A ceramic dielectric block filter combined with a microstrip and its base station and satellite

Abstract

The application relates to a filter combining a ceramic dielectric block and a microstrip and a base station and satellite thereof. The filter comprises at least two resonators, and adjacent two resonators are coupled through a coupling structure; the resonator comprises a dielectric substrate, a microstrip structure comprising one metal strip and two metal strips, the metal strip is located between the two metal strips, and the metal strip and the metal strips are arranged on the upper surface of the dielectric substrate. The filter provided by the application is composed of a ceramic dielectric block and a microstrip structure, the advantages of the two are integrated together, and the advantages are taken and the disadvantages are made up. The high machining precision of the microstrip structure is used to realize the tuning-free of the filter. The microstrip structure is connected and integrated with other subsystems to realize high integration, meanwhile, the microstrip structure can be well combined with lumped elements, so that the filter can realize a wider bandwidth.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of filter, in particular to a filter combining ceramic dielectric block and microstrip and base station and satellite thereof. BACKGROUND

[0002] In recent years, with the rapid development of new generation mobile communication, satellite communication, Internet of Things, new generation integrated radar system and other wireless technologies, the overall communication equipment is rapidly developing in the direction of miniaturization, high density, low cost, high performance, low delay and low power consumption. With the wide application of large-scale MIMO technology, the number of channels in the wireless communication system is also increasing. In order to improve the signal-to-noise ratio, a filter will be added to each channel, resulting in a geometric increase in the number of filters, which puts forward more stringent requirements on the size and performance of the filter. Modern communication systems increasingly require integration and integration, with all systems integrated together, usually integrated on a PCB, and various devices are installed in the form of patches. In the previous communication system, due to the large size of the filter, it is usually placed separately outside and connected to other parts through a cable.

[0003] In the prior art, the microstrip filter has the advantages of light weight, wide frequency band, high reliability, high processing precision and low manufacturing cost. At the same time, the microstrip filter itself is a planar structure filter, which is manufactured by PCB processing technology and can be debugged in batch production. It can be well integrated with other parts of the system on the PCB board, but it has the disadvantages of low Q value, large loss and large size. Moreover, the dielectric constant of the dielectric material of the microstrip is usually small, usually around 4. While the ceramic dielectric filter in the prior art can greatly reduce the overall size of the filter and improve the Q value of the filter due to the internal filling of high dielectric constant (usually 20 or even higher) and low loss tangent ceramic material. However, it also has the disadvantages of narrow frequency band, high debugging difficulty, low processing precision and high processing cost. Moreover, the ceramic dielectric filter needs to be installed separately due to different placement positions, directions and sizes, which adds an extra process in production, which is not conducive to integration and integration. SUMMARY

[0004] Therefore, it is necessary to provide a new filter combining ceramic dielectric block and microstrip to integrate the advantages of both and make up for each other's shortcomings in view of the respective shortcomings of the microstrip filter and the ceramic dielectric filter in the prior art.

[0005] The present application is realized by the following technical scheme: a filter combining ceramic dielectric block and microstrip, comprising at least two resonators, adjacent two resonators are connected through a coupling structure to realize cross-coupling or non-cross-coupling filter response; the resonator comprises:

[0006] Medium substrate

[0007] Microstrip structure, comprising one metal strip and two metal strips, the metal strip is located between the two metal strips, the metal strip and the metal strips are fixed on the upper surface of the medium substrate

[0008] Ceramic medium block, comprising a ceramic block body and a metal cover layer, the metal cover layer is arranged on the upper surface, rear surface and two side surfaces of the ceramic block body, the metal cover layer located on the two side surfaces of the ceramic block body extends to the lower surface of the ceramic block body, forming two narrow band-shaped flanges, the two flanges are respectively fixedly connected with two metal strips, the metal cover layer located on the rear surface of the ceramic block body is in contact with the metal strip, constituting the short-circuit end of the resonator; the resonant frequency of the resonator is adjusted by changing the position of the ceramic medium block on the metal strip; when the resonator resonates, the electromagnetic field is concentrated in the ceramic medium block.

[0009] As a preferred example, the two ends of the coupling structure are respectively connected with two adjacent metal strips.

[0010] As a preferred example, the coupling structure is a lumped element or an interdigital capacitor.

[0011] As a preferred example, in the two adjacent resonators, the two metal strips close to each other are in contact with each other to form an integral whole.

[0012] As a preferred example, the resonator is a quarter-wave resonator.

[0013] As a preferred example, the metal strip is in a T-shaped structure with a wide upper part and a narrow lower part; the ceramic medium block is any one of a cuboid, a square and a trapezoidal body.

[0014] As a preferred example, the two metal strips are symmetrically distributed about the metal strip as an axis, and the metal strip and the metal strips are both arranged to be grounded.

