CN112736387A - Dielectric ceramic filter - Google Patents
Dielectric ceramic filter Download PDFInfo
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- CN112736387A CN112736387A CN202011591093.1A CN202011591093A CN112736387A CN 112736387 A CN112736387 A CN 112736387A CN 202011591093 A CN202011591093 A CN 202011591093A CN 112736387 A CN112736387 A CN 112736387A
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- coupling window
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01P—WAVEGUIDES; RESONATORS, LINES, OR OTHER DEVICES OF THE WAVEGUIDE TYPE
- H01P1/00—Auxiliary devices
- H01P1/20—Frequency-selective devices, e.g. filters
- H01P1/212—Frequency-selective devices, e.g. filters suppressing or attenuating harmonic frequencies
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01P—WAVEGUIDES; RESONATORS, LINES, OR OTHER DEVICES OF THE WAVEGUIDE TYPE
- H01P1/00—Auxiliary devices
- H01P1/20—Frequency-selective devices, e.g. filters
- H01P1/207—Hollow waveguide filters
- H01P1/208—Cascaded cavities; Cascaded resonators inside a hollow waveguide structure
- H01P1/2084—Cascaded cavities; Cascaded resonators inside a hollow waveguide structure with dielectric resonators
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Abstract
The invention relates to a dielectric ceramic filter, which comprises a plurality of dielectric blocks, wherein the surfaces of the dielectric blocks are provided with conducting layers, each dielectric block comprises a plurality of microwave dielectric resonators, two adjacent dielectric blocks are connected to form a conducting contact surface, the conducting contact surface comprises a first area positioned around the centroid of the conducting contact surface, a second area positioned at the edge of the conducting contact surface and a transition area between the first area and the second area, the microwave dielectric resonators of the two adjacent dielectric blocks form a mixed electromagnetic coupling structure by virtue of coupling windows arranged on the conducting contact surface, and the coupling windows comprise mixed coupling windows arranged in the transition area and/or electric coupling windows respectively arranged in the first area and magnetic coupling windows arranged in the second area. The coupling window is arranged between the microwave dielectric resonators, so that the effect that transmission zero can be generated only by two microwave dielectric resonators is realized, the dielectric ceramic filter has higher out-of-band rejection characteristic and frequency selection characteristic, the structure is simple, and the size of the filter is reduced to a certain extent.
Description
Technical Field
The invention belongs to the technical field of dielectric filters, and relates to a dielectric ceramic filter.
Background
With the development of wireless communication technology, especially the application of large-scale antenna technology in 5G systems, the number of radio frequency channels will be multiplied to 64 channels or even 128 channels, the space required by the base station filter is huge, and meanwhile, the development of high integration and miniaturization of 5G base stations puts higher requirements on the size and heat generation performance of the filter. The dielectric filter becomes the mainstream of the 5G filter by virtue of the advantages of high Q value, low loss, small volume, light weight, low cost, good temperature drift resistance and the like, and has wide application prospect.
With the rapid development of microwave communication, especially mobile communication, limited spectrum resources are increasingly strained and deficient, which puts higher demands on the out-of-band rejection capability and frequency selection characteristics of the filter. The key of the dielectric filter for improving the out-of-band rejection characteristic and the frequency selection characteristic is to introduce a transmission zero, and the technologies for realizing the transmission zero by the existing dielectric filter mainly comprise cross coupling and source-load coupling technologies. The cross coupling technology is adopted to generate transmission zero points, a filter with more than three orders is generally needed, an additional coupling path is needed to be introduced by adopting the source-load coupling technology, the two technologies increase the complexity of the topological structure of the filter, the structural requirement is high, and improvement is needed.
Disclosure of Invention
The invention designs a dielectric ceramic filter, and realizes the effect that transmission zero can be generated only by two microwave dielectric resonators by arranging a coupling window between the microwave dielectric resonators.
