CN218734229U - Filter and duplexer - Google Patents
Filter and duplexer Download PDFInfo
- Publication number
- CN218734229U CN218734229U CN202222581635.8U CN202222581635U CN218734229U CN 218734229 U CN218734229 U CN 218734229U CN 202222581635 U CN202222581635 U CN 202222581635U CN 218734229 U CN218734229 U CN 218734229U
- Authority
- CN
- China
- Prior art keywords
- parallel
- resonant
- series
- filter
- resonance
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Images
Landscapes
- Control Of Motors That Do Not Use Commutators (AREA)
Abstract
The utility model provides a wave filter and duplexer, this wave filter includes at least: an input node, an output node, a plurality of series resonant cells, and a plurality of parallel resonant cells; connecting nodes are arranged between the input node and the series resonance units, between the series resonance units and the output node and between two adjacent series resonance units, and the input node, the plurality of series resonance units and the output node are sequentially connected through the connecting nodes; one end of any one of the plurality of parallel resonance units is connected with the connection node, and the other end of the any one of the plurality of parallel resonance units is connected with the grounding node; the resonance frequency of the parallel resonant cell near the input node and the parallel resonant cell near the output node is lower than the resonance frequency of the remaining parallel resonant cells of the plurality of parallel resonant cells. The utility model discloses a resonance frequency who is close to port parallel resonator in the selectivity adjustment filter can further improve the impedance matching performance in the whole passband of wave filter.
Description
Technical Field
The utility model belongs to the technical field of the semiconductor, especially, relate to a wave filter and duplexer.
Background
With the development of wireless communication applications, filters and duplexers based on bulk acoustic wave resonators have been widely used in wireless communication systems due to their characteristics of small size, low loss of resonators, high quality factor, and the like. At present, the bandwidth of a filter can be formed by applying a mass loading layer on the parallel resonator branches inside the filter, so that the resonance frequency of the parallel resonators is lower than the resonance frequency of the series resonators. However, even with the above adjustments, there is room for optimization of the passband of the filter.
SUMMERY OF THE UTILITY MODEL
In order to overcome the above-mentioned defect among the prior art, the utility model provides a wave filter and duplexer improves the interior impedance matching performance of passband through the frequency of adjustment syntonizer.
The utility model provides a filter, this filter includes at least: an input node, an output node, a plurality of series resonant cells, and a plurality of parallel resonant cells;
connecting nodes are arranged between the input node and the series resonant units, between the series resonant units and the output node, and between two adjacent series resonant units, and the input node, the plurality of series resonant units and the output node are sequentially connected through the connecting nodes; one end of any one of the plurality of parallel resonance units is connected with the connection node, and the other end of the any one of the plurality of parallel resonance units is connected with the grounding node;
the resonance frequency of the parallel resonant cell near the input node and the parallel resonant cell near the output node is lower than the resonance frequency of the remaining parallel resonant cells of the plurality of parallel resonant cells.
Optionally, the resonant frequency of the parallel resonant cell near the input node and the resonant frequency of the parallel resonant cell near the output node are the same.
Optionally, the parallel resonance unit comprises parallel resonators, each of said parallel resonators comprising a first mass loading layer; the parallel resonator in the parallel resonant cell near the input node and the parallel resonator in the parallel resonant cell near the output node further includes at least one second mass loading layer disposed above the first mass loading layer.
Optionally, the thickness of the first mass loading layer is greater than the thickness of the second mass loading layer.
Optionally, among the plurality of series resonant units, a resonant frequency of a series resonant unit located at an intermediate position is lower than resonant frequencies of series resonant units located at other positions.
Alternatively, when the number of the plurality of series resonant units is an even number, the series resonant units located at the intermediate positions are even numbers, and their resonant frequencies are the same.
Optionally, each series resonant cell comprises a series resonator, and the series resonator in the centrally located series resonant cell comprises a third mass loading layer having a thickness less than the thickness of the first mass loading layer.
Optionally, the parallel resonator is a bulk acoustic wave resonator or a surface acoustic wave resonator; the series resonator is a bulk acoustic wave resonator or a surface acoustic wave resonator.
