CN112953432A - Band-stop filter - Google Patents
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- CN112953432A CN112953432A CN202110146667.2A CN202110146667A CN112953432A CN 112953432 A CN112953432 A CN 112953432A CN 202110146667 A CN202110146667 A CN 202110146667A CN 112953432 A CN112953432 A CN 112953432A
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- 230000001939 inductive effect Effects 0.000 claims abstract description 49
- 230000005540 biological transmission Effects 0.000 claims abstract description 16
- 238000000034 method Methods 0.000 claims description 14
- 238000010897 surface acoustic wave method Methods 0.000 claims description 8
- 239000000919 ceramic Substances 0.000 claims description 6
- 230000010354 integration Effects 0.000 claims description 5
- 239000010409 thin film Substances 0.000 claims description 5
- 239000007787 solid Substances 0.000 claims description 2
- 230000008030 elimination Effects 0.000 abstract description 25
- 238000003379 elimination reaction Methods 0.000 abstract description 25
- 238000010586 diagram Methods 0.000 description 7
- 238000003780 insertion Methods 0.000 description 3
- 230000037431 insertion Effects 0.000 description 3
- 239000000758 substrate Substances 0.000 description 3
- 238000013461 design Methods 0.000 description 2
- 238000010295 mobile communication Methods 0.000 description 2
- 230000037237 body shape Effects 0.000 description 1
- 238000004891 communication Methods 0.000 description 1
- 230000001276 controlling effect Effects 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 238000010030 laminating Methods 0.000 description 1
- 238000003475 lamination Methods 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
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- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03H—IMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS
- H03H7/00—Multiple-port networks comprising only passive electrical elements as network components
- H03H7/01—Frequency selective two-port networks
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- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03H—IMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS
- H03H7/00—Multiple-port networks comprising only passive electrical elements as network components
- H03H7/01—Frequency selective two-port networks
- H03H2007/013—Notch or bandstop filters
Abstract
The present invention provides a band elimination filter, which includes: an input port and an output port; at least one series resonant cell connected in series between the input port and the output port; the band-stop filter comprises at least one parallel branch, one end of each parallel branch is connected to a node between the input port and the output port, the other end of each parallel branch is grounded, a parallel resonance unit is arranged in each parallel branch, and an inductive element connected with the parallel resonance unit in series is arranged in part or all of the parallel branches, wherein the resonance frequency of the parallel resonance unit is smaller than the resonance frequency of the series resonance unit, the inductive element enables the band-stop filter to form a transmission zero point, and the transmission zero point falls within the range of stop band frequency of the band-stop filter to provide a minimum impedance point. The band-stop filter provided by the invention has high attenuation performance in the frequency range of the stop band and low loss performance near the stop band.
Description
Technical Field
The invention relates to the technical field of communication, in particular to a band-stop filter.
Background
A band-stop filter refers to a filter that passes most of the frequency components, but attenuates some range of frequency components to a very low level.
A typical structure of a conventional band-stop filter is shown in fig. 1. As shown in fig. 1, two series resonators 10 and 11 are connected in series with one input port 1 and one output port 2, respectively. The two parallel resonators 20 and 21 are connected to the ladder frame between the two series resonators 10 and 11 and one ground terminal 3. By regulating and controlling the lamination parameters of the resonators, the two series resonators 10 and 11 can present anti-resonance on a target frequency band, and further high impedance, namely band rejection characteristic is realized. Similarly, the parallel- arm resonators 20 and 21 can be controlled to exhibit a low impedance at or near the resonance point in the target frequency band.
The typical stopband attenuation of the conventional bandstop filter formed based on the resonators can reach about-20 dB, and the requirements of most application scenes can be met. However, with the development of mobile communication technology, spectrum resources are more and more crowded, and interference is more and more serious, and a high-performance filter becomes an optimal choice for solving the problem. Furthermore, as the demand for integration of functional components for mobile communication increases, the area occupancy of each element is also greatly limited. Small area, high performance filters have become a trend.