The technical scheme adopted by the invention is that,
the dielectric ceramic filter comprises a dielectric block group, wherein the dielectric block group comprises a plurality of dielectric blocks, the surfaces of the dielectric blocks are provided with conducting layers, each dielectric block comprises a plurality of microwave dielectric resonators, two adjacent dielectric blocks are connected to form a conducting contact surface, each conducting contact surface comprises a first area positioned around the centroid of the conducting contact surface, a second area positioned on the edge of the conducting contact surface and a transition area between the first area and the second area, the conducting contact surfaces are provided with coupling windows, the microwave dielectric resonators of the two adjacent dielectric blocks form a hybrid electromagnetic coupling structure by means of the coupling windows, each coupling window comprises a hybrid coupling window and/or an electromagnetic coupling window, the hybrid coupling windows are arranged in the transition areas, and the electromagnetic coupling windows are an electric coupling window arranged in the first area and a magnetic coupling window arranged in the second area respectively.
The hybrid coupling windows include a first hybrid coupling window and a second hybrid coupling window disposed within the transition region and symmetrically distributed about a center of the conductive contact profile.
The first hybrid coupling window and the second hybrid coupling window are both polygonal structures.
The electromagnetic coupling windows include a first electrical coupling window disposed in the middle of the first zone, a first magnetic coupling window and a second magnetic coupling window disposed within the second zone and symmetrically distributed about the center of the conductive contact surface.
The first electrical coupling window is square.
The first magnetic coupling window and the second magnetic coupling window are polygons.
And an input port and an output port are respectively arranged in the middle of the back separating surface of the two adjacent dielectric blocks.
The input port and the output port are round blind holes.
The dielectric block group is made of microwave dielectric ceramics.
The conductive layer is silver.
The working principle and the beneficial effects of the invention are as follows:
the invention realizes coupling by adopting a method of arranging the coupling window on the conductive contact surface of the two connected microwave dielectric resonators and utilizing a hybrid electromagnetic coupling structure formed by combining the electric coupling window and the magnetic coupling window or independently forming the hybrid coupling window, can realize the introduction of a transmission zero point in a direct-connected microwave dielectric resonator, can generate the transmission zero point only by two microwave dielectric resonators, and can realize the flexible adjustment of the transmission zero point, thereby leading the dielectric ceramic filter to have higher out-of-band rejection characteristic and frequency selection characteristic, having simple structure and reducing the size of the filter to a certain extent.
The present invention will be described in detail with reference to the accompanying drawings.
Drawings
FIG. 1 is a schematic perspective view of embodiment 1 of the present invention;
fig. 2 is an S parameter response curve of a filter when the total coupling coefficient of the hybrid electromagnetic coupling structure for realizing coupling is positive in embodiment 1 of the present invention;
FIG. 3 is a schematic perspective view of embodiment 2 of the present invention;
fig. 4 is an S-parameter response curve of the filter when the total coupling coefficient of the hybrid electromagnetic coupling structure for realizing coupling is negative in embodiment 2 of the present invention;
FIG. 5 is a schematic perspective view of embodiment 3 of the present invention;
FIG. 6 is the S parameter response curve of the filter when the total coupling coefficient of the hybrid electromagnetic coupling structure for realizing coupling is positive in the embodiment 3 of the present invention
In the figure, 1, a dielectric block, 2, a first hybrid coupling window, 3, a second hybrid coupling window, 4, a first electric coupling window, 5, a first magnetic coupling window, 6, a second magnetic coupling window, 7, an input port, 8 and an output port.
Detailed Description
The technical solutions of the present invention are further described in detail below with reference to specific examples and drawings, but the scope and implementation of the present invention are not limited thereto.
The invention relates to a dielectric ceramic filter, which comprises a dielectric block group, wherein the dielectric block group comprises a plurality of dielectric blocks 1, the surfaces of the dielectric blocks are provided with conducting layers, each dielectric block 1 comprises a plurality of microwave dielectric resonators, a first dielectric block 1 and a second dielectric block 1 are connected together through welding to form a conducting contact surface, and the central axes of cavities of the microwave dielectric resonators on the upper layer and the lower layer are overlapped.
