Filter Design Method, Device and Related Equipment

Abstract

An embodiment of the present invention provides a filter design method, apparatus, and related equipment. The filter includes an input end and an output end, as well as a plurality of resonant units located therebetween. The method includes: obtaining the level numbers corresponding to each resonant unit in the preset structure of the filter, which are used to indicate the electrical connection order of the resonant units from the input end to the output end; selecting one or more resonant units as the resonant units to be split based on a preset rule; the preset rule at least includes selecting the resonant units to be split based on the priority, and the higher the level number of the resonant unit, the higher the corresponding priority; splitting the resonant unit to be split into a combination of a plurality of resonators. When the resonant unit to be split is a series resonant unit, it is split into a combination of a plurality of resonators connected in series or in parallel. The present invention improves the nonlinear characteristics of the filter.

Description

Technical Field

[0001] Embodiments of the present invention relate to the field of filter manufacturing, and particularly to a filter design method, apparatus, and related equipment. Background Art

[0002] With the continuous development of mobile communication devices, the trend of high utilization rate of spectrum resources and spectrum complexity is accelerating. Currently, the number of frequency bands used in mobile communication has increased significantly from 4 frequency bands to more than 50 frequency bands (5G), and the complexity of communication protocols has also made the requirements for the performance of radio frequency systems increasingly stringent. Among them, as an important part of the radio frequency system, the good performance of the filter is of great significance for improving the transmission rate, lifespan, and reliability of the radio frequency system.

[0003] Therefore, how to improve the performance of the filter has always been a problem studied by those skilled in the art. Summary of the Invention

[0004] In view of this, embodiments of the present invention provide a filter design method, apparatus, and related equipment to improve the non-linear characteristics of the filter and achieve the improvement of the filter performance.

[0005] To solve the above problems, embodiments of the present invention provide the following technical solutions:

[0006] In a first aspect, embodiments of the present invention provide a filter design method. The filter includes an input end and an output end, and a plurality of resonant units located between the input end and the output end. The method includes:

[0007] Obtain the level numbers corresponding to each resonant unit in the preset structure of the filter. The level number is used to indicate the electrical connection order of the resonant unit between the input end and the output end, where the electrical connection order is sorted starting from the input end;

[0008] Based on a preset rule, select one or more resonant units from the plurality of resonant units as the resonant units to be split; where the preset rule at least includes: select the resonant units to be split based on the priority of the resonant unit. The higher the level number of the resonant unit, the higher the corresponding priority;

[0009] Split the resonant unit to be split into a combination of a plurality of resonators. When the resonant unit to be split is a series-stage resonant unit, split the resonant unit to be split into a combination of a plurality of resonators connected in series or parallel; when the resonant unit to be split is a parallel-stage resonant unit, split the resonant unit to be split into a combination of a plurality of resonators connected in parallel.

[0010] Optionally, the preset rule further includes: based on the non-linear splitting series, selecting a corresponding number of resonating units to be split, where the non-linear splitting series indicates the number of resonating units continuously split in descending order of priority;

[0011] Based on the preset rule, selecting one or more resonating units from multiple resonating units as the resonating units to be split, specifically:

[0012] According to the non-linear splitting series, selecting, from multiple resonating units, a number of resonating units corresponding to the non-linear splitting series as the resonating units to be split based on the priority of the resonating units.

[0013] Optionally, the non-linear splitting series is greater than or equal to 1 / 2 of the total number of resonating units in the preset structure of the filter.

[0014] Optionally, splitting the resonating unit to be split into a combination of multiple resonators, specifically, splitting the resonating unit to be split into a first resonator and a second resonator.

[0015] Optionally, when the resonating unit to be split is a series-connected resonating unit, splitting the resonating unit to be split into a combination of multiple resonators connected based on a series or parallel connection manner includes:

[0016] When the resonating unit to be split is a series-connected resonating unit, the first resonator is connected in series with the second resonator, the upper electrode of the first resonator is electrically connected to the upper electrode of the second resonator, the lower electrode of the first resonator and the lower electrode of the second resonator respectively correspond to the input end and the output end of the signal, or the lower electrode of the first resonator is electrically connected to the lower electrode of the second resonator, and the upper electrode of the first resonator and the upper electrode of the second resonator respectively correspond to the input end and the output end of the signal; or,

[0017] When the resonating unit to be split is a series-connected resonating unit, the first resonator is connected in parallel with the second resonator, the upper electrode of the first resonator is electrically connected to the lower electrode of the second resonator, and the lower electrode of the first resonator is electrically connected to the upper electrode of the second resonator, and the upper electrode or the lower electrode of the first resonator and the second resonator respectively correspond to the input end and the output end of the signal.

[0018] Optionally, when the resonating unit to be split is a parallel-connected resonating unit, splitting the resonating unit to be split into a combination of multiple resonators connected based on a parallel connection manner includes:

[0019] When the resonator unit to be split is a parallel - stage resonator unit, the first resonator and the second resonator are connected in parallel. The upper electrode of the first resonator is electrically connected to the lower electrode of the second resonator, and the lower electrode of the first resonator is electrically connected to the upper electrode of the second resonator. The upper electrode or the lower electrode of the first resonator and the second resonator respectively correspond to the input terminal and the output terminal of the signal.

[0020] Optionally, in the preset structure of the filter, any resonator unit is a series - stage resonator unit or a parallel - stage resonator unit. The number of levels includes the number of series levels and the number of parallel levels. Obtaining the number of levels corresponding to each resonator unit in the filter includes:

[0021] Obtain the number of series levels of each series - stage resonator unit. The number of series levels is used to indicate the electrical connection order of the series - stage resonator units between the input terminal and the output terminal. The higher the number of levels of the series - stage resonator unit closer to the output terminal, the higher the level.

[0022] Obtain the number of parallel levels of each parallel - stage resonator unit. The number of parallel levels is used to indicate the electrical connection order of the parallel - stage resonator units between the input terminal and the output terminal. The higher the number of levels of the parallel - stage resonator unit closer to the output terminal, the higher the level.

[0023] Based on the preset structure of the filter, obtain the number of levels of each resonator unit. The number of levels is used to indicate the arrangement order of the resonator units between the input terminal and the output terminal. The higher the number of levels of the resonator unit closer to the output terminal, the higher the level.

[0024] In a second aspect, an embodiment of the present invention further provides a filter, including: an input terminal, an output terminal, and a plurality of resonator units located between the input terminal and the output terminal;

[0025] Among them, the resonator unit corresponds to a number of levels in the preset structure of the filter. The number of levels is used to indicate the electrical connection order of the resonator unit between the input terminal and the output terminal, where the electrical connection order is sorted starting from the input terminal;

[0026] Use at least one resonator unit as the split resonator unit in the split unit group. The split resonator unit is selected based on the priority of the resonator unit. The higher the number of levels of the resonator unit, the higher the corresponding priority;

[0027] The split resonator unit in the split unit group is a combination of multiple resonators. When the split resonator unit is a series - stage resonator unit, the split resonator unit is a combination of multiple resonators based on series or parallel connection methods; when the split resonator unit is a parallel - stage resonator unit, the split resonator unit is a combination of multiple resonators based on parallel connection methods.

[0028] Optionally, the split resonant unit is specifically a combination of a first resonator and a second resonator;

[0029] Wherein, the first resonator and the second resonator include a substrate, a lower electrode located on the substrate, a piezoelectric layer covering the lower electrode, and an upper electrode located on the piezoelectric layer.

[0030] Optionally, when the split resonant unit is a series cascaded resonant unit, the split resonant unit is a combination of multiple resonators based on a series or parallel connection method, including:

[0031] The first resonator is connected in series with the second resonator, and the upper electrode of the first resonator is electrically connected to the upper electrode of the second resonator. Then, the lower electrode of the first resonator and the lower electrode of the second resonator respectively correspond to the input end and the output end of the signal. Or, the lower electrode of the first resonator is electrically connected to the lower electrode of the second resonator, and then the upper electrode of the first resonator and the upper electrode of the second resonator respectively correspond to the input end and the output end of the signal; or,

[0032] The first resonator is connected in parallel with the second resonator, the upper electrode of the first resonator is electrically connected to the lower electrode of the second resonator, and the lower electrode of the first resonator is electrically connected to the upper electrode of the second resonator. Then, the upper electrode or the lower electrode of the first resonator and the second resonator respectively correspond to the input end and the output end of the signal.

[0033] Optionally, when the split resonant unit is a parallel cascaded resonant unit, the split resonant unit is a combination of multiple resonators based on a parallel connection method, including:

[0034] The first resonator is connected in parallel with the second resonator, the upper electrode of the first resonator is electrically connected to the lower electrode of the second resonator, and the lower electrode of the first resonator is electrically connected to the upper electrode of the second resonator. Then, the upper electrode or the lower electrode of the first resonator and the second resonator respectively correspond to the input end and the output end of the signal.