The utility model also provides a duplexer, it includes: a filter according to any of the preceding.
The present embodiment provides a filter, which at least includes: the resonant frequency of the parallel resonant unit close to the input node and the resonant frequency of the parallel resonant unit close to the output node are lower than the resonant frequency of the rest parallel resonant units in the plurality of parallel resonators; by selectively adjusting the resonant frequency of the parallel resonators close to the port in the filter, the impedance matching performance of the filter in the whole pass band is improved.
Drawings
In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the description of the embodiments will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained without inventive work according to the drawings:
fig. 1 is an equivalent circuit diagram of a conventional filter provided according to an embodiment of the present invention;
fig. 2 is an equivalent circuit diagram of a filter according to an embodiment of the present invention;
fig. 3 is an equivalent circuit diagram of another filter provided according to an embodiment of the present invention;
fig. 4 is a comparison graph of a pass band and a roll-off of a filter provided according to an embodiment of the present invention;
fig. 5 is an equivalent circuit diagram of another filter provided according to an embodiment of the present invention;
fig. 6 is an equivalent circuit diagram of another filter provided according to an embodiment of the present invention;
fig. 7 is an equivalent circuit diagram of another filter provided according to an embodiment of the present invention.
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, which is illustrated in the accompanying drawings. The present invention is not limited to these embodiments. On the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the scope of the invention as defined by the appended claims.
It should be noted that numerous specific details are set forth in the following detailed description. It will be understood by those skilled in the art that the present invention may be practiced without these specific details. In the following detailed description, numerous specific details are set forth such as examples of well-known principles, structures, and components in order to provide a thorough understanding of the present invention.
Referring to fig. 1, fig. 1 is an equivalent circuit diagram of a conventional filter according to an embodiment of the present invention. As shown IN fig. 1, the filter includes an input node IN, an output node OUT, a plurality of series resonant cells (S11, S12, S13, S14) and a plurality of parallel resonant cells (P11, P12, P13), wherein the parallel resonant cells include parallel resonators, each of which includes a mass loading layer (not identified IN the figure).
As shown IN fig. 1, an input node IN, a plurality of series resonant cells (S11, S12, S13, S14), and an output node OUT are sequentially connected through a connection node (not identified IN the drawing). Specifically, connection nodes are arranged between the input node IN and the series resonant unit S11, between the series resonant unit S14 and the output node OUT, and between two adjacent series resonant units; the series resonator S11 and the series resonator S12 are connected in series by a connection node therebetween, the series resonator S12 and the series resonator S13 are connected in series by a connection node therebetween, and the series resonator S13 and the series resonator S14 are connected in series by a connection node therebetween.
One end of any one of the plurality of parallel resonant cells (P11, P12, P13) is connected to the connection node, and the other end is connected to the Ground Node (GND). Specifically, the parallel resonant unit P11 is disposed between the ground node GND and a connection node between the series resonant unit S11 and the series resonant unit S12, the parallel resonant unit P12 is disposed between the ground node GND and a connection node between the series resonant unit S12 and the series resonant unit S13, and the parallel resonant unit P13 is disposed between the ground node GND and a connection node between the series resonant unit S13 and the series resonant unit S14.
It is worth mentioning that the series resonance unit and the parallel resonance unit herein may be constituted by a single resonator, or may be constituted by a series and/or parallel circuit of a resonator and an inductor and/or a capacitor. For example, each of the parallel resonance units P11 to P13 may be constituted by a resonator and an inductor connected in series between the connection node and the ground node.
The related art adjusts the resonance frequency of the parallel resonator by adding a mass loading layer in the parallel resonator so that the resonance frequency of the parallel resonator is close to the resonance frequency of the series resonator. On the basis of the prior art, the same mass loading layer is generally arranged in a plurality of parallel resonators, and the mass loading layer can be of the same thickness or the same density. Although the resonance frequency of the parallel resonators can be made close to the resonance frequency of the series resonators by applying the same or different mass loading layers to the parallel resonators, when the number of the parallel resonators is increased, for example, in a filter composed of three or more parallel resonators, there is a large space for optimizing the passband matching characteristic of the entire filter.