An input port 7 and an output port 8 are respectively arranged in the middle of the back-to-back surfaces of the two adjacent dielectric blocks 1 to realize the input and output of communication signals, and the input port 7 and the output port 8 are round blind holes.
The conductive contact surface comprises a first area located around the centroid of the conductive contact surface, a second area located at the edge of the conductive contact surface and a transition area between the first area and the second area, the conductive contact surface is provided with a coupling window, the microwave dielectric resonators of two adjacent dielectric blocks 1 form a hybrid electromagnetic coupling structure through the coupling window, the coupling window comprises a hybrid coupling window and/or an electromagnetic coupling window, the hybrid coupling window is arranged in the transition area, and the electromagnetic coupling window is an electric coupling window arranged in the first area and a magnetic coupling window arranged in the second area.
In specific embodiment 1, as shown in fig. 1, the hybrid coupling window includes a first hybrid coupling window 2 and a second hybrid coupling window 3, which are two metal avoiding regions that are centrosymmetric with respect to a centroid of a conductive contact surface between two microwave dielectric resonators on an upper layer and a lower layer, and are located at a transition position between the center and an edge of the conductive contact surface. The first hybrid coupling window 2 and the second hybrid coupling window 3 are polygonal windows, and rectangular windows are preferred in the present invention.
The coupling between the microwave dielectric resonators includes coupling between electric fields and coupling between magnetic fields, the coupling between the electric fields is also called electric coupling, the electric coupling coefficient ke is negative, the coupling between the magnetic fields is also called magnetic coupling, the coefficient km of the magnetic coupling is positive, and the total coupling coefficient k is ke + km, so that the contributions of the electric coupling coefficient and the magnetic coupling coefficient to the total coupling coefficient k are mutually cancelled. The rectangular dielectric resonator with the TE101 mode as the basic mode has strongest electric field in the center of the cavity of the resonator, strongest magnetic field near the edge of the cavity, and non-coincidence position of the electric field energy concentration and the magnetic field energy concentration in the cavity of the resonator, so that the vertical coupling between the resonators can control the electric coupling and the magnetic coupling more conveniently and flexibly.
The first and second hybrid coupling windows 3 are correspondingly arranged in the cavity region of the microwave dielectric resonator, so that both stronger electric field energy and stronger magnetic field energy exist, and the simultaneous action of the electric coupling and the magnetic coupling between the two microwave dielectric resonators can be realized.
When the magnitude of the electric coupling amount and the magnitude of the magnetic coupling amount are the same, the total coupling coefficient k is 0. The total coupling is zero, which does not mean that there is no transmission and exchange of electromagnetic field energy between the two microwave dielectric resonators, but the conversion of the electromagnetic field energy between the two microwave dielectric resonators is balanced, a new resonance is introduced, the energy transmission is blocked, and the transmission zero point is represented in the dielectric ceramic filter.
The position of the transmission zero point generated by the simultaneous action of the electric coupling and the magnetic coupling is determined by the magnitude of the electric coupling quantity, the magnitude of the magnetic coupling quantity and the ratio of the two quantities, when the magnetic coupling is dominant, namely when the total coupling coefficient is positive, the transmission zero point is positioned on the left side of the passband, and when the electric coupling is dominant, namely when the total coupling coefficient is negative, the transmission zero point is positioned on the right side of the passband. In this embodiment, the magnitude of the electric coupling amount, the magnitude of the magnetic coupling amount, and the positive or negative of the total coupling coefficient are determined by the size and the position of the hybrid coupling window, and may be adjusted according to the parameter index of the filter in practical application, which is not specifically limited herein. When the magnetic coupling is dominant in this embodiment, the transmission zero point is located on the left side of the pass band, as shown in fig. 2, and when the amount of magnetic coupling decreases but remains dominant, the transmission zero point moves to the right.