[0035] Optionally, in the preset structure of the filter, any resonant unit is a series cascaded resonant unit or a parallel cascaded resonant unit, and the number of levels includes the number of series levels and the number of parallel levels;

[0036] When the resonant units are connected in series at the input end and the output end, the resonant unit has a number of series levels, and the higher the number of series levels of the resonant unit closer to the output end;

[0037] When the resonance units are in a parallel electrical connection order between the input end and the output end, the resonance units have parallel levels, and the resonance unit closer to the output end has a higher parallel level;

[0038] When the resonance units have an arrangement order between the input end and the output end, based on the preset structure of the filter, the resonance unit closer to the output end has a higher level.

[0039] Optionally, the number of split resonance units in the split unit group corresponds to the non-linear split level number, and the non-linear split level number indicates the number of resonance units continuously split in descending order of priority, where the non-linear split level number is greater than or equal to 1 / 2 of the total number of resonance units in the preset structure of the filter.

[0040] In a third aspect, an embodiment of the present invention further provides a terminal, and the terminal includes the filter described in the second aspect above.

[0041] In a fourth aspect, an embodiment of the present invention further provides a base station, and the base station includes the filter described in the second aspect above.

[0042] In a fifth aspect, an embodiment of the present invention further provides a duplexer, and the duplexer includes the filter described in the second aspect above.

[0043] In a sixth aspect, an embodiment of the present invention further provides a filter design device, including:

[0044] An acquisition module, configured to acquire the level number corresponding to each resonance unit in the preset structure of the filter, where the level number is used to indicate the electrical connection order of the resonance unit between the input end and the output end, and the electrical connection order is sorted starting from the input end;

[0045] A selection module, configured to select one or more resonance units from multiple resonance units as the resonance units to be split based on a preset rule; where the preset rule at least includes: selecting the resonance units to be split based on the priority of the resonance unit, and the higher the level number of the resonance unit, the higher the corresponding priority;

[0046] A splitting module, configured to split the resonance unit to be split into a combination of multiple resonators, where when the resonance unit to be split is a series-stage resonance unit, the resonance unit to be split is split into a combination of multiple resonators connected in series or parallel; when the resonance unit to be split is a parallel-stage resonance unit, the resonance unit to be split is split into a combination of multiple resonators connected in parallel.

[0047] In a seventh aspect, an embodiment of the present invention further provides a storage medium storing one or more computer-executable instructions for executing the filter design method described in the first aspect above.

[0048] An embodiment of the present invention provides a filter design method, apparatus, and related equipment. The filter includes an input end and an output end, and a plurality of resonant units located between the input end and the output end. The method includes: obtaining the level numbers corresponding to the respective resonant units in the preset structure of the filter, where the level numbers are used to indicate the electrical connection order of the resonant units between the input end and the output end, and wherein the electrical connection order is sorted starting from the input end; selecting one or more resonant units from the plurality of resonant units as the resonant units to be split based on a preset rule; where the preset rule at least includes selecting the resonant units to be split based on the priority, and the higher the level number of the resonant unit, the higher the corresponding priority; splitting the resonant unit to be split into a combination of a plurality of resonators, where when the resonant unit to be split is a series-stage resonant unit, splitting the resonant unit to be split into a combination of a plurality of resonators connected in series or in parallel; and when the resonant unit to be split is a parallel-stage resonant unit, splitting the resonant unit to be split into a combination of a plurality of resonators connected in parallel.

[0049] Among them, in the filter design method of the embodiment of the present invention, by determining the resonant units to be split based on obtaining the level numbers corresponding to the respective resonant units in the preset structure of the filter and the preset rule, considering the influence of the second-order nonlinear harmonic components generated by the resonant units with different level numbers on the nonlinear characteristics of the filter, and then splitting the resonant unit to be split into a combination of a plurality of resonators according to the circuit connection mode corresponding to the resonant unit to be split, the generation of the second-order nonlinear harmonics is suppressed, thereby improving the nonlinear characteristics of the filter and enhancing the filter performance. Description of the Drawings

[0050] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only the embodiments of the present invention, and those of ordinary skill in the art can obtain other drawings according to the provided drawings without creative efforts.

[0051] Figure 1 is a schematic diagram of an optional structure of the filter;

[0052] Figure 2 is a schematic diagram of an optional structure of the resonator;

[0053] Figure 3 is a schematic diagram of the electrical symbol of the resonator;

[0054] Figure 4 is another optional structural schematic diagram of the filter;

[0055] Figure 5 is an optional flowchart of the filter design method provided by the embodiments of the present invention;

[0056] Figure 6 is a schematic diagram of the relationship curve between the non - linear characteristics of the filter and the number of non - linear splitting levels provided by the embodiments of the present invention;

[0057] Figure 7 and Figure 8 is a schematic diagram of the series splitting structure of the resonant unit provided by the embodiments of the present invention;

[0058] Figure 9 and Figure 10 is a schematic diagram of the parallel splitting structure of the resonant unit provided by the embodiments of the present invention;

[0059] Figure 11 is an optional structural schematic diagram of the resonant unit with series non - linear splitting of the upper electrode interconnection provided by the embodiments of the present invention;

[0060] Figure 12 is an optional structural schematic diagram of the resonant unit with series non - linear splitting of the lower electrode interconnection provided by the embodiments of the present invention;

[0061] Figure 13 is provided by the embodiments of the present invention Figure 11 and Figure 12 is a schematic diagram of the equivalent circuit of the resonant unit with the structure shown;

[0062] Figure 14 is a schematic diagram of the second - order non - linear harmonic frequency characteristics curve of the series - split resonant unit provided by the embodiments of the present invention;

[0063] Figure 15 is an optional structural schematic diagram of the duplexer provided by the embodiments of the present invention;

[0064] Figure 16 is an optional block diagram of the filter design device provided by the embodiments of the present invention. Detailed implementation manners

[0065] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0066] A filter can effectively filter out frequency points of a specific frequency or frequencies outside that frequency point, obtaining a signal of a specific frequency or a signal after eliminating a specific frequency. Among them, the basic component that makes up the filter is a resonator. For a filter, it is generally composed of resonators, plus a certain number of inductors to ground and matching inductors. Moreover, in a filter, the resonators connected in parallel can be called parallel resonators, and the resonators connected in series can be called series resonators. In a filter, there can be at least one series resonator and at least one parallel resonator, and at least one inductor to ground is connected to each parallel resonator. Taking Figure 1 an optional structure of a filter shown as an example, in the figure, S1 to S4 are multi-stage series resonators, P1 to P4 are multi-stage parallel resonators, L1 to L2 are series inductors, L3 to L6 are parallel inductors, IN is the filter signal input terminal, and OUT is the filter signal output terminal. It should be noted that in order to better achieve the stability of the filter, an LC matching circuit may also be included at the filter signal input terminal and / or signal output terminal.

[0067] Corresponding to Figure 1 the filter structure shown, Figure 2 a schematic diagram of an optional structure of a resonator is shown. As Figure 2 shown, the resonator can include a substrate 201, a lower electrode 202 located on the substrate, a piezoelectric layer 203 covering the lower electrode 202, and an upper electrode 204 located on the piezoelectric layer 203.

[0068] Among them, the substrate 201 is used to provide a support platform for the device and a process basis for forming the corresponding structure of the device. The material of the substrate can be a semiconductor material, such as silicon, germanium, gallium arsenide, etc., or an insulating material, such as quartz, sapphire, etc. The lower electrode 202 corresponds to the upper electrode 204 and is used to provide a corresponding electrical environment for the resonator together with the upper electrode 204. The piezoelectric layer 203 is used to process electrical signals based on the electrical environment provided by the upper electrode and the lower electrode. Taking a bulk acoustic wave resonator as an example, the piezoelectric layer is used to process acoustic signals accordingly. The materials of the upper electrode and the lower electrode can be metal materials, such as molybdenum, ruthenium, gold, aluminum, magnesium, tungsten, copper, titanium, iridium, osmium, chromium, etc., or composite materials of the above metals or their alloy materials, etc. The material of the piezoelectric layer can be one or more of single crystal aluminum nitride, polycrystalline aluminum nitride, zinc oxide, PZT materials, etc., or a material doped with a certain atomic ratio of rare earth elements in the above materials.

