Filter device and multiplexer

Abstract

The invention provides a filter device and a multiplexer, which can suppress the influence of useless waves. The excitation angle change resonator includes a piezoelectric substrate including a piezoelectric layer, and an IDT electrode including a plurality of curved electrode fingers. The piezoelectric layer has a propagation axis. When the excitation angle is the angle formed by the excitation direction and the direction in which the propagation axis extends, the excitation angles are different in the IDT electrodes of the excitation angle change resonator. A plurality of trapezoidal portions are formed between the first and second signal terminals. In adjacent trapezoidal portions, at least one of the series arm resonators and the parallel arm resonators is different from each other. A series arm resonator and a parallel arm resonator from a resonator located closest to a first signal terminal side to a trapezoid portion located closest to a second signal terminal side among half trapezoid portions located on the first signal terminal side among the plurality of resonators are set as the front half resonator. At least one of the first half resonators is an excitation angle change type resonator.

Description

Technical Field

[0001] The present invention relates to a filter device and a multiplexer having a plurality of elastic wave resonators. Background Art

[0002] In the past, filters including multiple elastic wave resonators were widely used in portable phones and the like. Patent document 1 below discloses an example of a quadplexer as a multiplexer. The quadplexer has a transmitting filter and a receiving filter for Band 1, and a transmitting filter and a receiving filter for Band 3. Each filter is connected to a common terminal. The common terminal is a terminal on the antenna side. Each filter includes multiple resonators. These resonators all have IDT (Interdigital Transducer) electrodes.

[0003] Prior Art Literature

[0004] Patent Literature

[0005] Patent Document 1: International Publication No. 2018 / 003296 Summary of the invention

[0006] Problem that the invention aims to solve

[0007] When filters of multiple communication frequency bands are commonly connected to a terminal connected to an antenna, the useless waves generated in the resonator near the terminal often affect the filter characteristics of other filters. For example, when a Rayleigh wave is generated in the resonator of the receiving filter of Band 1, the frequency of the Rayleigh wave is located in the passband of the transmitting filter of Band 3. Therefore, in the transmitting filter of Band 3 in the quadplexer described in Patent Document 1, the insertion loss tends to increase due to the Rayleigh wave generated in the resonator of the receiving filter of Band 1.

[0008] An object of the present invention is to provide a filter device capable of suppressing the influence of unnecessary waves when used in a multiplexer, and a multiplexer capable of suppressing the influence of unnecessary waves.

[0009] Means used to solve problems

[0010] The filter device of the present invention comprises: a first signal terminal and a second signal terminal; and a plurality of resonators including a plurality of series arm resonators and a plurality of parallel arm resonators, at least one of the plurality of series arm resonators and the plurality of parallel arm resonators is an excitation angle variable resonator, the excitation angle variable resonator comprising: a piezoelectric substrate including a piezoelectric layer; and an IDT electrode including a plurality of electrode fingers arranged on the piezoelectric substrate, the piezoelectric layer having a propagation axis, the plurality of electrode fingers being bent, the excitation direction of elastic waves in any portion of any electrode finger among the plurality of electrode fingers being any one of a first direction to a third direction, the first direction being a direction perpendicular to the direction in which the electrode finger extends, the second direction being a direction connecting the shortest distance between the electrode finger and the electrode finger adjacent to the electrode finger, the third direction being a direction of an electric field vector generated between the electrode finger and the electrode finger adjacent to the electrode finger, and the excitation direction and the third direction being a direction of an electric field vector generated between the electrode finger and the electrode finger adjacent to the electrode finger, and the excitation direction and the third direction being a direction in which the excitation direction and the third direction are connected. When the angle formed by the directions in which the propagation axes extend is set as the excitation angle, the excitation angle is different in the IDT electrodes of the excitation angle variable resonator, and when an adjacent group of the series arm resonators and the parallel arm resonators are set as a trapezoidal portion, a plurality of the trapezoidal portions are formed between the first signal terminal and the second signal terminal, and in the adjacent trapezoidal portions, at least one of the series arm resonators and the parallel arm resonators is a mutually different resonator, and half of the trapezoidal portions located on the first signal terminal side among all the trapezoidal portions are set as the first half of the trapezoidal portions, and the series arm resonators and the parallel arm resonators from the resonator located closest to the first signal terminal to the trapezoidal portion located closest to the second signal terminal among the plurality of resonators in the first half of the trapezoidal portions are set as the first half of the resonators, and in this case, at least one of the resonators in the first half is the excitation angle variable resonator.

[0011] The multiplexer according to the present invention comprises: a common connection terminal; and a plurality of filters commonly connected to the common connection terminal, including a first filter and a second filter, wherein at least the first filter among the plurality of filters is a filter device constructed according to the present invention.

[0012] Effects of the Invention

[0013] According to the present invention, it is possible to provide a filter device that can suppress the influence of unnecessary waves when used in a multiplexer, and a multiplexer that can suppress the influence of unnecessary waves. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 This is a schematic circuit diagram of a multiplexer according to a first embodiment of the present invention.

[0015] Figure 2 This is a circuit diagram for explaining the ladder section of the first filter in the first embodiment of the present invention.

[0016] Figure 3 It is a schematic top view of the first filter in the first embodiment of the present invention.

[0017] Figure 4 It is along Figure 3 Schematic cross-sectional view of line II in FIG.

[0018] Figure 5 It is a schematic plan view of the excitation angle variable resonator of the first filter in the first embodiment of the present invention.

[0019] Figure 6 It is a schematic top view of the first filter in the first embodiment of the present invention.

[0020] Figure 7 It is a schematic plan view of the elastic wave resonators other than the excitation angle variable resonator of the first filter in the first embodiment of the present invention.

[0021] Figure 8 It is a diagram showing attenuation frequency characteristics of the first filter, the second filter, the third filter, and the fourth filter in the first embodiment of the present invention.

[0022] Fig. 9 It is a diagram showing the attenuation frequency characteristics of the second filter in the first embodiment of the present invention and the first comparative example.

[0023] Fig.10 FIG. 1 is a diagram showing phase characteristics of an excitation angle-variable resonator and an elastic wave resonator having an inclined IDT electrode.

[0024] Fig.11 It is a graph showing the return loss in the first embodiment of the present invention and its first to fourth modifications and a first comparative example.

[0025] Fig.12 This is a schematic plan view showing a circle including an arc when the shape of the electrode fingers of the IDT electrode in the first embodiment of the present invention in a plan view is approximated as an arc.

[0026] Fig.13 It is a schematic plan view of the excitation angle variable resonator of the first filter in the fifth modification of the first embodiment of the present invention.

[0027] Fig.14 It is a schematic plan view of the excitation angle variable resonator of the first filter in the sixth modification of the first embodiment of the present invention.

[0028] Fig.15 It is a schematic plan view showing the parallel region and the non-parallel region in the sixth modification example of the first embodiment of the present invention.

[0029] Fig.16 It is a schematic plan view of the excitation angle variable resonator of the first filter in the seventh modification of the first embodiment of the present invention.

[0030] Fig.17 It is a schematic plan view of an excitation angle variable resonator of the first filter in the eighth modification of the first embodiment of the present invention.

[0031] Fig.18 It is a schematic plan view of the excitation angle variable resonator of the first filter in the ninth modification of the first embodiment of the present invention.

[0032] Fig.19 This is a schematic plan view showing the vicinity of the first edge region and the second edge region in the excitation angle variable resonator of the first filter in the tenth modification of the first embodiment of the present invention.

[0033] Fig. 20 (a) is a schematic cross-sectional view showing a cross section of a first electrode finger, a first edge region, a second edge region, and a vicinity of a central region along a direction in which the first electrode finger extends in the eleventh modification of the first embodiment of the present invention. Fig. 20 (b) is a schematic cross-sectional view showing a cross section of the second electrode finger in the eleventh modification example of the first embodiment of the present invention, in the first edge region, the second edge region, and the vicinity of the central region, along the direction in which the second electrode finger extends.

[0034] Fig.21 It is a schematic plan view of the excitation angle variable resonator of the first filter in the twelfth modified example of the first embodiment of the present invention.

[0035] Fig. 22 This is a schematic circuit diagram of a multiplexer according to a second embodiment of the present invention.

[0036] Fig.23 It is a schematic top view of the first filter in the second embodiment of the present invention.

[0037] Fig.24 It is a diagram showing the attenuation frequency characteristics of the first filter in the second embodiment of the present invention and the first comparative example in the vicinity of the frequency at which Rayleigh waves are generated.

[0038] Fig.25It is a diagram showing the attenuation frequency characteristics of the first filter in the first embodiment of the present invention and the first comparative example in the vicinity of the frequency at which Rayleigh waves are generated.

[0039] Fig.26 It is a graph showing the return loss in the first embodiment and the second embodiment of the present invention and the first comparative example.

[0040] Fig. 27 This is a schematic circuit diagram of a multiplexer according to a third embodiment of the present invention.

[0041] Fig.28 This is a schematic circuit diagram of a multiplexer according to a modified example of the third embodiment of the present invention.

[0042] Fig.29 It is a diagram showing the return loss in the third embodiment of the present invention and its modified example and the second comparative example.

[0043] Fig.30 This is a schematic circuit diagram of a multiplexer according to a fourth embodiment of the present invention.

[0044] Fig.31 This is a schematic circuit diagram of a multiplexer according to a fifth embodiment of the present invention.

[0045] Fig.32 This is a circuit diagram for explaining the ladder portion of the first filter in the fifth embodiment of the present invention.

[0046] Fig.33 It is a schematic plan view of a plurality of variable excitation angle resonators of the first filter in the sixth embodiment of the present invention.

[0047] Fig.34 It is a diagram showing the phase characteristics of each excitation angle variable resonator in the sixth embodiment of the present invention.

[0048] Fig.35 It is a graph showing the return loss in the first embodiment and the sixth embodiment of the present invention and the first comparative example.

[0049] Fig.36 This is a circuit diagram of a multiplexer according to a seventh embodiment of the present invention.

[0050] Fig.37 It is a schematic front cross-sectional view of an excitation angle variable resonator of the first filter in the eighth embodiment of the present invention.

[0051] Fig.38 It is a schematic front cross-sectional view of an excitation angle variable resonator of a first filter in a first modified example of the eighth embodiment of the present invention.

[0052] Fig.39 It is a schematic front cross-sectional view of the excitation angle variable resonator of the first filter in the second modified example of the eighth embodiment of the present invention.

[0053] Fig.40 It is a schematic front cross-sectional view of the excitation angle variable resonator of the first filter in the ninth embodiment of the present invention.

[0054] Fig.41 It is a schematic front cross-sectional view of an excitation angle variable resonator of the first filter in the tenth embodiment of the present invention.

[0055] Fig.42 It is a schematic front cross-sectional view of an excitation angle variable resonator of a first filter in a first modified example of the tenth embodiment of the present invention.

[0056] Fig.43 It is a schematic front cross-sectional view of the excitation angle variable resonator of the first filter in the second modified example of the tenth embodiment of the present invention.

[0057] Fig.44 It is a schematic front cross-sectional view of the excitation angle variable resonator of the first filter in the third modified example of the tenth embodiment of the present invention.

[0058] Description of Reference Numerals

[0059] 1...Multiplexer;

[0060] 1A~1D...1st filter to 4th filter;

[0061] 2...Piezoelectric substrate;

[0062] 3...supporting member;

[0063] 3A, 3B...1st signal terminal, 2nd signal terminal;

[0064] 4...support base plate;

[0065] 5...Middle layer;

[0066] 5a, 5b...1st layer, 2nd layer;

[0067] 6...Piezoelectric layer;

[0068] 6a, 6b...1st main surface, 2nd main surface;

[0069] 7...Common connection terminal;

[0070] 8... Dielectric film;

[0071] 9A~9H...Reflector;

[0072] 9a, 9b...reflector busbar;

[0073] 9c ... a plurality of reflector electrode fingers;

[0074] 9d, 9e...reflector busbar;

[0075] 9f...a plurality of reflector electrode fingers;

[0076] 12, 12B, 12C, 12H... first offset electrode;

[0077] 13, 13B, 13C, 13H... second offset electrode;

[0078] 14, 14A...Bus No. 1;

[0079] 15, 15A...Bus No. 2;

[0080] 16, 16B, 16C, 16E-16G...1st electrode finger;

[0081] 16a, 16b ... wide width portion;

[0082] 17, 17B, 17C, 17E-17G...second electrode finger;

[0083] 17a, 17b ... wide width portion;

[0084] 18, 18A~_18H...IDT electrode;

[0085] 19...Quality additional film;

[0086] 21A, 31A, 41A, 51A...1st filter;

[0087] 55...Longitudinal coupled resonator type elastic wave filter;

[0088] 71...Multiplexer;

[0089] 71B to 71D ... the second filter to the fourth filter;

[0090] 73B, 73D...Signal terminals;

[0091] 82, 82A, 82B ... piezoelectric substrate;

[0092] 82c...Hollow part;

[0093] 84...support base plate;

[0094] 85, 85A...middle layer;

[0095] 87...Sound reflection film;

[0096] 87a...high acoustic impedance layer;

[0097] 87b... low acoustic impedance layer;

[0098] 87c...high acoustic impedance layer;

[0099] 87d...Low acoustic impedance layer;

[0100] 87e...high acoustic impedance layer;

[0101] 99...Protective film;

[0102] 99a, 99b...a first protective layer, a second protective layer;

[0103] 118...Electrode;

[0104] A...parallel area;

[0105] B...non-parallel region;

[0106] C1, C2...capacitor components;

[0107] D...node;

[0108] E1, E1A...1st envelope;

[0109] E2, E2A...Second envelope;

[0110] F...Central Region;

[0111] H1, H2...1st marginal area, 2nd marginal area;

[0112] J...intersection area;

[0113] K1, K2...1st curve area, 2nd curve area;

[0114] L, L1~L4...inductors;

[0115] P...Parallel arm;

[0116] P1 to P4, P21, P31 to P34, P51, P52, P71B to P71D, P72B to P72D, P73B to P73D, P74B to P74D ... parallel arm resonator section;

[0117] P31a, P31b, P51a, P51b...parallel arm resonator;

[0118] S...tandem arm;

[0119] S1 to S5, S31 to S34, S51 to S53, S61, S71B to S71D, S72B to S72D, S73B to S73D, S74B to S74D, S75C ... series arm resonator section;

[0120] S1a~S1c, S2a, S2b, S3a~S3c, S31a, S31b, S32a~S32c, S51a, S51b, S53a, S53b, S61a~S61c...series arm resonator;

[0121] V1, V2...bending part;

[0122] W1~W3...Area 1 to Area 3. DETAILED DESCRIPTION

[0123] Hereinafter, specific embodiments of the present invention will be described with reference to the accompanying drawings to clarify the present invention.