[0015] As a preferred example, the filter further comprises a metal feed line, the metal feed line is connected with the middle part of the metal strips of the first and last resonators; or, the metal feed line is connected with the open end of the metal strips of the first and last resonators.

[0016] A base station employing the filter combining the ceramic medium block and the microstrip as described above.

[0017] A satellite employing the filter combining the ceramic medium block and the microstrip as described above.

[0018] The present application has the following advantages:

[0019] 1. This invention provides a filter composed of a ceramic dielectric block and a microstrip structure, integrating the advantages of both to compensate for their respective shortcomings. The high fabrication precision of the microstrip structure enables adjustment-free operation of the filter. The microstrip structure is integrated with other subsystems to achieve high integration, and it can also be well integrated with lumped elements, resulting in a wider achievable bandwidth for the filter. The small size and high Q value of the ceramic dielectric block significantly reduce the overall size and insertion loss of the filter.

[0020] 2. The filter provided by this invention has the same size ceramic dielectric block, simple structure, and low processing requirements, which greatly reduces the manufacturing cost and makes it suitable for mass production. Attached Figure Description

[0021] Figure 1 A schematic diagram of the resonator provided by the present invention from a front-view perspective;

[0022] Figure 2 for Figure 1 A schematic diagram of the structure of the mid-resonator from a rear-view top angle;

[0023] Figure 3 for Figure 1 Schematic diagram of the explosion decomposition of the intermediate resonator;

[0024] Figure 4 for Figure 1 Another structural schematic diagram of the mid-range resonator;

[0025] Figure 5 The adoption provided for the embodiments of the present invention Figure 1 The diagram shows a dual-cavity filter structure where the resonator is coupled through lumped elements.

[0026] Figure 6 The adoption provided for the embodiments of the present invention Figure 1 The diagram shows a dual-cavity filter structure where the resonator is coupled via interdigital capacitors.

[0027] Figure 7 The adoption provided for the embodiments of the present invention Figure 1 The resonator shown is a sixth-order filter with a tapped feed structure.

[0028] Figure 8 for Figure 7 Another perspective on the structure of a sixth-order filter;

[0029] Figure 9 for Figure 7 A top-view structural diagram of the first resonator of a sixth-order filter;

[0030] Figure 10The six-order filter with the lumped element feeding structure provided by the embodiment of the present application is composed of the resonator shown in Figure 1 The six-order filter with the lumped element feeding structure provided by the embodiment of the present application is composed of the resonator shown in

[0031] Figure 11 The six-order filter with the lumped element feeding structure provided by the embodiment of the present application is composed of the resonator shown in Figure 7 The six-order filter with the lumped element feeding structure provided by the embodiment of the present application is composed of the resonator shown in

[0032] In the figure: medium substrate 1, metal conducting band 2, metal strip 3, ceramic block body 4, two side faces 41 of the ceramic block body, back face 42 of the ceramic block body, metal covering layer 5, flange 51, lumped element 6, interdigital capacitor 7, metal feeding line 8, clearance groove 9. DETAILED DESCRIPTION

[0033] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work fall within the scope of protection of the present application.

[0034] It should be noted that when a component is referred to as being "mounted on" another component, it can be directly on the other component or there can be a middle component. When a component is referred to as being "disposed on" another component, it can be directly disposed on the other component or there can be a middle component. When a component is referred to as being "fixed on" another component, it can be directly fixed on the other component or there can be a middle component.

[0035] It should be understood that the terms "length", "width", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", and the like indicate the orientation or positional relationship shown in the drawings based on the orientation or positional relationship shown in the drawings, and are only for the purpose of facilitating the description of the present application and simplifying the description, and therefore cannot be understood as indicating or implying that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application.

[0036] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the present application belongs. The terminology used in the description of the present application herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the present application. As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items.

[0037] The filter provided by this invention consists of at least two resonators, and filters of different orders can be formed by using different numbers of resonators. A detailed description of a single resonator is provided below; please refer to the provided text. Figures 1 to 4 This is a schematic diagram of the resonator proposed in this invention. The resonator includes: a dielectric substrate 1, a microstrip structure, and a ceramic dielectric block. The dielectric substrate 1 is made of PCB material and has a metal layer on its bottom. Grooves are etched on the top of the dielectric substrate 1 for mounting the microstrip structure. The microstrip structure includes a metal conductor 2 and two metal strips 3, both fixed to the dielectric substrate 1. The metal conductor 2 has a T-shaped structure that is wider at the top and narrower at the bottom. The two metal strips 3 are symmetrically distributed about the metal conductor 2 as an axis.