[0069] In a specific example, the upper electrode 204 and / or the lower electrode 202 may include a mass loading layer (not shown in the figure), such that a certain frequency difference is formed between the parallel resonator and the series resonator, thereby achieving a passband with a certain bandwidth. There is also a cavity 205 between the lower electrode 202 and the substrate 201, which is used to form an acoustic mirror for reflecting acoustic waves, thereby improving the quality factor of the resonator. Additionally, the present invention does not specifically limit the formation method of the cavity 205. For example, it may be formed by being supported by other materials above the substrate 201. Thus, the acoustic mirror can also be formed based on other forms, such as forming an acoustic mirror based on a Bragg reflector layer. The present invention does not specifically limit this either. In the thickness direction of the resonator, that is Figure 2 as shown in the direction of the Y-axis of the rectangular coordinate system shown in

[0070] Corresponding to Figure 2 , Figure 3 a schematic electrical symbol diagram of the resonator is shown. As Figure 3 shown, node N1 can be connected to the upper electrode 204 of the resonator, and node N2 can be connected to the lower electrode 202 of the resonator. The half-wavelength of the fundamental resonance frequency of the resonator is approximately equal to the thickness of the piezoelectric layer of the resonator (i.e., half-wavelength resonance). Among them, when the upper electrode 204 is of positive polarity, the lower electrode 202 is of negative polarity, or when the upper electrode 204 is of negative polarity, the lower electrode 202 is of positive polarity, then the polarization direction c of the resonator is defined as pointing from node N2 to node N1 in the thickness direction of the resonator.

[0071] The wavelength of the second-order nonlinear harmonic component generated by the resonator is approximately equal to the thickness of the piezoelectric layer, that is, when the upper and lower electrodes are of positive polarity, the center of the piezoelectric layer is of negative polarity, or when the upper and lower electrodes are of negative polarity, the center of the piezoelectric layer is of positive polarity; when the piezoelectric layer has a symmetry axis in the thickness direction of the resonator, that is, when the piezoelectric layer is symmetric in the thickness direction of the resonator, then the upper and lower electrodes have the same electric potential. At this time, the resonator does not generate a second-order nonlinear harmonic. However, in the actual application process, in order to obtain good resonator performance, usually the piezoelectric layer is asymmetric in the thickness direction of the resonator. The asymmetry of the piezoelectric layer makes the distribution of the electric field therein uneven. The uneven distribution of the electric field causes a second-order nonlinear harmonic potential difference between the upper and lower electrodes, thereby the resonator generates a second-order nonlinear harmonic, and the generated second-order nonlinear harmonic will affect the nonlinear characteristics of the filter and reduce the filter performance.

[0072] Therefore, it is necessary to effectively improve the nonlinear characteristics of the filter to enhance the filter performance.

[0073] In an alternative example, since the areas of the resonators may vary, when designing the filter, the resonator can be split into a combination of multiple resonators based on the area of the resonator connected correspondingly, so as to improve the nonlinear characteristics of the filter. As Figure 4 Another alternative structural schematic diagram of the filter shown in the figure. Among them, the area of the series resonator S13 is smaller than the area of at least one resonator among the series resonator S11 near the signal input end, the parallel resonator P11, the series resonator S15 near the signal output end, and the parallel resonator P14. Then, the series resonator S13 can be split nonlinearly in series and split into a combination of two series resonators. Or, the area of the parallel resonator P12 is smaller than the area of at least one resonator among the series resonator S11 near the signal input end, the parallel resonator P11, the series resonator S15 near the signal output end, and the parallel resonator P14. Then, the parallel resonator P12 can be split nonlinearly in series and split into a combination of two resonators in series. Among them, the series resonator S11 and the parallel resonator P11 can be the first-stage resonators near the signal input end, and the series resonator S15 and the parallel resonator P14 can be the first-stage resonators near the signal output end.

[0074] However, the inventors have found through research that: in the filter design method of splitting the resonator into a combination of multiple series resonators based on the area of the correspondingly connected resonator, the improvement effect on the nonlinear characteristics of the filter is not obvious. The reason is that: when the signal is input from the signal input port IN, the second-order nonlinear harmonic components generated by the resonator near the signal input end will be suppressed and attenuated by the subsequent resonator. Taking Figure 1 the structure shown in the figure as an example, the second-order nonlinear harmonic components generated by S1 and P1 will be suppressed by S2 and P2 and thus attenuated. Then, the closer the resonator is to the signal input end, the smaller the influence of the second-order nonlinear harmonic components generated by the resonator on the nonlinear characteristics of the filter. However, the second-order nonlinear harmonic components generated by the resonators S4 and P4 near the signal output end are not suppressed by any subsequent resonator, so second-order nonlinear harmonic components will be generated at the signal output end OUT. That is to say, the resonator near the signal output end in the filter has a greater impact on the filter nonlinearity. Therefore, splitting the resonator into a combination of multiple series resonators based on the area of the correspondingly connected resonator does not have an obvious improvement effect on the nonlinear characteristics of the filter.

[0075] In view of this, an embodiment of the present invention provides an improved filter design scheme. By obtaining the level numbers corresponding to each resonant unit in the preset structure of the filter and preset rules, the resonant unit to be split is determined. Considering the influence of the second-order nonlinear harmonic components generated by the resonant units with different level numbers on the nonlinear characteristics of the filter, and then according to the circuit connection mode corresponding to the resonant unit to be split in the filter, the resonant unit to be split is split into a combination of multiple resonators, so as to suppress the generation of second-order nonlinear harmonic components, improve the nonlinear characteristics of the filter, and enhance the filter performance.

[0076] Among them, Figure 5 An optional flowchart of the filter design method provided by the embodiment of the present invention is exemplarily shown. The filter may include an input end and an output end, and a plurality of resonant units located between the input end and the output end. The resonant unit can be understood as an overall of different resonators or a resonator composed of a combination of multiple resonators in the filter. Among them, the resonant unit on the series branch can be called a series resonant unit, and the resonant unit on the parallel branch can be called a parallel resonant unit. For example Figure 1 S1 and P1 shown, or Figure 2 S13 and P12 shown. As Figure 5 shown, the filter design method may include the following steps:

[0077] Step S51: Obtain the level numbers corresponding to each resonant unit in the preset structure of the filter.

[0078] The preset structure of the filter can be understood as the structure of a filter that is pre-designed and contains multiple resonant units. Among them, the preset structure contains multiple resonant units and the corresponding electrical connection relationships of each resonant unit. The preset structure can be understood as the initial architecture of the filter or the specific basic structure to be adjusted / designed. The level number can be used to indicate the electrical connection order of the resonant unit between the input end and the output end, where the electrical connection order is sorted starting from the input end.

[0079] In an optional example, when each resonant unit is connected in series, sorting each resonant unit from the input end to the output end can obtain the level numbers of the series-connected resonant units; taking Figure 1 the structure of the filter shown as an example, S1 is a first-level series resonant unit, S2 is a second-level series resonant unit, S3 is a third-level series resonant unit, and S4 is a fourth-level series resonant unit. In another optional example, when each resonant unit is connected in parallel, sorting each resonant unit from the input end to the output end can obtain the level numbers of the parallel-connected resonant units; taking Figure 1Taking the structure of the filter shown as an example, P1 is the first-stage parallel resonance unit, P2 is the second-stage parallel resonance unit, P3 is the third-stage parallel resonance unit, and P4 is the fourth-stage parallel resonance unit. In another alternative example, when each resonance unit includes series connection and parallel connection, based on the preset structure of the filter, each resonance unit can be sorted from the input end to the output end according to certain rules. For example, the rule can be to alternately sort one series-connected resonance unit and one parallel-connected resonance unit starting from the input end, so as to obtain the level numbers of each resonance unit; taking Figure 1 Taking the structure of the filter shown as an example, S1 is the first-stage resonance unit, P1 is the second-stage resonance unit, S2 is the third-stage resonance unit, P2 is the fourth-stage resonance unit, and so on.

[0080] Step S52: Based on the preset rules, select one or more resonance units from multiple resonance units as the resonance units to be split.

[0081] The resonance unit to be split can be understood as a resonance unit that can be split into a combination of multiple resonators.

[0082] Since the resonator near the signal output end in the filter has a greater impact on the nonlinear characteristics of the filter, in the embodiments of the present invention, the preset rules can be preset based on the priorities corresponding to each resonance unit, and can at least include selecting the resonance units to be split based on the priorities of the resonance units. The higher the level number of the resonance unit, the higher the corresponding priority. Taking Figure 1 Taking the filter structure shown as an example, S1 is the first-stage series resonance unit, P1 is the first-stage parallel resonance unit, S2 is the second-stage series resonance unit, P2 is the second-stage parallel resonance unit, S3 is the third-stage series resonance unit, P3 is the third-stage parallel resonance unit, S4 is the fourth-stage series resonance unit, and P4 is the fourth-stage parallel resonance unit. Then, the level numbers of S4 and P4 are the highest, and the corresponding priorities are the highest. The level numbers of S1 and P1 are the lowest, and the corresponding priorities are the lowest.

