Filter and radio frequency front-end module

Abstract

The invention discloses a filter and a radio frequency front-end module. The filter comprises an input terminal, an output terminal, a grounding terminal and at least two-order resonance units. The resonance unit comprises a series arm resonance group and a parallel arm resonance group. At least one of the series arm resonance group and the parallel arm resonance group comprises at least two resonators which are connected in series, and a common bus bar is arranged between any two adjacent resonators in the at least two resonators which are connected in series. The at least two-order resonance unit comprises a first-order resonance unit and a second-order resonance unit, and the first-order resonance unit is closer to the input terminal than the second-order resonance unit. Wherein the thickness of the common bus bar of the first-order resonance unit is larger than that of the common bus bar of the second-order resonance unit, and / or the width of the common bus bar of the first-order resonance unit is larger than that of the common bus bar of the second-order resonance unit. The power density borne by the common bus bar of each order of resonance unit is balanced, and the breakdown risk is effectively reduced.

Description

Technical Field

[0001] The present application relates to the field of radio frequency filtering technology, and in particular to a filter and a radio frequency front-end module. Background Art

[0002] Surface Acoustic Wave (SAW) filter is a device that uses the piezoelectric properties of piezoelectric materials to achieve signal filtering. SAW resonator is the basic building block of SAW filter. SAW resonator usually includes a piezoelectric substrate and an interdigital transducer (IDT) formed on the piezoelectric substrate. The interdigital transducer can be used to convert electrical signals into acoustic signals or convert acoustic signals into electrical signals.

[0003] Generally, in high-power applications, the resonators in the surface acoustic wave filter are prone to breakdown or burning due to the high power they bear.

[0004] Therefore, how to improve the power tolerance performance of the device becomes an urgent problem to be solved. Summary of the invention

[0005] In view of this, the present application proposes a filter and a radio frequency front-end module.

[0006] A first aspect of the present application provides a filter, comprising an input terminal, an output terminal, a ground terminal, and at least two-order resonance units connected between the input terminal and the output terminal, wherein the resonance unit comprises:

[0007] A series arm resonance group connected to the series path between the input terminal and the output terminal;

[0008] A parallel arm resonance group, one end of the parallel arm resonance group is connected to the input end or the output end of the series arm resonance group, and the other end of the parallel arm resonance group is connected to the ground terminal;

[0009] At least one of the series arm resonance group and the parallel arm resonance group includes at least two series resonators, and any two adjacent resonators of the at least two series resonators have a common bus bar between them;

[0010] The at least two-order resonance units include a first-order resonance unit and a second-order resonance unit, wherein the first-order resonance unit is closer to the input terminal than the second-order resonance unit;

[0011] The thickness of the common bus bar of the first-order resonance unit is greater than the thickness of the common bus bar of the second-order resonance unit, and / or the width of the common bus bar of the first-order resonance unit is greater than the width of the common bus bar of the second-order resonance unit.

[0012] A second aspect of the present application proposes a radio frequency front-end module, comprising a packaging substrate and a filter chip arranged on the packaging substrate, wherein the filter chip comprises the above-mentioned filter.

[0013] It can be seen from the above technical solution that the filter proposed in the present application makes the common bus bar of the first-order resonant unit close to the input terminal wider and / or thicker than the common bus bar of the second-order resonant unit in at least two-order resonant units, thereby balancing the power density borne by the common bus bars of each order of resonant units and effectively reducing the risk of breakdown. Widening and / or thickening the common bus bar of the first-order resonant unit closer to the input terminal than the second-order resonant unit, thereby reducing the resistance value of the common bus bar itself, can effectively avoid heat accumulation, reduce the risk of heating, burning and breakdown, not only improve the heat dissipation performance, but also increase the power resistance of the common bus bar, reduce the risk of filter failure due to common bus bar breakdown, and improve the power tolerance performance of the filter. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained like these drawings without paying any creative work.

[0015] Figure 1 is a circuit architecture diagram of a filter proposed in an embodiment of the present application;

[0016] Figure 2 This is a circuit architecture diagram of a filter provided with a heat dissipation structure according to an embodiment of the present application;

[0017] Figure 3 It is a schematic diagram of the structure of widening the common bus bar of the series arm resonance group proposed in the embodiment of the present application;

[0018] Figure 4 It is a schematic diagram of a structure in which a common bus bar of a series arm resonance group proposed in an embodiment of the present application is widened and thickened;

[0019] Figure 5 is a schematic diagram of the structure of the filter proposed in the embodiment of the present application;

[0020] Figure 6 It is a graph of the input voltage of each order resonance unit at different frequencies proposed in the embodiment of the present application.

[0021] Description of reference numerals:

[0022] 100, filter; 10, input terminal; 20, output terminal; 30, ground terminal; 40, resonance unit; 40a, first order resonance unit; 40b, second order resonance unit; 40c, third order resonance unit; 40d, fourth order resonance unit; 41, series arm resonance group; S1, first series arm resonance group; S2, second series arm resonance group; S3, third series arm resonance group; S4, fourth series arm resonance group; 411, common bus bar; 411a, first common bus bar bus bar; 411b, second common bus bar; 411c, third common bus bar; 411d, fourth common bus bar; 412, non-common bus bar; 413, electrode finger; 414, reflection grid; 42, parallel arm resonance group; P1, first parallel arm resonance group; P2, second parallel arm resonance group; P3, third parallel arm resonance group; P4, fourth parallel arm resonance group; 50, piezoelectric substrate; 51, first solder pad; 52, second solder pad; 53, third solder pad; 60, heat dissipation structure. DETAILED DESCRIPTION

[0023] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0024] It should be understood that all directional indications in the embodiments of the present application (such as up, down, left, right, front, back, etc.) are only used to explain the relative position relationship, movement status, etc. between the components in a certain specific posture. If the specific posture changes, the directional indication will also change accordingly.

[0025] It should also be understood that when an element is referred to as being "fixed" or "disposed on" another element, it can be directly on the other element or there may be an intermediate element at the same time. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or it can be indirectly connected to the other element through an intermediate element.

[0026] The terms used in this specification of the present application are only for the purpose of describing specific embodiments and are not intended to limit the present application. For example, the descriptions of "first", "second", etc. in the present application are only for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" or "second" may explicitly or implicitly include at least one of the features.

[0027] It should be further understood that the term “and / or” used in the specification and appended claims refers to any combination and all possible combinations of one or more of the associated listed items, and includes these combinations.

[0028] Generally, in high-power applications, the resonator in the surface acoustic wave filter is prone to breakdown or burning due to the high power it bears. Specifically, since the resonator bears the highest power near the input terminal, the busbar closer to the input terminal is more likely to break down or burn, causing the filter to fail.

[0029] Therefore, the embodiment of the present application proposes a filter that can reduce the risk of filter failure caused by busbar breakdown and improve the power tolerance performance of the filter.