[0038] The ceramic dielectric blocks in multiple resonators all have the same structure; taking one ceramic dielectric block as an example, this will be explained. This ceramic dielectric block includes a ceramic block body 4 and a metal capping layer 5. The metal capping layer 5 metallizes the top, back 42, and both sides 41 of the ceramic block body 4, and extends from the sides 41 to the bottom of the ceramic block body 4, forming two narrow strip-shaped flanges 51. This ceramic dielectric block, as part of the entire resonator, is surface-mounted on the dielectric substrate 1, forming a quarter-wavelength resonator in close contact with the microstrip structure on the dielectric substrate 1. Specifically, the ceramic block body 4 is symmetrically placed on the metal conductor strip 2, and the two metallized flanges 51 formed by the extension of the metal capping layer 5 act as solder pads, soldered to the metal strip 3. The bottom of the metal conductor strip 2 is grounded, and the metal strip 3 is grounded through metallized vias between itself and the metal layer at the bottom of the dielectric substrate 1. Figure 2 As shown, the metal cover layer 5 located at the rear 42 of the ceramic block body is welded to and contacts the metal strip 3, and also contacts the metal conductor 2, thus forming the short-circuit end of the resonator, creating a quarter-wavelength resonator. The ceramic block body 4 is made of high-dielectric-constant ceramic powder and can be any of a cuboid, cube, or trapezoid. In this embodiment, a cuboid is chosen because it has the advantages of small size and high Q-value in the resonator. Since the dielectric constant of the ceramic dielectric block is much higher than that of the dielectric substrate 1, the electromagnetic field is concentrated on the ceramic dielectric block for resonance, greatly reducing the resonator size and dielectric loss. Furthermore, the resonant frequency of this resonator can be adjusted by adjusting the position of the ceramic dielectric block on the metal conductor 2. Figure 4 As shown, the open end of the metal conductor 2 ( Figure 4 The shortest distance L between the wide side of the T-shaped structure and the ceramic dielectric block. Increasing the distance L will decrease the resonant frequency of the resonator, and conversely, decreasing the distance L will increase the resonant frequency of the resonator.

[0039] When the aforementioned resonator resonates, the electromagnetic field is mainly concentrated inside the ceramic dielectric block, rather than inside the dielectric substrate 1. Because the ceramic dielectric block has a relatively low loss tangent, the Q value of the resonator is far superior to that of a simple microstrip resonator. Furthermore, multiple resonators constituting the filter can be made from completely identical products of the same size, requiring less sophisticated processing and significantly reducing manufacturing costs, making it suitable for mass production.

[0040] Multiple resonators are connected together through coupling structures on the dielectric substrate 1 to achieve cross-coupled or non-cross-coupled filter responses. One embodiment is a filter constructed using two resonators as the basic resonant unit. Two resonators are placed side-by-side, with two adjacent metal strips 3 in contact, forming a single unit (equivalent to two ceramic dielectric blocks pressed onto three metal strips 3). Coupling between the resonators occurs at the open-circuit end of the metal conductor 2 (…). Figure 5 , Figure 6 This is done between the wide side sections of the T-shaped structure. For example... Figure 5 As shown, the coupling structure between the two metal conductors 2 uses a lumped element 6. This lumped element 6 is a functional unit composed of components such as surface-mount inductors, surface-mount capacitors, wire-wound inductors, and ferrite beads. Using the lumped element 6 to achieve coupling between resonators is mainly used to achieve a larger channel bandwidth; the polarity of the coupling can be changed simply by altering the types of components within the lumped element 6. In another embodiment, as... Figure 6 As shown, the coupling structure between the two metal conductors 2 adopts a distributed coupling structure, such as the interdigital capacitor 7. This interdigital capacitor 7 has a spiral-like structure with staggered finger-shaped electrode plates, storing charge between the staggered metal electrode plates to form a capacitor. It is mainly used in filters with narrow bandwidth. Both the lumped element 6 and the interdigital capacitor 7 mentioned above are existing technologies; appropriate models and specifications can be selected according to the desired coupling effect, and will not be elaborated further here.

[0041] The feeding method of this filter also varies. Taking a sixth-order filter with six resonators as the basic resonant unit and a coupling structure consisting of six lumped elements as an example, please refer to the following: Figures 7 to 9 The feeding method used is tapped. The tapped metal feed line 8 is directly connected to the metal conductor strip 2 of the first and last resonators. Figure 9 (Only one side is shown in perspective), and accordingly, the metal strips 3 at both ends of the filter are removed. For example... Figure 8 As shown, in the section through which the metal feed line 8 passes, the metal coating layer 5 on the ceramic dielectric block has corresponding clearance grooves 9, forming a non-metallized area to avoid contact between the metal feed line 8 and the surface metal coating of the ceramic dielectric block, thus preventing short circuits that could prevent energy from being fed in. Simulation experiments were conducted on this sixth-order filter, and the results are as follows... Figure 11The frequency response curve is shown. The center frequency is 7GHz and the bandwidth is 1GHz.

