusted through material formulation and process experience); and then grinding and polishing. After sintering, mechanical or chemical polishing is used to fine-tune the dimensions to achieve the target frequency. As an essential component in the manufacture of ceramic filters, the resonant frequency of a ceramic resonator is inversely proportional to the dielectric constant of the ceramic and inversely proportional to the length of the through-hole. For higher frequencies, ceramic powders with lower dielectric constants are generally selected to prepare the ceramic matrix, thus addressing the problem of inconvenient manufacturing processes for excessively short lengths.
[0003] However, the shortcomings of the existing technology are that as the frequency of the resonator increases, the dielectric constant of the ceramic powder cannot be lowered further (generally around 9). At this point, the length of the resonator will be very short, that is, the thickness of the resonator will be very thin, which makes the processing more difficult and is not convenient for industrial mass production. Utility Model Content
[0004] Therefore, the technical problem to be solved by this utility model is to overcome the shortcomings of the prior art and provide a resonator and a combined filter. The resonator adopts a double-ended open-circuit structure design. Compared with the prior art, it can make the thickness of the resonator larger and the length of the hole longer under the premise of the same resonant frequency, thereby reducing the processing difficulty, facilitating processing, and making it suitable for industrial mass production.
[0005] To solve the above-mentioned technical problems, this utility model provides a resonator, comprising,
[0006] The substrate has a first metal layer attached to its surface;
[0007] Ground surface, which is disposed on the substrate;
[0008] An electrode surface is disposed on the substrate;
[0009] The circuit printing surface includes a first end face and a second end face, the first end face being insulated and disposed on the substrate; the second end face being insulated and disposed on the substrate, and the second end face being opposite to the first end face;
[0010] A resonant cavity unit includes a through hole disposed in the substrate, one end of the through hole being connected to the first end face and the other end of the through hole being connected to the second end face.
[0011] In one embodiment of this utility model, the resonant cavity unit is disposed at the geometric center of the substrate.
[0012] In one embodiment of the present invention, the resonant cavity unit includes a plurality of through holes, which are spaced apart on the substrate.
[0013] In one embodiment of this utility model, a second metal layer is provided on the inner wall of the through hole.
[0014] In one embodiment of the present invention, the second metal layer includes a silver layer.
[0015] In one embodiment of the present invention, the first metal layer includes a silver layer.
[0016] In one embodiment of this utility model, a first silver block is provided on the first end face. The first silver block is disposed around the through hole and is electrically connected to the through hole. The first silver block is insulated from the first metal layer.
[0017] In one embodiment of this utility model, a second silver block is provided on the second end face. The second silver block is disposed around the through hole and is electrically connected to the through hole. The second silver block is insulated from the first metal layer.
[0018] In one embodiment of this utility model, the projected shape of the through hole along the axial direction includes a circle and an ellipse.
[0019] This invention also provides a combined filter, including at least one resonator as described above.
[0020] The above-mentioned technical solution of this utility model has the following advantages compared with the prior art:
[0021] This invention discloses a resonator comprising a substrate, an electrode surface, a ground surface, a circuit printing surface, and a resonant cavity unit disposed on the substrate. The circuit printing surface includes a first end face and a second end face disposed opposite to each other on the substrate. The resonant cavity unit includes a through-hole penetrating the first and second end faces. The first end face is insulated from the substrate, and the second end face is also insulated from the substrate, thus forming a double-ended open-circuit filter structure. In existing single-ended open-circuit filters, the resonant frequency is typically a quarter wavelength. Compared to existing technologies, this invention achieves a resonant frequency of half a wavelength. Therefore, under the premise of the same resonant frequency, this invention can increase the length of the through-hole, thereby increasing the thickness of the resonator and allowing for a larger distance between the first and second end faces. This reduces the difficulty of manufacturing and makes the resonator easier to process. Furthermore, it minimizes deformation during processing, allowing for controlled processing precision, ensuring product quality meets requirements, and making it suitable for mass industrial production. Attached Figure Description
[0022] To make the content of this utility model easier to understand, the present utility model will be further described in detail below with reference to specific embodiments and accompanying drawings.
[0023] Figure 1 This is a front view of the end face of a single-ended open-circuit filter in the prior art (the shaded area is the metal layer).
[0024] Figure 2 This is a schematic diagram of the overall structure of the filter according to a preferred embodiment of the present invention.
[0025] Figure 3 yes Figure 2 Front view diagram.
[0026] Figure 4 yes Figure 2 Rear view diagram.
[0027] Figure 5 yes Figure 2 A front view diagram showing the through hole being set to an ellipse shape.