[0030] See also Figures 1 to 4 The embodiment of the present application proposes a filter 100, comprising an input terminal 10, an output terminal 20, a ground terminal 30 and at least two-order resonance units 40 connected between the input terminal 10 and the output terminal 20. The resonance unit 40 comprises a series arm resonance group 41 and a parallel arm resonance group 42, wherein the series arm resonance group 41 is connected to the series path between the input terminal 10 and the output terminal 20. One end of the parallel arm resonance group 42 is connected to the input end or the output end of the series arm resonance group 41, and the other end of the parallel arm resonance group 42 is connected to the ground terminal 30. At least one of the series arm resonance group 41 and the parallel arm resonance group 42 comprises at least two series resonators, and any two adjacent resonators of the at least two series resonators have a common bus bar 411. The at least two-order resonance unit 40 comprises a first-order resonance unit 40a and a second-order resonance unit 40b, wherein the first-order resonance unit 40a is closer to the input terminal 10 than the second-order resonance unit 40b. Among them, the thickness of the common bus bar 411 of the first-order resonance unit 40a is greater than the thickness of the common bus bar 411 of the second-order resonance unit 40b, and / or the width of the common bus bar 411 of the first-order resonance unit 40a is greater than the width of the common bus bar 411 of the second-order resonance unit 40b.

[0031] The filter 100 proposed in the embodiment of the present application makes the common bus bar 411 of the first-order resonance unit 40a close to the input terminal 10 wider and / or thicker than the common bus bar 411 of the second-order resonance unit 40b in at least two-order resonance units 40, so as to balance the power density borne by the common bus bar 411 of each order resonance unit 40 and effectively reduce the risk of breakdown. The common bus bar 411 of the first-order resonance unit 40a closer to the input terminal 10 than the second-order resonance unit 40b is widened and / or thickened to reduce the resistance value of the common bus bar 411 itself, which can effectively avoid heat accumulation and reduce the risk of heating, burning and breakdown, which can not only improve the heat dissipation performance, but also increase the power resistance of the common bus bar 411, reduce the risk of failure of the filter 100 caused by the breakdown of the common bus bar 411, and improve the power tolerance performance of the filter 100.

[0032] In an optional embodiment, the first-order resonance unit and the second-order resonance unit may be any two-order resonance units among the at least two-order resonance units, and any two-order resonance units may be adjacent two-order resonance units, for example, Figure 1 As shown, in the direction from the input terminal to the output terminal, the first-order resonant unit and the second-order resonant unit may be the first resonant unit 40a and the second resonant unit 40b, respectively. Of course, in other examples, the first-order resonant unit and the second-order resonant unit may also be the second resonant unit 40b and the third resonant unit 40c, respectively. Of course, in other examples, the first-order resonant unit and the second-order resonant unit may also be the third resonant unit 40c and the fourth resonant unit 40d, respectively.

[0033] In an optional embodiment, any two-order resonance units may also be two non-adjacent-order resonance units. Figure 1 As shown, in the direction from the input terminal to the output terminal, the first-order resonant unit and the second-order resonant unit can be the first resonant unit 40a and the third resonant unit 40c, respectively. Of course, in other examples, the first-order resonant unit and the second-order resonant unit can also be the second resonant unit 40b and the fourth resonant unit 40d, respectively. Of course, in other examples, the first-order resonant unit and the second-order resonant unit can also be the first resonant unit 40a and the fourth resonant unit 40d, respectively.

[0034] It can be understood that at least two-order resonance units 40 may include two-order, three-order, four-order or even more-order resonance units 40, and in any two-order resonance units 40, the common bus bar 411 of one-order resonance unit 40 close to the input terminal 10 is wider and / or thicker than the common bus bar 411 of the other-order resonance unit 40. Specifically, each order of resonance units 40 includes a series arm resonance group 41 and a parallel arm resonance group 42. Any one-order resonance unit 40 may be that only the series arm resonance group 41 includes at least two series resonators, or only the parallel arm resonance group 42 includes at least two series resonators, or both the series arm resonance group 41 and the parallel arm resonance group 42 include at least two series resonators. The series resonators are electrically connected through the common bus bar 411, and the power density borne by the resonator can be reduced by setting the common bus bar 411.

[0035] Exemplarily, in at least two-order resonant units 40, all resonant units 40 may be provided with a common bus bar 411 only in the series arm resonant group 41. That is, in any two-order resonant units 40, the common bus bar 411 of the series arm resonant group 41 of one-order resonant unit 40 close to the input terminal 10 may be wider and / or thicker than the common bus bar 411 of the series arm resonant group 41 of the other-order resonant unit 40. It can be understood that any two-order resonant units 40 here may be adjacent or not adjacent.

[0036] Exemplarily, at least two-order resonance units 40, or all resonance units 40, are provided with a common bus bar 411 only in the parallel arm resonance group 42. That is, in any two-order resonance units 40, the common bus bar 411 of the parallel arm resonance group 42 of one-order resonance unit 40 close to the input terminal 10 is wider and / or thicker than the common bus bar 411 of the parallel arm resonance group 42 of the other-order resonance unit 40. It can be understood that any two-order resonance units 40 here may be adjacent or not adjacent.

[0037] Exemplarily, among at least two-order resonance units 40, some resonance units 40 may be provided with a common bus bar 411 in the series arm resonance group 41, and another part of the resonance units 40 may be provided with a common bus bar in the parallel arm resonance group 42. That is, among any two-order resonance units 40, the common bus bar 411 of the series arm resonance group 41 of one of the order resonance units 40 close to the input terminal 10 may be wider and / or thicker than the common bus bar 411 of the series arm resonance group 41 of the other order resonance unit 40. The common bus bar 411 of the parallel arm resonance group 42 of one of the order resonance units 40 close to the input terminal 10 may also be wider and / or thicker than the common bus bar 411 of the parallel arm resonance group 42 of the other order resonance unit 40. It is also possible that the common bus bar 411 of the series arm resonance group 41 of one of the first-order resonance units 40 near the input terminal 10 is wider and / or thicker than the common bus bar 411 of the parallel arm resonance group 42 of another order resonance unit 40. It is also possible that the common bus bar 411 of the parallel arm resonance group 42 of one of the first-order resonance units 40 near the input terminal 10 is wider and / or thicker than the common bus bar 411 of the series arm resonance group 41 of another order resonance unit 40. It can be understood that any two order resonance units 40 here may be adjacent or not adjacent.

[0038] See also Figures 3 to 5 In some embodiments, at least one of the series arm resonance group 41 and the parallel arm resonance group 42 of each order resonance unit 40 includes at least two series resonators, and also includes a non-shared bus bar 412 located at the edge and arranged opposite to the shared bus bar 411, a plurality of electrode fingers 413 located between the shared bus bar 411 and the non-shared bus bar 412, and two reflection grids 414. The shared bus bar 411 and the non-shared bus bar 412 both extend along the propagation direction of the sound wave. The shared bus bar 411, the non-shared bus bar 412, and the plurality of electrode fingers 413 form an interdigital transducer. The filter 100 also includes a piezoelectric substrate 50. The series arm resonance group 41 and the parallel arm resonance group 42 of each order resonance unit 40 can be arranged on the same piezoelectric substrate 50. The piezoelectric substrate 50 has a piezoelectric effect, that is, when an electric field or mechanical stress is applied, charge distribution and mechanical deformation will be generated. As an important component of the resonator, the function of the interdigital transducer is to complete the conversion of electrical energy and mechanical energy, that is, to generate and detect surface acoustic waves. The structure of the interdigital transducer is usually manufactured on the piezoelectric substrate 50 using a photolithography-coating-stripping or coating-photolithography-etching process, and can also be manufactured by other process methods. When a voltage signal is applied to the piezoelectric substrate 50, the interdigital transducer excites acoustic waves in the piezoelectric material. The changing voltage causes the piezoelectric substrate 50 to deform, thereby exciting surface acoustic waves, and the piezoelectric effect is used to generate and propagate surface acoustic waves on the surface of the piezoelectric substrate 50, thereby realizing signal processing and transmission.