[0042] In another embodiment, the same six-order filter is used as an example, and the feeding mode is in lumped form. As shown in the figure, Figure 10 The input / output feed line is connected to the open end of the metal strip 2 of the first and last resonators through the lumped element 6 to complete the input and output of energy.

[0043] In summary, the above filter uses a ceramic dielectric block and a microstrip structure to form a resonator, concentrates electromagnetic fields in the ceramic dielectric block, improves Q value and reduces resonator size. The microstrip structure is easy to integrate, has high processing precision and low manufacturing cost. The filter very well concentrates the advantages of the two structures together, so that the coupling, feeding and frequency tuning of the filter are realized on the microstrip. The ceramic dielectric block is installed on the microstrip in a manner similar to a patch component, and debugging is not required. The filter described in the present application has the characteristics of low insertion loss, small size, wide bandwidth, high processing precision and low manufacturing cost. The filter provided by the present application can be applied in the fields of mobile communication, satellite communication, radar and the like. It is particularly suitable for use in the transceiver channel of the radio frequency front end of a wireless communication and radar system. The transceiver channel includes a transceiver channel on a base station or a satellite.

[0044] The technical features of the above-described embodiments can be combined in any manner. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described, but as long as the combinations of the technical features do not contradict, they should be considered within the scope of the present disclosure.

[0045] The above-described embodiments only express several embodiments of the present application, and the description is more specific and detailed, but it should not be understood as limiting the scope of the patent. It should be noted that for ordinary skilled in the art, without departing from the concept of the present application, a number of modifications and improvements can be made, which are within the scope of the present application. Therefore, the scope of protection of the present application should be subject to the appended claims.

Claims

1. A filter combining a ceramic dielectric block and a microstrip, characterized in that, The filter comprises at least two resonators, with adjacent resonators connected by a coupling structure to achieve a cross-coupled or non-cross-coupled filter response; the resonators include: Dielectric substrate (1); The microstrip structure includes a metal conductor (2) and two metal strips (3), wherein the metal conductor (2) is located between the two metal strips (3), and both the metal conductor (2) and the metal strips (3) are fixed to the upper surface of the dielectric substrate (1); The ceramic dielectric block includes a ceramic block body (4) and a metal cover layer (5). The metal cover layer (5) is disposed on the top, back and sides of the ceramic block body (4). The metal cover layer (5) located on the sides of the ceramic block body (4) extends to the bottom of the ceramic block body (4) to form two narrow strip-shaped flanges (51). The two flanges (51) are fixedly connected to two metal strips (3) respectively. The metal cover layer (5) located on the back of the ceramic block body (4) contacts the metal conductor (2) to form the short-circuit end of the resonator. The resonant frequency of the resonator is adjusted by changing the position of the ceramic dielectric block on the metal conductor (2). When the resonator resonates, the electromagnetic field is concentrated in the ceramic dielectric block.

2. The filter combining a ceramic dielectric block and a microstrip as described in claim 1, characterized in that, The two ends of the coupling structure are respectively connected to two adjacent metal conductors (2).

3. The filter combining a ceramic dielectric block and a microstrip according to claim 2, characterized in that, The coupling structure is a lumped element (6) or an interdigital capacitor (7).

4. The filter combining a ceramic dielectric block and a microstrip according to claim 1, characterized in that, In two adjacent resonators, the two metal strips (3) that are close to each other are in contact with each other and form a whole.

5. The filter combining a ceramic dielectric block and a microstrip according to claim 1, characterized in that, The resonator is a quarter-wavelength resonator.

6. The filter combining a ceramic dielectric block and a microstrip according to claim 1, characterized in that, The metal conductor (2) has a T-shaped structure that is wider at the top and narrower at the bottom; the ceramic dielectric block is any one of a cuboid, a cube, and a trapezoid.

7. The filter combining a ceramic dielectric block and a microstrip according to claim 1, characterized in that, The two metal strips (3) are symmetrically distributed about the metal conductor (2) as the axis, and both the metal strips (3) and the metal conductor (2) are grounded.

8. The filter combining a ceramic dielectric block and a microstrip according to claim 1, characterized in that, The filter also includes a metal feed line (8), which is connected to the middle part of the metal conductor strips (2) of the first and last resonators; or, the metal feed line (8) is connected to the open end of the metal conductor strips (2) of the first and last resonators.

9. A base station, characterized in that, It employs a filter that combines a ceramic dielectric block with a microstrip as described in any one of claims 1 to 8.

10. A satellite, characterized in that, It employs a filter that combines a ceramic dielectric block with a microstrip as described in any one of claims 1 to 8.

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