[0124] In addition, it should be noted that each embodiment described in this specification is an example, and that some structures may be replaced or combined between different embodiments.

[0125] Figure 1 FIG. 1 is a schematic circuit diagram of a multiplexer according to a first embodiment of the present invention. Figure 1 In FIG. 1 , the second to fourth filters described later are shown by a block diagram.

[0126] like Figure 1 As shown, the multiplexer 1 of the present embodiment is a quadruplexer. The multiplexer 1 includes a first filter 1A, a second filter 1B, a third filter 1C, and a fourth filter 1D. The first filter 1A is a filter device according to one embodiment of the present invention.

[0127] The multiplexer 1 is not limited to a quadplexer. The multiplexer 1 may include at least the first filter 1A and the second filter 1B. The multiplexer 1 may be a multiplexer including two or more filters, such as a duplexer, a triplexer, or a quintuplexer.

[0128] Each filter of the multiplexer 1 is a bandpass filter. Therefore, each filter has a passband. More specifically, the communication frequency bands of the multiplexer 1 are Band 1 and Band 3.

[0129] The first filter 1A is a receiving filter for Band 1. The passband of the first filter 1A is 2110 MHz to 2170 MHz. The second filter 1B is a transmitting filter for Band 3. The passband of the second filter 1B is 1710 MHz to 1785 MHz. The third filter 1C is a receiving filter for Band 3. The passband of the third filter 1C is 1805 MHz to 1880 MHz. The fourth filter 1D is a transmitting filter for Band 1. The passband of the fourth filter 1D is 1920 MHz to 1980 MHz. However, the communication frequency band of the multiplexer 1 is not limited to the above.

[0130] The multiplexer 1 has a common connection terminal 7. The first filter 1A, the second filter 1B, the third filter 1C, and the fourth filter 1D are commonly connected to the common connection terminal 7. In the present embodiment, the common connection terminal 7 is an antenna terminal. The antenna terminal is connected to an antenna. The common connection terminal 7 can be configured as a wiring or an electrode pad, for example.

[0131] An inductor L is connected between the common connection terminal 7 and the ground potential. The inductor L is an inductor for impedance adjustment. In addition, the inductor L does not necessarily need to be provided.

[0132] The first filter 1A has a first signal terminal 3A and a second signal terminal 3B, a plurality of ground terminals, and a plurality of resonators. The first signal terminal 3A is an input terminal of the first filter 1A. The second signal terminal 3B is an output terminal of the first filter 1A. The ground terminal is a terminal connected to a ground potential. The plurality of resonators are a plurality of series arm resonators and a plurality of parallel arm resonators. The first filter 1A is a ladder filter.

[0133] The first signal terminal 3A of the first signal terminal 3A and the second signal terminal 3B is located on the side of the common connection terminal 7. The first signal terminal 3A is electrically connected to the common connection terminal 7 via wiring or the like. Therefore, in the first filter 1A, the first signal terminal 3A is an antenna terminal.

[0134] In the present embodiment, all the series arm resonators and all the parallel arm resonators in the first filter 1A are elastic wave resonators. All the elastic wave resonators in the first filter 1A have IDT electrodes.

[0135] In addition, in the circuit structure of the first filter 1A, a series arm S, a plurality of parallel arms P, and a plurality of nodes D are provided. The series arm S is a path connecting the first signal terminal 3A as an input terminal and the second signal terminal 3B as an output terminal. Each series arm resonator is provided in the series arm S. On the other hand, each parallel arm P is a path branching from the series arm S to each ground terminal. Each parallel arm P is provided with each parallel arm resonator. On the other hand, the node D is a connection point between the series arm S and the parallel arm P.

[0136] The first filter 1A has a plurality of series arm resonator sections. The series arm resonator section is one series arm resonator or a group of a plurality of series arm resonators connected in series or in parallel to each other without passing through a node D. More specifically, the series arm resonator section is a portion where one or more series arm resonators are provided between an input terminal and a node D, between nodes D, or between a node D and an output terminal. In addition, as described above, in the first filter 1A, the input terminal is the first signal terminal 3A. The output terminal is the second signal terminal 3B. The series arm resonator section may also be, for example, a portion including a plurality of split-type series arm resonators.

[0137] The plurality of series arm resonator sections of the first filter 1A are specifically a series arm resonator section S1, a series arm resonator section S2, a series arm resonator section S3, a series arm resonator section S4, and a series arm resonator section S5. In the present embodiment, the series arm resonator section S1 includes a plurality of series arm resonators divided in series. That is, in the series arm resonator section S1, a plurality of divided series arm resonators are connected in series with each other. The series arm resonator section S2 and the series arm resonator section S3 also include a plurality of series arm resonators divided in series. On the other hand, the series arm resonator section S4 and the series arm resonator section S5 each include one series arm resonator.

[0138] In addition, when the series arm resonator unit includes a plurality of series arm resonators, the plurality of series arm resonators may not be series-divided series arm resonators. The relationship between the design parameters of the plurality of series arm resonators of the series arm resonator unit is not particularly limited. The plurality of series arm resonators of the series arm resonator unit may be connected in series or in parallel.

[0139] A plurality of series arm resonator sections are connected in series between the first signal terminal 3A and the second signal terminal 3B. More specifically, from the first signal terminal 3A side, a series arm resonator section S1, a series arm resonator section S2, a series arm resonator section S3, a series arm resonator section S4, and a series arm resonator section S5 are connected in order.

[0140] In addition, the series arm resonator section S1 and the series arm resonator section S3 each include three split-type series arm resonators. The series arm resonator section S2 includes two split-type series arm resonators. More specifically, the series arm resonator section S1 includes a series arm resonator S1a, a series arm resonator S1b, and a series arm resonator S1c. The series arm resonator section S2 includes a series arm resonator S2a and a series arm resonator S2b. The series arm resonator section S3 includes a series arm resonator S3a, a series arm resonator S3b, and a series arm resonator S3c.

[0141] In the present embodiment, there is only one node D disposed between the series arm resonator sections. In addition, for example, a plurality of nodes D may be disposed between the series arm resonator sections. When the section between the first signal terminal 3A and the series arm resonator section, the section between the second signal terminal 3B and the series arm resonator section, and the section between adjacent series arm resonator sections are respectively set as sections, at least one node D may be located at least in each section between adjacent series arm resonator sections.

[0142] The first filter 1A has a plurality of parallel arm resonator sections. Specifically, one parallel arm resonator section is a parallel arm resonator located in a parallel arm connected to a node D located in the same interval. For example, as in the present embodiment, when only one node D and only one parallel arm P are configured in the same interval, the parallel arm resonator section is one parallel arm resonator, or a group of multiple parallel arm resonators connected in series or in parallel to each other in the parallel arm P. On the other hand, for example, when multiple nodes D and multiple parallel arms P are configured in the same interval, multiple parallel arm resonators located in the multiple parallel arms P are included in one parallel arm resonator section.

[0143] When only one node D and only one parallel arm P are arranged in the same section, the parallel arm resonator section may be a section including a plurality of split parallel arm resonators.

[0144] Specifically, the plurality of parallel arm resonator sections of the first filter 1A are parallel arm resonator section P1, parallel arm resonator section P2, parallel arm resonator section P3, and parallel arm resonator section P4. In the present embodiment, all the parallel arm resonator sections of the first filter 1A include one parallel arm resonator.

[0145] The parallel arm resonator section P1 is connected between the node D between the series arm resonator section S1 and the series arm resonator section S2 and the ground potential. The parallel arm resonator section P2 is connected between the node D between the series arm resonator section S2 and the series arm resonator section S3 and the ground potential. The parallel arm resonator section P3 is connected between the node D between the series arm resonator section S3 and the series arm resonator section S4 and the ground potential. The parallel arm resonator section P4 is connected between the node D between the series arm resonator section S4 and the series arm resonator section S5 and the ground potential.

[0146] Figure 2 1 is a circuit diagram for explaining the ladder section of the first filter in the first embodiment. Figure 2 In order to explain the trapezoidal part described later, for convenience, one series arm resonator part is represented by the mark of one or two resonators. Similarly, for convenience, one parallel arm and the parallel arm resonator part located in the parallel arm are represented by the marks of two parallel arms and two resonators.

[0147] The following, such as Figure 2 As shown by the dotted line in , a set of adjacent series arm resonators and parallel arm resonators is set as a ladder section of one stage. In the first filter 1A, a plurality of ladder sections are formed between the first signal terminal 3A and the second signal terminal 3B. Specifically, eight ladder sections are formed. The first to eighth ladder sections are arranged in order from the first signal terminal 3A side to the second signal terminal 3B side.

[0148] The first level of the trapezoidal part consists of Figure 1 The series arm resonator S1c shown in the figure and the parallel arm resonator of the parallel arm resonator section P1 are formed. The second-stage trapezoidal section next to the trapezoidal section is formed by the parallel arm resonator of the parallel arm resonator section P1 and the series arm resonator S2a. In these adjacent trapezoidal sections, the series arm resonators are different from each other, and the parallel arm resonators are common.

[0149] However, it is not limited to this. For example, Figure 2 The third-stage trapezoidal portion shown consists of Figure 1 The parallel arm resonator structure of the series arm resonator S2b and the parallel arm resonator section P2 shown in FIG. Therefore, in the adjacent second-stage trapezoidal section and third-stage trapezoidal section, the series arm resonators are different from each other, and the parallel arm resonators are different from each other.

[0150] Or, for example, Figure 2The 6th-stage trapezoidal section shown is composed of the parallel arm resonator of the parallel arm resonator section P3 and the series arm resonator of the series arm resonator section S4. The 7th-stage trapezoidal section is composed of the series arm resonator of the series arm resonator section S4 and the parallel arm resonator of the parallel arm resonator section P4. Therefore, in the adjacent 6th-stage trapezoidal section and the 7th-stage trapezoidal section, the parallel arm resonators are different from each other, and the series arm resonators are common. Like these, in the adjacent trapezoidal sections, at least one of the series arm resonator and the parallel arm resonator can be a different resonator.

[0151] Here, the half of the trapezoidal parts located on the first signal terminal 3A side among all the trapezoidal parts is set as the first half of the trapezoidal parts. Moreover, the series arm resonators and the parallel arm resonators from the resonator located closest to the first signal terminal 3A side to the trapezoidal part located closest to the second signal terminal 3B side among the plurality of resonators are set as the first half of the resonators. In the present embodiment, the first half of the trapezoidal parts are the trapezoidal parts from the first stage to the fourth stage. The first half of the resonators are the series arm resonator S1a, the series arm resonator S1b, the series arm resonator S1c, the parallel arm resonator of the parallel arm resonator part P1, the series arm resonator S2a, the series arm resonator S2b, the parallel arm resonator of the parallel arm resonator part P2, and the series arm resonator S3a.

[0152] As described above, the plurality of series arm resonators and the plurality of parallel arm resonators of the first filter 1A are elastic wave resonators. These elastic wave resonators include excitation angle variable resonators and elastic wave resonators other than excitation angle variable resonators, which will be described in detail later. Figure 1 In FIG. 1 , the resonator surrounded by a dashed line is an excitation angle variable resonator. The same is true in other schematic circuit diagrams and circuit diagrams.

[0153] This embodiment is characterized in that at least one of the resonators in the first half is an excitation angle variable resonator. Specifically, in this embodiment, each series arm resonator of the series arm resonator unit S1 is an excitation angle variable resonator. In addition, the so-called excitation angle variable resonator is a resonator whose excitation angle changes in the crossover region. As a result, in the multiplexer 1, the influence of useless waves can be suppressed. The following describes the details of the above-mentioned effect together with the structure of this embodiment, the excitation angle, and the details of the excitation angle variable resonator.

[0154] Figure 3 It is a schematic top view of the first filter in the first embodiment. Figure 4 It is along Figure 3 Schematic cross-sectional view of line II in FIG. Figure 5FIG. 1 is a schematic top view of the excitation angle variable resonator of the first filter in the first embodiment. Figure 3 In the diagram, the IDT electrode and the reflector described later are represented by a graph including a curve and a simplified diagram with two diagonal lines added to a rectangle. The same is true for other simplified top views. Figure 3 as well as Figure 5 In the above diagram, a dielectric film described later is omitted. The same is true in other top views.

[0155] like Figure 3 As shown, the first filter 1A includes a piezoelectric substrate 2. The piezoelectric substrate 2 is a laminated substrate including a piezoelectric layer 6. That is, the piezoelectric substrate 2 is a substrate having piezoelectricity. All elastic wave resonators in the first filter 1A share the piezoelectric substrate 2. Each elastic wave resonator has an IDT electrode. The IDT electrode of each elastic wave resonator is provided on the piezoelectric substrate 2.

[0156] like Figure 4 As shown, the piezoelectric substrate 2 has a supporting member 3 and a piezoelectric layer 6. More specifically, the supporting member 3 has a supporting substrate 4 and an intermediate layer 5. The intermediate layer 5 includes a first layer 5a and a second layer 5b. The first layer 5a is provided on the supporting substrate 4. The second layer 5b is provided on the first layer 5a. The piezoelectric layer 6 is provided on the second layer 5b. In addition, the layer structure of the piezoelectric substrate 2 is not limited to the above. For example, the intermediate layer 5 may also be a single-layer dielectric film. Alternatively, the piezoelectric substrate 2 may also be a substrate including only the piezoelectric layer 6.