[0039] In some embodiments, Figure 3 and Figure 4 As shown, in at least two series-connected resonators, each resonator may be provided with two reflection gratings 414, and the two reflection gratings 414 of each resonator are arranged on both sides of the IDT along the propagation direction of the sound wave. The reflection gratings 414 are used to confine the surface acoustic wave within the IDT. Adjacent reflection gratings 414 may share the same bus bar, and of course, may not share the same bus bar in other cases.

[0040] In other embodiments, at least two series resonators may share a reflection grating, that is, at least two series resonators included in at least one of the series arm resonance group 41 and the parallel arm resonance group 42 only need two reflection gratings in total.

[0041] See also Figures 1 to 4 In some embodiments, among the at least two series-connected resonators included in at least one of the series arm resonance group 41 and the parallel arm resonance group 42, the two resonators located at the edge positions also include non-shared bus bars 412 facing away from the adjacent resonators. The width of the shared bus bar 411 is greater than the width of the non-shared bus bar 412, and / or the thickness of the shared bus bar 411 is greater than the thickness of the non-shared bus bar 412. Since the shared bus bar 411 needs to bear a larger current load, the shared bus bar 411 is wider and / or thicker than the non-shared bus bar 412 to help reduce the resistance of the shared bus bar 411, avoid heat accumulation, and reduce the risk of heating, burning, and breakdown.

[0042] Exemplarily, in at least two-order resonance units 40, the width of the common bus bar 411 of the same-order resonance unit 40 may be greater than the width of the non-common bus bar 412, and / or the thickness of the common bus bar 411 of the same-order resonance unit 40 may be greater than the thickness of the non-common bus bar 412. Alternatively, the width of the common bus bar 411 of all resonance units 40 may be greater than the width of the non-common bus bar 412, and / or the thickness of the common bus bar 411 of all resonance units 40 may be greater than the thickness of the non-common bus bar 412.

[0043] In some embodiments, the width of the common bus bar 411 of any order resonance unit 40 with an input power greater than or equal to 25 dBm is greater than the width of the non-common bus bar 412 of the order resonance unit 40. When the input power is greater than or equal to 25 dBm, the breakdown risk of the common bus bar 411 is greater, and the width of the common bus bar 411 is greater than the width of the non-common bus bar 412 of the order resonance unit 40, which can effectively reduce the breakdown risk.

[0044] Of course, in other embodiments, the width of the common bus bar 411 of any order resonance unit 40 may be greater than the width of the non-common bus bar 412 of the resonance unit 40 of the order. That is, it is not limited to that the width of the common bus bar 411 of any order resonance unit 40 with an input power greater than or equal to 25 dBm is greater than the width of the non-common bus bar 412 of the resonance unit 40 of the order, and the width of the common bus bar 411 of any order resonance unit 40 with an input power less than 25 dBm is also greater than the width of the non-common bus bar 412 of the resonance unit 40 of the order.

[0045] Of course, in other embodiments, the width of the common bus bar 411 of any order resonance unit 40 with input power less than 25 dBm may be equal to the width of the non-common bus bar 412 of the resonance unit 40 of the order. Alternatively, the width of the common bus bar 411 of any order resonance unit 40 with input power less than 25 dBm may be greater than or equal to twice the width of the non-common bus bar 412 of the resonance unit 40 of the order.

[0046] In some embodiments, the thickness of the common bus bar 411 of any order resonance unit 40 with an input power greater than or equal to 25 dBm is greater than the thickness of the non-common bus bar 412 of the order resonance unit 40. When the input power is greater than or equal to 25 dBm, the breakdown risk of the common bus bar 411 is greater, and the thickness of the common bus bar 411 is greater than the thickness of the non-common bus bar 412 of the order resonance unit 40, which can effectively reduce the breakdown risk.

[0047] Of course, in other embodiments, the thickness of the common bus bar 411 of any order resonance unit 40 may be greater than the thickness of the non-common bus bar 412 of the resonance unit 40 of the order. That is, it is not limited to the thickness of the common bus bar 411 of any order resonance unit 40 with an input power greater than or equal to 25 dBm being greater than the thickness of the non-common bus bar 412 of the resonance unit 40 of the order, and the thickness of the common bus bar 411 of any order resonance unit 40 with an input power less than 25 dBm is also greater than the thickness of the non-common bus bar 412 of the resonance unit 40 of the order.

[0048] Of course, in other embodiments, the thickness of the common bus bar 411 of any order resonance unit 40 with input power less than 25 dBm may be equal to the thickness of the non-common bus bar 412 of the resonance unit 40 of the order. Alternatively, the thickness of the common bus bar 411 of any order resonance unit 40 with input power less than 25 dBm may be greater than or equal to twice the thickness of the non-common bus bar 412 of the resonance unit 40 of the order.

[0049] In some embodiments, the ratio of the width of the common bus bar 411 to the width of the non-common bus bar 412 is greater than or equal to 2, and / or the ratio of the thickness of the common bus bar 411 to the thickness of the non-common bus bar 412 is greater than or equal to 2. Since the common bus bar 411 needs to bear a larger current load, the width and / or thickness of the common bus bar 411 is set to be more than twice the width and / or thickness of the non-common bus bar 412 to help reduce the resistance of the common bus bar 411, avoid heat accumulation, and reduce the risk of heating, burning, and breakdown.

[0050] See also Figures 3 to 5 In some embodiments, the series arm resonance group 41 of the first-order resonance unit 40a includes at least two first resonators connected in series, and a first common bus bar 411a is provided between any two adjacent first resonators of the at least two first resonators connected in series; the series arm resonance group 41 of the second-order resonance unit 40b includes at least two second resonators connected in series, and a second common bus bar 411b is provided between any two adjacent second resonators of the at least two second resonators connected in series. The thickness of the first common bus bar 411a is greater than the thickness of the second common bus bar 411b; and / or the width of the first common bus bar 411a is greater than the width of the second common bus bar 411b. Generally, since the series arm resonance group 41 is more susceptible to breakdown and burning than the parallel arm resonance group 42, the series arm resonance group 41 of the first-order resonance unit 40a is configured to include at least two first resonators connected in series, and a first common bus bar 411a is provided between any two adjacent first resonators of the at least two first resonators connected in series, and the series arm resonance group 41 of the second-order resonance unit 40b is configured to include at least two second resonators connected in series, and a second common bus bar 411b is provided between any two adjacent second resonators of the at least two second resonators connected in series, and the first common bus bar 411a is made wider and / or thicker than the second common bus bar 411b, thereby balancing the power density borne by the first-order resonance unit 40a and the first-order resonance unit 40a, and effectively reducing the risk of breakdown.