In specific embodiment 2, as shown in fig. 3, the electromagnetic coupling window includes a first electrical coupling window 4, a first magnetic coupling window 5, and a second magnetic coupling window 6, where the first electrical coupling window 4 is located in a metal avoiding region at the center of a conductive contact surface between two upper and lower microwave dielectric resonators, and the first electrical coupling window 4 may be a polygonal window or a circular window, a square window is preferred in the present invention, and the center of the square window coincides with a central axis of a cavity of the microwave dielectric resonator; the first magnetic coupling window 5 and the second magnetic coupling window 6 are two metal avoiding regions which are centrosymmetric about the centroid of the conductive contact surface between the two microwave dielectric resonators on the upper layer and the lower layer, are positioned on the edge of the conductive contact surface between the two microwave dielectric resonators, and the first magnetic coupling window 5 and the second magnetic coupling window 6 are polygonal windows, preferably rectangular windows.
In this embodiment, the first electric coupling window 4 provided in the center of the conductive contact surface realizes electric coupling between two microwave dielectric resonators in an upper layer and a lower layer, and the first magnetic coupling window 5 and the second magnetic coupling window 6 provided in the edge of the conductive contact surface realize magnetic coupling between two microwave dielectric resonators in an upper layer and a lower layer. And the electric coupling and the magnetic coupling jointly form hybrid electromagnetic coupling, so that the simultaneous action of the electric coupling and the magnetic coupling between the upper microwave dielectric resonator and the lower microwave dielectric resonator is realized.
When the magnitude of the electric coupling amount and the magnitude of the magnetic coupling amount are the same, the total coupling coefficient k is 0. The total coupling is zero, a new resonance is introduced, the energy transmission is blocked, and the total coupling is represented as a transmission zero point in the dielectric ceramic filter. In this embodiment, the magnitude of the electric coupling amount, the magnitude of the magnetic coupling amount, and the positive or negative of the total coupling coefficient realized by the hybrid electromagnetic coupling structure are determined by the size and the position of the electric coupling window and the size and the position of the magnetic coupling window, and may be adjusted according to the parameter index of the filter in practical application, which is not specifically limited herein. When the electrical coupling is dominant in this embodiment, i.e., the total coupling coefficient is negative, the transmission zero is located on the right side of the pass band, as shown in fig. 4, and when the amount of electrical coupling is reduced but remains dominant, the transmission zero is shifted to the left.
In specific embodiment 3, as shown in fig. 5, the hybrid coupling window and the electromagnetic coupling window exist at the same time, the hybrid coupling window includes a first hybrid coupling window 2 and a second hybrid coupling window 3, and is two metal avoiding regions that are centrosymmetric with respect to the centroid of the conductive contact surface between the two microwave dielectric resonators on the upper and lower layers, and the position of the metal avoiding region is located in the transition region between the center and the edge of the conductive contact surface. The first hybrid coupling window 2 and the second hybrid coupling window 3 are polygonal windows, and rectangular windows are preferred in the present invention. The electromagnetic coupling window comprises a first electric coupling window 4, a first magnetic coupling window 5 and a second magnetic coupling window 6, wherein the first electric coupling window 4 is positioned in a metal avoiding area at the center of a conductive contact surface between two microwave dielectric resonators on an upper layer and a lower layer, the first electric coupling window 4 can be a polygonal window or a circular window, a square window is preferred in the invention, and the center of the square window is overlapped with the central axis of a cavity of the microwave dielectric resonator; the first magnetic coupling window 5 and the second magnetic coupling window 6 are two metal avoiding regions which are centrosymmetric about the centroid of the conductive contact surface between the two microwave dielectric resonators on the upper layer and the lower layer, are positioned on the edge of the conductive contact surface between the two microwave dielectric resonators, and the first magnetic coupling window 5 and the second magnetic coupling window 6 are polygonal windows, preferably rectangular windows.