Disclosure of Invention
In order to meet the market demand for high performance filters, the present invention provides a band stop filter comprising:
an input port and an output port;
at least one series resonant cell connected in series between the input port and the output port;
the band-stop filter comprises at least one parallel branch, one end of each parallel branch is connected to a node between the input port and the output port, the other end of each parallel branch is grounded, a parallel resonance unit is arranged in each parallel branch, and an inductive element connected with the parallel resonance units in series is arranged in part or all of the parallel branches, wherein the resonance frequency of the parallel resonance unit is less than that of the series resonance unit, the inductive element enables the band-stop filter to form a transmission zero point, and the transmission zero point is located in the range of the stop band frequency of the band-stop filter.
According to an aspect of the present invention, in the band elimination filter, in the parallel branches where the inductive element is disposed, the parallel resonance unit in each of the parallel branches is independently connected in series with the inductive element.
According to another aspect of the invention, in the band reject filter, at least two parallel branches are present in series with the inductive element through a common terminal among the parallel branches provided with the inductive element.
According to still another aspect of the present invention, in the band elimination filter, the inductive element, the parallel resonant unit, and the series resonant unit are integrated through a low temperature co-fired ceramic process, a high temperature co-fired ceramic process, a printed circuit board process, and a monolithic integration process to form the band elimination filter.
According to yet another aspect of the invention, in the band reject filter, the inductive elements are lumped inductive elements.
According to yet another aspect of the invention, in the band reject filter, the inductive element is an inductance.
According to still another aspect of the present invention, in the band elimination filter, the series resonance unit is an acoustic resonator or an acoustic resonator equivalent circuit; the parallel resonance unit is an acoustic resonator or an acoustic resonator equivalent circuit.
According to yet another aspect of the invention, in the band reject filter, the acoustic resonators are one or more of surface acoustic wave resonators, thin film bulk acoustic wave resonators, or solid state fabricated bulk acoustic wave resonators.
The band-stop filter provided by the invention comprises an input port, an output port, at least one series resonance unit and at least one parallel branch, wherein the series resonance unit is connected in series between the input port and the output port; one end of each parallel branch is connected to a node between the input port and the output port, and the other end of each parallel branch is grounded; each parallel branch is provided with a parallel resonance unit, and part or all of the parallel branches are also provided with inductive elements connected in series with the parallel resonance units, wherein the resonance frequency of the parallel resonance units is less than that of the series resonance units, and the inductive elements enable the band elimination filter to form transmission zeros positioned in the frequency range of the stop band. Compared with the existing band elimination filter only consisting of resonators, the band elimination filter provided by the invention not only comprises the resonance unit, but also arranges the inductive element in the parallel branch to enable the filter to form the transmission zero point positioned in the frequency range of the stop band, wherein, besides the influence of the high Q value characteristic of the resonance unit on the attenuation performance of the stop band of the band elimination filter, the transmission zero point positioned in the frequency range of the stop band and formed by the inductive element in the parallel branch can further improve the in-band attenuation, and simultaneously can increase the bandwidth of the stop band, thereby enabling the band elimination filter provided by the invention to have better performance in the frequency range of the stop band compared with the existing band elimination filter.
Drawings
Other features, objects and advantages of the invention will become more apparent upon reading of the detailed description of non-limiting embodiments made with reference to the following drawings:
FIG. 1 is a circuit diagram of a typical prior art band stop filter;
fig. 2 is a circuit diagram of a band reject filter according to a specific embodiment of the present invention;
fig. 3 is a circuit diagram of a band reject filter according to another embodiment of the present invention;
fig. 4 is a circuit diagram of a band-stop filter according to yet another embodiment of the invention;
fig. 5 is a circuit diagram of a band-stop filter according to yet another embodiment of the invention;
fig. 6 is a graph of the relationship between the s-parameter and the frequency of the band-stop filter shown in fig. 3.
The same or similar reference numbers in the drawings identify the same or similar elements.
Detailed Description
For a better understanding and explanation of the present invention, reference will now be made in detail to the present invention as illustrated in the accompanying drawings.