[0083] Step S53: Split the resonance unit to be split into a combination of multiple resonators.

[0084] In the embodiments of the present invention, when splitting the resonance unit to be split, it can be realized based on the electrical connection mode corresponding to the resonance unit to be split. Among them, when the resonance unit to be split is a series-stage resonance unit, the resonance unit to be split can be split into a combination of multiple resonators connected in series or in parallel; when the resonance unit to be split is a parallel-stage resonance unit, the resonance unit to be split can be split into a combination of multiple resonators connected in parallel.

[0085] It should be noted that the parallel resonance frequency of the series resonance unit in the filter is located at the high-frequency end outside the filter passband, and the series resonance frequency of the series resonance unit is located near the center of the filter passband; the series resonance frequency of the parallel resonance unit is located at the low-frequency end outside the filter passband, and the parallel resonance frequency of the parallel resonance unit is located near the center of the filter passband. Moreover, the parallel resonance unit in the filter has a greater impact on the nonlinear characteristics of the filter after being split nonlinearly in series, while the series nonlinear splitting of the series resonance unit has almost no impact on the nonlinear characteristics of the filter. In addition, after the series resonance unit or the parallel resonance unit is split nonlinearly in parallel, the input end and the output end can be directly connected to the two split resonators, and the parallel nonlinear splitting of the series resonance unit or the parallel resonance unit has almost no impact on the nonlinear characteristics of the filter. Therefore, when the resonance unit to be split is a series-stage resonance unit, the resonance unit to be split can be split into a combination of multiple resonators connected based on a series or parallel connection method; when the resonance unit to be split is a parallel-stage resonance unit, the resonance unit to be split can be split into a combination of multiple resonators connected based on a parallel connection method, so as to effectively improve the nonlinear characteristics of the filter and enhance the filter performance.

[0086] It should be further noted that the resonance unit to be split in the embodiment of the present invention can be obtained by considering the impact on the nonlinear characteristics of the filter, so as to split the resonance unit to be split and design a filter. The splitting of the resonance unit for other considerations is not limited in the embodiment of the present invention. For example, in order to improve the power capacity of the filter product, the first-stage series resonator near the signal input end is split in series.

[0087] It can be seen that the filter design method in the embodiment of the present invention determines the resonance unit to be split by obtaining the level numbers and preset rules corresponding to the resonance units in the preset structure of the filter, considers the impact of the second-order nonlinear harmonics generated by the resonance units of different level numbers on the nonlinear characteristics of the filter, and then splits the resonance unit to be split into a combination of multiple resonators according to the circuit connection method corresponding to the resonance unit to be split in the filter, so as to suppress the generation of second-order nonlinear harmonic components, thereby improving the nonlinear characteristics of the filter and enhancing the filter performance.

[0088] In some embodiments, the resonant units to be split can be selected according to the non-linear splitting levels. In a specific example, the non-linear splitting levels can be obtained by considering the improvement of the non-linear characteristics of the filter. Then, the preset rule can further include selecting the corresponding number of resonant units to be split based on the non-linear splitting levels. The non-linear splitting levels indicate the number of resonant units split continuously from the highest to the lowest priority. Thus, in the step of selecting one or more resonant units from multiple resonant units as the resonant units to be split based on the preset rule, it can be specifically that according to the non-linear splitting levels, from multiple resonant units, the number of resonant units corresponding to the non-linear splitting levels is selected based on the priority of the resonant units as the resonant units to be split.

[0089] Among them, taking Figure 1 the shown filter structure as an example, the priority of the resonant units from the highest to the lowest can correspond to the level numbers of P4, S4, P3, S3, P2, S2, P1, S1. When the non-linear splitting level is 1, P4 can be selected as the resonant unit to be split based on the priority for non-linear splitting; when the non-linear splitting level is 2, two consecutive resonant units P4 and S4 can be selected as the resonant units to be split based on the priority for non-linear splitting, and so on.

[0090] In some embodiments, taking Figure 1 the shown filter structure as the preset structure of the filter as an example, Figure 6 an exemplary schematic diagram of the relationship curve between the non-linear characteristics of the filter and the non-linear splitting levels is shown. As Figure 6 shown, the horizontal axis is the non-linear splitting level of the split resonant units, and the vertical axis is the corresponding non-linear worst point of the filter.

[0091] Referring to Figure 6 , when the non-linear splitting level is greater than or equal to 5, if the resonant units of the filter are continued to be non-linearly split, the contribution to improving the non-linear characteristics of the filter is small. It can be determined that when splitting the filter, the non-linear splitting level should be greater than or equal to 1 / 2 of the total number of resonant units in the preset structure of the filter, that is, when designing the filter, the non-linear splitting level should be greater than or equal to 50% of the total number of resonant units in the preset structure of the filter. For example, it can be 60% of the total number of resonant units. Thus, after splitting the resonant units corresponding to the non-linear splitting level, the obtained filter can have better non-linear characteristics.

[0092] It should be noted that the non - linear splitting levels in the embodiments of the present invention can be the splitting levels obtained by considering the impact on the non - linear characteristics of the filter. For splitting levels determined for other considerations, the embodiments of the present invention do not limit them. For example, in order to improve the power capacity of the filter product, the splitting level for series - splitting the first - stage series resonator near the signal input end is determined.

[0093] In some embodiments, splitting the resonator unit to be split into a combination of multiple resonators can specifically be splitting the resonator unit to be split into a first resonator and a second resonator.

[0094] Further, in some embodiments, when the resonator unit to be split is a series - stage resonator unit, in splitting the resonator unit to be split into a combination of multiple resonators connected in a series or parallel connection manner, as an optional implementation, the resonator unit to be split can be split into a first resonator and a second resonator connected in series. The upper electrode of the first resonator is electrically connected to the upper electrode of the second resonator, and the lower electrode of the first resonator and the lower electrode of the second resonator respectively correspond to the signal input end and the output end. Or, the lower electrode of the first resonator is electrically connected to the lower electrode of the second resonator, then the upper electrode of the first resonator and the upper electrode of the second resonator respectively correspond to the signal input end and the output end; as another optional implementation, the resonator unit to be split can be split into a first resonator and a second resonator connected in parallel. The upper electrode of the first resonator is electrically connected to the lower electrode of the second resonator, and the lower electrode of the first resonator is electrically connected to the upper electrode of the second resonator. The upper electrode or the lower electrode of the first resonator and the second resonator respectively correspond to the signal input end and the output end.

[0095] Further, in some embodiments, when the resonator unit to be split is a parallel - stage resonator unit, in splitting the resonator unit to be split into a combination of multiple resonators connected in a parallel connection manner, the resonator unit to be split can be split into a first resonator and a second resonator connected in parallel. The upper electrode of the first resonator is electrically connected to the lower electrode of the second resonator, and the lower electrode of the first resonator is electrically connected to the upper electrode of the second resonator. The upper electrode or the lower electrode of the first resonator and the second resonator respectively correspond to the signal input end and the output end.

[0096] To verify the improvement effect on the non - linear characteristics of the filter structure obtained by splitting the resonator unit to be split in the filter design method of the embodiments of the present invention, in an optional example, Figure 7 and Figure 8 respectively show the schematic diagrams of the series - splitting structures of the resonator unit. As Figure 7As shown, the resonant unit R is equivalently split into two series-connected first resonators R1 and second resonators R2. Among them, the areas and shapes of the first resonator R1 and the second resonator R2 are approximately equal, and the areas are both approximately equal to twice the area of the resonant unit R. The average resonant frequencies of the first resonator R1 and the second resonator R2 are approximately equal to the resonant frequency of the resonant unit R. Moreover, the signal terminals T1 and T2 can respectively correspond to the input terminal and the output terminal of the signal. Starting from the signal terminal T1 or T2, the polarization directions c of the first resonator R1 and the second resonator R2 are the same (such as Figure 7 the polarization direction indicated by the arrow in

[0097] Combined with Figure 7 , referring to Figure 8, the resonant unit R is equivalently split into two series-connected first resonators R1 and second resonators R2. Among them, the areas and shapes of the first resonator R1 and the second resonator R2 are approximately equal, and the areas are both approximately equal to twice the area of the resonant unit R. The average resonant frequencies of the first resonator R1 and the second resonator R2 are approximately equal to the resonant frequency of the resonant unit R. Moreover, the signal terminals T1 and T2 can respectively correspond to the input terminal and the output terminal of the signal. Starting from the signal terminal T1 or T2, the polarization directions c of the first resonator R1 and the second resonator R2 are opposite (such as Figure 8 the polarization direction indicated by the solid arrow or the dotted arrow in Figure 8 ), that is, it is called that the polarization direction c of the first resonator R1 is opposite to the polarization direction of the second resonator R2. That is to say, the upper electrode of the first resonator R1 is connected to the upper electrode of the second resonator R2, or the lower electrode of the first resonator R1 is connected to the lower electrode of the second resonator R2. After the first resonator R1 and the second resonator R2 generate the second-order nonlinear voltage, the second-order nonlinear voltages of the two will cancel each other out. Then, if the resonant unit is split in this way, the nonlinear characteristics of the designed filter can be effectively improved. Among them,

