Port coupling structures and filters
By adopting a port coupling structure of grooves and through holes in the dielectric filter, the problems of fragility and high production difficulty in the existing technology are solved, and the high bandwidth application and mass production of dielectric filters are achieved. Reduces costs and improves product consistency.
Patent Information
- Application Number
- CN202110807120.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2021-07-16
- Publication Date
- 2024-12-31
- Estimated Expiration
- 2041-07-16
AI Technical Summary
The existing dielectric filter port coupling schemes have problems such as fragile structure, high difficulty in forming and production processes, high cost, and unadjustable coupling strength under high bandwidth conditions, resulting in poor product consistency and low debugging yield.
Using a port coupling structure including a groove and a through hole, the groove extends from the first surface of the medium body to the frequency-tuning blind hole, the through hole extends from the bottom of the groove to the second surface, and is provided with an insulating ring and a metal lead to achieve Flexible adjustment of coupling strength avoids thin and brittle structures and complex molding methods.
It realizes the application of high bandwidth of dielectric filters, avoids cracking and hidden cracking problems, reduces production difficulty and cost, improves product consistency and debugging pass rate, and is suitable for mass production.
Smart Images
Figure CN113451726B_ABST
Abstract
Description
Technical Field
[0001] The invention relates to a communication device, and in particular to a filter port coupling technology. Background Art
[0002] With the construction of 5G communication systems, the integration requirements of its equipment are getting higher and higher. The miniaturization and lightweight of microwave filters are the future application trends. Dielectric waveguide filters can greatly reduce the size of products, and have the advantages of high Q value and small temperature drift, which is a good miniaturization solution.
[0003] Signal transmission between the signal source (input and output ports) and the filter is achieved through a port coupling structure. The strength of this coupling is positively correlated with the bandwidth of the filter, that is, the wider the filter passband, the stronger the required port coupling. There are two main port coupling schemes for existing dielectric filters. The first scheme is as follows Figure 4 As shown, the dielectric filter generally uses a small blind hole 22 on the back of the tuning blind hole 21 to achieve capacitive port coupling, and sends the signal from the port to the first cavity resonator through the small blind hole. Figure 5 As shown, the port coupling of the dielectric filter can also be achieved by providing a through hole 32 between the side surface of the dielectric filter and the side surface of the tuning blind hole 31 .
[0004] For the first solution in the prior art, when the filter bandwidth is wide, the required port coupling strength will make the small blind hole deeper, and its bottom will be very close to the bottom of the tuning blind hole. On the one hand, the position between the two holes will be very fragile, and cracks or perforations will easily occur during the molding process. Subsequent SMT, debugging and other process links and long-term use will also easily cause fractures and perforations at this position. On the other hand, the deeper small blind hole will bring problems such as the life of the mold core rod and the reliability of the press demolding during the dry pressing molding process.
[0005] For the second solution in the prior art, the holes on the side cannot be formed by dry pressing, and ceramics can be made by injection molding, which is a high-cost molding method. Or holes can be made by mechanical processing on the side of the dry-pressed ceramics, but due to the accumulation of errors such as positioning, clamping and processing accuracy during product processing, the production yield will be relatively low, the product consistency will be slightly worse, and the overall cost will increase.
[0006] In actual product debugging, the above two solutions cannot effectively and independently adjust the strength of port coupling. When the port coupling consistency between products is poor, the debugging yield rate will be significantly reduced. Summary of the invention
[0007] The technical problem to be solved by the present invention is to propose a port coupling structure and a communication base station which are easy to realize batch processing, have excellent coupling performance and adjustable coupling strength in view of the above-mentioned defects of the prior art.
[0008] The technical solution adopted by the present invention to solve the technical problem is:
[0009] A port coupling structure is provided, comprising a groove and a through hole intersecting on a dielectric body, wherein the groove is located on a first surface of the dielectric body and extends from a side wall of the dielectric body to be connected to a frequency tuning blind hole located on the first surface, and the through hole extends from a bottom of the groove to a second surface of the dielectric body opposite to the first surface.
[0010] Further:
[0011] The groove and the through hole intersect vertically.
[0012] An insulating ring area is arranged around one end of the through hole located on the second surface.