The present invention provides a band elimination filter, which includes:
an input port and an output port;
at least one series resonant cell connected in series between the input port and the output port;
the band-stop filter comprises at least one parallel branch, one end of each parallel branch is connected to a node between the input port and the output port, the other end of each parallel branch is grounded, a parallel resonance unit is arranged in each parallel branch, and an inductive element connected with the parallel resonance units in series is arranged in part or all of the parallel branches, wherein the resonance frequency of the parallel resonance unit is less than that of the series resonance unit, the inductive element enables the band-stop filter to form a transmission zero point, and the transmission zero point is located in the range of the stop band frequency of the band-stop filter.
The respective components of the band elimination filter will be described in detail below.
Specifically, the band-stop filter provided by the invention comprises an input port, an output port and at least one series resonance unit connected between the input port and the output port in series. In the present embodiment, the series resonant unit is implemented by using an acoustic resonator, such as a surface acoustic wave resonator, a thin film bulk acoustic wave resonator, a solid-state assembly acoustic wave resonator, or the like. When the number of the series resonance units is two or more, the two or more series resonance units may be implemented by using the same type of resonator (for example, all the series resonance units may be implemented by using surface acoustic wave resonators), or may be implemented by using different types of resonators (for example, some of the series resonance units may be implemented by using surface acoustic wave resonators, and others may be implemented by using thin film acoustic wave resonators). In other embodiments, the series resonant unit may also be implemented using an acoustic resonator equivalent circuit. The invention does not limit the concrete implementation mode of the equivalent circuit of the acoustic resonator at all, and can be realized by a lumped unit, for example.
The band-stop filter provided by the invention also comprises at least one parallel branch, wherein the at least one parallel branch is connected between the input port and the output port in parallel, namely one end of each parallel branch is connected to a node between the input port and the output port, and the other end of each parallel branch is grounded. Each parallel branch is provided with a parallel resonance unit, and some or all of the parallel branches are provided with an inductive element connected in series with the parallel resonance unit, that is, an inductive circuit element, including but not limited to an inductor, in addition to the parallel resonance unit. That is, in one case, part of the parallel branches includes the parallel resonant unit and the inductive element connected in series, and the rest of the parallel branches includes only the parallel resonant unit; in another case all parallel branches comprise a series connection of a parallel resonance unit and an inductive element. For the parallel branch including the parallel resonance unit and the inductive element, the connection sequence of the parallel resonance unit and the inductor is not limited in any way, one end of the parallel resonance unit may be connected to a node between the input port and the output port, the other end of the parallel resonance unit may be grounded through the inductive element, and one end of the parallel resonance unit may be grounded, and the other end of the parallel resonance unit may be connected to a node between the input port and the output port through the inductive element. For a parallel branch including only a parallel resonant cell, one end of the parallel resonant cell is connected to a node between the input port and the output port, and the other end is grounded. The above two cases will be described separately with reference to the drawings by taking the example that the inductive element is an inductor.
Referring to fig. 2, fig. 2 is a circuit diagram of a band-stop filter according to an embodiment of the invention, in which some parallel branches include parallel resonant cells and inductors connected in series, and the rest of the parallel branches include only parallel resonant cells. As shown, the band-stop filter includes an input port 100a and an output port 100b, a series leg connected between the input port 100a and the output port 100b, and three parallel legs. The series branch includes a series resonant unit 200a, a series resonant unit 200b, a series resonant unit 200c, and a series resonant unit 200d, which are connected in series in sequence from the input port 100a to the output port 100 b. One of the parallel branches includes a parallel resonance unit 201a and an inductor 202, one end of the parallel resonance unit 201a is connected to a node between the series resonance unit 200a and the series resonance unit 200b, the other end is connected to the inductor 202, and the other end of the inductor 202 is grounded; the other two parallel branches include a parallel resonant unit 201b and a parallel resonant unit 201c, respectively, one end of the parallel resonant unit 201b is connected to a node between the series resonant unit 200b and the series resonant unit 200c, and the other end is grounded, and one end of the parallel resonant unit 201c is connected to a node between the series resonant unit 200c and the series resonant unit 200d, and the other end is grounded. It will be understood by those skilled in the art that fig. 2 is only a schematic example, and the specific number of series resonant cells in the series branch, the specific number and arrangement position of the parallel branches, etc. may be determined according to actual design requirements, and is not limited to the structure shown in fig. 2.