The utility model discloses a further improve the in-band impedance match of wave filter, can set the resonant frequency of the parallel resonator who is close to input node and output node to be less than the resonant frequency of the parallel resonator who keeps away from input node and output node, through the control to the resonant frequency of parallel resonator, can be so that the wave filter obtains better roll-off and insertion loss performance.
Referring to fig. 2, fig. 2 is an equivalent circuit diagram of a filter according to an embodiment of the present invention, the filter at least includes: an input node IN, an output node OUT, a plurality of series resonant cells 10, and a plurality of parallel resonant cells 20, each parallel resonant cell 20 including a parallel resonator, each parallel resonator including a mass loading layer (not shown IN the figure).
The input node IN, the plurality of series resonant cells 10, and the output node OUT are sequentially connected by a connection node (not shown IN the figure); one end of any one of the plurality of parallel resonant cells 20 is connected to the connection node, and the other end of the parallel resonant cell 20 is connected to the ground node GND.
The resonance frequency of the parallel resonant cell 20 near the input node and the parallel resonant cell 20 near the output node is lower than the resonance frequency of the remaining parallel resonant cells 20 of the plurality of parallel resonant cells 20. It is to be understood that the series resonant unit 10 and the parallel resonant unit 20 may be formed of a single resonator, or may be formed of a series and/or parallel circuit of a resonator and an inductor and/or a capacitor. For example, each of the parallel resonance units 20 may be constituted by a parallel resonator and an inductor connected in series between the connection node and the ground node.
Referring to fig. 3, fig. 3 is an equivalent circuit diagram of another filter according to an embodiment of the present invention. As shown in fig. 3, the circuit structure of the filter is similar to that of the filter shown in fig. 1, and is a four-serial-three-parallel topology structure, which is not described herein again. IN fig. 3, each of the parallel resonators includes a first mass loading layer, and the resonance frequency of the parallel resonant cell PP1 near the input node IN and the parallel resonant cell PP2 near the output node OUT is lower than the resonance frequency of the remaining parallel resonant cells P12 of all the parallel resonant cells. It should be noted that the parallel resonant unit close to the input node IN herein refers to the parallel resonant unit closest to the input node IN, i.e., the leftmost parallel resonant unit IN the figure; the parallel resonant cell close to the output node OUT refers to the parallel resonant cell closest to the output node OUT, i.e., the rightmost parallel resonant cell in the drawing.
The utility model discloses a resonant frequency that will be close to the parallel resonator of input node and output node sets to the resonant frequency who is less than the parallel resonator who is located the intermediate position, can improve the left side roll-off of wave filter and the performance such as insertion loss echo.
In order to further improve the impedance matching in the pass band of the filter, the resonance frequencies of the parallel resonance units at the two sides in the filter may be set lower than the resonance frequency of the parallel resonance unit at the middle, and the resonance frequencies of the parallel resonance units at the two sides may be set to the same frequency value, which may further improve the insertion loss at the left side of the pass band of the filter and improve the roll-off characteristic at the left side of the pass band.
Specifically, as shown IN fig. 3, the resonance frequencies of the parallel resonant cell PP1 near the input node IN and the parallel resonant cell PP2 near the output node OUT are the same. For example, parallel resonant unit PP1 and parallelThe resonant frequency value of the resonant unit PP2 is fpp, and the resonant frequency of the parallel resonant unit P12 at the middle position is f p12 And fpp<f p12 。
Alternatively, the parallel resonant cell PP1 near the input node IN and the parallel resonant cell PP2 near the output node OUT may include at least one second mass loading layer disposed above the first mass loading layer. Specifically, the thickness of the first mass loading layer is greater than that of the second mass loading layer, and the first mass loading layer is used for ensuring the difference between the resonance frequency of the parallel resonator and the resonance frequency of the series resonator so as to form a passband; the purpose of adding the second mass loading layer on the first mass loading layer is to finely adjust the resonant frequency of the parallel resonators, so that the impedance matching in the pass band of the filter is improved, namely, the insertion loss on the left side of the pass band of the filter can be effectively improved and the roll-off characteristic on the left side of the pass band is enhanced by selectively adjusting the resonant frequency of part of the parallel resonators.