[0051] See also Figures 1 to 4In some embodiments, the input end of the series arm resonance group 41 of the first-order resonance unit 40a is connected to the input terminal 10. That is, in at least two-order resonance units 40, the first-order resonance unit 40a is closest to the input terminal 10, so that the common bus bar 411 of the first-order resonance unit 40a closest to the input terminal 10 is wider and / or thicker than the common bus bars 411 at other positions, balancing the power density borne by the common bus bars 411 of each order resonance unit 40, and effectively reducing the risk of breakdown. Widening and / or thickening the common bus bar 411 closest to the input terminal 10, thereby reducing the resistance value of the common bus bar 411 itself, can effectively avoid heat accumulation, reduce the risk of heating, burning and breakdown, not only improve the heat dissipation performance, but also increase the power resistance of the common bus bar 411, reduce the risk of failure of the filter 100 caused by the breakdown of the common bus bar 411, and improve the power tolerance performance of the filter 100.

[0052] In some embodiments, the thickness of the common bus bar 411 of each order resonance unit 40 in the at least two order resonance units 40 is 0.2 μm-2.5 μm. In the at least two order resonance units 40, on the basis of making the common bus bar 411 of one order resonance unit 40 close to the input terminal 10 wider and / or thicker than the common bus bar 41 of the other order resonance unit 40, the thickness of the common bus bar 411 of each order resonance unit 40 is limited to the range of 0.2 μm-2.5 μm, which can reduce the resistance value of the common bus bar 411 itself, avoid heat accumulation, and reduce the risk of heating, burning and breakdown.

[0053] Exemplarily, the thickness of the common bus bar 411 of each order resonance unit 40 can be selected from 0.2μm, 0.3μm, 0.4μm, 0.5μm, 0.6μm, 0.7μm, 0.8μm, 0.9μm, 1μm, 1.1μm, 1.2μm, 1.3μm, 1.4μm, 1.5μm, 1.6μm, 1.7μm, 1.8μm, 1.9μm, 2μm, 2.1μm, 2.2μm, 2.3μm, 2.4μm or 2.5μm according to actual needs.

[0054] In some embodiments, the width Wn of the common bus bar 411 of each order resonance unit 40 in the at least two order resonance units 40 is 4 μm-30 μm. In the at least two order resonance units 40, on the basis of making the common bus bar 411 of one order resonance unit 40 close to the input terminal 10 wider and / or thicker than the common bus bar 41 of the other order resonance unit 40, the width of the common bus bar 411 of each order resonance unit 40 is limited to the range of 4 μm-30 μm, which can reduce the resistance value of the common bus bar 411 itself, avoid heat accumulation, and reduce the risk of heating, burning and breakdown.

[0055] Exemplarily, the width Wn of the common bus bar 411 of each order resonance unit 40 can be selected from 4μm, 5μm, 6μm, 7μm, 8μm, 9μm, 10μm, 11μm, 12μm, 13μm, 14μm, 15μm, 16μm, 17μm, 18μm, 19μm, 20μm, 21μm, 22μm, 23μm, 24μm, 25μm, 26μm, 27μm, 28μm, 29μm or 30μm according to actual needs.

[0056] In some embodiments, the width and / or thickness of the common bus bar 411 of each order resonance unit 40 decreases gradually from the input terminal 10 to the output terminal 20. Thus, the power density of the common bus bar 411 of each order resonance unit 40 is balanced, effectively reducing the risk of breakdown.

[0057] Exemplarily, the at least two-order resonant units may include two-order, three-order, four-order or even more-order resonant units. When the at least two-order resonant units are two-order resonant units, that is, there are only first-order resonant units and second-order resonant units, and the width and / or thickness of the first-order resonant unit and the second-order resonant unit decreases step by step. When the at least two-order resonant units are three-order resonant units, that is, in addition to the first-order resonant unit and the second-order resonant unit, the third-order resonant unit is also included, and the width and / or thickness of the first-order resonant unit, the second-order resonant unit and the third-order resonant unit decrease step by step. When the at least two-order resonant units are four-order resonant units (such as Figure 1 and Figure 2 As shown, that is, in addition to the first-order resonance unit 40a and the second-order resonance unit 40b, the third-order resonance unit 40c and the fourth-order resonance unit 40d are also included. At this time, the width and / or thickness of the first-order resonance unit 40a, the second-order resonance unit 40b, the third-order resonance unit 40c and the fourth-order resonance unit 40d are gradually reduced. Of course, the at least two-order resonance units can also include a fifth-order resonance unit, a sixth-order resonance unit or even more, which will not be repeated here.

[0058] See also Figure 3 to Figure 4 In some embodiments, at least one of the series arm resonance group 41 and the parallel arm resonance group 42 includes two series resonators, and there is a common bus bar 411 between the two series resonators. Thus, each order resonance unit 40 in the at least two order resonance units 40 may have only one common bus bar 411.

[0059] In other embodiments, at least one of the series arm resonance group 41 and the parallel arm resonance group 42 includes more than three series resonators, which may be three, four, five or even more series resonators, and the width and / or thickness of the common bus bar 411 between any two adjacent resonators in the three or more series resonators are equal, or, in the direction from the input terminal 10 to the output terminal 20, the width and / or thickness of the common bus bar 411 between any two adjacent resonators in the three or more series resonators decreases step by step. Thus, each order of the at least two-order resonance unit 40 may have multiple common bus bars 411, and the width and / or thickness of the multiple common bus bars 411 of each order of the resonance unit 40 may be equal or may decrease step by step.

[0060] In some embodiments, the width of the common bus bar 411 of each order resonance unit 40 in at least two order resonance units 40 is positively correlated with the input power of the filter 100. Therefore, the width of the common bus bar 411 of each order resonance unit 40 can be set according to the input power of the filter 100, so as to balance the power density borne by the common bus bar 411 of each order resonance unit 40, and effectively reduce the breakdown risk.

[0061] In some embodiments, the thickness of the common bus bar 411 of each order resonance unit 40 in at least two order resonance units 40 is positively correlated with the input power of the filter 100. Therefore, the thickness of the common bus bar 411 of each order resonance unit 40 can be set according to the input power of the filter 100, so as to balance the power density borne by the common bus bar 411 of each order resonance unit 40, and effectively reduce the breakdown risk.

[0062] In some embodiments, when the input power of the filter 100 is 25dBm-30dBm, the width of the common bus bar 411 of each order resonance unit 40 in at least two order resonance units 40 is greater than or equal to 8μm. In the case where the input power of the filter 100 is relatively large, the power borne by the first few order resonance units close to the input terminal is relatively large, so that the common bus bar 411 of one order resonance unit 40 close to the input terminal 10 is wider than the common bus bar 411 of the other order resonance unit 40, and the width of the common bus bar 411 of each order resonance unit 40 is set to be greater than or equal to 8μm, which is more conducive to reducing the risk of breakdown.

[0063] Exemplarily, when the input power of the filter 100 is between 25dBm and 30dBm, the width of the common bus bar 411 of each order resonance unit 40 can be selected from 8μm, 9μm, 10μm, 11μm, 12μm, 13μm, 14μm, 15μm, 16μm, 17μm, 18μm, 19μm, 20μm, 21μm, 22μm, 23μm, 24μm, 25μm, 26μm, 27μm, 28μm, 29μm or 30μm according to actual needs.