For the case where all the parallel branches include the parallel resonant units and the inductors connected in series, please refer to fig. 3; fig. 3 is a circuit diagram of a band-stop filter according to another embodiment of the present invention. As shown, the band-stop filter includes an input port 100a and an output port 100b, a series branch connected between the input port 100a and the output port 100b, and two parallel branches. The series branch includes a series resonant unit 300a, a series resonant unit 300b, and a series resonant unit 300c connected in series from the input port 100a to the output port 100 b. One of the parallel branches includes a parallel resonance unit 301a and an inductor 302a, one end of the parallel resonance unit 301a is connected to a node between the series resonance unit 300a and the series resonance unit 300b, the other end is connected to the inductor 302a, and the other end of the inductor 302a is grounded; the other parallel branch includes a parallel resonant unit 301b and an inductor 302b, wherein one end of the parallel resonant unit 301b is connected to a node between the series resonant unit 300b and the series resonant unit 300c, the other end is connected to the inductor 302b, and the other end of the inductor 302b is grounded. It will be understood by those skilled in the art that fig. 3 is only a schematic example, and the specific number of series resonant cells in the series branch, the specific number and arrangement position of the parallel branches, etc. may be determined according to actual design requirements, and is not limited to the structure shown in fig. 3.
For the parallel branches provided with the parallel resonance unit and the inductor, the parallel resonance unit in each parallel branch can be independently connected in series with the inductor, or at least two parallel branches exist, wherein the parallel resonance unit is connected in series with the inductor through a common end. In view of the fact that the parallel branch circuit provided with the parallel resonance unit and the inductance is addressed, the following description will be given taking as an example that all the parallel branch circuits include the parallel resonance unit and the inductance.
The parallel resonance unit in each parallel branch is independently connected in series with the inductor, i.e. the parallel resonance units in different parallel branches are connected in series with different inductors. Fig. 3 shows an example of such a case, and the band-stop filter includes two parallel branches, in which a parallel resonant unit 301a is connected to an inductor 302a, and a parallel resonant unit 301b is connected to an inductor 302 b. Those skilled in the art will appreciate that the number of parallel branches in fig. 3 is merely a schematic example.
At least two parallel resonance units in the parallel branches are connected with the inductor in series through a common end, namely at least two parallel resonance units are connected with the same inductor and grounded through the inductor. This situation can be further divided into two possibilities. One possibility is that the parallel resonant unit in any parallel branch is grounded via the same inductance as the parallel resonant units in one or more other parallel branches. As shown in fig. 4, the band-stop filter includes an input port 100a and an output port 100b, a series branch connected between the input port 100a and the output port 100b, and two parallel branches. The series branch includes a series resonant unit 400a, a series resonant unit 400b, and a series resonant unit 400c connected in series in this order from the input port 100a side to the output port 100b side. One of the parallel branches includes a parallel resonance unit 401a, the other parallel branch includes a parallel resonance unit 401b, one end of the parallel resonance unit 401a is connected to a node between the series resonance unit 400a and the series resonance unit 400b, one end of the parallel resonance unit 401b is connected to a node between the series resonance unit 400b and the series resonance unit 400c, the other ends of the parallel resonance unit 401a and the parallel resonator 401b are connected to form a common terminal, and an inductor 402 is disposed between the common terminal and the ground. Another possibility is that, in the parallel branch provided with the parallel resonance unit and the inductor, there is both a parallel branch in which the parallel resonance unit is independently connected in series with the inductor, and a parallel branch in which two or more parallel resonance units are connected to the inductor through a common terminal. As shown in fig. 5, the band-stop filter includes an input port 100a and an output port 100b, a series arm connected between the input port 100a and the output port 100b, and three parallel arms. The series branch includes a series resonant unit 500a, a series resonant unit 500b, a series resonant unit 500c, and a series resonant unit 500d, which are connected in series in this order from the input port 100a side to the output port 100b side. One of the parallel branches includes a parallel resonance unit 501a and an inductor 502a, one end of the parallel resonance unit 501a is connected to a node between the series resonance unit 500a and the series resonance unit 500b, the other end is connected to the inductor 502a, and the other end of the inductor 502a is grounded; the other two branches respectively include a parallel resonant unit 501b and a parallel resonant unit 501c, one end of the parallel resonant unit 501b is connected to a node between the series resonant unit 500b and the series resonant unit 500c, one end of the parallel resonant unit 501c is connected to a node between the series resonant unit 500c and the series resonant unit 500d, the other ends of the parallel resonant unit 501a and the parallel resonant unit 501b are connected to form a common end, and an inductor 502b is arranged between the common end and the ground.