[0028] Figure 6 This is a schematic diagram of an embodiment of the filter of this utility model having multiple through holes.
[0029] Figure 7 This is a schematic diagram of an embodiment of the filter of this utility model, which includes a first silver block.
[0030] Figure 8 This is a schematic diagram of an embodiment of the filter of this utility model having multiple through holes and a first silver block.
[0031] Figure 9 This is a schematic diagram of the structure of the integrated filter according to a preferred embodiment of the present invention.
[0032] Explanation of reference numerals in the accompanying drawings: 1. Substrate; 11. First end face; 12. Second end face; 2. Through hole; 3. First silver block; 41. First through hole; 42. Second through hole; 43. Third through hole; 44. Fourth through hole; 45. Fifth through hole; 51. Third silver block; 52. Fourth silver block; 53. Fifth silver block; 54. Sixth silver block; 55. Seventh silver block. Detailed Implementation
[0033] The present invention will be further described below with reference to the accompanying drawings and specific embodiments, so that those skilled in the art can better understand and implement the present invention. However, the embodiments are not intended to limit the present invention.
[0034] The resonant frequency (fr) of a ceramic resonator is mainly determined by its physical dimensions and material properties. The formula for the resonant frequency is: fr ∝ V / 2L, where:
[0035] L is the length of the resonator, and also the dimension in the direction of vibration; v is the propagation speed of the sound wave in the ceramic material, which is usually determined by the material's elastic constant and density.
[0036] The formula for calculating the length L of the resonator is:
[0037] L=300000000000 / (4*f*1000000*SQRT(Er))
[0038] Where L is the length of the resonator; f is the resonant frequency; and Er is the dielectric constant of the ceramic powder. Example 1
[0039] Reference Figures 1 to 5 As shown, this utility model discloses a resonator, including a substrate 1, on the surface of which a first metal layer is attached. Specifically, the first metal layer can be formed on the substrate 1 by coating or wetting.
[0040] The resonator also includes a ground plane, which is disposed on the substrate 1;
[0041] The resonator further includes an electrode surface disposed on the substrate 1; preferably, the ground plane is opposite to the electrode surface.
[0042] Furthermore, the resonator also includes a circuit printing surface, which includes a first end face 11 and a second end face 12, wherein the first end face 11 is insulated from the substrate, or in other words, the first end face 11 and the first metal layer are mutually insulated.
[0043] The second end face 12 is insulated from the substrate 1, and the second end face 12 is opposite to the first end face 11;
[0044] Furthermore, the resonator also includes a resonant cavity unit, which includes a through hole 2 disposed through the substrate 1. One end of the through hole 2 is connected to the first end face 11, and the other end of the through hole 2 is connected to the second end face 12. It should be noted that the through hole 2 is electrically connected to both the first end face 11 and the second end face 12.
[0045] Therefore, it can be understood that the resonator protected by this utility model includes a substrate and electrode surfaces, ground surfaces, circuit printing surfaces, and resonant cavity units disposed on the substrate. The circuit printing surfaces include a first end face and a second end face disposed opposite to each other on the substrate. The resonant cavity unit includes a through-hole penetrating the first and second end faces. The first end face is insulated from the substrate, and the second end face is also insulated from the substrate, thus forming a double-ended open-circuit filter structure. In the prior art, the resonant frequency of a single-ended open-circuit filter is typically a quarter wavelength. Compared to the prior art, the resonant frequency of this utility model can reach half a wavelength. Therefore, under the premise of the same resonant frequency, this utility model can increase the length of the through-hole of the resonator, thereby increasing the thickness of the resonator and making the distance between the first and second end faces larger. This reduces the difficulty of manufacturing and processing, making the resonator easier to process. Simultaneously, it is less prone to deformation during processing, allowing for control of processing accuracy, ensuring product quality meets requirements, and making it suitable for mass industrial production.
[0046] In a preferred embodiment, the resonant cavity unit is located at the geometric center of the substrate 1. This arrangement ensures the symmetrical distribution of the electric and magnetic fields within the resonator, improving the purity of the master mode; and it also allows the resonant cavity to be located away from the physical boundary of the resonator, reducing energy loss caused by edge scattering, radiation, or conductor losses, thus reducing energy consumption.
[0047] In addition, combined Figure 5 As shown, the resonant cavity unit may further include a plurality of through holes 2, which are spaced apart on the substrate 1.
[0048] Preferably, a plurality of the through holes 2 are uniformly arranged in an array on the substrate to improve the uniformity of cross coupling.
[0049] Furthermore, a second metal layer is provided on the inner wall of the through hole 2.