Referring to fig. 4, fig. 4 is a comparison graph of pass band and roll-off of a filter according to an embodiment of the present invention, where the abscissa represents frequency (frequency), dB (S (2, 1)), and dB (S (1, 2)) represents insertion loss (i.e., plug loss). The upper part of fig. 4 is a comparison graph of the pass band of the filter, wherein the curve shown by the thin line is the curve obtained by the filter in the prior art, and the curve shown by the thick line is the curve obtained by the embodiment shown in fig. 2; it can be seen that the insertion loss on the left side of the passband can be made good by adjusting the parallel resonant unit PP1 and the parallel resonant unit PP2 at the same frequency. Fig. 4 is a graph showing the roll-off comparison of the filter, the curve shown by the thin line is the curve obtained by the filter in the prior art, and the curve shown by the thick line is the curve obtained by the embodiment shown in fig. 2; it can be seen that the roll-off on the left side of the filter is significantly better than the roll-off on the left side of the unadjusted filter after the parallel resonant unit PP1 and the parallel resonant unit PP2 are adjusted.
Alternatively, referring to fig. 5, fig. 5 is an equivalent circuit diagram of another filter according to an embodiment of the present invention. The filter comprises an input node IN, an output node OUT, a plurality of series resonant cells (S11, S12, S13, S14) and a plurality of parallel resonant cells (PP 1, P12, PP 2), each parallel resonant cell comprising a parallel resonator, each parallel resonator comprising a first mass loading layer (not identified IN the figure).
Among the plurality of series resonant units (S11, S12, S13, S14), the resonance frequency of the series resonant unit (S12, S13) located at the middle position is lower than the resonance frequency of the series resonant unit (S11, S14) located at the other position.
Alternatively, when the number of series resonant cells is an even number, the number of series resonant cells located at the intermediate position is an even number, and the resonant frequencies of the series resonant cells (S12, S13) at the intermediate position are the same. When the number of series resonant cells is an even number, the series resonant cell located at the intermediate position may be a plurality of series resonant cells located at intermediate positions other than near the input node and the output node, for example, as shown in fig. 5, when the number of series resonant cells is 4, the series resonant cell located at the intermediate position may be the series resonant cell S12 and the series resonant cell S13. For another example, when the number of the series resonant cells is 6, the 6 series resonant cells are numbered in the direction from the input node to the output node, and are 1,2,3,4,5,6 in this order, the intermediate series resonant cell may be a plurality of series resonant cells at intermediate positions other than near the input node and the output node, that is, the intermediate series resonant cell may be 2,3,4,5, or the intermediate series resonant cell may be 3,4.
Further, the series resonance unit may include a series resonator. The series resonator at the intermediate position includes a third mass loading layer having a thickness smaller than that of the first mass loading layer.
Wherein the thicknesses of the first, second and third mass loading layers may be different. The thickness of the second mass loading layer and the third mass loading layer is smaller than that of the first mass loading layer.
The purpose of adding the third mass loading layer in part of the series resonators is to finely adjust the resonance frequency of the series resonators and improve the impedance matching in the pass band of the filter, namely, the insertion loss on the right side of the pass band of the filter can be effectively improved and the roll-off characteristic on the right side of the pass band can be enhanced by selectively adjusting the resonance frequency of part of the series resonators.