[0064] In some embodiments, when the input power of the filter 100 is 25dBm-30dBm, the thickness of the common bus bar 411 of each order of the resonance unit 40 in at least two order resonance units 40 is greater than or equal to 0.8μm. In the case where the input power of the filter 100 is relatively large, the power borne by the first few order resonance units close to the input terminal is relatively large, so that the common bus bar 411 of one order resonance unit 40 close to the input terminal 10 is thicker than the common bus bar 411 of the other order resonance unit 40, and the thickness of the common bus bar 411 of each order resonance unit 40 is set to be greater than or equal to 0.8μm, which is more conducive to reducing the risk of breakdown.

[0065] Exemplarily, when the input power of the filter 100 is between 25dBm and 30dBm, the thickness of the common bus bar 411 of each order resonance unit 40 can be selected from 0.8μm, 0.9μm, 1μm, 1.1μm, 1.2μm, 1.3μm, 1.4μm, 1.5μm, 1.6μm, 1.7μm, 1.8μm, 1.9μm, 2μm, 2.1μm, 2.2μm, 2.3μm, 2.4μm or 2.5μm according to actual needs.

[0066] In some embodiments, when the input power of the filter 100 is greater than 30 dBm (an input signal greater than 30 dBm is defined as a high-power input signal), the width of the common bus bar 411 of each order of the resonance unit 40 in at least two order resonance units 40 is greater than or equal to 15 μm. In the case where the input power of the filter 100D is relatively large, the power borne by the first few order resonance units close to the input terminal is relatively large, so that the common bus bar 411 of one order resonance unit 40 close to the input terminal 10 is wider than the common bus bar 411 of the other order resonance unit 40, and the width of the common bus bar 411 of each order resonance unit 40 is limited to be greater than or equal to 15 μm, which is more conducive to reducing the risk of breakdown.

[0067] Exemplarily, when the input power of the filter 100 is greater than 30 dBm, the width of the common bus bar 411 of each order resonance unit 40 can be selected from 15 μm, 16 μm, 17 μm, 18 μm, 19 μm, 20 μm, 21 μm, 22 μm, 23 μm, 24 μm, 25 μm, 26 μm, 27 μm, 28 μm, 29 μm or 30 μm according to actual needs.

[0068] In some embodiments, when the input power of the filter 100 is greater than 30 dBm, the thickness of the common bus bar 411 of each order of the resonance unit 40 in at least two order resonance units 40 is greater than or equal to 1.5 μm. In the case where the input power of the filter 100D is relatively large, the power borne by the first few order resonance units close to the input terminal is relatively large, so that the common bus bar 411 of one order resonance unit 40 close to the input terminal 10 is thicker than the common bus bar 411 of the other order resonance unit 40, and the thickness of the common bus bar 411 of each order resonance unit 40 is limited to be greater than or equal to 1.5 μm, which is more conducive to reducing the risk of breakdown.

[0069] Exemplarily, when the input power of the filter 100 is greater than 30 dBm, the thickness of the common bus bar 411 of each order resonance unit 40 can be selected from 1.5 μm, 1.6 μm, 1.7 μm, 1.8 μm, 1.9 μm, 2 μm, 2.1 μm, 2.2 μm, 2.3 μm, 2.4 μm or 2.5 μm according to actual needs.

[0070] It can be understood that the input power of the filter 100 refers to the input power of the input terminal 10 of the filter 100. As the signal propagates from the input terminal 10 to the output terminal 20 through each order resonance unit 40 in sequence, each order resonance unit 40 may absorb or reflect part of the signal energy, resulting in a decrease in the signal power transmitted to the next resonance unit 40 or the output terminal 20. Of course, in other cases, the signal power may also remain unchanged. Therefore, the input power of each order resonance unit 40 may at least partially decrease step by step, or may at least partially remain unchanged.

[0071] In some embodiments, the width and / or thickness of the common bus bar 411 of each order resonance unit 40 with an input power greater than or equal to 25 dBm decreases step by step from the input terminal 10 to the output terminal 20. This helps to balance the power density of the common bus bar 411 of each order resonance unit 40 and effectively reduce the risk of breakdown.

[0072] In some embodiments, the width and / or thickness of the common bus bar 411 of each order resonance unit 40 with an input power less than 25 dBm are equal. When the input power of each order resonance unit 40 is less than 25 dBm, the common bus bar 411 is not easy to burn. Therefore, setting the width and / or thickness of the common bus bar 411 of each order resonance unit 40 with an input power less than 25 dBm to be equal can reduce the chip size and reduce the processing cost to a certain extent.

[0073] In some embodiments, the input power of filter 100 is greater than 30 dBm.

[0074] When the input power of the filter 100 is greater than 30dBm, the resonators of the resonance units 40 of each order of the filter 100 and the common bus bar 411 are prone to breakdown or burning due to the large power they bear. In the embodiment of the present application, the common bus bar 411 close to the input terminal 10 is widened and / or thickened, thereby reducing the resistance value of the common bus bar 411 itself, which can effectively avoid heat accumulation and reduce the risks of heating, burning and breakdown. It can not only improve the heat dissipation performance, but also increase the power resistance of the common bus bar 411, reduce the risk of failure of the filter 100 due to the breakdown of the common bus bar 411, and improve the power tolerance performance of the filter 100.

[0075] In some embodiments, the filter 100 is a transmitting filter. Generally, the power of the transmitting filter is relatively large. Under high power conditions, widening and / or thickening the common bus bar 411 of the resonance unit 40 close to the input terminal 10 is helpful to reduce the risk of breakdown.

[0076] In some usage scenarios, the transmit filter is used to selectively transmit signals within a specific frequency range while suppressing or attenuating signals of other frequencies, which helps to reduce spectrum interference and improve communication quality. Among them, the input terminal 10 is mainly used to receive the original signal from the transmitter or other signal source, and the output terminal 20 is used to send out the signal processed by the filter 100.

[0077] Exemplarily, the transmit filter may be a low-pass filter, a high-pass filter, a band-pass filter, a band-stop filter, and the like.

[0078] In some embodiments, the width of the common bus bar 411 of each order resonance unit 40 in at least two order resonance units 40 is positively correlated with the input voltage of each order resonance unit 40. Therefore, the width of the common bus bar 411 of each order resonance unit 40 can be set according to the input voltage of each order resonance unit 40, so as to balance the power density borne by the common bus bar 411 of each order resonance unit 40 and effectively reduce the risk of breakdown.

[0079] In some embodiments, the thickness of the common bus bar 411 of each order resonance unit 40 in at least two order resonance units 40 is positively correlated with the input voltage of each order resonance unit 40. Therefore, the thickness of the common bus bar 411 of each order resonance unit 40 can be set according to the input voltage of each order resonance unit 40, so as to balance the power density borne by the common bus bar 411 of each order resonance unit 40 and effectively reduce the risk of breakdown.

[0080] In some embodiments, the ratio of the input voltages of the resonance units 40 of each order in at least two resonance units 40 is equal to the ratio of the widths of the common bus bars 411 of the resonance units 40 of each order. Thus, the width ratio of the common bus bars 411 of the resonance units 40 of each order can be calculated according to the ratio of the input voltages of the resonance units 40 of each order, so as to balance the power density of the common bus bars 411 of the resonance units 40 of each order, and effectively reduce the risk of breakdown.

[0081] In some embodiments, the ratio of the input voltages of the resonance units 40 of each order in at least two resonance units 40 is equal to the ratio of the thicknesses of the common bus bars 411 of the resonance units 40 of each order. Thus, the thickness ratio of the common bus bars 411 of the resonance units 40 of each order can be calculated according to the ratio of the input voltages of the resonance units 40 of each order, so as to balance the power density borne by the common bus bars 411 of the resonance units 40 of each order, and effectively reduce the risk of breakdown.