[0098] In another alternative example, Figure 9 and Figure 10 show the schematic diagram of the parallel split structure of the resonant unit in the embodiment of the present invention. As Figure 9As shown, the resonant unit R is equivalently split into two parallel-connected first resonators R1 and second resonators R2. The areas and shapes of the first resonator R1 and the second resonator R2 are approximately equal, and the area of each is approximately equal to 1 / 2 of the area of the resonant unit R. The average resonant frequencies of the first resonator R1 and the second resonator R2 are approximately equal to the resonant frequency of the resonant unit R. Moreover, the signal terminals T1 and T2 can respectively correspond to the input terminal and output terminal of the signal. Starting from the signal terminal T1 or T2, the polarization direction c of the first resonator R1 is the same as that of the second resonator R2 (as shown by the polarization direction indicated by the arrow in Figure 9 ), that is to say, the upper electrode of the first resonator R1 is connected to the upper electrode of the second resonator R2, and the lower electrode of the first resonator R1 is connected to the lower electrode of the second resonator R2. After the first resonator R1 and the second resonator R2 generate second-order nonlinear voltages, the second-order nonlinear voltages of the two will be superimposed on each other. If the resonator is split in this way, the nonlinear characteristics of the designed filter will not be improved.

[0099] Combined with Figure 9 , as shown in Figure 10, the resonant unit R is equivalently split into two mutually parallel-connected first resonators R1 and second resonators R2. The areas and shapes of the first resonator R1 and the second resonator R2 are approximately equal, and the area is approximately equal to 1 / 2 of the area of the resonant unit R. The average resonant frequencies of the first resonator R1 and the second resonator R2 are approximately equal to the resonant frequency of the resonant unit R. Moreover, the signal terminals T1 and T2 can respectively correspond to the input terminal and output terminal of the signal. Starting from the signal terminal T1 or T2, the polarization direction c of the first resonator R1 and the polarization direction c of the second resonator R2 are opposite (as shown by the polarization direction indicated by the arrow in Figure 10 ), that is to say, the upper electrode of the first resonator R1 is connected to the lower electrode of the second resonator R2, and the lower electrode of the first resonator R1 is connected to the upper electrode of the second resonator R2. After the first resonator R1 and the second resonator R2 generate second-order nonlinear voltages, the second-order nonlinear voltages of the two will cancel each other out. Then, if the resonant unit is split in this way, the nonlinear characteristics of the designed filter can be effectively improved. Among them, Figure 10 The splitting method of the resonant unit shown in Figure 10 can be called parallel nonlinear splitting.

[0100] Corresponding to Figure 8 the polarization direction indicated by the solid arrow in Figure 11, Figure 11 Figure 12 exemplarily shows a schematic diagram of an optional structure of a resonant unit with series nonlinear splitting of upper electrode interconnection. As shown in Figure 11As shown, the regions shown as 110 and 120 are respectively the effective resonance regions of the two resonators obtained after the series nonlinear splitting of the resonance unit. The region shown as 130 is the interconnection metal region for electrical connection between the two resonators. The interconnection metal of the shown structure is composed of the upper electrode. Among them, the upper electrode corresponding to the region 100 formed by the effective resonance regions 110, 120 and the interconnection metal region 130 and its surrounding ground structure will generate a parasitic capacitance Cp. The existence of this parasitic capacitance will affect the improvement effect of the nonlinear characteristics of the filter of the corresponding split resonance unit.

[0101] corresponding Figure 8 to the polarization direction indicated by the dashed arrow in Figure 12 exemplarily shows a schematic diagram of an optional structure of a resonance unit with series nonlinear splitting of lower electrode interconnection. As Figure 12 shown, the regions shown as 210 and 220 are respectively the effective resonance regions of the two resonators obtained after the series nonlinear splitting of the resonance unit. The region shown as 230 is the interconnection metal region for electrical connection between the two resonators. The interconnection metal region of the shown structure is composed of the lower electrode. Among them, the lower electrode corresponding to the region 200 formed by the effective resonance regions 210, 220 and the interconnection metal region 230 and its surrounding ground structure will generate a parasitic capacitance Cp. The existence of this parasitic capacitance will affect the improvement effect of the nonlinear characteristics of the filter of the corresponding split resonance unit.

[0102] corresponding Figure 11 and Figure 12 the shown structure, Figure 13 shows a schematic diagram of the equivalent circuit of the resonance unit. Referring to Figure 13 shown, when a radio frequency signal with an input power of 22 dBm is input at the T1 end, a second-order nonlinear harmonic output will occur at the T2 end. Through simulation experiments, it is obtained that the average series resonance frequency of the first resonator R1 and the second resonator R2 is 2460 MHz, the average parallel resonance frequency Fp is 2580 MHz, the average effective electromechanical coupling coefficient is 11.0%, the area is 10 K square micrometers, and the simulated parasitic capacitance Cp value is 0.02 pF.

[0103] Combined with Figure 13 shown, Figure 14 shows a schematic diagram of the second-order nonlinear harmonic frequency characteristic curve of the series-split resonance unit. As Figure 14 shown, the curve marked with triangles is Figure 13 the simulation result when the parasitic capacitance Cp of the circuit shown in Figure 13 is equal to 0, that is, the simulation result without parasitic capacitance; the curve marked with circles is Figure 14As shown, it can be seen that due to the existence of the parasitic capacitance Cp, the second-order nonlinear harmonic generated by the resonant unit will generate a relatively high peak near the fundamental frequency Fp. If the corresponding frequency of the second-order nonlinear harmonic is near 2*Fp, then the second-order nonlinear harmonic deteriorates significantly in this frequency range. That is to say, due to the existence of the parasitic capacitance, a peak with an amplitude of 15 dB is generated near the 2*Fp frequency.

[0104] It can be understood that the parallel resonance frequency of the series resonance unit in the filter is located at the high-frequency end outside the filter passband, and the series resonance frequency of the series resonance unit is near the center of the filter passband; the series resonance frequency of the parallel resonance unit is located at the low-frequency end outside the filter passband, and the parallel resonance frequency of the parallel resonance unit is near the center of the filter passband. From Figure 14 the simulation results shown, the parasitic capacitance generated by the parallel resonance unit after series nonlinear splitting has a greater impact on the nonlinear characteristics of the filter, while the series nonlinear splitting of the series resonance unit has almost no impact on the nonlinear characteristics of the filter. Moreover, after parallel nonlinear splitting of the parallel resonance unit or the series resonance unit, the input and output ends are directly connected to the two split resonators. Therefore, in the parallel nonlinear splitting of the parallel resonance unit or the series resonance unit, the impact of the parasitic capacitance on the nonlinear characteristics of the filter is very small and can be ignored.

[0105] To further understand the impact of the parasitic capacitance Cp on the nonlinear characteristics of the filter during series nonlinear splitting of different parallel branches, taking Figure 1 the filter structure shown as an example, a high-frequency signal with an input power of 22 dBm is input at the signal input end, and a simulation experiment is carried out on the filter obtained by series nonlinear splitting of the parallel resonance units P1 to P4. Among them, the parasitic capacitance Cp is equal to 0.02 pF. When series nonlinear splitting of different parallel branches, the impact of the parasitic capacitance Cp on the nonlinearity of the filter is shown in Table 1:

[0106] Parallel branch P4 P3 P2 P1 Peak amplitude (dB) 11 6 3 1.2

[0107] Table 1

[0108] When the first parallel resonator P4 near the signal output end is split in series non-linearly, with parasitic capacitance Cp compared to without parasitic capacitance Cp, the output second-order non-linear harmonic curve will generate a peak with an amplitude of 11 dB near twice the parallel resonance frequency; when the second parallel resonator P3 near the signal output end is split in series non-linearly, with parasitic capacitance Cp compared to without parasitic capacitance Cp, the output second-order non-linear harmonic curve will generate a peak with an amplitude of 6 dB near twice the parallel resonance frequency; when the third parallel resonator P2 near the signal output end is split in series non-linearly, with parasitic capacitance Cp compared to without parasitic capacitance Cp, the output second-order non-linear harmonic curve will generate a peak with an amplitude of 3 dB near twice the parallel resonance frequency; when the fourth parallel resonator P1 near the signal output end is split in series non-linearly, with parasitic capacitance Cp compared to without parasitic capacitance Cp, the output second-order non-linear harmonic curve will generate a peak with an amplitude of 1.2 dB near twice the parallel resonance frequency.