In this embodiment, the hybrid coupling window realizes simultaneous existence of the electric coupling and the magnetic coupling realized by the hybrid electromagnetic coupling and the electromagnetic coupling window, and theoretically realizes simultaneous action of the electric coupling and the magnetic coupling between the upper microwave dielectric resonator and the lower microwave dielectric resonator. When the magnitude of the electric coupling amount and the magnitude of the magnetic coupling amount are the same, the total coupling coefficient k is 0. The total coupling is zero, a new resonance is introduced, the energy transmission is blocked, and the total coupling is represented as a transmission zero point in the dielectric ceramic filter. In this embodiment, the magnitude of the electric coupling amount, the magnitude of the magnetic coupling amount, and the positive or negative of the total coupling coefficient realized by the hybrid electromagnetic coupling structure are determined by the size and the position of the hybrid coupling window, the size and the position of the electric coupling window, and the size and the position of the magnetic coupling window, and may be adjusted according to a parameter index of the filter in practical application, which is not specifically limited herein. When the magnetic coupling is dominant in this embodiment, the transmission zero point is located on the left side of the pass band, as shown in fig. 6, and when the amount of magnetic coupling decreases but remains dominant, the transmission zero point moves rightward.
In the invention, when stronger electric coupling and magnetic coupling exist in the dielectric ceramic filter at the same time, the electric coupling amount and the magnetic coupling amount need to be considered at the same time, and the transmission zero point can be generated only by two dielectric resonators when the electric coupling and the magnetic coupling act at the same time, thereby reducing the size of the filter to a certain extent.
In addition, the bottom surface or the top surface of the microwave dielectric resonator can be provided with a tuning blind hole, the tuning blind hole can adjust the resonant frequency of the microwave dielectric resonator, and then adjust the performance index of the filter, and the tuning blind hole can also reduce the size of the dielectric ceramic filter, thereby being beneficial to the miniaturization of the dielectric ceramic filter.
In the above embodiment, only one pair of microwave dielectric resonator units has the simultaneous action of electric coupling and magnetic coupling, and only one transmission zero is generated, but certainly each pair of microwave dielectric resonator units generating the transmission zero can be cascaded to form a high-order dielectric ceramic filter, and by selecting a proper hybrid electromagnetic coupling structure, more transmission zeros can be generated outside the filter band, so that the filter has higher out-of-band rejection characteristic and frequency selection characteristic.
Furthermore, the dielectric material of the dielectric block 1 group is ceramic, and the relative dielectric constant of the microwave dielectric ceramic is greater than 1, so that the size of the filter can be effectively reduced, and the miniaturization of the filter is facilitated; the conducting layer is made of metal silver, and the metal silver has high conductivity and can effectively reduce the circuit loss of the dielectric ceramic filter.
Claims (10)
1. Dielectric ceramic filter, including the dielectric block group, the dielectric block group all is equipped with a plurality of dielectric blocks (1) of conducting layer including the surface, every dielectric block (1) all contains a plurality of microwave dielectric resonators, and two adjacent dielectric blocks (1) are connected and are formed electrically conductive contact surface, its characterized in that: the conductive contact surface includes a first region located around a centroid thereof, a second region located at an edge thereof, and a transition region between the first region and the second region,
the conductive contact surface is provided with a coupling window, the microwave dielectric resonators of two adjacent dielectric blocks (1) form a hybrid electromagnetic coupling structure by means of the coupling window,
the coupling window comprises a hybrid coupling window and/or an electromagnetic coupling window,
the hybrid coupling window is disposed in the transition region,
the electromagnetic coupling windows are respectively arranged on the electric coupling window of the first area and the magnetic coupling window of the second area.