[0082] See also Figure 5 and Figure 6 , in some embodiments, at least two-order resonance units 40 further include a third-order resonance unit 40c. When the input power of the filter 100 is 32 dBm, the input voltages of the first-order resonance unit 40a, the second-order resonance unit 40b, and the third-order resonance unit 40c are V1, V2, and V3, respectively, the widths of the common bus bar 411 of the first-order resonance unit 40a, the second-order resonance unit 40b, and the third-order resonance unit 40c are W1, W2, and W3, respectively, and the thicknesses of the common bus bar 411 of the first-order resonance unit 40a, the second-order resonance unit 40b, and the third-order resonance unit 40c are H1, H2, and H3, respectively; V1:V2:V3=5:4:3; W1:W2:W3=5:4:3, and / or, H1:H2:H3=5:4:3. Exemplarily, the input voltages of each order resonance unit 40 are as follows: Figure 6 As shown, the value is taken at the frequency point M1 where the input voltage is the largest (rounded to one decimal place), at the frequency point M1, freq (frequency) = 1.881 GHz, V1:V2:V3 = 5:4:3. Among them, S1-1 is the input voltage V1 of the first-order resonance unit 40a, S2-1 is the input voltage V2 of the second-order resonance unit 40b, and S3-1 is the input voltage V3 of the third-order resonance unit 40c.

[0083] Among them, the power signal is input from the input terminal 10, and the input voltage of the resonance unit 40 close to the input terminal 10 is the largest and is more likely to burn out. The ratio of the width and / or thickness of the common bus bar 411 of each order of resonance units 40 is calculated according to the ratio of the input voltages of each order of resonance units 40, which can help balance the power density of the common bus bar 411 of each order of resonance units 40 and effectively reduce the risk of breakdown.

[0084] In specific applications, the width and / or thickness range of the common bus bar 411 of each order of resonance unit 40 can be set according to the input power of the filter 100, and the specific parameters of thickening and / or widening the common bus bar 411 of each order of resonance unit 40 can be further determined according to the ratio of the input voltage of each order of resonators.

[0085] See also Figure 1 and Figure 5 Taking a fourth-order filter 100 as an example, at least two-order resonance units 40 include a first-order resonance unit 40a, a second-order resonance unit 40b, a third-order resonance unit 40c and a fourth-order resonance unit 40d. The first-order resonance unit 40a includes a first series arm resonance group S1 and a first parallel arm resonance group P1. The first series arm resonance group S1 includes two first resonators connected in series, and a first common bus bar 411a is provided between the two first resonators connected in series. The second-order resonance unit 40b includes a second series arm resonance group S2 and a second parallel arm resonance group P2. The second series arm resonance group S2 includes two second resonators connected in series, and a second common bus bar 411b is provided between the two second resonators connected in series. The third-order resonance unit 40c includes a third series arm resonance group S3 and a third parallel arm resonance group P3. The third series arm resonance group S3 includes two third resonators connected in series, and a third common bus bar 411c is provided between the two third resonators connected in series. The fourth-order resonance unit 40d includes a fourth series arm resonance group S4 and a fourth parallel arm resonance group P4, the fourth series arm resonance group S4 includes two fourth resonators connected in series, and a fourth common bus bar 411d is provided between the two fourth resonators connected in series. The input end of the series arm resonance group 41 of the first-order resonance unit 40a is connected to the input terminal 10, the output end of the series arm resonance group 41 of the first-order resonance unit 40a is connected to the input end of the series arm resonance group 41 of the second-order resonance unit 40b, the output end of the series arm resonance group 41 of the second-order resonance unit 40b is connected to the input end of the series arm resonance group 41 of the third-order resonance unit 40c, the output end of the series arm resonance group 41 of the third-order resonance unit 40c is connected to the input end of the series arm resonance group 41 of the fourth-order resonance unit 40d, and the output end of the series arm resonance group 41 of the fourth-order resonance unit 40d is connected to the output terminal 20.

[0086] When the input power of the filter 100 is 32 dBm, the width of the common bus bar 411 of each order resonance unit 40 can be selected from 15 μm, 16 μm, 17 μm, 18 μm, 19 μm, 20 μm, 21 μm, 22 μm, 23 μm, 24 μm, 25 μm, 26 μm, 27 μm, 28 μm, 29 μm or 30 μm. The thickness of the common bus bar 411 of each order resonance unit 40 can be selected from 1.5 μm, 1.6 μm, 1.7 μm, 1.8 μm, 1.9 μm, 2 μm, 2.1 μm, 2.2 μm, 2.3 μm, 2.4 μm or 2.5 μm.

[0087] The input voltage of each order resonant unit 40 is as follows: Figure 6 As shown, the value is taken at the frequency point M1 where the input voltage is the largest (rounded to one decimal place), at the frequency point M1, freq (frequency) = 1.881GHz, V1:V2:V3:V4 = 5:4:3:3. Among them, S1-1 is the input voltage V1 of the first-order resonance unit 40a, S2-1 is the input voltage V2 of the second-order resonance unit 40b, S3-1 is the input voltage V3 of the third-order resonance unit 40c, and S4-1 is the input voltage V4 of the fourth-order resonance unit 40d. The widths of the common bus bar 411 of the first-order resonant unit 40a, the second-order resonant unit 40b, the third-order resonant unit 40c and the fourth-order resonant unit 40d are W1, W2, W3 and W4, respectively, and the thicknesses of the common bus bar 411 of the second-order resonant unit 40b, the third-order resonant unit 40c and the fourth-order resonant unit 40d are H1, H2, H3 and H4, respectively, W1:W2:W3:W4=5:4:3:3, and / or, H1:H2:H3:W4=5:4:3:3.

[0088] Thus, the width of the common bus bar 411 of the first order resonance unit 40a, the second order resonance unit 40b, the third order resonance unit 40c and the fourth order resonance unit 40d may be 25 μm, 20 μm, 15 μm and 15 μm respectively. The thickness of the common bus bar 411 of the first order resonance unit 40a, the second order resonance unit 40b, the third order resonance unit 40c and the fourth order resonance unit 40d may be 2.5 μm, 2 μm, 1.5 μm and 1.5 μm respectively.

[0089] In other embodiments, in the direction from the input terminal 10 to the output terminal 20, in any adjacent two-order resonance units 40, the ratio of the input voltage of the resonance unit 40 close to the output terminal 20 to the input voltage of the resonance unit 40 close to the input terminal 10 is greater than or equal to 0.9 and less than 1, and the width and / or thickness of the common bus bar 411 of the two-order resonance units 40 are the same. Therefore, the width and / or thickness of the common bus bar 411 of the resonance units 40 with similar input voltages can be set to be the same, which can reduce the processing cost without affecting the power density borne by the common bus bar 411 of the resonance units 40 of each order. Of course, in other embodiments, the width and / or thickness of the common bus bar 411 of the two-order resonance units 40 may also be different, that is, the corresponding common bus bar 411 is widened and / or thickened according to the specific ratio of the input voltage of each order resonance unit 40.