[0109] It can be determined from the above that for the parallel resonance unit closer to the signal output end, that is, the parallel resonance unit with a higher level number, when it is split in series non-linearly, the influence of its parasitic capacitance on the non-linear characteristics of the filter is greater. Therefore, when splitting the resonance unit in the parallel branch with a higher level number non-linearly, a parallel non-linear splitting form should be adopted. For the resonance unit in the parallel branch closer to the signal input end, that is, the parallel resonance unit with a lower level number, when splitting it non-linearly, either series non-linear splitting or parallel non-linear splitting can be used. However, in all the parallel branches of the filter, when the resonance unit in the parallel branch with a lower level number is split in series non-linearly, the influence of its parasitic capacitance on the non-linearity of the filter can be ignored, and then this part of the resonance unit can not be split.

[0110] It can be seen that the non-linear characteristics of the filter designed based on the filter design method in the embodiments of the present invention can be significantly improved, thereby improving the filter performance.

[0111] It should be noted that in the filter structure, the resonator unit to be split can be split into a structure of multiple resonators in series, multiple resonators in parallel, and a combination of multiple resonators in series and parallel. Among them, in the circuit where the resonator unit to be split is split into a combination of multiple resonators, regardless of how the resonators in the combination are electrically connected internally, the multiple resonators corresponding to the resonator unit on the parallel branch are regarded as parallel resonators; the multiple resonators corresponding to the resonator unit on the series branch are regarded as series resonators.

[0112] In some embodiments, based on the series connection or parallel connection mode of each resonant unit, in the preset structure of the filter, any resonant unit can be a series-stage resonant unit or a parallel-stage resonant unit, and the number of levels can include the series number of levels and the parallel number of levels. Thus, obtaining the number of levels corresponding to each resonant unit in the filter, as an optional implementation, can be to obtain the series number of levels of each series-stage resonant unit, and the series number of levels is used to indicate the electrical connection order of the series-stage resonant units at the input end and the output end. For example Figure 1 S1, S2, S3, S4 in Figure 1 , and the S4 closest to the output end has the highest number of levels; as another optional implementation, it can be to obtain the parallel number of levels of each parallel-stage resonant unit, and the parallel number of levels is used to indicate the electrical connection order of the parallel-stage resonant units at the input end and the output end. For example Figure 1 P1, P2, P3, P4 in

[0113] , and the P4 closest to the output end has the highest number of levels; as yet another optional implementation, it can be to obtain the number of levels of each resonant unit based on the preset structure of the filter, and the number of levels is used to indicate the arrangement order of the resonant units at the input end and the output end. The closer the resonant unit is to the output end, the higher its number of levels. For example Figure 1 S1 in it is the first level, P1 is the second level, S2 is the third level, P2 is the fourth level,... and so on, and the P4 closest to the output end has the highest number of levels.

[0113] It should be noted that when obtaining the number of levels of each resonant unit based on the preset structure of the filter, the first-stage resonant unit close to the signal input end of the filter or the first-stage resonant unit close to the signal output end of the filter can be a series resonant unit or a parallel resonant unit.

[0114] It can be seen that in the filter design method in the embodiments of the present invention, by determining the resonant unit to be split based on the number of levels corresponding to each resonant unit in the preset structure of the filter and the preset rules, considering the influence of the second-order non-linear harmonics generated by the resonant units with different numbers of levels on the non-linear characteristics of the filter, and then splitting the resonant unit to be split into a combination of multiple resonators according to the circuit connection mode corresponding to the resonant unit to be split in the filter, the generation of the second-order non-linear harmonic components is suppressed, thereby improving the non-linear characteristics of the filter and enhancing the performance of the filter.

[0115] In a further embodiment of the present invention, a filter is further provided. The filter provided in the embodiment of the present invention will be introduced below. The filter can be considered to be designed based on the filter design method in the embodiment of the present invention, and the content described below can be correspondingly referred to the content described above.

[0116] The filter may include an input end and an output end, and a plurality of resonant units located between the input end and the output end;

[0117] Wherein, the resonant units correspond to a number of levels in a preset structure of the filter, and the number of levels is used to indicate the electrical connection order of the resonant units between the input end and the output end, wherein the electrical connection order is sorted starting from the input end;

[0118] Using at least one resonant unit as the split resonant unit in the split unit group, the split resonant unit is selected based on the priority of the resonant unit, and the higher the number of levels of the resonant unit, the higher the corresponding priority;

[0119] The split resonant unit in the split unit group is a combination of a plurality of resonators. When the split resonant unit is a series-stage resonant unit, the split resonant unit is a combination of a plurality of resonators based on a series or parallel connection method; when the split resonant unit is a parallel-stage resonant unit, the split resonant unit is a combination of a plurality of resonators based on a parallel connection method.

[0120] It should be noted that the filter in the embodiment of the present invention is designed based on the filter design method in the embodiment of the present invention. Then, the split unit group can be understood as a set of split resonant units in the filter design method, and the split resonant unit can be understood as the split resonant unit in the filter design method.

[0121] Optionally, the split resonant unit may specifically be a combination of a first resonator and a second resonator;

[0122] Wherein, the first resonator and the second resonator include a substrate, a lower electrode located on the substrate, a piezoelectric layer covering the lower electrode, and an upper electrode located on the piezoelectric layer.

[0123] Optionally, when the split resonant unit is a series-stage resonant unit, the split resonant unit is a combination of a plurality of resonators connected based on a series or parallel connection method, including:

[0124] The first resonator is connected in series with the second resonator. Referring to Figure 8 the circuit shown, corresponding to Figure 11 the structure shown, the upper electrode of the first resonator is electrically connected to the upper electrode of the second resonator, and the lower electrode of the first resonator and the lower electrode of the second resonator respectively correspond to the input end and the output end of the signal, or, corresponding to Figure 12 the structure shown, the lower electrode of the first resonator is electrically connected to the lower electrode of the second resonator, and the upper electrode of the first resonator and the upper electrode of the second resonator respectively correspond to the input end and the output end of the signal; or,

[0125] The first resonator is connected in parallel with the second resonator. Referring to Figure 10 the circuit shown, the upper electrode of the first resonator is electrically connected to the lower electrode of the second resonator, and the lower electrode of the first resonator is electrically connected to the upper electrode of the second resonator. The upper electrode or the lower electrode of the first resonator and the second resonator respectively correspond to the input terminal and the output terminal of the signal.

[0126] Optionally, when the split resonator unit is a parallel-stage resonator unit, the split resonator unit is a combination of a plurality of resonators connected in a parallel connection manner, including:

[0127] The first resonator is connected in parallel with the second resonator. Referring to Figure 10 the circuit shown, the upper electrode of the first resonator is electrically connected to the lower electrode of the second resonator, and the lower electrode of the first resonator is electrically connected to the upper electrode of the second resonator. Then, the upper electrode or the lower electrode of the first resonator and the second resonator respectively correspond to the input terminal and the output terminal of the signal.

[0128] Optionally, in the preset structure of the filter, any resonator unit is a series-stage resonator unit or a parallel-stage resonator unit, and the number of levels includes the series number of levels and the parallel number of levels;

[0129] When the resonator units are connected in series in the electrical connection order between the input terminal and the output terminal, the resonator unit has a series number of levels, and the higher the series number of levels of the resonator unit closer to the output terminal;

[0130] When the resonator units are connected in parallel in the electrical connection order between the input terminal and the output terminal, the resonator unit has a parallel number of levels, and the higher the parallel number of levels of the resonator unit closer to the output terminal;

[0131] When the resonator units have an arrangement order between the input terminal and the output terminal, based on the preset structure of the filter, the higher the number of levels of the resonator unit closer to the output terminal.

[0132] Optionally, in the filter according to the embodiment of the present invention, the number of split resonator units in the split unit group may correspond to the non-linear splitting level number, and the non-linear splitting level number indicates the number of resonator units continuously split in descending order of priority. Among them, the non-linear splitting level number is greater than or equal to 1 / 2 of the total number of resonator units in the preset structure of the filter.

[0133] It can be understood that the resonant unit near the signal output end has a greater non-linear influence on the filter. Moreover, splitting the resonant units with a number less than 1 / 2 of the total number of resonant units in the preset structure of the filter has a relatively small contribution to improving the non-linear characteristics of the filter. Therefore, in the splitting unit group of the filter according to the embodiment of the present invention, if the number of splitting resonant units included corresponds to a non-linear splitting level greater than or equal to 1 / 2 of the total number of resonant units in the preset structure of the filter, and the non-linear splitting level indicates the number of continuously split resonant units in descending order of priority, the non-linear characteristics of the filter can be effectively improved, and the filter performance can be effectively enhanced.