[0157] In this embodiment, silicon is used as the material of the support substrate 4. Silicon nitride is used as the material of the first layer 5a. Silicon oxide is used as the material of the second layer 5b. Lithium tantalate that rotates Y-cut and propagates X-propagating is used as the material of the piezoelectric layer 6. In this way, the piezoelectric layer 6 has a propagation axis. And the direction of the propagation axis is the X direction. However, the materials of each layer of the piezoelectric substrate 2 are not limited to the above.

[0158] The piezoelectric layer 6 has a first main surface 6a and a second main surface 6b. The first main surface 6a and the second main surface 6b are opposite to each other. Of the first main surface 6a and the second main surface 6b, the second main surface 6b is located on the support substrate 4 side. The IDT electrode 18 of the series arm resonator S1a is provided on the first main surface 6a of the piezoelectric layer 6. In addition, the IDT electrodes of each elastic wave resonator other than the series arm resonator S1a are also provided on the first main surface 6a.

[0159] like Figure 5As shown, the IDT electrode 18 of the series arm resonator S1a as an excitation angle variable resonator has a pair of bus bars. The pair of bus bars are specifically the first bus bar 14 and the second bus bar 15. The first bus bar 14 and the second bus bar 15 are opposite to each other. The IDT electrode 18 has a plurality of electrode fingers. The plurality of electrode fingers are specifically the plurality of first electrode fingers 16 and the plurality of second electrode fingers 17. One end of the plurality of first electrode fingers 16 is connected to the first bus bar 14, respectively. One end of the plurality of second electrode fingers 17 is connected to the second bus bar 15, respectively.

[0160] The plurality of first electrode fingers 16 and the plurality of second electrode fingers 17 respectively include a base end portion, a front end portion, and a pair of end edges. Specifically, the base end portion of the first electrode finger 16 is a portion connected to the first bus bar 14. The pair of end edges of the first electrode finger 16 is a portion connecting the base end portion and the front end portion. The base end portion of the second electrode finger 17 is a portion connected to the second bus bar 15. The pair of end edges of the second electrode finger 17 is a portion connecting the base end portion and the front end portion in a plan view. The plurality of first electrode fingers 16 and the plurality of second electrode fingers 17 are interlaced with each other. In addition, in this specification, the so-called plan view refers to the view from the direction opposite to the first bus bar 14. Figure 4 Observe from the upper direction. Figure 4 For example, between the support substrate 4 side and the piezoelectric layer 6 side, the piezoelectric layer 6 side is at the upper side.

[0161] The front end portions of the plurality of first electrode fingers 16 and the plurality of second electrode fingers 17 respectively include front ends. A virtual line formed by connecting the front ends of the plurality of second electrode fingers 17 is set as a first envelope E1. Similarly, a virtual line formed by connecting the front ends of the plurality of first electrode fingers 16 is set as a second envelope E2. In addition, hereinafter, the first electrode fingers 16 and the second electrode fingers 17 are sometimes described simply as electrode fingers. The first bus bar 14 and the second bus bar 15 are sometimes described simply as bus bars.

[0162] The area between the first envelope E1 and the second envelope E2 is the intersection area J. More specifically, the area surrounded by the edge of the electrode finger at one end in the direction in which the plurality of electrode fingers are arranged, the edge of the electrode finger at the other end, the first envelope E1, and the second envelope E2 is the intersection area J. Therefore, the first envelope E1 corresponds to the edge on the first bus bar 14 side of the intersection area J. The second envelope E2 corresponds to the edge on the second bus bar 15 side of the intersection area J. In the intersection area J, when viewed from the direction in which the first envelope E1 or the second envelope E2 extends, adjacent electrode fingers overlap each other.

[0163] In the present embodiment, the intersection region J is composed of a curved region. The so-called curved region is a region where the shapes of the plurality of first electrode fingers 16 and the plurality of second electrode fingers 17 are curved when viewed from above. One end edge of the curved region constituting the intersection region J is the first envelope E1. The other end edge is the second envelope E2. In addition, in the series arm resonator S1a as an excitation angle variable resonator, the plurality of electrode fingers only need to be bent. For example, the shape of the plurality of electrode fingers when viewed from above may also be a shape bent at a plurality of sections.

[0164] The elastic wave is excited by applying an AC voltage to the IDT electrode 18. Specifically, for example, the SH mode is excited as the main mode. In this case, the Rayleigh wave becomes an unnecessary wave. However, the main mode is not limited to the SH mode.

[0165] The intersection region J of the IDT electrode 18 is a curved region. The shape of each electrode finger in the curved region is a curved shape in a plan view. Therefore, the excitation direction of the elastic wave is not the same in the curved region of the IDT electrode 18.

[0166] Specifically, the excitation direction of the elastic wave at any portion of any electrode finger among the plurality of first electrode fingers 16 and the plurality of second electrode fingers 17 in the curve region is any one of the following first to third directions. The first direction is a direction perpendicular to the direction in which the electrode finger extends. The second direction is a direction connecting the shortest distance between the electrode finger and the first electrode finger 16 or the second electrode finger 17 adjacent to the electrode finger. The third direction is a direction of an electric field vector generated between the electrode finger and the first electrode finger 16 or the second electrode finger 17 adjacent to the electrode finger.

[0167] In addition, since the shape of each electrode finger in the curved region is a curved shape, the direction in which one electrode finger extends differs for each position. In this specification, unless otherwise specified, the direction in which the curved electrode finger extends is defined as follows.

[0168] First, a pair of end edges of each electrode finger has a curved shape. In any part of the electrode finger, when a virtual line parallel to the direction in which the propagation axis extends is drawn to connect the two end edges, the center of gravity of the part located on the virtual line is set as the representative point on the virtual line. Countless virtual lines can be drawn on the electrode finger, and there are countless representative points. The direction in which the tangent of the curve connecting these representative points extends is set as the direction in which the electrode finger extends.

[0169] The angle formed by the excitation direction of the elastic wave and the direction in which the propagation axis of the piezoelectric layer 6 extends is defined as an excitation angle θ. C_prop The excitation angle variable resonator in the present invention refers to a resonator in which the excitation angle θ in the intersection region J is C_propIn other words, in the intersection region J of the excitation angle variation type resonator, the excitation angle θ C_prop no the same.

[0170] In this embodiment, the direction in which the propagation axis extends is Figure 5 The direction in which the double-dashed line N in FIG. extends is parallel. Moreover, in the portion indicated by the double-dashed line N, the excitation angle θ C_prop is 0°. Excitation angle θ C_prop The part with a 0° angle is arranged in a straight line. Figure 5 As shown in the curve M in FIG. 1 , in this embodiment, when the excitation angle θ is C_prop is other than 0° and the excitation angle θ C_prop When the same parts are connected, they form a curve. Figure 5 The curve M in the figure is the excitation angle θ C_prop is other than 0° and the excitation angle θ C_prop An example of the same portion. In the curve region, there are numerous curves that are the same as the curve M. In this way, the shapes of the plurality of first electrode fingers 16 and the plurality of second electrode fingers 17 in a plan view are set to the excitation angle θ. C_prop is other than 0° and the excitation angle θ C_prop The same parts are arranged in a curved shape.

[0171] In this specification, the excitation angle θ C_prop The positive direction is set to the counterclockwise direction when viewed from above. More specifically, the direction from the second bus bar 15 side toward the first bus bar 14 side is the positive direction. Hereinafter, unless otherwise specified, the direction in which the electrode finger is bent convexly is set to the outer direction. For example, Figure 5 The right direction in is the outer direction of the IDT electrode 18. The direction opposite to the outer direction is the inner direction. For example, Figure 5 The left direction in FIG. 1 is the inner direction of the IDT electrode 18 .

[0172] In the IDT electrode 18 of the present embodiment, at the excitation angle θ C_prop The electrode finger pitch and duty ratio are constant for the same parts. The electrode finger pitch refers to the distance between the centers of the adjacent first electrode fingers 16 and second electrode fingers 17. When the wavelength defined by the electrode finger pitch of the IDT electrode 18 is λ and the electrode finger pitch is p, λ=2p.

[0173] The first envelope E1 in the series arm resonator S1a has a plurality of portions inclined relative to the propagation axis. Moreover, the first envelope E1 has a plurality of bends V1. More specifically, the bends refer to portions where the direction in which the envelope extends changes. In the present embodiment, the shape of the first envelope E1 is a wavy shape formed by connecting adjacent bends V1 to each other through straight lines. In addition, the shape of the first envelope E1 may also be a wavy shape formed by connecting adjacent bends V1 to each other through curves.

[0174] Similarly, the second envelope E2 also has a plurality of portions inclined relative to the propagation axis. The second envelope E2 has a plurality of bends V2. The shape of the second envelope E2 is a wavy shape formed by connecting adjacent bends V2 with straight lines. In addition, the shape of the second envelope E2 may also be a wavy shape formed by connecting adjacent bends V2 with curved lines.

[0175] As described above, in the present embodiment, both the first envelope E1 and the second envelope E2 have a plurality of bends. However, at least one of the first envelope E1 and the second envelope E2 may have at least one bend.

[0176] The IDT electrode 18 has a plurality of segments with the electrode fingers passing through the bent portion V1 of the first envelope E1 as boundaries. The plurality of segments are arranged in the direction in which the propagation axis extends. Figure 5 , four segments are schematically shown.

[0177] The excitation angle θ of the end of the first envelope E1 or the portion located at the bent portion V1 is C_prop Let the excitation angle θ on the first envelope line be C_AP1_m m is a natural number. The excitation angle θ on the first envelope line C_AP1_m The excitation angle θ can be defined for the end of the first envelope E1 or each bend V1. Specifically, the excitation angle θ on the first envelope is sequentially increased from the end and bend V1 on the inner side of the IDT electrode 18. C_AP1_m m in is 1, 2, 3, ... In this way, the excitation angle θ on the first envelope line located on the inner side is C_AP1_m , the smaller the value of m is. For example, the excitation angle θ of the part of the above end located on the inner side is C_prop is the excitation angle θ on the first envelope line C_AP1_1 The excitation angle θ at the innermost bend V1 C_prop is the excitation angle θ on the first envelope line C_AP1_2 .

[0178] Similarly, the excitation angle θ of the end of the second envelope E2 or the portion located at the bent portion V2 is set to C_prop Let the excitation angle θ on the second envelope beC_AP2_m The more the second envelope is located on the inner side, the smaller the excitation angle θ is. C_AP2_m , the smaller the value of m.

[0179] As mentioned above, in Figure 5 , four segments are schematically shown. However, the IDT electrode 18 has five segments. Figure 6 5 segments of the IDT electrode 18 are schematically shown. In the present embodiment, m is a numerical value of 1 or more and 6 or less.

[0180] like Figure 5 As shown, the IDT electrode 18 has a plurality of offset electrodes. Specifically, the plurality of offset electrodes are a plurality of first offset electrodes 12 and a plurality of second offset electrodes 13. One ends of the plurality of first offset electrodes 12 are respectively connected to the first bus bar 14. The first electrode fingers 16 and the first offset electrodes 12 are arranged alternately. One ends of the plurality of second offset electrodes 13 are respectively connected to the second bus bar 15. The second electrode fingers 17 and the second offset electrodes 13 are arranged alternately.

[0181] The plurality of first offset electrodes 12 and the plurality of second offset electrodes 13 each include a base end portion and a front end portion, similarly to the plurality of first electrode fingers 16 and the plurality of second electrode fingers 17. The base ends of the first electrode fingers 16 and the first offset electrodes 12 are portions connected to the first bus bar 14. The base ends of the second electrode fingers 17 and the second offset electrodes 13 are portions connected to the second bus bar 15. The front ends of the first electrode fingers 16 and the second offset electrodes 13 are opposed to each other with a gap therebetween. The front ends of the second electrode fingers 17 and the first offset electrodes 12 are opposed to each other with a gap therebetween.

[0182] In addition, it is not necessary to provide a plurality of first offset electrodes 12 and a plurality of second offset electrodes 13. Hereinafter, the first offset electrodes 12 and the second offset electrodes 13 may be simply described as offset electrodes. The shapes of the plurality of offset electrodes in a plan view each include a curved portion.

[0183] A pair of reflectors 9A and 9B are provided on the piezoelectric layer 6. The reflectors 9A and 9B face each other with the IDT electrode 18 interposed therebetween in the direction in which the plurality of electrode fingers of the IDT electrode 18 are arranged.

[0184] The reflector 9A includes a pair of reflector bus bars 9a and a reflector bus bar 9b. The reflector bus bars 9a and the reflector bus bars 9b are opposed to each other. The reflector 9A includes a plurality of reflector electrode fingers 9c. One end of each of the plurality of reflector electrode fingers 9c is connected to the reflector bus bar 9a. The other ends of each of the plurality of reflector electrode fingers 9c are connected to the reflector bus bar 9b. The shapes of the plurality of reflector electrode fingers 9c of the reflector 9A in a plan view each include a curved shape.

[0185] Similarly, the reflector 9B has a pair of reflector bus bars 9d and a reflector bus bar 9e, and a plurality of reflector electrode fingers 9f. The IDT electrode 18, the reflector 9A, and the reflector 9B include a single-layer metal film. Specifically, in the present embodiment, Al is used as the material of the IDT electrode 18, the reflector 9A, and the reflector 9B. In addition, the materials of the IDT electrode 18, the reflector 9A, and the reflector 9B are not limited to the above. Alternatively, the IDT electrode 18, the reflector 9A, and the reflector 9B may also include a laminated metal film.

[0186] In the piezoelectric layer 6 of the first filter 1A, the direction in which the propagation axis extends is the X propagation direction. However, the present invention is not limited thereto. The direction in which the propagation axis extends may be, for example, the 90° X propagation direction, or may be a direction perpendicular to any of the directions in which the electrode fingers in the IDT electrode 18 extend.