It should be noted that, for the case that at least two parallel branches exist, in which the parallel resonant unit is connected in series with the inductor through the common terminal, the parallel resonant unit in the adjacent parallel branch may be connected in series with the inductor through the common terminal, or the parallel resonant unit in the nonadjacent parallel branch may be connected in series with the inductor through the common terminal (that is, one or more other parallel branches are spaced between the parallel branches connected in series with the inductor through the common terminal), or the parallel resonant unit in the adjacent parallel branch may be connected in series with the inductor through the common terminal, or the parallel resonant unit in the nonadjacent parallel branch may be connected in series with the inductor through the common terminal. The invention is not limited in this regard.
In the present embodiment, the parallel resonance unit is implemented using an acoustic resonator, such as a surface acoustic wave resonator, a bulk acoustic wave resonator, a solid-state bulk acoustic wave resonator, or the like. When the number of the parallel resonance units is two or more, the two or more parallel resonance units may be implemented by using the same type of resonator (for example, all the parallel resonance units are implemented by using the surface acoustic wave resonator), or may be implemented by using different types of resonators (for example, some parallel resonance units are implemented by using the surface acoustic wave resonator, and others are implemented by using the thin film acoustic wave resonator). In other embodiments, the parallel resonance unit may also be implemented using an acoustic resonator equivalent circuit. The invention does not limit the concrete implementation mode of the equivalent circuit of the acoustic resonator at all, and can be realized by a lumped unit, for example.
In this embodiment, the inductive element and the resonant unit (including the parallel resonant unit and the series resonant unit) are integrated by a Low Temperature Co-fired Ceramic (LTCC) process or a High Temperature Co-fired Ceramic (HTCC) process to form the band stop filter. The band elimination filter formed by the LTCC/HTCC process is in a laminated body shape, a plurality of substrates are laminated together along the laminating direction, and the inductive element, the parallel resonance unit and the series resonance unit are distributed on the substrates and connected through the metal through hole. The LTCC/HTCC process encapsulates the inductive element and the resonant unit in the multilayer wiring substrate, so that the layout of the band elimination filter is changed from a plane to a three-dimensional state to manufacture a tiny stacked filter, the cost is reduced, and the integration level and the reliability of the system are greatly improved. In other embodiments, the inductive element and the resonant unit may be integrated by Printed Circuit Board (PCB) process or monolithic process to form a band-stop filter with high integration, small size, light weight, good packaging performance, and high stability. Of course, it will be appreciated by those skilled in the art that the inductive elements may also be lumped inductive elements.