The utility model discloses select to finely tune the resonant frequency of part parallel resonator and the resonant frequency of part series resonator, to the resonant frequency of parallel resonator, it satisfies that the resonant frequency of the parallel resonator who is close to input node and output node position is less than the resonant frequency who keeps away from input node and output node, preferably, sets the resonant frequency of the parallel resonator who is close to input node and output node position to the same value; meanwhile, as for the resonance frequency of the series resonator, it is satisfied that the resonance frequency of the series resonator near the input node and the output node is larger than the resonance frequency of the series resonator far from the input node and the output node, and it is preferable that the resonance frequency of the series resonator far from the input node and the output node is set to the same value. The series resonators and the parallel resonators are simultaneously subjected to the selective adjustment, so that the impedance matching in the pass band of the filter can be improved more optimally, namely, the insertion loss on the left side of the pass band of the filter can be effectively improved and the roll-off characteristic on the left side of the pass band can be enhanced by selectively adjusting the resonant frequencies of part of the parallel resonators, and meanwhile, the insertion loss on the right side of the pass band of the filter can be effectively improved and the roll-off characteristic on the right side of the pass band can be enhanced by selectively adjusting the resonant frequencies of part of the series resonators.
Alternatively, referring to fig. 6, fig. 6 is an equivalent circuit diagram of another filter according to an embodiment of the present invention. As shown IN fig. 6, the filter includes an input node IN, an output node OUT, a plurality of series resonant cells (S11, S12, S13, S14), each of which includes a parallel resonator, and a plurality of parallel resonant cells (PP 1, P12, P13, PP 2), each of which includes a first mass loading layer (not identified IN the figure).
First mass loading layer of parallel resonator included in parallel resonance unit PP1 and parallel resonator included in parallel resonance unit PP2The thicknesses of the first mass loading layers of the parallel resonators included in the parallel resonance unit P12 and the thicknesses of the first mass loading layers of the parallel resonators included in the parallel resonance unit P13 are different. That is, the resonance frequencies of the parallel resonance unit PP1 and the parallel resonance unit PP2 are the same, and the resonance frequencies of the parallel resonance unit P12 and the parallel resonance unit P13 are different. For example, the resonance frequency f of the parallel resonance unit P12 p12 Greater than the resonance frequency f of the parallel resonant unit P13 p13 The resonant frequency of the parallel resonant unit PP1 and the parallel resonant unit PP2 is denoted as fpp, and the following conditions are met: fpp<f p13 <f p12 . Alternatively, the resonance frequency f of the parallel resonance unit P12 p12 Less than the resonance frequency f of the parallel resonant unit P13 p13 The resonant frequency of the parallel resonant unit PP1 and the parallel resonant unit PP2 is denoted as fpp, and the following conditions are met: fpp<f p12 <f p13 。
Alternatively, the parallel resonators included in the parallel resonance unit PP1 and the parallel resonance unit PP2 may include: a second mass loading layer disposed above the first mass loading layer. Specifically, the thicknesses of the second mass loading layer provided in the parallel resonator of the parallel resonance unit PP1 and the second mass loading layer provided in the parallel resonator of the parallel resonance unit PP2 may be the same, and the purpose thereof is to further reduce the resonance frequency of the parallel resonators included in the parallel resonance unit PP1 and the parallel resonance unit PP2, thereby effectively improving the passband left-side insertion loss of the filter and enhancing the passband left-side roll-off characteristic.
The utility model discloses a resonant frequency that will be close to the parallel resonance unit PP1 of input node IN and the parallel resonance unit PP2 that is close to output node OUT sets to the resonant frequency who is less than remaining parallel resonance unit P12 IN all parallel resonance units, and these two resonant frequency set to the same value, improve the left side roll-off performance of wave filter well and insert and decrease the echo performance.
Alternatively, referring to fig. 7, fig. 7 is an equivalent circuit diagram of another filter according to an embodiment of the present invention. As shown in fig. 7, the circuit structure is similar to that of the filter shown in fig. 6, and is not repeated here. Among the plurality of series resonant units (S11, S12, S13, S14), the resonance frequency of the series resonant unit (S12, S13) located at the middle position is lower than the resonance frequency of the series resonant units (S11, S14) located at the other positions, and the resonance frequencies of the series resonant units (S12, S13) are the same.