[0187] like Figure 4 As shown, a dielectric film 8 is provided on the piezoelectric layer 6 so as to cover the IDT electrode 18. Since the IDT electrode 18 is protected by the dielectric film 8, the IDT electrode 18 is not easily damaged. In this embodiment, silicon oxide is provided as a material of the dielectric film 8. In addition, the material of the dielectric film 8 is not limited to the above.

[0188] The dielectric film 8 also covers the IDT electrodes of each elastic wave resonator except the series arm resonator S1a. In the present embodiment, the thickness of the dielectric film 8 is constant. The structure in which the dielectric film 8 is provided can also be adopted in the embodiments of the present invention other than the present embodiment. In addition, the dielectric film 8 does not necessarily need to be provided.

[0189] As described above, in the first filter 1A, Figure 1 The series arm resonator S1a, the series arm resonator S1b, and the series arm resonator S1c of the series arm resonator section S1 shown are excitation angle variation type resonators. Figure 5 The structure of the series arm resonator S1a is described in the above description, but the series arm resonator S1b and the series arm resonator S1c are also configured in the same manner as the series arm resonator S1a. In the present embodiment, the series arm resonators of the series arm resonator unit S1 are resonators divided in series and have the same design parameters. However, the design parameters may be appropriately different between these series arm resonators.

[0190] On the other hand, resonators other than the series arm resonators in the series arm resonator section S1 are not excitation angle variable resonators. The structure of the series arm resonator S2a is shown as an example.

[0191] Figure 7It is a schematic plan view of the elastic wave resonators other than the excitation angle variable resonator of the first filter in the first embodiment.

[0192] In the series arm resonator S2a, the shape of each electrode finger of the IDT electrode 18A is linear. Therefore, in the intersection region, the excitation angle θ C_prop Specifically, in any part of the intersection area, the excitation angle θ C_prop The first envelope E1A and the second envelope E2A of the IDT electrode 18A are inclined relative to the propagation axis. In addition, the first bus bar 14A and the second bus bar 15A have a straight line shape. In this way, the IDT electrode 18A is an inclined IDT electrode. The shapes of the multiple reflector electrode fingers in the reflector 9C and the reflector 9D of the series arm resonator S2a are straight lines.

[0193] In the present embodiment, the elastic wave resonators other than the variable excitation angle resonator are configured similarly to the series arm resonator S2 a , but design parameters are appropriately set for each elastic wave resonator other than the variable excitation angle resonator.

[0194] As described above, in the first filter 1A of the multiplexer 1, among the first half resonators, Figure 1 Each series arm resonator of the series arm resonator unit S1 shown is an excitation angle variable resonator. Therefore, the influence of unnecessary waves can be suppressed in the multiplexer 1. The details are described below by comparing the present embodiment with the first comparative example.

[0195] The first comparative example is different from the first embodiment in that all elastic wave resonators and Figure 7 The elastic wave resonator shown is constructed in the same manner. In addition, the circuit structure of the multiplexer of the first comparative example is the same as the circuit structure of the first embodiment. The attenuation frequency characteristics of the second filter 1B in the first embodiment and the second filter in the first comparative example are compared. In addition, the attenuation frequency characteristics of each filter in the first embodiment are also shown.

[0196] The design parameters of the excitation angle variable resonator in the first embodiment are as follows. Here, the dimension of the offset electrode along the direction connecting the base end and the front end is defined as the length of the offset electrode. The dimension of the gap between the front end of the electrode finger and the front end of the offset electrode along the direction in which the electrode finger and the offset electrode are opposed is defined as the gap length. In this embodiment, the gap between the front end of the second electrode finger 17 and the front end of the first offset electrode 12 and the gap between the front end of the first electrode finger 16 and the front end of the second offset electrode 13 have the same gap length.

[0197] Support substrate 4: Material...Si, Surface orientation...(100), Euler angle ψ...45°

[0198] The first layer 5a of the intermediate layer 5: material ... SiN, thickness ... 0.514λ

[0199] Second layer 5b of intermediate layer 5: material ... SiO2, thickness ... 0.384λ

[0200] Piezoelectric layer 6: Material... Rotated Y-cut 50° X-propagated LiTaO3, thickness... 0.343λ

[0201] IDT electrode 18: Material...A1, Thickness...0.05λ

[0202] Dielectric film 8: Material...SiO2, Thickness...0.02λ

[0203] Wavelength λ: at excitation angle θ C_prop 1.7509μm in the 0° portion

[0204] Number of pairs of electrode fingers of IDT electrode 18: 100 pairs

[0205] Duty cycle: 0.5

[0206] Gap length: 0.135λ

[0207] Length of offset electrode: 3.5λ

[0208] The distance between the first envelope E1 and the second envelope E2 in the direction perpendicular to the propagation axis: 25λ

[0209] First envelope E1: absolute value of the inclination angle with respect to the propagation axis...20°, number of pairs of electrode fingers between bends V1...20 pairs

[0210] Second envelope E2: absolute value of the inclination angle with respect to the propagation axis: 20°, number of pairs of electrode fingers between bends V2: 20 pairs

[0211] Excitation angle on the first envelope line: θ C_AP1_1 =12°,θ C_AP1_2 =8°,θ C_AP1_3 =16°,θ C_AP1_4 =10°,θ C_AP1_5 =16°,θ C_AP1_6 =9°

[0212] Excitation angle on the second envelope line: θ C_AP2_1 =9°,θ C_AP2_2 =15°,θ C_AP2_3=8°,θ C_AP2_4 =15.5°,θ C_AP2_5 =10°,θ C_AP2_6 =16°

[0213] Reflector 9A and reflector 9B: Number of pairs of reflector electrode fingers: 20 pairs

[0214] In the first embodiment and the first comparative example, the IDT electrodes in the elastic wave resonators other than the IDT electrodes of the excitation angle variable resonator are inclined IDT electrodes. In the inclined IDT electrodes in the first embodiment and the first comparative example, the absolute value of the inclination angle of the first envelope and the second envelope with respect to the propagation angle is 7.5°.

[0215] Figure 8 It is a diagram showing attenuation frequency characteristics of the first filter, the second filter, the third filter, and the fourth filter in the first embodiment. Fig. 9 It is a diagram showing the attenuation frequency characteristics of the second filter in the first embodiment and the first comparative example.

[0216] like Figure 8 As shown, the insertion loss of each filter in the first embodiment is sufficiently small.

[0217] like Fig. 9 As shown, in the attenuation frequency characteristic of the second filter in the first comparative example, a large ripple is generated in the passband. In contrast, in the attenuation frequency characteristic of the second filter in the first embodiment, the ripple is suppressed in the passband. The above-mentioned ripple is caused by the unnecessary wave generated in the elastic wave resonator of the first filter. In the first embodiment, the unnecessary wave can be suppressed, so the insertion loss of the second filter can be suppressed from increasing. The reason is as follows.

[0218] exist Figure 5 In the cross region J of the series arm resonator S1a shown in FIG. C_prop is other than 0° and the excitation angle θ C_prop The same curved portions are arranged innumerable in the direction in which the first bus bar 14 and the second bus bar 15 are opposed to each other. In addition, the excitation angle θ between the curved portions is C_prop Different from each other. At the excitation angle θ C_prop In different parts, the propagation characteristics of the useless waves are different from each other. As a result, the useless waves can be dispersed and effectively suppressed. In particular, the useless waves outside the frequency band can be suppressed. In this specification, the so-called outside the frequency band in the elastic wave device refers to the low frequency side of the resonant frequency and the high frequency side of the anti-resonant frequency.

[0219] Furthermore, in the first filter 1A and the like, the Figure 1 When an unnecessary wave is generated in the elastic wave resonator of the common connection terminal 7 shown in FIG. 1 , the unnecessary wave has a great influence on other filters. Here, as described above, Figure 2 Of all the trapezoidal portions shown, the half of the trapezoidal portion located on the first signal terminal 3A side is the front half of the trapezoidal portion. On the other hand, the trapezoidal portion located on the second signal terminal 3B side of the front half of the trapezoidal portion is the rear half of the trapezoidal portion. Figure 1 In Figure 2 The two-dot chain line in shows the boundary between the front half trapezoidal portion and the rear half trapezoidal portion.

[0220] The series arm resonators and the parallel arm resonators from the resonator located closest to the first signal terminal 3A to the trapezoidal portion located closest to the second signal terminal 3B in the first half of the trapezoidal portion are the first half of the resonators. When unnecessary waves are generated in these first half of the resonators, the unnecessary waves have a particularly large impact on other filters.

[0221] In the first embodiment, the series arm resonator S1a, the series arm resonator S1b, and the series arm resonator S1c, which are the first half resonators, are excitation angle variable resonators. Thus, in the three first half resonators, it is possible to suppress the unwanted waves outside the frequency band. Therefore, it is possible to suppress the ripples caused by the unwanted waves in the second filter 1B. However, it is sufficient that at least one of the first half resonators is an excitation angle variable resonator.

[0222] Furthermore, all resonators except the first half of the resonators are elastic wave resonators that are not excitation angle variable resonators. Specifically, in all resonators except the first half of the resonators, the excitation angle θ is C_prop is fixed. Thus, in these resonators, the resonant frequency and the anti-resonant frequency can be easily made consistent in all the crossover regions, and the resonant characteristics can be easily improved. Therefore, the filter characteristics of the first filter 1A can be easily and effectively improved. Moreover, even if unnecessary waves are generated in these resonators, the influence on other filters is small.

[0223] Here, the case where the unnecessary waves outside the frequency band can be suppressed in the excitation angle variable resonator is specifically shown. Figure 7 The phase characteristics of the elastic wave resonators shown in FIG. 1 and FIG. 2 are compared. In addition, in this comparison, the resonators of both sides do not have Figure 4 The dielectric film 8 shown in FIG. 1 is a dielectric film 8 shown in FIG. 1. The design parameters of the excitation angle variable resonator are shown in FIG. Fig. 9The design parameters of the variable excitation angle resonator in the comparison shown are the same in the first envelope E1, the second envelope E2, the excitation angle on the first envelope, the excitation angle on the second envelope, and the number of pairs of reflector electrode fingers.

[0224] Support substrate: Material...Si, Surface orientation...(100), Euler angle ψ...45°

[0225] Intermediate layer 1: Material...SiN, thickness...0.45λ

[0226] Intermediate layer 2: Material...SiO2, thickness...0.337λ

[0227] Piezoelectric layer: Material... Rotated Y-cut 50°X-propagated LiTaO3, thickness... 0.3λ

[0228] IDT electrode: Material...A1, Thickness...0.07λ

[0229] Wavelength λ: at excitation angle θ C_prop 2μm in the 0° portion

[0230] Number of IDT electrode finger pairs: 100 pairs

[0231] Duty cycle: 0.5

[0232] Gap length: 0.135λ

[0233] Length of offset electrode: 3.5λ

[0234] The distance between the first envelope E1 and the second envelope E2 in the direction perpendicular to the propagation axis: 25λ

[0235] In addition, in the tilted IDT electrode in the elastic wave resonator that is not an excitation angle variable resonator, the absolute value of the tilt angle of the first envelope and the second envelope relative to the propagation angle is 7.5°. The duty ratio is 0.5. The number of pairs of electrode fingers of the IDT electrode is 100 pairs. The dimension of the intersection region along the direction in which the plurality of electrode fingers extend is 25λ.

[0236] Fig.10 FIG. 1 is a diagram showing phase characteristics of an excitation angle-variable resonator and an elastic wave resonator having an inclined IDT electrode.

[0237] like Fig.10As shown in FIG. 1 , in the elastic wave resonator having the inclined IDT electrode, large unwanted waves are generated near the frequencies indicated by arrows T1, T2, T3, and T4. In addition, the frequency indicated by arrow T1 is a frequency on the lower frequency side than the resonance frequency. The unwanted waves generated near the frequency indicated by arrow T1 are Rayleigh waves. On the other hand, the frequencies indicated by arrows T2, T3, and T4 are frequencies on the higher frequency side than the antiresonance frequency.

[0238] like Fig.10 As shown, it can be seen that in the excitation angle variation type resonator, unnecessary waves can be suppressed near any of the frequencies indicated by arrows T1 , T2 , T3 , and T4 .

[0239] In addition, in the first embodiment, all three series arm resonators of the series arm resonator unit S1 are excitation angle variable resonators. Here, only the number and arrangement of the excitation angle variable resonators in the series arm resonator unit S1 are changed to study the influence on the suppression of unnecessary waves. Specifically, the above study was conducted in the first embodiment and the first to fourth variations of the first embodiment.

[0240] More specifically, in the first variant, only the series arm resonator S1a is set as an excitation angle variable resonator. In the second variant, the series arm resonator S1a and the series arm resonator S1b are set as excitation angle variable resonators. In the third variant, only the series arm resonator S1c is set as an excitation angle variable resonator. In the fourth variant, the series arm resonator S1b and the series arm resonator S1c are set as excitation angle variable resonators.

[0241] In the first embodiment and its first to fourth modifications and the first comparative example, the return losses on the common connection terminal 7 side of the first filter were compared.

[0242] Fig.11 It is a diagram showing the return loss in the first embodiment and its first to fourth modifications and a first comparative example. Fig.11 The symbols in parentheses in denoted in show the symbols of the series arm resonators as the excitation angle variation type resonators.

[0243] Table 1 shows the return loss of the unnecessary waves generated around 1725 MHz in the first embodiment and its first to fourth modifications and the first comparative example. 1725 MHz is a frequency lower than the resonance frequency of each series arm resonator of the series arm resonator unit S1. Therefore, the unnecessary waves are unnecessary waves out of the frequency band.

[0244]

Table 1

[0245]

[0246] like Fig.11 As shown in Table 1, in the first comparative example, the absolute value of the return loss of the unnecessary wave generated near 1725 MHz is large, 5.7 dB. On the other hand, it can be seen that in the first embodiment and its first to fourth modifications, the unnecessary wave is suppressed.