[0013] A metal lead or a pin is fixed in the through hole.
[0014] The frequency tuning blind holes and through holes are in the shape of a circular cylinder, an elliptical cylinder or a polygonal cylinder.
[0015] A filter is provided, comprising a dielectric body, a surface of which is provided with a frequency tuning blind hole, and the port coupling structure as described above.
[0016] Further:
[0017] There are eight frequency tuning blind holes arranged in two rows and four columns.
[0018] The first frequency tuning blind hole in the second row and the third frequency tuning blind hole in the second row are respectively connected to the groove of the port coupling structure.
[0019] Compared with the first solution in the prior art, the present invention does not have a brittle structure, and does not have the problems of cracking and perforation that may occur during molding and other production processes, nor does it have reliability problems in long-term use; it can flexibly achieve stronger coupling strength, and thus can be used to realize a wider bandwidth dielectric filter.
[0020] Compared with the second solution in the prior art, the present invention does not need to introduce complex molding methods or processes, avoiding the risk of additional mechanical processing causing hidden cracks inside the medium. At the same time, the production difficulty is lower, the product consistency is good, and it is suitable for mass production.
[0021] Furthermore, the port coupling strength of the present invention has better adjustability, the debugging process and the overall pass rate are higher, and the production cost can be reduced. BRIEF DESCRIPTION OF THE DRAWINGS
[0022] Figure 1is a schematic diagram of the three-dimensional structure of an embodiment of the port coupling structure of the present invention;
[0023] Figure 2 is a schematic diagram of the three-dimensional structure of a filter embodiment of the present invention;
[0024] Figure 3 is a schematic diagram of the far-end frequency response of the passband of a filter embodiment of the present invention;
[0025] Figure 4 It is a three-dimensional structural schematic diagram of the first solution of the dielectric filter port coupling structure in the prior art;
[0026] Figure 5 It is a three-dimensional structural schematic diagram of the second solution of the dielectric filter port coupling structure in the prior art. DETAILED DESCRIPTION
[0027] Now, the preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.
[0028] A port coupling structure is used to achieve the conduction and energy coupling of communication signals between the filter port and the resonator. Figure 1 As shown, the port coupling structure includes an intersecting groove 13 and a through hole 14 located on a dielectric body 10. In this embodiment, the dielectric body 10 is a square body, the groove 13 is located on the first surface 11 of the dielectric body 10, and extends from a side wall 17 of the dielectric body 10 to connect with the dielectric resonator frequency tuning blind hole 12 located on the first surface 11. The through hole 14 extends from the bottom of the groove 13 to the second surface 15 of the dielectric body 10 opposite to the first surface 11. The frequency tuning blind hole 12 extends from the first surface 11 to the direction of the second surface 15. An insulating ring area 16 is provided around one end of the through hole 14 located on the second surface 15, and the insulating ring area 16 is the location of the input port or output port of the dielectric filter. The surface of the dielectric body 10, except for the insulating ring area 16, is covered with a metal layer.
[0029] In some embodiments, a welded metal lead, a pin, etc. may be disposed in the through hole 14. The electromagnetic wave signal is conducted from the source (port) to the metallized through hole, causing a change in the electromagnetic field, thereby coupling energy into the dielectric resonator.
[0030] In some embodiments, the port coupling strength can be controlled by the size of the groove 13 provided on the dielectric body 10 during molding. During actual product production and debugging, the port coupling strength can be adjusted by grinding the metal layer on the surface of the groove and the through hole.
[0031] In some embodiments, the frequency tuning blind holes and through holes may be in the shape of a cylinder such as a circle, an ellipse or a polygon.
[0032] Since the port coupling structure includes intersecting grooves 13 and through holes 14, there are no brittle parts in the dielectric body, so there are no cracking or perforation problems that may occur during molding and other production processes, and there are no reliability problems in long-term use. At the same time, the production and processing does not require the introduction of complex molding methods or processes, avoiding the risk of hidden cracks in the dielectric caused by additional mechanical processing. The production difficulty is lower, the product consistency is good, and it is suitable for mass production. In addition, the strength of the port coupling structure has better adjustability, and a stronger coupling strength can be flexibly achieved. The debugging process and the overall pass rate are higher, which can reduce production costs.