[0050] In a preferred embodiment, the second metal layer includes, but is not limited to, a silver layer.
[0051] In a preferred embodiment, the first metal layer includes, but is not limited to, a silver layer.
[0052] In other embodiments, combined with Figure 7 As shown, the first end face 11 is provided with a first silver block 3, which is disposed around the through hole 2. The first silver block 3 is electrically connected to the through hole 2, and the first silver block 3 is insulated from the first metal layer.
[0053] In addition, refer to Figure 8 As shown, when there are multiple through holes 2, there are also multiple first silver blocks 3 to match the through holes 2.
[0054] Correspondingly, the second end face 12 is provided with a second silver block, which is disposed around the through hole 2. The second silver block is electrically connected to the through hole 2 and is insulated from the first metal layer.
[0055] In a preferred embodiment, the projected shape of the through hole 2 along the axial direction includes a circle and an ellipse.
[0056] Of course, in some other embodiments, the projection shape is not limited to a circle or an ellipse, but can be other shapes. Example 2
[0057] This utility model also discloses a combined filter, see reference. Figure 9 As shown, the integrated filter includes at least one resonator as described in Embodiment 1.
[0058] In a preferred embodiment, the integrated filter includes five resonators as described in Embodiment 1.
[0059] Specifically, the integrated filter has a third end face 13 and a fourth end face, which are open-circuit designed, meaning that no metal surface layer is attached to the third end face 13 and the fourth end face, and the third end face 13 and the fourth end face are insulated from other surfaces.
[0060] The resonant cavity unit of the integrated filter includes a first through-hole 41, a second through-hole 42, a third through-hole 43, a fourth through-hole 44, and a fifth through-hole 45; wherein, the two ends of the first through-hole 41 are respectively connected to the third end face 14 and the fourth end face; the two ends of the second through-hole 42 are respectively connected to the third end face 14 and the fourth end face; the two ends of the third through-hole 43 are respectively connected to the third end face 14 and the fourth end face; the two ends of the fourth through-hole 44 are respectively connected to the third end face 14 and the fourth end face; and the two ends of the fifth through-hole 45 are respectively connected to the third end face 14 and the fourth end face.
[0061] In a preferred embodiment, a third silver block 51, a fourth silver block 52, a fifth silver block 53, a sixth silver block 54, and a seventh silver block 55 are further provided at intervals on the third end face 13. The third silver block 51 is electrically connected to the first through hole 41, the fourth silver block 52 is electrically connected to the second through hole 42, the fifth silver block 53 is electrically connected to the third through hole 43, the sixth through hole 54 is electrically connected to the fourth through hole 44, and the seventh silver block 55 is electrically connected to the fifth through hole 45.
[0062] In the description of this utility model, it should be understood that the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this utility model, "a plurality of" means two or more, unless otherwise explicitly specified.
[0063] In this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. For those skilled in the art, the specific meaning of the above terms in this utility model can be understood according to the specific circumstances.
[0064] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the protection scope of this invention.
Claims
1. A resonator characterized by: include, The substrate has a first metal layer attached to its surface; Ground surface, which is disposed on the substrate; An electrode surface is disposed on the substrate; The circuit printing surface includes a first end face and a second end face, the first end face being insulated and disposed on the substrate; the second end face being insulated and disposed on the substrate, and the second end face being opposite to the first end face; A resonant cavity unit includes a through hole disposed in the substrate, one end of the through hole being connected to the first end face and the other end of the through hole being connected to the second end face.
2. A resonator as claimed in claim 1, characterised in that: The resonant cavity unit is located at the geometric center of the substrate.
3. A resonator as claimed in claim 1, characterised in that: The resonant cavity unit includes multiple through holes, which are spaced apart on the substrate.
4. A resonator as claimed in claim 1 or 3, characterised in that: A second metal layer is provided on the inner wall of the through hole.
5. A resonator as claimed in claim 4, characterised in that: The second metal layer includes a silver layer.
6. A resonator as claimed in claim 1, characterised in that: The first metal layer includes a silver layer.
7. A resonator as claimed in claim 1, characterised in that: The first end face is provided with a first silver block, which is disposed around the through hole and is electrically connected to the through hole. The first silver block is insulated from the first metal layer.
8. A resonator as claimed in claim 1 or 7, characterised in that: The second end face is provided with a second silver block, which is disposed around the through hole and is electrically connected to the through hole. The second silver block is insulated from the first metal layer.
9. The resonator of claim 1, wherein: The axial projection shape of the through hole includes circular and elliptical shapes.
10. A coupled filter, characterized by: It includes at least one resonator as described in any one of claims 1-9.