[0247] In addition, the number of the excitation angle variable resonators included in the series arm resonator section S1 is 3 in the first embodiment, 2 in the second variant and the fourth variant, and 1 in the first variant and the third variant. In the first embodiment, the absolute value of the return loss of the above-mentioned unwanted wave is small, which is 1.74 dB. In the second variant and the fourth variant, the absolute value of the return loss of the above-mentioned unwanted wave is 2.52 dB. In the first variant and the third variant, the absolute value of the return loss of the above-mentioned unwanted wave is 4.3 dB. According to these results, the more the number of excitation angle variable resonators included in the series arm resonator section S1 is, the more the unwanted waves generated near 1725 MHz are suppressed.

[0248] In addition, in the first variant and the third variant, the configurations of the excitation angle variable resonators are different from each other. However, in the first variant and the third variant, the above-mentioned unwanted waves are suppressed to the same extent. In the second variant and the fourth variant, the configurations of the excitation angle variable resonators are different from each other. However, in the second variant and the fourth variant, the above-mentioned unwanted waves are suppressed to the same extent. As shown in these, it can be seen that the number of excitation angle variable resonators in the series arm resonator unit S1 has a greater influence on the suppression of unwanted waves outside the frequency band than the configuration of the excitation angle variable resonators in the series arm resonator unit S1.

[0249] In the filter, in the portion of the trapezoidal portion including only the first half and the first half of the trapezoidal portion of the second half, when the series arm resonator portion includes a plurality of series arm resonators, it is preferred that more than half of the series arm resonators of the series arm resonator portion are excitation angle variable resonators. It is more preferred that all the series arm resonators of the series arm resonator portion are excitation angle variable resonators. Thus, it is possible to effectively suppress unnecessary waves outside the frequency band. Thus, it is possible to effectively suppress the influence of unnecessary waves on the second filter 1B as another filter.

[0250] As in the first embodiment, it is preferred that at least one series arm resonator of the series arm resonator unit S1 located closest to the first signal terminal 3A among the plurality of series arm resonator units is an excitation angle variable resonator. It is more preferred that more than half of the series arm resonators of the series arm resonator unit S1 are excitation angle variable resonators, and it is further preferred that all the series arm resonators of the series arm resonator unit S1 are excitation angle variable resonators. Thus, the influence of unnecessary waves on other filters can be effectively suppressed.

[0251] The following describes further details of the first embodiment.

[0252] Figure 5 The portion of the first electrode finger 16 shown in the figure, which includes a portion located on the first envelope E1 and is adjacent to the front end of any second electrode finger 17, is the adjacent portion of the first electrode finger 16. The portion of the second electrode finger 17, which includes a portion located on the second envelope E2 and is adjacent to the front end of any first electrode finger 16, is the adjacent portion of the second electrode finger 17. The portion of the range of 1λ from the front end of the electrode finger along the direction in which the electrode finger extends is the front end of the electrode finger. The range of the adjacent portion is also the range of 1λ along the direction in which the electrode finger extends. The electrode finger pitch that serves as a reference for the range of the front end and the adjacent portion can also be set to, for example, the excitation angle θ. C_prop The narrowest electrode finger pitch in the 0° portion.

[0253] In the series arm resonator S1a as an excitation angle-variable resonator of the first embodiment, the shape of the plurality of first electrode fingers 16 and the plurality of second electrode fingers 17 when viewed from above is a shape whose curvature changes gently. Specifically, the shape of the plurality of first electrode fingers 16 and the plurality of second electrode fingers 17 when viewed from above is a shape that can be approximated as an arc. However, for example, the shape of the plurality of first electrode fingers 16 and the plurality of second electrode fingers 17 when viewed from above may also be a shape that can be approximated as an elliptical arc. In addition, the shape of each electrode finger when viewed from above may not necessarily be a shape that can be approximated as an arc or an elliptical arc. For example, the shape of each electrode finger when viewed from above may also be a parabola that cannot be approximated as an arc or an elliptical arc.

[0254] The following describes a structure that is preferably established in at least one excitation angle variable resonator in the present invention.

[0255] The shapes of all the electrode fingers in the IDT electrode 18 when viewed from above are preferably different curves. This example is specifically shown as three examples. As a first example, it is preferred that the curvatures are different between the front end portions of all the first electrode fingers 16 and all the second electrode fingers 17 located on the first envelope E1 side, between the adjacent portions, or between the front end portions and the adjacent portions. More specifically, it is preferred that the curvatures are different between the front end portions of all the second electrode fingers 17, between the adjacent portions of all the first electrode fingers 16, and between the front end portions of all the second electrode fingers 17 and the adjacent portions of all the first electrode fingers 16.

[0256] As a second example, it is preferred that the curvatures are different between the tip ends of all the first electrode fingers 16 and all the second electrode fingers 17 located on the second envelope E2 side, between adjacent portions, or between the tip ends and adjacent portions. More specifically, it is preferred that the curvatures are different between the tip ends of all the first electrode fingers 16, between adjacent portions of all the second electrode fingers 17, and between the tip ends of all the first electrode fingers 16 and adjacent portions of all the second electrode fingers 17.

[0257] As a third example, it is preferable that all the first electrode fingers 16 and all the second electrode fingers 17 are located at the excitation angle θ. C_prop The portions at 0° have different curvatures. As described above, by making the shapes of all electrode fingers in the IDT electrode 18 in a plan view have different curved shapes, it is possible to more reliably and effectively suppress unnecessary waves.

[0258] In the first embodiment, all of the above three examples are satisfied. However, it is sufficient that, in at least one group of electrode fingers among the plurality of first electrode fingers 16 and the plurality of second electrode fingers 17, the curvatures are different between the tip portions located on the first envelope E1 side, between the adjacent portions, or between the tip portion and the adjacent portion.

[0259] In the first embodiment, in the curved area, the shape of the plurality of electrode fingers when viewed from above is a curve that is not a circular arc or an elliptical arc. The shape of the plurality of electrode fingers when viewed from above is a shape that can be approximated as a circular arc. In other words, the shape of the plurality of electrode fingers is a state that appears to be approximated as a circular arc when viewed from above. Moreover, the shape of the plurality of electrode fingers when viewed from above is a shape of a curve that is different from one another. Therefore, Fig.12 The relationship shown holds.

[0260] Fig.12 This is a schematic plan view showing a circle including an arc when the shape of the electrode fingers of the IDT electrode in the first embodiment in a plan view is approximated as an arc.

[0261] exist Fig.12In FIG. 1 , two circles R1 and R2 are shown by dotted lines. Circles R1 and R2 are circles containing arcs when the shapes of two different electrode fingers in a plan view are approximated as arcs. The position of the center O1 of circle R1 and the position of the center O2 of circle R2 are different from each other.

[0262] In the curved area, it is preferred that the positions of the centers of the circles containing the arcs when the shapes of all the first electrode fingers 16 and all the second electrode fingers 17 when viewed from above are approximated as arcs are different from each other. In this case, as described above, the shapes of all the electrode fingers in the IDT electrode 18 when viewed from above are the shapes of curves that are different from each other. Thus, it is possible to suppress unnecessary waves more reliably and effectively. However, in the curved area, it is sufficient that the positions of the centers of the circles containing the arcs when the shapes of at least one group of electrode fingers among the plurality of first electrode fingers 16 and the plurality of second electrode fingers 17 when viewed from above are approximated as arcs are different from each other.

[0263] In addition, in the curved region, the shapes of the plurality of first electrode fingers 16 and the plurality of second electrode fingers 17 in a plan view may be approximated as an elliptical arc. In this case, in the curved region, it is preferred that the positions of the foci of the ellipse including the elliptical arc when the shapes of all the first electrode fingers 16 and all the second electrode fingers 17 in a plan view are approximated as an elliptical arc are different from each other. However, in the curved region, it is sufficient that the positions of the foci of the ellipse including the elliptical arc when the shapes of at least one group of electrode fingers among the plurality of first electrode fingers 16 and the plurality of second electrode fingers 17 in a plan view are approximated as an elliptical arc are different from each other.

[0264] It is preferred that the resonant frequencies or antiresonant frequencies of the main modes in at least one of the excitation angle-variable resonators such as the series arm resonator S1a substantially coincide with each other in all the intersection regions J. It is more preferred that the resonant frequencies or antiresonant frequencies substantially coincide with each other in each of the intersection regions J of all the excitation angle-variable resonators. C_prop In the mutually different parts, the relationship between the resonant frequency of the main mode and the unwanted wave and the relationship between the anti-resonant frequency are different. Therefore, in all the intersection regions J of the excitation angle variable resonator, when the resonant frequency or the anti-resonant frequency of the main mode is the same, at the excitation angle θ C_prop In the mutually different parts, the frequencies of the unnecessary waves are mutually different. Thus, the unnecessary waves outside the frequency band are dispersed. Therefore, the unnecessary waves outside the frequency band such as Rayleigh waves can be further suppressed.

[0265] Furthermore, since the resonant frequencies or antiresonant frequencies in the intersection region J are substantially consistent with each other, the main mode can be appropriately excited. Therefore, the resonance characteristics can be improved more reliably. Thus, the filter characteristics of the first filter 1A in the multiplexer 1 can be improved more reliably.

[0266] In this specification, the term "one frequency and the other frequency are substantially consistent" means that the absolute value of the difference between the two frequencies is less than 2% relative to the reference frequency. The reference frequency refers to the excitation angle θ. C_prop The frequency at 0°.

[0267] In the intersection region J of the excitation angle variable resonator, the absolute value of the difference between the highest resonant frequency and the lowest resonant frequency of the main mode is preferably 1% or less relative to the reference frequency. Alternatively, in the intersection region J of the excitation angle variable resonator, the absolute value of the difference between the highest anti-resonant frequency and the lowest anti-resonant frequency of the main mode is preferably 1% or less relative to the reference frequency. In this way, the resonance characteristics can be further reliably improved.

[0268] For example, in the series arm resonator S1a, it is preferable that at least one of the duty ratio, the electrode finger pitch, and the thickness of the first electrode fingers 16 and the second electrode fingers 17 be adjusted according to the excitation angle θ. C_prop Preferably, at least one of these parameters varies according to the excitation angle θ. C_prop The resonant frequency or the antiresonant frequency is substantially consistent in at least a portion of the intersection region J. It is more preferable that at least one of these parameters is changed according to the excitation angle θ. C_prop The resonant frequency or the antiresonant frequency is changed so as to be substantially the same in all the intersection regions J. This makes it possible to more reliably improve the resonance characteristics in the excitation angle variation type resonator.

[0269] Alternatively, when the thickness of the intermediate layer 5 in the piezoelectric substrate 2 or the like affects the frequency, the parameter may be adjusted in the intersection region J according to the excitation angle θ. C_prop When the dielectric film 8 is provided on the piezoelectric substrate 2 so as to cover the IDT electrode 18 as in the first embodiment, the thickness of the dielectric film may be varied in the intersection region J according to the excitation angle θ. C_prop It is also possible to make the above-mentioned IDT electrode 18 or multiple parameters other than the IDT electrode 18 in the intersection region J according to the excitation angle θ C_prop In these cases, the resonant frequency or the anti-resonant frequency can be made substantially consistent in at least a part or the entirety of the intersection region J.

[0270] It is preferable that the excitation angle θ of the IDT electrode 18 C_propIn the same part, at least one of the electrode finger pitch and the duty cycle is constant. C_prop In the same part, both the electrode finger pitch and the duty ratio are constant. This makes it possible to more reliably improve the resonance characteristics of the excitation angle variable resonator.

[0271] Examples of materials for the various components of the piezoelectric substrate 2 are shown below.

[0272] As Figure 4 The material of the support substrate 4 shown, for example, can also be aluminum nitride, lithium tantalate, lithium niobate, quartz and other piezoelectrics, alumina, sapphire, magnesium oxide, silicon nitride, silicon carbide, zirconium oxide, cordierite, mullite, steatite, forsterite, spinel, sialon and other ceramics, aluminum oxide, silicon oxynitride, DLC (diamond-like carbon), diamond and other dielectrics, or semiconductors such as silicon, or materials with the above materials as the main component. In addition, the above spinel contains an aluminum compound containing one or more elements selected from Mg, Fe, Zn, Mn and the like and oxygen. As examples of the above spinel, MgAl2O4, FeAl2O4, ZnAl2O4, and MnAl2O4 can be cited. It is preferred to use high-resistance silicon in the support substrate 4. The volume resistivity of the material of the support substrate 4 is preferably above 1000Ω·cm. In the first embodiment, high-resistance silicon is used as the material of the support substrate 4.

[0273] The first layer 5a of the intermediate layer 5 is a high-acoustic-velocity film. The high-acoustic-velocity film is a film with a relatively high-acoustic-velocity. More specifically, the acoustic velocity of the body wave propagating in the high-acoustic-velocity film is higher than the acoustic velocity of the elastic wave propagating in the piezoelectric layer 6. As the material of the high-acoustic-velocity film, i.e., the first layer 5a, for example, piezoelectrics such as aluminum nitride, lithium tantalate, lithium niobate, quartz, alumina, sapphire, magnesium oxide, silicon nitride, silicon carbide, zirconium oxide, cordierite, mullite, steatite, forsterite, spinel, ceramics such as sialon, dielectrics such as aluminum oxide, silicon oxynitride, DLC (diamond-like carbon), diamond, or semiconductors such as silicon, or materials with the above materials as the main component can also be used. In addition, the above spinel contains an aluminum compound containing one or more elements selected from Mg, Fe, Zn, Mn, etc. and oxygen. As examples of the above spinel, MgAl2O4, FeAl2O4, ZnAl2O4, and MnAl2O4 can be listed. In the first embodiment, silicon nitride is used as the material of the first layer 5 a.