[0090] See also Figure 2 and Figure 5 In some embodiments, the filter 100 further includes a heat dissipation structure 60, which is located on a series path close to the input terminal 10 and between two adjacent resonant units 40. Since the resonant unit 40 close to the input terminal 10 is subjected to a large power and is prone to heat generation, resulting in breakdown or burning of the resonator, adding the heat dissipation structure 60 can improve the heat dissipation capacity of the overall filter 100 circuit, effectively prevent the resonator from being broken down or burned, and further improve the power tolerance of the filter 100.

[0091] For example, Figure 2 As shown, the heat dissipation structure can be arranged between the series arm resonance group S1 of the first-order resonance unit 40a and the series arm resonance group S2 of the second-order resonance unit 40b. Of course, in other examples, the heat dissipation structure can also be arranged between the series arm resonance group S2 of the second-order resonance unit 40b and the series arm resonance group S3 of the third-order resonance unit 40c.

[0092] In some embodiments, the filter 100 further includes a piezoelectric substrate 50 and a wiring, at least two-order resonant units 40 are located on the piezoelectric substrate 50, each order resonant unit 40 is connected by a wiring, and a heat dissipation structure 60 is disposed on the wiring. Thus, disposing the heat dissipation structure 60 on the wiring can more effectively utilize the internal space of the filter 100, while reducing the thermal resistance of the heat dissipation path and improving the heat dissipation efficiency.

[0093] In some embodiments, the piezoelectric substrate 50 is provided with a first pad 51, a second pad 52 and a third pad 53, the first pad 51 is configured as an input terminal 10, the second pad 52 is configured as an output terminal 20, and the third pad 53 is configured as a ground terminal 30. The hardness of the material used by at least one of the first pad 51, the second pad 52 and the third pad 53 is greater than the hardness of the material used for the wiring. Thus, the hardness of the material used by at least one of the first pad 51, the second pad 52 and the third pad 53 is higher than the hardness of the material used for the wiring, so that the filter 100 has better stability when a high-power signal is input, thereby preventing at least one of the first pad 51, the second pad 52 and the third pad 53 from warping due to excessive input power and temperature increase, which is conducive to improving the power capacity of the filter 100, thereby improving the power tolerance of the filter 100.

[0094] For example, the hardness of the material used for one, two or all of the first pad 51 , the second pad 52 and the third pad 53 may be greater than the hardness of the material used for the trace.

[0095] In some embodiments, the wiring is made of pure metal material, and at least one of the first pad 51, the second pad 52, and the third pad 53 is made of alloy material. Since the alloy material has higher strength and hardness than the pure metal material, it prevents at least one of the first pad 51, the second pad 52, and the third pad 53 from warping due to excessive input power and temperature rise, which is beneficial to improve the power capacity of the filter 100, thereby improving the power tolerance of the filter 100.

[0096] By way of example, one, two or all of the first pad 51 , the second pad 52 and the third pad 53 may be made of an alloy material.

[0097] Exemplarily, the material used for the routing may be pure metal aluminum, and the material used for one of the first pad 51, the second pad 52, and the third pad 53 may be an aluminum alloy. Of course, the routing may also be made of other pure metal materials, and one of the first pad 51, the second pad 52, and the third pad 53 may also be made of other alloy materials, as long as the hardness of the material used for at least one of the first pad 51, the second pad 52, and the third pad 53 is greater than the hardness of the material used for the routing.

[0098] In some embodiments, the heat dissipation structure 60 can be a heat dissipation pad, which can be separately connected to the external circuit board and not in contact with the first pad 51, the second pad 52 and the third pad 53. The setting of the heat dissipation pad can improve the heat dissipation capacity of the overall filter 100 circuit and further improve the power tolerance of the filter 100.

[0099] In some embodiments, the hardness of the material used for the heat dissipation pad is greater than the hardness of the material used for the routing. Therefore, the hardness of the material used for the heat dissipation pad is higher than that of the material used for the routing, so that the filter 100 has better stability when a high-power signal is input, thereby preventing the heat dissipation pad from warping due to excessive input power and temperature rise, which is beneficial to improving the power capacity of the filter 100, thereby improving the power tolerance of the filter 100.

[0100] In some embodiments, the heat sink pad is made of alloy material and the wiring is made of pure metal material. Since the alloy material has higher strength and hardness than pure metal material, the heat sink pad is prevented from warping due to excessive input power and temperature rise, which is beneficial to improve the power capacity of the filter 100, thereby improving the power tolerance of the filter 100.

[0101] Exemplarily, the material used for the heat dissipation pad may be the same as or different from the first pad 51 , the second pad 52 and the third pad 53 , as long as the hardness of the material used for the heat dissipation pad is greater than the hardness of the material used for the routing.

[0102] Of course, in other embodiments, the heat dissipation structure 60 is not limited to using a heat dissipation pad, and other heat dissipation forms can be used as long as the heat dissipation capacity of the entire filter 100 circuit is improved.

[0103] The embodiment of the present application further proposes a radio frequency front-end module, including a packaging substrate and a filter chip arranged on the packaging substrate, and the filter chip includes the above-mentioned filter 100.

[0104] In some embodiments, the package substrate includes a signal input pad, a signal output pad, a signal ground pad, and a dummy pad, and the first pad 51, the second pad 53, and the third pad 53 of the filter 100 are respectively connected to the signal input pad, the signal output pad, and the signal ground pad through metal bumps, and the heat dissipation structure 60 of the filter 100 is connected to the dummy pad. Thus, the heat dissipation structure 60 can be connected to the package substrate alone, without contacting the signal input pad, the signal output pad, and the signal ground pad, to avoid mutual interference.

[0105] In some embodiments, the RF front-end module can be applied to electronic devices, which may include but are not limited to tablet computers, laptop computers, desktop computers, navigators, mobile phones, electronic watches and other electronic devices or components with wireless communication functions, which are not limited in this application.

[0106] In some embodiments, the RF front-end module may include a plurality of filters 100 , and the plurality of filters 100 may be two, three, and so on.

[0107] In some implementations, the RF front-end module may further include a low noise amplifier, a RF switch, a power amplifier, etc. The specific connection method thereof may refer to the prior art and will not be described in detail here.

[0108] In addition, since the RF front-end module includes the above-mentioned filter 100, the RF front-end module has all the beneficial effects of the filter 100, which will not be described in detail here.

[0109] Those skilled in the art may combine and associate different embodiments or examples described in this specification as well as features of different embodiments or examples without mutual contradiction.

[0110] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any technician familiar with the technical field can easily think of various equivalent modifications or replacements within the technical scope disclosed in the present application, and these modifications or replacements should be included in the protection scope of the present application. Therefore, the protection scope of the present application shall be based on the protection scope of the claims.

Claims

1. A filter, characterized in that: The device comprises an input terminal, an output terminal, a ground terminal and at least two-order resonance units connected between the input terminal and the output terminal, wherein the resonance unit comprises: A series arm resonance group connected to the series path between the input terminal and the output terminal; A parallel arm resonance group, one end of the parallel arm resonance group is connected to the input end or the output end of the series arm resonance group, and the other end of the parallel arm resonance group is connected to the ground terminal; At least one of the series arm resonance group and the parallel arm resonance group includes at least two series resonators, and any two adjacent resonators of the at least two series resonators have a common bus bar between them; The at least two-order resonance units include a first-order resonance unit and a second-order resonance unit, wherein the first-order resonance unit is closer to the input terminal than the second-order resonance unit; The thickness of the common bus bar of the first-order resonance unit is greater than the thickness of the common bus bar of the second-order resonance unit, and / or the width of the common bus bar of the first-order resonance unit is greater than the width of the common bus bar of the second-order resonance unit.