Further, the same mass loading layer is provided in the series resonators included in the series resonant units (S12, S13) so that the resonance frequencies thereof are made the same. For example, the resonance frequency f of the series resonance unit S12 is made to be higher than the resonance frequency f of the series resonance unit S12 by adding a third mass loading layer in the series resonator included in the series resonance unit (S12, S13) s12 And the resonance frequency f of the series resonant unit S13 s13 Are all lower than the resonance frequency f of the series resonance unit S11 s11 And the resonance frequency f of the series resonant unit S14 s14 Resonant frequency f of series resonant unit S11 s11 And the resonance frequency f of the series resonant unit S14 s14 May be different or the same.
The utility model discloses a resonance frequency to the parallel resonator of part carries out the selectivity adjustment, can improve the passband left side insertion loss of wave filter effectively to strengthen passband left side roll-off characteristic, carry out the selectivity adjustment to the resonance frequency of the series resonator of part again simultaneously, can improve the passband right side insertion loss of wave filter effectively, and strengthen passband right side roll-off characteristic.
Furthermore, the utility model also provides a duplexer, it includes the utility model discloses an above embodiment's wave filter.
The utility model provides a wave filter that duplexer includes can include a plurality of series resonance units and a plurality of parallel resonance unit, the utility model discloses select to finely tune the resonant frequency of partial parallel resonance unit and/or the resonant frequency of partial series resonance unit.
As for the resonance frequency of the parallel resonance unit, it is satisfied that the resonance frequency of the parallel resonance unit near the input node and the output node is lower than the resonance frequency of the parallel resonance unit far from the input node and the output node; specifically, a mass loading layer may be added to the parallel resonant unit close to the port of the filter, so that the frequency of the parallel resonant unit close to the port of the filter shifts to a lower position, and insertion loss on the left side of the passband becomes good and return loss becomes good.
It suffices for the resonance frequency of the series resonant cell that the resonance frequency of the series resonant cell close to the input node and the output node is greater than the resonance frequency of the series resonant cell far from the input node and the output node.
Preferably, if the parallel resonance unit or the series resonance unit included in the filter is a bilaterally symmetric structure, the resonance frequencies of the parallel resonance units near the input node and the output node may be set to the same value; meanwhile, the resonance frequencies of the series resonant cells distant from the input node and the output node are set to the same value.
The utility model discloses carry out above-mentioned adjustment simultaneously to series resonance unit and parallel resonance unit, impedance match obtains improving more optimally in can making the passband of wave filter, carry out selectivity adjustment through the resonant frequency to the parallel resonator of part promptly, can improve the passband left side insertion loss of wave filter effectively, and strengthen the passband left side roll-off characteristic, carry out selectivity adjustment to the resonant frequency of the series resonator of part again simultaneously, can improve the passband right side insertion loss of wave filter effectively, and strengthen the passband right side roll-off characteristic.
To sum up, according to the utility model provides a duplexer can guarantee all to have better roll-off characteristic in the passband left and right sides for when the resonant frequency on passband left side and right side all squinted to the low frequency direction, impedance matching performance in can also optimizing the passband makes its left side insertion loss and return loss all become good.
The above disclosure is intended to cover only some embodiments or implementations of the invention, and not all embodiments or implementations of the invention, which may be embodied or carried out in any suitable manner without departing from the scope of the invention.
Claims (9)
1. A filter, characterized in that it comprises at least: an input node, an output node, a plurality of series resonant cells, and a plurality of parallel resonant cells;
connecting nodes are arranged between the input node and the series resonance units, between the series resonance units and the output node and between two adjacent series resonance units, and the input node, the plurality of series resonance units and the output node are sequentially connected through the connecting nodes; one end of any one of the plurality of parallel resonance units is connected with the connection node, and the other end of the any one of the plurality of parallel resonance units is connected with the grounding node;
the resonance frequency of the parallel resonant cell near the input node and the parallel resonant cell near the output node is lower than the resonance frequency of the remaining parallel resonant cells of the plurality of parallel resonant cells.
2. The filter of claim 1, wherein the resonant frequencies of the parallel resonant cells near the input node and the parallel resonant cells near the output node are the same.