[0033] The dielectric filter including the above-mentioned port coupling structure is described in detail below.
[0034] As shown in Figure 2, the dielectric filter 100 in this embodiment includes a dielectric body 10 with a silver-plated outer layer. Eight dielectric resonators numbered 1 to 8 are arranged on the dielectric body. Coupling windows are arranged between the dielectric resonators, and capacitive coupling structures and inductive coupling structures are arranged in the corresponding open coupling windows. The frequency tuning blind holes of each resonator are located on the first surface of the dielectric body 10. The frequency is adjusted by removing the silver layer on the surface of the dielectric body, and the coupling between the resonators is adjusted by removing the metallization layer of the coupling window. The serial numbers of the dielectric resonators are arranged according to the signal transmission order.
[0035] Among the eight dielectric resonators, resonator 1 and resonator 8 are provided with the above-mentioned port coupling structure, which includes intersecting grooves 13 and through holes 14. Resonator 1 and resonator 8 and the port coupling structure form the input and output port structure of the filter. The eight frequency tuning blind holes are arranged in two rows and four columns, and the first frequency tuning blind hole in the second row (the frequency tuning blind hole of resonator 1) and the third frequency tuning blind hole in the second row (the frequency tuning blind hole of resonator 8) are connected to the groove of the port coupling structure. The port coupling strength can be controlled by the size of the groove 13 set on the dielectric body 10 during molding. During molding, the port coupling strength is adjusted by controlling the size of the groove 13 set on the dielectric body 10; during actual product production and debugging, the port coupling strength can be adjusted by grinding the metal layer on the surface of the groove and the through hole, so as to achieve the port coupling pre-amplitude required for the frequency response of the filter.
[0036] This filter realizes a total of 6 transmission zeros, as shown in 3, of which 3 transmission zeros are located close to the filter passband, thereby achieving the near-end strong suppression index requirement. Due to the coupling between resonator 3 and resonator 8, the coupling between the two ports of this filter enables the filter to generate an additional pair of controllable transmission zeros (located at 2.15GHz and 3.03GHz), further enhancing the filter's out-of-band suppression. The coupling structure of this technical solution is simple to implement, easy to process, and convenient for mass production.
[0037] The filter using the port coupling structure is not limited to the number of resonators, the number of transmission zeros and the topological structure. The resonator frequency tuning blind hole is not limited to being set on a single surface or the upper surface, and can be all single-sided, partly double-sided or all double-sided.
[0038] A filter comprises any port coupling structure as described above.
[0039] It should be understood that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. For those skilled in the art, the technical solutions described in the above embodiments can be modified, or some of the technical features therein can be replaced by equivalents; and these modifications and replacements should all fall within the scope of protection of the claims attached to the present invention.
Claims
1. A port coupling structure, characterized in that: The invention comprises a groove and a through hole which intersect each other on a dielectric body. The groove is located on a first surface of the dielectric body and extends from a side wall of the dielectric body to be connected with a frequency tuning blind hole located on the first surface. The through hole extends from a bottom of the groove to a second surface of the dielectric body opposite to the first surface.
2. The port coupling structure according to claim 1, characterized in that: The groove and the through hole intersect vertically.
3. The port coupling structure according to claim 1, characterized in that: An insulating ring area is arranged around one end of the through hole located on the second surface.
4. The port coupling structure according to claim 1, characterized in that: A metal lead or a pin is fixed in the through hole.
5. The port coupling structure according to claim 1, characterized in that: The frequency tuning blind holes and through holes are in the shape of a circular cylinder, an elliptical cylinder or a polygonal cylinder.
6. A filter, comprising a dielectric body, wherein a frequency tuning blind hole is provided on the surface of the dielectric body, characterized in that: It also includes the port coupling structure according to any one of claims 1 to 5.
7. The filter according to claim 6, characterized in that: There are eight frequency tuning blind holes arranged in two rows and four columns.
8. The filter according to claim 7, characterized in that: The first frequency tuning blind hole in the second row and the third frequency tuning blind hole in the second row are respectively connected to the groove of the port coupling structure.