[0274] The second layer 5b of the intermediate layer 5 is a low-acoustic-velocity film. The low-acoustic-velocity film is a film with a relatively low-acoustic-velocity. More specifically, the acoustic velocity of the body wave propagating in the low-acoustic-velocity film is lower than the acoustic velocity of the body wave propagating in the piezoelectric layer 6. As the material of the low-acoustic-velocity film, i.e., the second layer 5b, for example, dielectrics such as glass, silicon oxide, silicon oxynitride, lithium oxide, tantalum oxide, or compounds in which fluorine, carbon, or boron is added to silicon oxide, or materials containing the above materials as main components can be used. In the first embodiment, silicon oxide is used as the material of the second layer 5b.

[0275] As Figure 4 The material of the piezoelectric layer 6 shown may be, for example, lithium tantalate, lithium niobate, zinc oxide, aluminum nitride, quartz, or PZT (lead zirconate titanate). Lithium tantalate or lithium niobate is preferably used as the material of the piezoelectric layer 6. In the first embodiment, lithium tantalate is used as the material of the piezoelectric layer 6.

[0276] In the first embodiment, the first layer 5a as a high acoustic velocity film, the second layer 5b as a low acoustic velocity film, and the piezoelectric layer 6 are sequentially stacked on the piezoelectric substrate 2. This effectively confines the energy of the elastic wave to the piezoelectric layer 6 side.

[0277] As the material of the IDT electrode 18, the reflector 9A and the reflector 9B, for example, one or more metals selected from the group consisting of Ti, Mo, Ru, W, Al, Pt, Ir, Cu, Cr and Sc can be used. The IDT electrode 18 and each reflector can include a single-layer metal film or a stacked metal film. In the first embodiment, Al is used as the material of the IDT electrode 18, the reflector 9A and the reflector 9B.

[0278] In this specification, the main component refers to a component that accounts for more than 50% by weight. The material of the main component may be in any state of single crystal, polycrystalline, or amorphous, or in a state of a mixture of these.

[0279] In addition, if Figure 5 As shown, the first envelope E1 of the IDT electrode 18 has a plurality of bends V1. However, the first envelope E1 may also be a straight line shape without the bends V1. The first envelope E1 may also extend parallel to the direction in which the propagation axis extends. Similarly, the second envelope E2 may also be a straight line shape without the bends V2. The second envelope E2 may also extend parallel to the direction in which the propagation axis extends.

[0280] In this embodiment, the intersection region J includes only one curved region. Alternatively, the intersection region J may include a plurality of curved regions.

[0281] return Figure 1, the second filter 1B, the third filter 1C and the fourth filter 1D respectively have substrates different from the piezoelectric substrate of the first filter 1A. That is, each filter has a separate piezoelectric substrate. Moreover, each of these filters is constructed as a separate component chip. More specifically, the first filter 1A is a WLP (Wafer Level Package) structure. The same is true for the other filters. The multiplexer 1 has a mounting substrate not shown in the figure. The first filter 1A, the second filter 1B, the third filter 1C and the fourth filter 1D are mounted on the mounting substrate.

[0282] In addition, the multiplexer 1 may also be a CSP (Chip Size Package) structure. Specifically, for example, at least one of the first filter 1A, the second filter 1B, the third filter 1C, and the fourth filter 1D may be mounted on a mounting substrate using a conductive adhesive provided at each terminal.

[0283] Figure 1 The common connection terminal 7 shown is provided on the mounting substrate. The first signal terminal 3A of the first filter 1A is electrically connected to the common connection terminal 7 via wiring or the like. Similarly, one signal terminal of each of the other filters is electrically connected to the common connection terminal 7 via wiring or the like.

[0284] All resonators in the first filter 1A share the same piezoelectric substrate 2. However, each resonator in the first filter 1A may have another piezoelectric substrate. Alternatively, a plurality of resonators of a part of all resonators may share one piezoelectric substrate, and the other plurality of resonators may share another piezoelectric substrate. For example, a plurality of excitation angle variable resonators may share one piezoelectric substrate, and a plurality of resonators other than excitation angle variable resonators may share another piezoelectric substrate. The same is true for each filter other than the first filter 1A.

[0285] In addition, in the multiplexer, a plurality of filters may share the same piezoelectric substrate. In this case, all resonators of the plurality of filters are formed on the same piezoelectric substrate.

[0286] In the first embodiment, the passband of the first filter 1A is located on the high-frequency side relative to the passband of the second filter 1B. In this case, it is preferred that the passband of the second filter 1B includes at least a portion of the frequencies that are 0.5 times or more and 0.9 times or less of the resonant frequency of the excitation angle variable resonator of the first filter 1A. In the above frequency range, it is possible to more reliably suppress unnecessary waves in the excitation angle variable resonator of the first filter 1A. Therefore, it is possible to more reliably suppress the influence of unnecessary waves on the second filter 1B.

[0287] On the other hand, the passband of the first filter 1A may be located at a lower frequency side than the passband of the second filter 1B. In the excitation angle variable resonator of the first filter 1A, it is possible to suppress unnecessary waves generated at a higher frequency side than the antiresonance frequency. Therefore, it is possible to more reliably suppress the influence of unnecessary waves on the second filter 1B.

[0288] The following shows the fifth to twelfth variations of the first embodiment in which only the structures of the IDT electrodes and the reflectors in the excitation angle variable resonator are different from those in the first embodiment. In the first filter of the fifth to twelfth variations, the excitation angle variable resonator is also configured as in the first embodiment. Moreover, in the excitation angle variable resonator, it is possible to suppress unnecessary waves outside the frequency band. Therefore, in the multiplexers of the fifth to twelfth variations, it is also possible to suppress the influence of unnecessary waves and suppress the situation where the insertion loss in each filter is reduced.

[0289] Fig.13 It is a schematic plan view of the excitation angle variable resonator of the first filter in the fifth modification of the first embodiment.

[0290] In this modification, the shapes of the plurality of first electrode fingers 16B and second electrode fingers 17B of the IDT electrode 18B in plan view are arc shapes. Alternatively, the shapes of the plurality of electrode fingers in plan view may include elliptical arc shapes.

[0291] In the IDT electrode 18B, the shapes of the plurality of electrode fingers in a plan view are shapes corresponding to arcs of the plurality of concentric circles, and therefore the centers of the circles including the arcs in the shapes of the plurality of electrode fingers coincide with each other. Fig.13 The two-dot chain line N1 in is a straight line passing through the center and the intersection region J. More specifically, the two-dot chain line N1 passes through the center of the intersection region J. In the present modification, the two-dot chain line N1 extends parallel to the direction in which the propagation axis extends.

[0292] When the ellipticity coefficient of the circle or ellipse of the arc in the shape including the plurality of electrode fingers is set to α2 / α1, the ellipticity coefficient α2 / α1 in this modification is 1. α1 corresponds to the dimension of the major axis and the minor axis of the ellipse along the direction of the axis passing through the intersection region J. α2 corresponds to the dimension of the major axis and the minor axis of the ellipse along the direction of the axis not passing through the intersection region J.

[0293] The first envelope E1A is linear and inclined relative to the propagation axis. Similarly, the second envelope E2A is linear and inclined relative to the propagation axis. When the axis extending parallel to the propagation axis is set as the symmetry axis, the intersection region J of the IDT electrode 18B is a line-symmetrical shape. However, the first envelope E1A and the second envelope E2A may also extend in parallel. In addition, in this modification, the first bus bar 14A and the second bus bar 15A have a linear shape.

[0294] When the straight line passing through the center of the intersection region J is used as the reference line, in this variant, the double-dotted line N1 is consistent with the reference line. In addition, the reference line does not necessarily extend parallel to the direction in which the propagation axis extends. As described above, the centers of the circles of the arcs in the shape of the plurality of electrode fingers are consistent. This center is used as a fixed point. The angle formed by the straight line passing through the first envelope E1A and the fixed point and the reference line is set as the intersection angle θ C1_AP However, in this modification, the extension line of the first envelope E1A passes through the fixed point. Therefore, the intersection angle θ C1_AP The angle is synonymous with the angle formed by the extension line of the first envelope E1A and the reference line.

[0295] The angle formed by the straight line passing through the second envelope E2 and the fixed point and the reference line is defined as the intersection angle θ C2_AP However, in this modified example, the extension line of the second envelope E2A passes through the fixed point. Therefore, the intersection angle θ C2_AP The angle is synonymous with the angle formed by the extension line of the second envelope E2A and the reference line. C_prop Next, θ C_AP2 ≤θ C_prop ≤θ C_AP1 In this modification, the intersection angle θ C_AP1 and the intersection angle θ C_AP2 The absolute value of is the same. Therefore, the excitation angle θ C_prop The absolute value of is 0°≤|θ C_prop |≤|θ C_AP1 |=|θ C_AP2 |.

[0296] The shapes of the plurality of first offset electrodes 12B and the plurality of second offset electrodes 13B in a plan view are arc-shaped. Specifically, the shapes of the plurality of first offset electrodes 12B and the plurality of second offset electrodes 13B in a plan view are shapes corresponding to respective arcs in a plurality of concentric circles. Therefore, the centers of the circles including the arcs in the shapes of the plurality of offset electrodes coincide. More specifically, in this modification, the centers of the circles including the arcs in the shapes of the plurality of electrode fingers and the plurality of offset electrodes coincide. Thus, leakage from the intersection region J of the main mold can be effectively suppressed.

[0297] However, the shape of the plurality of offset electrodes is not limited to the above. For example, the shape of the plurality of offset electrodes in a plan view may be a straight line. In this case, the length of the plurality of offset electrodes can be shortened. Thus, the resistance of the IDT electrode 18B can be reduced.

[0298] The shapes of the multiple reflector electrode fingers of reflector 9E and reflector 9F in a top view are shapes corresponding to the respective arcs in the multiple concentric circles. More specifically, in this modification, the centers of the circles including the arcs in the shapes of the multiple electrode fingers and the multiple reflector electrode fingers are consistent. Thus, the resonance characteristics can be improved more reliably. However, the shapes of the multiple reflector electrode fingers are not limited to the above.

[0299] In addition, the shapes of the multiple electrode fingers when viewed from above may also include the shapes of elliptical arcs. More specifically, in this case, the shapes of the multiple electrode fingers when viewed from above respectively include shapes corresponding to the respective elliptical arcs in the multiple ellipses whose centers of gravity are at the same position. The center of gravity referred to here refers to the center of the two foci of the ellipse. In this case, in the excitation angle variable resonator, it is also possible to suppress useless waves outside the frequency band such as Rayleigh waves in the same manner as in the fifth variant. In the case where the shape of the arc in the shape including the multiple electrode fingers is an ellipse, the ellipticity coefficient α2 / α1 becomes other than 1.

[0300] When the shapes of the plurality of electrode fingers in a plan view include an elliptical arc, it is preferred that the shapes of the plurality of offset electrodes in a plan view also include an elliptical arc. In this case, it is preferred that the centers of gravity of the ellipses including the elliptical arcs in the shapes of the plurality of electrode fingers and the plurality of offset electrodes coincide with each other. Thus, leakage from the intersection region J of the main mold can be effectively suppressed.

[0301] When the shapes of the plurality of electrode fingers in a plan view include an elliptical arc, it is preferred that the shapes of the plurality of reflector electrode fingers of each reflector in a plan view also include an elliptical arc. In this case, it is preferred that the centers of gravity of the ellipses including the elliptical arcs in the shapes of the plurality of electrode fingers and the plurality of reflector electrode fingers are consistent. Thus, the resonance characteristics can be more reliably improved.

[0302] Fig.14 It is a schematic plan view of the excitation angle variable resonator of the first filter in the sixth modification of the first embodiment.

[0303] In the IDT electrode 18C of this modified example, the shapes of the plurality of first electrode fingers 16C and the plurality of second electrode fingers 17C when viewed from above are bent at a plurality of sections. More specifically, the shapes of the plurality of first electrode fingers 16C and the plurality of second electrode fingers 17C when viewed from above are connected to each other in straight lines at their respective sections. In addition, in this modified example, each electrode finger is bent as a whole so as to be directed in a direction opposite to the first electrode finger. Fig.14The shape of each electrode finger in a plan view can be approximated to a circular arc, an elliptical arc, or a parabola.

[0304] Fig.15 FIG. 1 is a schematic top view showing parallel regions and non-parallel regions in the sixth variation of the first embodiment. Fig.15 In the figure, each region is shown with hatching. In addition, the parallel region described later and the region obtained by extending the parallel region are hatched with the same hatching. In the non-parallel region described later and the region obtained by extending the non-parallel region are hatched with the same hatching.

[0305] The intersection region J has a plurality of parallel regions A and a plurality of non-parallel regions B. Specifically, the so-called parallel region A refers to a region where a plurality of first electrode fingers 16C and a plurality of second electrode fingers 17C extend in parallel. The so-called non-parallel region B refers to a region where the directions in which the plurality of first electrode fingers 16C and the plurality of second electrode fingers 17C extend intersect with each other. In addition, the intersection region J only needs to include at least two parallel regions A and at least one non-parallel region B.

[0306] In the IDT electrode 18C, all parallel regions A and all non-parallel regions B include a portion of all first electrode fingers 16C and a portion of all second electrode fingers 17C, respectively. However, the parallel region A does not necessarily need to include a portion of all first electrode fingers 16C and a portion of all second electrode fingers 17C. The same applies to the non-parallel region B.

[0307] The parallel regions A and the non-parallel regions B are arranged alternately. The plurality of first electrode fingers 16C and the second electrode fingers 17C extend linearly in the plurality of parallel regions A and the non-parallel regions B, respectively, and are bent at the boundaries between the parallel regions A and the non-parallel regions B. In the present embodiment, the parallel regions A and the non-parallel regions B are arranged alternately in the entire intersection region J. In addition, the parallel regions A and the non-parallel regions B may be arranged alternately in at least a portion of the intersection region J.

[0308] In the parallel regions A, the directions in which the electrode fingers extend are different from each other. Therefore, in the intersection region J, the excitation direction and the excitation angle θ of the elastic wave are different. C_prop no the same.