For the band elimination filter provided by the invention, certain requirements exist on the parameter settings of the series resonance unit, the parallel resonance unit and the inductive element. Specifically, the resonance frequency of the parallel resonance unit is equal to or less than the resonance frequency of the series resonance unit, that is, the maximum value of the resonance frequencies of all the parallel resonance units is smaller than the minimum value of the resonance frequencies of all the series resonance units. In addition, the inductive elements need to be arranged such that the band stop filter generates transmission zeroes within the stopband frequency range. Compared with the conventional band elimination filter only consisting of resonators, the band elimination filter provided by the invention has the advantages that the attenuation performance in the range of the stop band frequency is improved due to the high Q value characteristic of the resonance unit, and the transmission zero point generated by the inductive element is further improved. The attenuation in the stop band of the band-stop filter provided by the invention can reach 40dB, and is obviously superior to the attenuation characteristic in the stop band of the existing band-stop filter. The frequency range outside the stop band includes a frequency range above the stop band and a frequency range below the stop band. In a range higher than the stop band frequency, the series resonant unit and the parallel resonant unit exhibit a capacitance characteristic and thus can be regarded as a capacitance, and the band elimination filter at this time exhibits a pass band characteristic of a high-pass filter in the frequency range, that is, has a low insertion loss characteristic in the frequency range, and the insertion loss is slightly reduced as the frequency increases. In a range lower than the stop band frequency, since the resonance frequency of the parallel resonance unit is smaller than that of the series resonance unit, in this frequency range, the stop band stop filter provided by the present invention exhibits the characteristics of a band pass filter, that is, has a low insertion loss characteristic in a certain frequency range near the stop band and has a high rejection characteristic in a frequency range far from the stop band. With the increase of the Q value of the resonant unit, the roll-off at the frequency close to the stop band is steeper, which can provide a basis for the application with a narrower band gap.
The performance of the band-stop filter provided by the invention is explained by taking the structure shown in fig. 3 as an example. Specifically, the performance of the band-stop filter shown in fig. 3 is simulated to obtain fig. 6, and fig. 6 is a graph showing the relationship between the s-parameter and the frequency of the band-stop filter shown in fig. 3. As can be seen from fig. 6, the band-stop filter shown in fig. 3 has an attenuation of 40dB or more in the stopband frequency range, and is excellent in attenuation characteristics, and exhibits band-pass characteristics in the frequency range higher than the stopband and exhibits band-pass characteristics in the frequency range lower than the stopband.
It will be evident to those skilled in the art that the invention is not limited to the details of the foregoing illustrative embodiments, and that the present invention may be embodied in other specific forms without departing from the spirit or essential attributes thereof. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein. Any reference sign in a claim should not be construed as limiting the claim concerned. Furthermore, it will be obvious that the term "comprising" does not exclude other elements, units or steps, and the singular does not exclude the plural. A plurality of components, units or means recited in the system claims may also be implemented by one component, unit or means in software or hardware.
The band-stop filter provided by the invention comprises an input port, an output port, at least one series resonance unit and at least one parallel branch, wherein the series resonance unit is connected in series between the input port and the output port; one end of each parallel branch is connected to a node between the input port and the output port, and the other end of each parallel branch is grounded; each parallel branch is provided with a parallel resonance unit, and part or all of the parallel branches are also provided with inductive elements connected in series with the parallel resonance units, wherein the resonance frequency of the parallel resonance units is less than that of the series resonance units, and the inductive elements enable the band elimination filter to form transmission zeros positioned in the frequency range of the stop band. Compared with the existing band elimination filter only consisting of resonators, the band elimination filter provided by the invention not only comprises the resonance unit, but also arranges the inductive element in the parallel branch to enable the filter to form the transmission zero point positioned in the frequency range of the stop band, wherein, besides the influence of the high Q value characteristic of the resonance unit on the attenuation performance of the stop band of the band elimination filter, the transmission zero point positioned in the frequency range of the stop band and formed by the inductive element in the parallel branch can further improve the in-band attenuation, and simultaneously can increase the bandwidth of the stop band, thereby enabling the band elimination filter provided by the invention to have better performance in the frequency range of the stop band compared with the existing band elimination filter.
While the invention has been described with reference to a preferred embodiment, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention.
Claims (8)
1. A band reject filter, comprising:
an input port and an output port;
at least one series resonant cell connected in series between the input port and the output port;
the band-stop filter comprises at least one parallel branch, one end of each parallel branch is connected to a node between the input port and the output port, the other end of each parallel branch is grounded, a parallel resonance unit is arranged in each parallel branch, and an inductive element connected with the parallel resonance units in series is arranged in part or all of the parallel branches, wherein the resonance frequency of the parallel resonance unit is less than that of the series resonance unit, the inductive element enables the band-stop filter to form a transmission zero point, and the transmission zero point is located in the range of the stop band frequency of the band-stop filter.