2. The filter according to claim 1, characterized in that The series arm resonance group of the first-order resonance unit includes at least two first resonators connected in series, and a first common bus bar is provided between any two adjacent first resonators of the at least two first resonators connected in series; The series arm resonance group of the second-order resonance unit comprises at least two second resonators connected in series, and a second common bus bar is provided between any two adjacent second resonators of the at least two second resonators connected in series; The thickness of the first common bus bar is greater than the thickness of the second common bus bar; And / or, the width of the first common bus bar is greater than the width of the second common bus bar.

3. The filter according to claim 1, characterized in that The input end of the series arm resonance group of the first-order resonance unit is connected to the input terminal.

4. The filter according to claim 1, characterized in that The thickness of the common bus bar of each order of the resonance units in the at least two orders of resonance units is 0.2 μm-2.5 μm; and / or, The width of the common bus bar of each order of the resonance units in the at least two orders of resonance units is 4 μm-30 μm.

5. The filter according to claim 1, characterized in that In a direction from the input terminal to the output terminal, the width and / or thickness of the common bus bar of each order of the resonance units decreases step by step.

6. The filter according to claim 1, characterized in that At least one of the series arm resonance group and the parallel arm resonance group includes two series resonators, and there is one common bus bar between the two series resonators; or, At least one of the series arm resonance group and the parallel arm resonance group includes more than three series resonators, and the width and / or thickness of the common bus bar between any two adjacent resonators among the more than three series resonators are equal, or, in the direction from the input terminal to the output terminal, the width and / or thickness of the common bus bar between any two adjacent resonators among the more than three series resonators decreases step by step.

7. The filter according to claim 1, characterized in that The width of the common bus bar of each order of the resonance units in the at least two orders of resonance units is positively correlated with the input power of the filter; and / or, The thickness of the common bus bar of each order of the resonance units in the at least two orders of resonance units is positively correlated with the input power of the filter.

8. The filter according to claim 1, characterized in that When the input power of the filter is 25dBm-30dBm, the width of the common bus bar of each order of the resonance unit in the at least two-order resonance unit is greater than or equal to 8μm, and / or the thickness of the common bus bar of each order of the resonance unit in the at least two-order resonance unit is greater than or equal to 0.8μm; and / or, When the input power of the filter is greater than 30dBm, the width of the common bus bar of each order of the at least two-order resonance units is greater than or equal to 15μm, and / or the thickness of the common bus bar of each order of the at least two-order resonance units is greater than or equal to 1.5μm.

9. The filter according to claim 1, characterized in that In the direction from the input terminal to the output terminal, the width and / or thickness of the common busbar of each order of the resonance unit with input power greater than or equal to 25dBm decreases step by step; and / or, The width and / or thickness of the common busbars of the resonance units of each order with input power less than 25 dBm are equal.

10. The filter according to claim 1, characterized in that Among the at least two series-connected resonators included in at least one of the series-arm resonant group and the parallel-arm resonant group, two resonators located at the edge positions respectively further include non-shared bus bars facing away from adjacent resonators; The width of the common bus bar is greater than the width of the non-common bus bar, and / or the thickness of the common bus bar is greater than the thickness of the non-common bus bar.

11. The filter according to claim 10, characterized in that The width of the common bus bar of any order resonant unit with input power greater than or equal to 25 dBm is greater than the width of the non-common bus bar of the order resonant unit, and / or, The thickness of the common bus bar of any order resonance unit with input power greater than or equal to 25 dBm is greater than the thickness of the non-common bus bar of the order resonance unit.

12. The filter according to claim 10, characterized in that A ratio of a width of the common bus bar to a width of the non-common bus bar is greater than or equal to 2, and / or a ratio of a thickness of the common bus bar to a thickness of the non-common bus bar is greater than or equal to 2.

13. The filter according to claim 1, characterized in that The input power of the filter is greater than 30dBm; and / or, The filter is a transmit filter.

14. The filter according to claim 1, characterized in that The width of the common bus bar of each order of the resonance units in the at least two orders of resonance units is positively correlated with the input voltage of each order of the resonance units; and / or, The thickness of the common bus bar of each order of the resonance units in the at least two orders of resonance units is positively correlated with the input voltage of each order of the resonance units.

15. The filter according to claim 14, characterized in that The ratio of the input voltages of the resonance units of each order in the at least two order resonance units is equal to the ratio of the widths of the common bus bars of the resonance units of each order; and / or, The ratio of the input voltages of the resonance units of each order in the at least two orders of resonance units is equal to the ratio of the thicknesses of the common bus bars of the resonance units of each order.

16. The filter according to claim 15, characterized in that The at least two-order resonance unit also includes a third-order resonance unit; When the input power of the filter is 32 dBm, the input voltages of the first-order resonance unit, the second-order resonance unit and the third-order resonance unit are V1, V2 and V3 respectively, the widths of the common busbars of the first-order resonance unit, the second-order resonance unit and the third-order resonance unit are W1, W2 and W3 respectively, and the thicknesses of the common busbars of the first-order resonance unit, the second-order resonance unit and the third-order resonance unit are H1, H2 and H3 respectively; V1:V2:V3=5:4:3; W1:W2:W3=5:4:3, and / or, H1:H2:H3=5:4:

3.

17. The filter according to claim 1, characterized in that In the direction from the input terminal to the output terminal, in any two adjacent resonant units, the ratio of the input voltage of the resonant unit close to the output terminal to the input voltage of the resonant unit close to the input terminal is greater than or equal to 0.9 and less than 1, and the width and / or thickness of the common bus bar of the two resonant units are the same.

18. The filter according to any one of claims 1 to 17, characterized in that: The filter further comprises a heat dissipation structure, which is located on a series path close to the input terminal and between two adjacent resonant units of the order.

19. The filter according to claim 18, characterized in that The filter further comprises a piezoelectric substrate and a wiring. The at least two-order resonance units are located on the piezoelectric substrate. The resonance units of each order are connected via the wiring. The heat dissipation structure is arranged on the wiring.

20. The filter according to claim 19, characterized in that The piezoelectric substrate is provided with a first pad, a second pad and a third pad, the first pad is configured as the input terminal, the second pad is configured as the output terminal, and the third pad is configured as the ground terminal; The hardness of the material used for at least one of the first pad, the second pad and the third pad is greater than the hardness of the material used for the routing; and / or the routing is made of pure metal material, and at least one of the first pad, the second pad and the third pad is made of alloy material.

21. A radio frequency front-end module, characterized in that: It comprises a packaging substrate and a filter chip arranged on the packaging substrate, and the filter chip comprises the filter according to any one of claims 1 to 20.

22. The radio frequency front-end module according to claim 21, characterized in that: The packaging substrate includes a signal input pad, a signal output pad, a signal ground pad and a virtual pad. The first pad, the second pad and the third pad of the filter are respectively connected to the signal input pad, the signal output pad and the signal ground pad through metal bumps, and the heat dissipation structure of the filter is connected to the virtual pad.

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