[0309] The shapes of the multiple reflector electrode fingers of the reflectors 9G and 9H in a plan view are bent at multiple nodes, similar to the electrode fingers of the IDT electrode 18C. Specifically, the multiple reflector electrode fingers extend linearly in the region where the parallel region A is extended and the region where the non-parallel region B is extended. In addition, the multiple reflector electrode fingers are bent at the boundary between the region where the parallel region A is extended and the region where the non-parallel region B is extended. Thus, the resonance characteristics can be more reliably improved.

[0310] In this modification, the first offset electrodes 12C and the second offset electrodes 13C are linear in plan view. Alternatively, the first offset electrodes 12C and the second offset electrodes 13C may be curved in plan view with straight lines connected to each other.

[0311] Fig.16 It is a schematic plan view of the excitation angle variable resonator of the first filter in the seventh modification of the first embodiment.

[0312] In this variation, the plurality of electrode fingers of the IDT electrode 18D include a linear portion. Specifically, the intersection region of the IDT electrode 18D includes a first region W1, a second region W2, and a third region W3. The first region W1, the second region W2, and the third region W3 are arranged in a direction in which the first bus bar 14A and the second bus bar 15A are opposite to each other. More specifically, the first region W1 and the second region W2 are opposite to each other with the third region W3 sandwiched therebetween. The first region W1 is located on the first bus bar 14A side. The second region W2 is located on the second bus bar 15A side. In the third region W3, the shape of the plurality of electrode fingers when viewed from above is a linear shape.

[0313] On the other hand, in the first region W1 and the second region W2, the shape of the plurality of electrode fingers when viewed from above is an elliptical arc shape. In this way, each electrode finger includes a portion of a shape with a different curvature when viewed from above. In addition, in the first region W1 and the second region W2, the shape of the plurality of electrode fingers when viewed from above may be an arc shape. Alternatively, in the first region W1 and the second region W2, the shape of the plurality of electrode fingers when viewed from above may be a curved shape that can be approximated as an arc or an elliptical arc. In this variant, the excitation direction and excitation angle θ of the elastic wave in the intersection region are C_prop Not the same either.

[0314] In this modification, in all third regions W3, the direction in which the propagation axis of the piezoelectric layer 6 extends is orthogonal to the direction in which the plurality of electrode fingers extend. In the third region W3, the excitation angle θ C_propis 0°. Therefore, the third region W3 is a region that is stable relative to the propagation axis. By having the third region W3 in the intersection region, it is possible to suppress the degradation of the relative bandwidth. When the resonant frequency is fr and the antiresonant frequency is fa, the relative bandwidth is represented by |fr-fa| / fr×100[%]. In addition, the excitation angle θ in the third region W3 is C_prop Not limited to 0°.

[0315] Fig.17 It is a schematic plan view of the excitation angle variable resonator of the first filter in the eighth modification of the first embodiment.

[0316] In this variation, the intersection region has a plurality of curve regions. Specifically, the plurality of curve regions are a first curve region K1 and a second curve region K2. The first curve region K1 includes a first envelope E1A. The second curve region K2 includes a second envelope E2A. The boundary between the first curve region K1 and the second curve region K2 is a straight line.

[0317] In this variation, in each curved region, the shapes of the plurality of first electrode fingers 16E and the plurality of second electrode fingers 17E when viewed from above are each a single arc shape. The shapes of the plurality of electrode fingers when viewed from above are each a shape connecting two arcs. In each electrode finger, at the boundary between the first curved region K1 and the second curved region K2, the two curved shapes are inverted.

[0318] Specifically, in the first curve region K1, the plurality of electrode fingers are bent so as to Fig.17 The arcs in the shapes of the portions of the plurality of electrode fingers located in the first curve region K1 are respective arcs in the plurality of concentric circles. Therefore, the centers of the circles including the arcs in the shapes of the plurality of electrode fingers in the first curve region K1 coincide with each other.

[0319] On the other hand, in the second curve region K2, the plurality of electrode fingers are bent so as to Fig.17 The arcs in the shapes of the portions of the plurality of electrode fingers located in the second curve region K2 are respective arcs in the plurality of concentric circles. Therefore, the centers of the circles including the arcs in the shapes of the plurality of electrode fingers in the second curve region K2 coincide with each other.

[0320] The center of the circle including the arc in the shape of the plurality of electrode fingers in the first curved region K1 and the center of the circle including the arc in the shape of the plurality of electrode fingers in the second curved region K2 face each other with the IDT electrode 18E interposed therebetween.

[0321] As described above, the shapes of the plurality of first electrode fingers 16E and the plurality of second electrode fingers 17E in a plan view each include at least two curved portions in which the bending directions of the first electrode fingers 16E and the second electrode fingers 17E are different in the intersection region. In this case, the excitation direction and the excitation angle θ of the elastic wave in the intersection region are C_prop no the same.

[0322] In addition, in each curved region, the shape of the plurality of electrode fingers in a plan view may be a single elliptical arc. Alternatively, for example, in each curved region, the shape of the plurality of electrode fingers in a plan view may be a curved shape that can be approximated by a single circular arc or elliptical arc.

[0323] Similar to the multiple electrode fingers of the IDT electrode 18E, the shapes of the multiple reflector electrode fingers of each reflector when viewed from above are shapes formed by connecting two circular arcs. In addition, the shapes of the reflector electrode fingers when viewed from above may be shapes formed by connecting two elliptical arcs. Alternatively, for example, the shapes of the reflector electrode fingers when viewed from above may be shapes formed by connecting two curves that can be approximated as circular arcs or elliptical arcs.

[0324] Fig.18 It is a schematic plan view of the excitation angle variable resonator of the first filter in the ninth modification of the first embodiment.

[0325] The intersection region J of the IDT electrode 18F has a central region F and a pair of edge regions. The pair of edge regions are specifically a first edge region H1 and a second edge region H2. The first edge region H1 includes a first envelope E1A as an end edge. The second edge region H2 includes a second envelope E2A as an end edge. The first edge region H1 and the second edge region H2 are opposed to each other with the central region F sandwiched therebetween. It is to be noted that each intersection region of other embodiments and modified examples also has a first edge region, a second edge region, and a central region.

[0326] In addition, the first edge region H1 is a region where the front end of the second electrode finger 17F and the adjacent portion of the first electrode finger 16F are located. That is, if the second electrode finger 17F is used as a reference, the first edge region H1 is a region with a range of about 1λ from the front end of the second electrode finger 17F along the direction in which the electrode finger extends. Similarly, if the first electrode finger is used as a reference, the second edge region H2 is a region with a range of about 1λ from the front end of the first electrode finger 16F along the direction in which the electrode finger extends.

[0327] Each electrode finger of the IDT electrode 18F has a wide portion in the first edge region H1 and the second edge region H2 . The width of the electrode finger in the wide portion is wider than the width of the electrode finger in the central region F.

[0328] Specifically, the first electrode finger 16F has a wide portion 16a in the first edge region H1. The second electrode finger 17F also has a wide portion 17a in the first edge region H1. On the other hand, the first electrode finger 16F has a wide portion 16b in the second edge region H2. The second electrode finger 17F also has a wide portion 17b in the second edge region H2. As a result, the sound velocity in the first edge region H1 and the second edge region H2 is lower than the sound velocity in the central region F. As a result, a low sound velocity region is formed in the first edge region H1 and the second edge region H2. The so-called low sound velocity region refers to a region where the sound velocity is lower than the sound velocity in the central region F. In addition, with respect to the low sound velocity region, it is sufficient as long as at least a portion of at least one of the first edge region H1 and the second edge region H2 constitutes a low sound velocity region. However, it is preferred that the low sound velocity region is formed in the entirety of both the first edge region H1 and the second edge region H2 as in this variant.

[0329] In this modified example, a central region F and a pair of low sound velocity regions are sequentially arranged from the inside to the outside in the direction in which the first bus bar 14A and the second bus bar 15A are opposed. Thus, a piston mode is established. Thus, the transverse mode can be suppressed. Moreover, the energy of the main mode can be effectively confined in the central side of the intersection region J, and the characteristics of the main mode can be improved.

[0330] The structure of the IDT electrode 18F is the same as that of the fifth modification except for the first edge region H1 and the second edge region H2. Therefore, in the intersection region, the excitation direction and the excitation angle θ of the elastic wave are C_prop no the same.

[0331] In addition, at least one electrode finger may have a wide portion in at least one of the first edge region H1 and the second edge region H2. However, it is preferred that a plurality of electrode fingers have a wide portion in at least one of the first edge region H1 and the second edge region H2, and it is more preferred that all electrode fingers have a wide portion. Furthermore, it is more preferred that a plurality of electrode fingers have a wide portion in both the first edge region H1 and the second edge region H2, and it is further preferred that all electrode fingers have a wide portion. Thus, the piston mode can be established more reliably.

[0332] The shape of the plurality of electrode fingers of the IDT electrode 18F in a plan view is an arc shape. However, the structure in which the low acoustic velocity region is provided in the first edge region H1 or the second edge region H2 of the elastic wave resonator can also be adopted in other structures of the present invention in which the shape of the electrode fingers is different from that of the present variation.

[0333] In the IDT electrode 18F, the width of each electrode finger is widened throughout the entire edge region. The shape of each wide portion when viewed from above is a quadrilateral. However, each electrode finger may be widened in at least a portion of each edge region. The shape of each wide portion when viewed from above is not limited to a quadrilateral. Each reflector electrode finger of each reflector may also be widened in a portion located on an extension line of the first edge region H1 and a portion located on an extension line of the second edge region H2.

[0334] On the other hand, Fig.19 In the tenth modification shown, a plurality of mass addition films 19 are provided, thereby forming a low acoustic velocity region in the first edge region H1 and the second edge region H2. Specifically, in the first edge region H1, a mass addition film 19 is provided on each first electrode finger 16B and each second electrode finger 17B. The same is true in the second edge region H2. In addition, the structure of the IDT electrode 18B is the same as that of the fifth modification.

[0335] In this modification, the mass-added film 19 is provided only on one electrode finger. In this case, a suitable metal or dielectric can be used as the material of the mass-added film 19. However, the mass-added film 19 can also be provided across a plurality of electrode fingers. In this case, a suitable dielectric can be used as the material of the mass-added film 19.

[0336] The mass addition film 19 may be stacked with at least one of the plurality of electrode fingers in at least one of the first edge region H1 and the second edge region H2. Specifically, the mass addition film 19 may be arranged in at least one of the first edge region H1 and the second edge region H2 so as to overlap with at least one of the plurality of first electrode fingers 16B and the plurality of second electrode fingers 17B in a plan view. In this case, at least a portion of at least one of the first edge region H1 and the second edge region H2 constitutes a low sound velocity region.

[0337] Preferably, in at least one of the first edge region H1 and the second edge region H2, a plurality of electrode fingers are stacked with the mass addition film 19, and more preferably, all of the electrode fingers are stacked with the mass addition film 19. Alternatively, more preferably, in both the first edge region H1 and the second edge region H2, a plurality of electrode fingers are stacked with the mass addition film 19. Thus, the piston mode can be established more reliably. Further preferably, in the edge regions of both sides, all of the electrode fingers are stacked with the mass addition film 19. In this case, the entire edge region of both sides constitutes a low sound velocity region. Thus, the piston mode can be established more reliably.

[0338] In the portion where the electrode fingers and the mass-added film 19 are stacked, the piezoelectric substrate 2, the electrode fingers, and the mass-added film 19 are stacked in sequence. However, it is also possible that in the portion where the electrode fingers and the mass-added film 19 are stacked, the piezoelectric substrate 2, the mass-added film 19, and the electrode fingers are stacked in sequence. That is, the mass-added film 19 may also be provided between the piezoelectric substrate 2 and the electrode fingers. It is also possible that the portion of the reflector electrode fingers of each reflector located on the extension line of the first edge region H1 and the portion located on the extension line of the second edge region H2 are also stacked with the mass-added film 19.

[0339] The material of the mass additional film 19 can also be the same metal as that used for each electrode finger. Fig. 20 (a) and Fig. 20 The structure of the 11th variant shown in (b) is as follows. Fig. 20 As shown in (a), in the IDT electrode 18G, the thickness of the first electrode finger 16G in the first edge region H1 and the second edge region H2 is thicker than the thickness of the first electrode finger 16G in the central region F. Fig. 20 As shown in (b), the thickness of the second electrode finger 17G in the first edge region H1 and the second edge region H2 is thicker than the thickness of the second electrode finger 17G in the central region F. Thus, low acoustic velocity regions are respectively formed in the first edge region H1 and the second edge region H2.

[0340] In addition, Fig. 20 In (a), a cross section of the first electrode finger 16G along the direction in which the first electrode finger 16G extends is schematically shown. Fig. 20 (b) schematically shows a cross section of the second electrode finger 17G along the direction in which the second electrode finger 17G extends. The structure of the IDT electrode 18G is the same as that of the fifth modification example except for the first edge region H1 and the second edge region H2.

[0341] The thickness of at least one electrode finger in at least one of the first edge region H1 and the second edge region H2 may be thicker than the thickness of the electrode finger in the central region F. However, it is preferred that the thickness of a plurality of electrode fingers in at least one of the first edge region H1 and the second edge region H2 is thicker than the thickness of the electrode finger in the central region F. It is more preferred that the thickness of all electrode fingers in at least one of the first edge region H1 and the second edge region H2 is thicker than the thickness of the electrode finger in the central region F.

[0342] Furthermore, it is more preferable that the thickness of the plurality of electrode fingers in both the first edge region H1 and the second edge region H2 is thicker than the thickness of the electrode fingers in the central region F. It is further preferable that the thickness of all electrode fingers in both the first edge region H1 and the second edge region H2 is thicker than the thickness of the electrode fingers in the central region F. Thus, the piston mode can be established more reliably.