2. The band-stop filter of claim 1, wherein:
in the parallel branches provided with the inductive element, the parallel resonance unit in each parallel branch is independently connected in series with the inductive element.
3. The band-stop filter of claim 1, wherein:
at least two parallel branches are connected with the inductive element in series through a common end in the parallel branches provided with the inductive element.
4. The band-stop filter of claim 1, wherein:
the inductive element, the parallel resonance unit and the series resonance unit are integrated through a low-temperature co-fired ceramic process, a high-temperature co-fired ceramic process, a printed circuit board process and a monolithic integration process to form the band-stop filter.
5. The band reject filter according to claim 1, wherein the inductive elements are lumped inductive elements.
6. The band reject filter according to any of claims 1 to 5, wherein the inductive element is an inductance.
7. The band reject filter of any one of claims 1 to 3, wherein:
the series resonance unit is an acoustic resonator or an acoustic resonator equivalent circuit;
the parallel resonance unit is an acoustic resonator or an acoustic resonator equivalent circuit.
8. The band reject filter of claim 7, wherein the acoustic resonators are one or more of surface acoustic wave resonators, thin film bulk acoustic resonators, or solid state fabricated bulk acoustic wave resonators.
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| CN202110146667.2A CN112953432A (en) | 2021-02-03 | 2021-02-03 | Band-stop filter |
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| CN202110146667.2A CN112953432A (en) | 2021-02-03 | 2021-02-03 | Band-stop filter |
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114465601A (en) * | 2022-04-13 | 2022-05-10 | 苏州汉天下电子有限公司 | Filter, duplexer and multiplexer |
| CN116192081A (en) * | 2022-12-23 | 2023-05-30 | 北京芯溪半导体科技有限公司 | Filter, terminal and base station |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102055430A (en) * | 2009-01-27 | 2011-05-11 | 太阳诱电株式会社 | Filter, duplexer and communication module |
| CN104716926A (en) * | 2013-12-17 | 2015-06-17 | 贵州中科汉天下电子有限公司 | Piezoelectric filter |
| CN111600574A (en) * | 2019-08-30 | 2020-08-28 | 天津大学 | Bulk acoustic wave filter and out-of-band rejection improvement method thereof |
| CN111917392A (en) * | 2020-04-14 | 2020-11-10 | 诺思(天津)微系统有限责任公司 | Piezoelectric filter, out-of-band rejection improvement method for piezoelectric filter, multiplexer, and communication device |
| CN111953317A (en) * | 2019-05-14 | 2020-11-17 | 三星电机株式会社 | Filter comprising acoustic wave resonators |
-
2021
- 2021-02-03 CN CN202110146667.2A patent/CN112953432A/en active Pending
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102055430A (en) * | 2009-01-27 | 2011-05-11 | 太阳诱电株式会社 | Filter, duplexer and communication module |
| CN104716926A (en) * | 2013-12-17 | 2015-06-17 | 贵州中科汉天下电子有限公司 | Piezoelectric filter |
| CN111953317A (en) * | 2019-05-14 | 2020-11-17 | 三星电机株式会社 | Filter comprising acoustic wave resonators |
| CN111600574A (en) * | 2019-08-30 | 2020-08-28 | 天津大学 | Bulk acoustic wave filter and out-of-band rejection improvement method thereof |
| CN111917392A (en) * | 2020-04-14 | 2020-11-10 | 诺思(天津)微系统有限责任公司 | Piezoelectric filter, out-of-band rejection improvement method for piezoelectric filter, multiplexer, and communication device |
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| CN114465601A (en) * | 2022-04-13 | 2022-05-10 | 苏州汉天下电子有限公司 | Filter, duplexer and multiplexer |
| CN114465601B (en) * | 2022-04-13 | 2022-08-12 | 苏州汉天下电子有限公司 | Filter, duplexer and multiplexer |
| CN116192081A (en) * | 2022-12-23 | 2023-05-30 | 北京芯溪半导体科技有限公司 | Filter, terminal and base station |
| CN116192081B (en) * | 2022-12-23 | 2024-01-19 | 北京芯溪半导体科技有限公司 | Filter, terminal and base station |
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