[0134] In a further embodiment of the present invention, a terminal is further provided, and the terminal includes the filter described in the above embodiment.

[0135] In a further embodiment of the present invention, a base station is further provided, and the base station includes the filter described in the above embodiment.

[0136] In a further embodiment of the present invention, a duplexer is further provided, and the duplexer includes the filter described in the above embodiment. Figure 15 An optional structural schematic diagram of the duplexer in the embodiment of the present invention is exemplarily shown. As Figure 15 shown, the duplexer may include: a first filter (shown as Filter1 in the figure), a second filter (shown as Filter2 in the figure), wherein the first filter and the second filter are determined based on the filter design method according to the embodiment of the present invention.

[0137] In Figure 15 the shown duplexer, the first filter is connected between the antenna port Ant and the first port T1, the second filter is connected between the antenna port Ant and the second port T2, and moreover, the passbands of the first filter and the second filter do not overlap. The first filter can pass the signals with the corresponding passband frequencies and suppress the signals of other frequencies, and the second filter can pass the signals with the corresponding passband frequencies and suppress the signals of other frequencies.

[0138] It should be noted that the filter determined based on the filter design method according to the embodiment of the present invention can also be applied to multiplexers such as a triplexer and a quadruplexer, or electronic devices including the filter or multiplexer described in the above embodiment. The embodiment of the present invention only takes the duplexer as an example for illustration, and it does not limit the devices including the filter described in the above embodiment.

[0139] In a further embodiment of the present invention, a filter design device is also provided. The filter design device provided in the embodiment of the present invention will be introduced below. The device content described below can be considered as the functional modules required to implement the filter design method provided in the embodiment of the present invention. The content described below can be mutually corresponding and referenced with the content described above.

[0140] As an optional implementation, Figure 16 An optional block diagram of the filter design device provided in the embodiment of the present invention is exemplarily shown. The filter design device can be understood as a virtual device corresponding to the filter design method described in the above embodiment. The filter design device includes:

[0141] An acquisition module 161, configured to acquire the level numbers corresponding to each resonator unit in the preset structure of the filter. The level numbers are used to indicate the electrical connection order of the resonator units at the input end and the output end, where the electrical connection order is sorted starting from the input end;

[0142] A selection module 162, configured to select one or more resonator units from multiple resonator units as the resonator units to be split based on a preset rule; wherein the preset rule at least includes: selecting the resonator units to be split based on the priority of the resonator units, and the higher the level number of the resonator unit, the higher the corresponding priority;

[0143] A splitting module 163, configured to split the resonator unit to be split into a combination of multiple resonators. When the resonator unit to be split is a series-stage resonator unit, the resonator unit to be split is split into a combination of multiple resonators connected in series or in parallel; when the resonator unit to be split is a parallel-stage resonator unit, the resonator unit to be split is split into a combination of multiple resonators connected in parallel.

[0144] Optionally, the preset rule further includes: selecting the corresponding number of resonator units to be split based on the non-linear splitting level number, and the non-linear splitting level number indicates the number of resonator units continuously split in descending order of priority;

[0145] The step of the selection module 162 for selecting one or more resonator units from multiple resonator units as the resonator units to be split based on a preset rule is specifically:

[0146] According to the non-linear splitting level number, select the corresponding number of resonator units as the resonator units to be split from multiple resonator units based on the priority of the resonator units.

[0147] Optionally, the non-linear splitting level number is greater than or equal to 1 / 2 of the total number of resonator units in the preset structure of the filter.

[0148] Optionally, the splitting module 163 is configured to split the resonator unit to be split into a combination of multiple resonators. Specifically, the resonator unit to be split is split into a first resonator and a second resonator.

[0149] Optionally, when the resonator unit to be split is a series cascade resonator unit, splitting the resonator unit to be split into a combination of multiple resonators connected in a series or parallel connection manner includes:

[0150] When the resonator unit to be split is a series cascade resonator unit, the resonator unit to be split is split into a first resonator and a second resonator connected in series. The upper electrode of the first resonator is electrically connected to the upper electrode of the second resonator, and the lower electrode of the first resonator and the lower electrode of the second resonator respectively correspond to the input end and the output end of the signal. Or, the lower electrode of the first resonator is electrically connected to the lower electrode of the second resonator, and the upper electrode of the first resonator and the upper electrode of the second resonator respectively correspond to the input end and the output end of the signal; or,

[0151] When the resonator unit to be split is a series cascade resonator unit, the resonator unit to be split is split into a first resonator and a second resonator connected in parallel. The upper electrode of the first resonator is electrically connected to the lower electrode of the second resonator, and the lower electrode of the first resonator is electrically connected to the upper electrode of the second resonator. The upper electrode or the lower electrode of the first resonator and the second resonator respectively correspond to the input end and the output end of the signal.

[0152] Optionally, when the resonator unit to be split is a parallel cascade resonator unit, splitting the resonator unit to be split into a combination of multiple resonators connected in a parallel connection manner includes:

[0153] When the resonator unit to be split is a parallel cascade resonator unit, the resonator unit to be split is split into a first resonator and a second resonator connected in parallel. The upper electrode of the first resonator is electrically connected to the lower electrode of the second resonator, and the lower electrode of the first resonator is electrically connected to the upper electrode of the second resonator. The upper electrode or the lower electrode of the first resonator and the second resonator respectively correspond to the input end and the output end of the signal.

[0154] Optionally, in the preset structure of the filter, any resonator unit is a series cascade resonator unit or a parallel cascade resonator unit. The number of levels includes the series number of levels and the parallel number of levels. The obtaining module 161 is configured to obtain the number of levels corresponding to each resonator unit in the preset structure of the filter. The steps include:

[0155] Obtain the series level numbers of each series resonant unit, where the series level numbers are used to indicate the electrical connection order of the series resonant units between the input end and the output end, and the higher the level number of the series resonant unit closer to the output end;

[0156] Obtain the parallel level numbers of each parallel resonant unit, where the parallel level numbers are used to indicate the electrical connection order of the parallel resonant units between the input end and the output end, and the higher the level number of the parallel resonant unit closer to the output end;

[0157] Based on the preset structure of the filter, obtain the level numbers of each resonant unit, where the level numbers are used to indicate the arrangement order of the resonant units between the input end and the output end, and the higher the level number of the resonant unit closer to the output end.

[0158] In a further embodiment provided by the present invention, a storage medium is also provided. The storage medium stores one or more computer-executable instructions, and the one or more computer-executable instructions are used to execute the filter design method as described in the above embodiment.

[0159] The above describes multiple embodiment solutions provided by the embodiments of the present invention. The various optional ways described in each embodiment solution can be combined and cross-referenced with each other without conflict, so as to extend a variety of possible embodiment solutions, and all of these can be considered as the embodiment solutions disclosed and made public by the embodiments of the present invention.

[0160] Although the embodiments of the present invention are disclosed as above, the present invention is not limited thereto. Any person skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the protection scope of the present invention should be subject to the scope defined by the claims.

Claims

1. A filter design method, characterized in that, The filter includes an input end and an output end, and a plurality of resonant units located between the input end and the output end. The method includes: Obtaining the level numbers corresponding to each resonant unit in the preset structure of the filter, where the level numbers are used to indicate the electrical connection sequence of the resonant units between the input end and the output end. Among them, the electrical connection sequence is sorted starting from the input end; Based on a preset rule, selecting one or more resonant units from the plurality of resonant units as the resonant units to be split; Among them, the preset rule at least includes: selecting the resonant units to be split based on the priority of the resonant units, where the higher the level number of the resonant unit, the higher the corresponding priority; selecting the corresponding number of resonant units to be split based on the non-linear splitting level number, where the non-linear splitting level number indicates the number of resonant units continuously split in descending order of priority; the non-linear splitting level number is greater than or equal to 1 / 2 of the total number of resonant units in the preset structure of the filter, and the non-linear splitting level number is obtained considering the improvement of the non-linear characteristics of the filter; Splitting the resonant unit to be split into a first resonator and a second resonator, where the areas and shapes of the first resonator and the second resonator are the same; Among them, when the resonant unit to be split is a series-stage resonant unit, splitting the resonant unit to be split into a combination of a first resonator and a second resonator connected in series or in parallel; when the resonant unit to be split is a parallel-stage resonant unit, splitting the resonant unit to be split into a combination of a first resonator and a second resonator connected in parallel.