3. A filter according to claim 1 or 2, wherein the parallel resonance unit comprises parallel resonators, each of the parallel resonators comprising a first mass loading layer; the parallel resonator in the parallel resonant cell near the input node and the parallel resonator in the parallel resonant cell near the output node further includes at least one second mass loading layer disposed above the first mass loading layer.
4. The filter of claim 3, wherein the thickness of the first mass loading layer is greater than the thickness of the second mass loading layer.
5. The filter according to claim 1 or 2, wherein, among the plurality of series resonant units, a resonance frequency of a series resonant unit located at an intermediate position is lower than resonance frequencies of series resonant units located at other positions.
6. The filter according to claim 5, wherein when the number of the plurality of series resonant units is an even number, the series resonant units located at the intermediate positions are an even number, and their resonant frequencies are the same.
7. A filter as claimed in claim 3, wherein each of the series resonant cells comprises a series resonator, the series resonator in the centrally located series resonant cell comprising a third mass loading layer, the thickness of the third mass loading layer being less than the thickness of the first mass loading layer.
8. The filter of claim 7, wherein the parallel resonators are bulk acoustic wave resonators or surface acoustic wave resonators; the series resonator is a bulk acoustic wave resonator or a surface acoustic wave resonator.
9. A duplexer comprising the filter of any one of claims 1 to 8.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202222581635.8U CN218734229U (en) | 2022-09-27 | 2022-09-27 | Filter and duplexer |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202222581635.8U CN218734229U (en) | 2022-09-27 | 2022-09-27 | Filter and duplexer |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN218734229U true CN218734229U (en) | 2023-03-24 |
Family
ID=85637796
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202222581635.8U Active CN218734229U (en) | 2022-09-27 | 2022-09-27 | Filter and duplexer |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN218734229U (en) |
-
2022
- 2022-09-27 CN CN202222581635.8U patent/CN218734229U/en active Active
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN110492864B (en) | Packaging structure of bulk acoustic wave filter and manufacturing method of filter | |
| CN104412268B (en) | The Curve guide impeller of microwave acoustic wave filter | |
| CN111327288B (en) | Bulk acoustic wave resonator, ultra-narrow band filter, duplexer and multiplexer | |
| CN107342749B (en) | Band-pass filter | |
| CN103929148A (en) | Low-insertion-loss piezoelectric sound wave band pass filter and realization method | |
| CN110995195B (en) | Filter | |
| CN111600565A (en) | Filter circuit, signal processing device and method for manufacturing filter circuit | |
| CN116781035A (en) | Filter, multiplexer and RF front-end module | |
| CN111147037A (en) | Method for adjusting resonator frequency in bulk acoustic wave filter and bulk acoustic wave filter | |
| CN114567282A (en) | High-selectivity IPD filter chip suitable for N77 frequency band | |
| WO2021185258A1 (en) | Method for adjusting resonant frequency, and filter, multiplexer, and communication device | |
| CN111130498A (en) | Duplexer | |
| CN218734229U (en) | Filter and duplexer | |
| CN111342806B (en) | Piezoelectric filter having lamb wave resonator, duplexer, and electronic device | |
| CN116032243A (en) | Band-pass filter circuit of high roll-off of big bandwidth | |
| CN112511126B (en) | Multiplexer and method for improving isolation of multiplexer and communication equipment | |
| CN211830724U (en) | Band-pass filter circuit and multiplexer | |
| CN113067561A (en) | Band-stop filter and multi-frequency band-stop filter | |
| CN112886945A (en) | Notch filter and multi-frequency notch filter | |
| CN106025454A (en) | Improved Jerusalem cross unit double-layer FSS structure | |
| CN113541635A (en) | High-linearity phase film bulk acoustic wave filter based on phase perturbation layer | |
| CN107834135B (en) | Planar triplexer based on branch knot loading structure | |
| CN107508019B (en) | Duplexer | |
| CN215186667U (en) | Band-stop filter and multi-frequency band-stop filter | |
| CN116346069B (en) | Filter and electronic device |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| GR01 | Patent grant | ||
| GR01 | Patent grant |