2. A dielectric ceramic filter as claimed in claim 1, wherein: the hybrid coupling windows comprise a first hybrid coupling window (2) and a second hybrid coupling window (3), the first hybrid coupling window (2) and the second hybrid coupling window (3) being arranged in the transition region and being distributed centrosymmetrically with respect to the center of the conductive contact surface.
3. A dielectric ceramic filter as claimed in claim 2, wherein: the first hybrid coupling window (2) and the second hybrid coupling window (3) are both polygonal structures.
4. A dielectric ceramic filter as claimed in claim 1, wherein: the electromagnetic coupling windows comprise a first electric coupling window (4), a first magnetic coupling window (5) and a second magnetic coupling window (6), the first electric coupling window (4) is arranged in the middle of the first area, and the first magnetic coupling window (5) and the second magnetic coupling window (6) are arranged in the second area and are symmetrically distributed in the center of the conductive contact surface.
5. A dielectric ceramic filter as claimed in claim 4, wherein: the first electrical coupling window (4) is square.
6. A dielectric ceramic filter as claimed in claim 4, wherein: the first magnetic coupling window (5) and the second magnetic coupling window (6) are polygonal.
7. A dielectric ceramic filter as claimed in claim 1, wherein: and an input port (7) and an output port (8) are respectively arranged in the middle of the back surfaces of the two adjacent medium blocks (1).
8. A dielectric ceramic filter as claimed in claim 7, wherein: the input port (7) and the output port (8) are round blind holes.
9. A dielectric ceramic filter as claimed in any one of claims 1 to 8, wherein: the dielectric block group is made of microwave dielectric ceramics.
10. A dielectric ceramic filter as claimed in any one of claims 1 to 8, wherein: the conductive layer is silver.
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202011591093.1A CN112736387A (en) | 2020-12-29 | 2020-12-29 | Dielectric ceramic filter |
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| Application Number | Priority Date | Filing Date | Title |
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| CN202011591093.1A CN112736387A (en) | 2020-12-29 | 2020-12-29 | Dielectric ceramic filter |
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Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109904571A (en) * | 2019-02-25 | 2019-06-18 | 江南大学 | Substrate integral wave guide filter based on electromagnetism hybrid coupled |
| CN210111005U (en) * | 2019-07-09 | 2020-02-21 | 重庆思睿创瓷电科技有限公司 | Dielectric waveguide filter for improving harmonic performance, radio frequency module and base station |
| CN111129669A (en) * | 2020-01-08 | 2020-05-08 | 摩比天线技术（深圳）有限公司 | Hybrid electromagnetic coupling all-dielectric filter |
| CN111755781A (en) * | 2020-07-02 | 2020-10-09 | 电子科技大学 | LTCC process-based three-order hybrid electromagnetic coupling SIW filter |
| CN112086719A (en) * | 2020-09-16 | 2020-12-15 | 石家庄市鹿泉区麦特思电子科技有限公司 | Microwave dielectric waveguide filter with six-order and four-transmission zero |
-
2020
- 2020-12-29 CN CN202011591093.1A patent/CN112736387A/en active Pending
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109904571A (en) * | 2019-02-25 | 2019-06-18 | 江南大学 | Substrate integral wave guide filter based on electromagnetism hybrid coupled |
| CN210111005U (en) * | 2019-07-09 | 2020-02-21 | 重庆思睿创瓷电科技有限公司 | Dielectric waveguide filter for improving harmonic performance, radio frequency module and base station |
| CN111129669A (en) * | 2020-01-08 | 2020-05-08 | 摩比天线技术（深圳）有限公司 | Hybrid electromagnetic coupling all-dielectric filter |
| CN111755781A (en) * | 2020-07-02 | 2020-10-09 | 电子科技大学 | LTCC process-based three-order hybrid electromagnetic coupling SIW filter |
| CN112086719A (en) * | 2020-09-16 | 2020-12-15 | 石家庄市鹿泉区麦特思电子科技有限公司 | Microwave dielectric waveguide filter with six-order and four-transmission zero |
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Application publication date: 20210430 |