2. The filter design method according to claim 1, wherein The step of, based on a preset rule, selecting one or more resonant units from the plurality of resonant units as the resonant units to be split is specifically: According to the non-linear splitting level number, selecting from the plurality of resonant units, based on the priority of the resonant units, the corresponding number of resonant units as the resonant units to be split.

3. The filter design method according to claim 1, characterized in that The step of, when the resonant unit to be split is a series-stage resonant unit, splitting the resonant unit to be split into a combination of a plurality of resonators connected in series or in parallel includes: When the resonant unit to be split is a series-stage resonant unit, splitting the resonant unit to be split into a first resonator and a second resonator connected in series, where the upper electrode of the first resonator is electrically connected to the upper electrode of the second resonator, and the lower electrode of the first resonator and the lower electrode of the second resonator respectively correspond to the input end and the output end of the signal, or the lower electrode of the first resonator is electrically connected to the lower electrode of the second resonator, and the upper electrode of the first resonator and the upper electrode of the second resonator respectively correspond to the input end and the output end of the signal; Or When the resonator unit to be split is a series - stage resonator unit, split the resonator unit to be split into a first resonator and a second resonator connected in parallel, where the upper electrode of the first resonator is electrically connected to the lower electrode of the second resonator, and the lower electrode of the first resonator is electrically connected to the upper electrode of the second resonator. The upper electrode or the lower electrode of the first resonator and the second resonator respectively corresponds to the input terminal and the output terminal of the signal.

4. The filter design method according to claim 1, wherein When the resonator unit to be split is a parallel - stage resonator unit, split the resonator unit to be split into a combination of multiple resonators connected based on a parallel connection method, including: When the resonator unit to be split is a parallel - stage resonator unit, split the resonator unit to be split into a first resonator and a second resonator connected in parallel, where the upper electrode of the first resonator is electrically connected to the lower electrode of the second resonator, and the lower electrode of the first resonator is electrically connected to the upper electrode of the second resonator. The upper electrode or the lower electrode of the first resonator and the second resonator respectively corresponds to the input terminal and the output terminal of the signal.

5. The filter design method according to claim 1, characterized in that, In the preset structure of the filter, any resonator unit is a series - stage resonator unit or a parallel - stage resonator unit. The number of levels includes the series number of levels and the parallel number of levels. Obtaining the number of levels corresponding to each resonator unit in the preset structure of the filter includes: Obtain the series number of levels of each series - stage resonator unit. The series number of levels is used to indicate the electrical connection order of the series - stage resonator unit between the input terminal and the output terminal. The higher the number of levels of the series - stage resonator unit closer to the output terminal, the higher the level. Obtain the parallel number of levels of each parallel - stage resonator unit. The parallel number of levels is used to indicate the electrical connection order of the parallel - stage resonator unit between the input terminal and the output terminal. The higher the number of levels of the parallel - stage resonator unit closer to the output terminal, the higher the level. Based on the preset structure of the filter, obtain the number of levels of each resonator unit. The number of levels is used to indicate the arrangement order of the resonator unit between the input terminal and the output terminal. The higher the number of levels of the resonator unit closer to the output terminal, the higher the level.

6. A filter, characterized in that, Including: An input terminal and an output terminal, and a plurality of resonator units located between the input terminal and the output terminal; Wherein, each resonator unit corresponds to a number of levels in the preset structure of the filter. The number of levels is used to indicate the electrical connection order of the resonator unit between the input terminal and the output terminal, and the electrical connection order is sorted starting from the input terminal; Use at least one resonator unit as the split resonator unit in the split unit group. The split resonator unit is selected based on the priority of the resonator unit. The higher the number of levels of the resonator unit, the higher the corresponding priority. The number of split resonator units in the split unit group corresponds to the non - linear split level number. The non - linear split level number indicates the number of resonator units continuously split in descending order of priority. Among them, the non - linear split level number is greater than or equal to 1 / 2 of the total number of resonator units in the preset structure of the filter, and the non - linear split level number is obtained considering the improvement of the non - linear characteristics of the filter; The splitting resonant unit in the splitting unit group is a combination of a first resonator and a second resonator, and the first resonator and the second resonator have the same area and shape; When the splitting resonant unit is a series cascaded resonant unit, the splitting resonant unit is a combination of a first resonator and a second resonator connected in a series or parallel connection manner; when the splitting resonant unit is a parallel cascaded resonant unit, the splitting resonant unit is a combination of a first resonator and a second resonator connected in a parallel connection manner.

7. The filter according to claim 6, wherein The first resonator and the second resonator include a substrate, a lower electrode located on the substrate, a piezoelectric layer covering the lower electrode, and an upper electrode located on the piezoelectric layer.

8. The filter according to claim 7, wherein When the splitting resonant unit is a series cascaded resonant unit, the splitting resonant unit is a combination of multiple resonators connected in a series or parallel connection manner, including: The first resonator is connected in series with the second resonator, the upper electrode of the first resonator is electrically connected to the upper electrode of the second resonator, and the lower electrode of the first resonator and the lower electrode of the second resonator respectively correspond to the input terminal and the output terminal of the signal, or the lower electrode of the first resonator is electrically connected to the lower electrode of the second resonator, and the upper electrode of the first resonator and the upper electrode of the second resonator respectively correspond to the input terminal and the output terminal of the signal; or, The first resonator is connected in parallel with the second resonator, the upper electrode of the first resonator is electrically connected to the lower electrode of the second resonator, and the lower electrode of the first resonator is electrically connected to the upper electrode of the second resonator, and the upper electrode or the lower electrode of the first resonator and the second resonator respectively correspond to the input terminal and the output terminal of the signal.

9. The filter according to claim 7, wherein When the splitting resonant unit is a parallel cascaded resonant unit, the splitting resonant unit is a combination of multiple resonators connected in a parallel connection manner, including: The first resonator is connected in parallel with the second resonator, the upper electrode of the first resonator is electrically connected to the lower electrode of the second resonator, and the lower electrode of the first resonator is electrically connected to the upper electrode of the second resonator, then the upper electrode or the lower electrode of the first resonator and the second resonator respectively correspond to the input terminal and the output terminal of the signal.

10. The filter according to claim 6, wherein In the preset structure of the filter, any resonant unit is a series cascaded resonant unit or a parallel cascaded resonant unit, and the number of levels includes the series number of levels and the parallel number of levels; the resonant unit corresponds to the number of levels in the preset structure of the filter, including: When the electrical connection sequence of each resonant unit is in series connection at the input terminal and the output terminal, the resonant unit has a series number of levels, and the higher the series number of levels of the resonant unit closer to the output terminal; When the electrical connection sequence of each resonant unit is in parallel connection at the input terminal and the output terminal, the resonant unit has a parallel number of levels, and the higher the parallel number of levels of the resonant unit closer to the output terminal; When each resonant unit has an arrangement order at the input terminal and the output terminal, based on the preset structure of the filter, the higher the number of levels of the resonant unit closer to the output terminal.

11. A terminal, characterized in that, The terminal includes the filter described in any one of claims 6-10.

12. A base station, characterized in that, The base station includes the filter described in any one of claims 6-10.

13. A duplexer, characterized in that, The duplexer includes the filter described in any one of claims 6-10.

14. A filter design device, characterized in that, Comprising: An acquisition module, configured to acquire the level numbers corresponding to each resonant unit in the preset structure of the filter, where the level numbers are used to indicate the electrical connection order of the resonant units at the input end and the output end, and wherein the electrical connection order is sorted starting from the input end; A selection module, configured to select one or more resonant units from multiple resonant units as the resonant units to be split based on a preset rule; wherein the preset rule at least includes: selecting the resonant units to be split based on the priority of the resonant units, the higher the level number of the resonant unit, the higher the corresponding priority; selecting the corresponding number of resonant units to be split based on the non-linear splitting level number, the non-linear splitting level number indicating the number of resonant units continuously split in descending order of priority; the non-linear splitting level number is greater than or equal to 1 / 2 of the total number of resonant units in the preset structure of the filter, and the non-linear splitting level number is obtained considering the improvement of the non-linear characteristics of the filter; A splitting module, configured to split the resonant unit to be split into a first resonator and a second resonator, where the areas and shapes of the first resonator and the second resonator are the same, and wherein when the resonant unit to be split is a series-stage resonant unit, the resonant unit to be split is split into a combination of a first resonator and a second resonator connected in a series or parallel connection manner; when the resonant unit to be split is a parallel-stage resonant unit, the resonant unit to be split is split into a combination of a first resonator and a second resonator connected in a parallel connection manner.

15. A storage medium, characterized in that, The storage medium stores one or more computer-executable instructions, and the one or more computer-executable instructions are used to execute the filter design method described in any one of claims 1-5.

Images