[0343] In this modification, the thickness of each electrode finger increases throughout the entire edge region. However, the thickness of each electrode finger may also increase in at least a portion of each edge region. Alternatively, the thickness of each reflector electrode finger of each reflector may also increase in the portion located on the extension line of the first edge region H1 and the portion located on the extension line of the second edge region H2. In addition, a low sound velocity region may be formed by applying multiple structures from the 9th to 11th modifications.

[0344] Fig.21 It is a schematic plan view of the excitation angle variable resonator of the first filter in the twelfth modification of the first embodiment.

[0345] The structure of the IDT electrode 18H in this modification is the same as that of the IDT electrode 18F in the ninth modification except for the first offset electrode 12H and the second offset electrode 13H. Therefore, in the intersection region J, the excitation direction and the excitation angle θ of the elastic wave are C_prop The width of the tip portion of the first offset electrode 12H in this modification is wider than the width of the other portion of the first offset electrode 12H. The width of the tip portion of the second offset electrode 13H is wider than the width of the other portion of the second offset electrode 13H.

[0346] Fig. 22 This is a schematic circuit diagram of a multiplexer according to the second embodiment. Fig.23 It is a schematic top view of the first filter in the second embodiment.

[0347] like Fig. 22 as well as Fig.23 As shown, the difference between this embodiment and the first embodiment is that the parallel arm resonator of the parallel arm resonator unit P21 is an excitation angle variable resonator. Except for the above aspects, the multiplexer of this embodiment has the same structure as the multiplexer 1 of the first embodiment. In addition, in the second embodiment, the circuit structure is the same as that of the first embodiment.

[0348] The first filter 21A in the second embodiment and the first filter in the first comparative example are compared in terms of attenuation frequency characteristics around the frequency at which Rayleigh waves, which are out-of-band unwanted waves, are generated. Fig. 9The comparison shown in FIG. 1 is the same as the comparative example involved in the comparison. In addition, the attenuation frequency characteristics in the first embodiment are also shown. The design parameters of the parallel arm resonator of the parallel arm resonator unit P21 are shown below. In addition, the design parameters of each series arm resonator in the series arm resonator unit S1 are set to be the same as Fig. 9 The design parameters in the first embodiment related to the comparison shown are the same.

[0349] The thickness of each component in the parallel arm resonator is the same as the thickness of each component in the series arm resonator. However, the wavelength λ in the parallel arm resonator is different from the wavelength λ in the series arm resonator. Therefore, the value of the thickness of each component in the parallel arm resonator based on the wavelength λ is different from the thickness of each component in the series arm resonator based on the wavelength λ.

[0350] Support substrate: Material...Si, Surface orientation...(100), Euler angle ψ...45°

[0351] Intermediate layer 1: Material...SiN, thickness...0.491λ

[0352] Intermediate layer 2: Material...SiO2, thickness...0.367λ

[0353] Piezoelectric layer: Material... Rotated Y-cut 50°X-propagated LiTaO3, thickness... 0.327λ

[0354] IDT electrode: Material...Al, Thickness...0.0791λ

[0355] Dielectric film: Material...SiO2, Thickness...0.0191λ

[0356] Wavelength λ: at excitation angle θ C_prop 1.8325 μm in the 0° portion

[0357] Fig.24 It is a diagram showing the attenuation frequency characteristics of the first filter in the second embodiment and the first comparative example in the vicinity of the frequency at which Rayleigh waves are generated. Fig.25 It is a diagram showing the attenuation frequency characteristics of the first filter in the first embodiment and the first comparative example in the vicinity of the frequency at which Rayleigh waves are generated.

[0358] like Fig.24 As shown, in the first comparative example, Rayleigh waves are generated near the frequencies indicated by arrows T5 and T6. Rayleigh waves are unnecessary waves outside the frequency band. In contrast, it can be seen that Rayleigh waves are suppressed in the second embodiment.

[0359] On the other hand, Fig.25As shown, in the first embodiment, the Rayleigh wave is not suppressed. Figure 1 In the first embodiment shown, unlike the second embodiment, the parallel arm resonator of the parallel arm resonator unit P1 in the first filter 1A is not an excitation angle variable resonator. Therefore, it can be seen that Rayleigh waves are generated in the parallel arm resonators of the parallel arm resonator unit P1. In addition, it can be seen that in the second embodiment, since the parallel arm resonator is an excitation angle variable resonator, Rayleigh waves, which are unnecessary waves outside the frequency band, can be suppressed.

[0360] In the first filter in the first embodiment, the second embodiment, and the first comparative example, the return loss on the commonly connected terminal side was measured.

[0361] Fig.26 It is a graph showing the return loss in the first embodiment, the second embodiment, and the first comparative example.

[0362] like Fig.26 As shown, in the first embodiment and the second embodiment, the unwanted waves near 1725MHz can be suppressed compared with the first comparative example. The unwanted waves are unwanted waves generated in the series arm resonator. Furthermore, it can be seen that in the second embodiment, the unwanted waves near 1650MHz can also be suppressed. The unwanted waves are unwanted waves generated in the parallel arm resonator. Therefore, in the second embodiment, both the unwanted waves outside the frequency band caused by the series arm resonator and the unwanted waves outside the frequency band caused by the parallel arm resonator can be effectively suppressed. As a result, the influence of the unwanted waves in the multiplexer on the filters other than the first filter 21A can be effectively suppressed.

[0363] In the second embodiment, the parallel arm resonator section P21 includes only one parallel arm resonator, but the parallel arm resonator section P21 may also include a plurality of parallel arm resonators. In this case, it is preferred that at least one parallel arm resonator of the parallel arm resonator section P21 located closest to the first signal terminal 3A among the plurality of parallel arm resonator sections is an excitation angle variable resonator. It is more preferred that more than half of the parallel arm resonators of the parallel arm resonator section P21 are excitation angle variable resonators, and it is further preferred that all the parallel arm resonators of the parallel arm resonator section P21 are excitation angle variable resonators. Thus, the influence of useless waves on other filters can be effectively suppressed.

[0364] It is preferred that at least one resonator of at least one of the series arm resonator section S1 located closest to the first signal terminal 3A side and the parallel arm resonator section P21 located closest to the first signal terminal 3A side is an excitation angle variable resonator. In the case where both the series arm resonator section S1 and the parallel arm resonator section P21 include a plurality of resonators, it is more preferred that more than half of the resonators in both the series arm resonator section S1 and the parallel arm resonator section P21 are excitation angle variable resonators. It is further preferred that all the resonators in both the above two sides are excitation angle variable resonators. Thus, the influence of unwanted waves on other filters can be more reliably and effectively suppressed.

[0365] Fig. 27 This is a schematic circuit diagram of a multiplexer according to the third embodiment.

[0366] This embodiment is different from the second embodiment in the circuit configuration of the first filter 31A and the arrangement of the excitation angle variable resonator. Except for the above points, the multiplexer of this embodiment has the same configuration as the multiplexer of the second embodiment.

[0367] The plurality of series arm resonator sections of the first filter 31A are a series arm resonator section S31, a series arm resonator section S32, a series arm resonator section S33, and a series arm resonator section S34. In the present embodiment, the series arm resonator section S31 includes a series arm resonator S31a and a series arm resonator S31b. The series arm resonator S31a and the series arm resonator S31b are connected in series with each other. The series arm resonator section S32 includes a series arm resonator S32a, a series arm resonator S32b, and a series arm resonator S32c. The series arm resonator S32a, the series arm resonator S32b, and the series arm resonator S32c are connected in series with each other in sequence. On the other hand, the series arm resonator section S33 and the series arm resonator section S34 each include one series arm resonator.

[0368] The series arm resonator section S31 , the series arm resonator section S32 , the series arm resonator section S33 , and the series arm resonator section S34 are connected in series with one another in this order from the first signal terminal 3A side.

[0369] The plurality of parallel arm resonator sections of the first filter 31A are a parallel arm resonator section P31, a parallel arm resonator section P32, a parallel arm resonator section P33, and a parallel arm resonator section P34. The parallel arm resonator section P31 includes a parallel arm resonator P31a and a parallel arm resonator P31b. The parallel arm resonator P31a and the parallel arm resonator P31b are connected in series with each other. In the present embodiment, the parallel arm resonator P31a and the parallel arm resonator P31b are resonators divided in series. On the other hand, the parallel arm resonator section P32, the parallel arm resonator section P33, and the parallel arm resonator section P34 include one parallel arm resonator.

[0370] In addition, in the case where the parallel arm resonator unit includes a plurality of parallel arm resonators, the plurality of parallel arm resonators may not be parallel arm resonators divided in series. The relationship between the design parameters of the plurality of parallel arm resonators of the parallel arm resonator unit is not particularly limited. The plurality of parallel arm resonators of the parallel arm resonator unit may be connected in series with each other or in parallel with each other. Alternatively, the plurality of parallel arm resonators of the parallel arm resonator unit may also be located in different parallel arms in the same interval.

[0371] A parallel arm resonator section P31 is connected between a node D between the first signal terminal 3A and the series arm resonator section S31 and the ground potential. A parallel arm resonator section P32 is connected between a node D between the series arm resonator section S31 and the series arm resonator section S32 and the ground potential. A parallel arm resonator section P33 is connected between a node D between the series arm resonator section S32 and the series arm resonator section S33 and the ground potential. A parallel arm resonator section P34 is connected between a node D between the series arm resonator section S33 and the series arm resonator section S34 and the ground potential. In the present embodiment, the resonator sections located closest to the first signal terminal 3A side among the plurality of resonator sections are the series arm resonator section S31 and the parallel arm resonator section P31.

[0372] In the first filter 31A of the present embodiment, all the series arm resonators of the series arm resonator section S31 and all the parallel arm resonators of the parallel arm resonator section P31 are excitation angle variable resonators. On the other hand, all the elastic wave resonators other than these are not excitation angle variable resonators. Specifically, each elastic wave resonator that is not an excitation angle variable resonator is connected to Figure 7 The elastic wave resonators shown are configured similarly. That is, the IDT electrodes of the elastic wave resonators are inclined IDT electrodes.

[0373] In addition, for example, only the parallel arm resonator of the parallel arm resonator portion P31 may be an excitation angle variable resonator. Fig.28In the modified example of the third embodiment shown in the figure, in the first filter, all the parallel arm resonators of the parallel arm resonator section P31 are excitation angle variable resonators. On the other hand, all the elastic wave resonators other than the parallel arm resonators of the parallel arm resonator section P31 are Figure 7 The elastic wave resonator shown is constructed in the same way.

[0374] In the third embodiment and its modified example and the second comparative example, the return loss on the common connection terminal side of the first filter is compared. The second comparative example is different from the third embodiment in that all elastic wave resonators are connected to Figure 7 The elastic wave resonator shown is configured similarly. The circuit configuration of the multiplexer of the second comparative example is the same as that of the third embodiment.

[0375] Fig.29 It is a diagram showing the return loss in the third embodiment and its modified example and the second comparative example.

[0376] Fig.29 The unwanted waves generated near 1725MHz are the unwanted waves generated in the series arm resonator. The unwanted waves generated near 1650MHz are the unwanted waves generated in the parallel arm resonator. It can be seen that in the third embodiment and its modified example, the unwanted waves caused by the parallel arm resonator can be suppressed compared with the second comparative example. This is because, in the third embodiment and its modified example, each parallel arm resonator of the parallel arm resonator unit P31 is an excitation angle variable resonator.

[0377] In the modified example of the third embodiment, unnecessary waves around 1725 MHz are generated to the same extent as in the second comparative example. On the other hand, in the third embodiment, unnecessary waves around 1725 MHz can be suppressed. This is because, in the third embodiment, each series arm resonator of the series arm resonator unit S31 is an excitation angle variable resonator.

[0378] In the third embodiment, both the out-of-band unnecessary waves caused by the series arm resonators and the out-of-band unnecessary waves caused by the parallel arm resonators can be effectively suppressed. Thus, the influence of the unnecessary waves on filters other than the first filter 31A in the multiplexer can be effectively suppressed.

[0379] Fig.30 This is a schematic circuit diagram of a multiplexer according to a fourth embodiment.

[0380] The present embodiment is different from the first embodiment in that all the first half resonators are excitation angle variable resonators. Except for the above point, the multiplexer of the present embodiment has the same structure as the multiplexer of the second embodiment.

[0381] As described above, when an out-of-band unnecessary wave is generated in the first half resonator, the unnecessary wave has a particularly large influence on other filters. Therefore, in this embodiment, all the first half resonators are excitation angle variable resonators. Therefore, in all the first half resonators, the out-of-band unnecessary wave can be suppressed. Thus, the influence of the unnecessary wave such as Rayleigh wave in the multiplexer on the filters other than the first filter 41A can be suppressed.

[0382] Fig.31 This is a schematic circuit diagram of a multiplexer according to the fifth embodiment.

[0383] This embodiment differs from the second embodiment in the circuit structure of the first filter 51A and the configuration of the excitation angle variable resonator. This embodiment also differs from the second embodiment in that the first filter 51A includes a longitudinally coupled resonator type elastic wave filter 55. Except for the above aspects, the multiplexer of this embodiment has the same structure as the multiplexer of the second embodiment.

[0384] The longitudinally coupled resonator type elastic wave filter 55 of the first filter 51A has a 5IDT type and a single-stage structure. However, the number of IDT electrodes of the longitudinally coupled resonator type elastic wave filter 55 is not limited to 5. The longitudinally coupled resonator type elastic wave filter 55 may be, for example, a 3IDT type, a 7IDT type, or a 9IDT type. The longitudinally coupled resonator type elastic wave filter 55 may have a structure of two or more stages.

[0385] In this specification, a longitudinally coupled resonator-type elastic wave filter is treated as a series arm resonator section in a ladder section constituting a filter. When the longitudinally coupled resonator-type elastic wave filter has a two-stage or more structure, the longitudinally coupled resonator-type elastic wave filter is also treated as one series arm resonator section in the ladder section.

[0386] The longitudinally coupled resonator-type elastic wave filter 55 is provided between the first signal terminal 3A and the second signal terminal 3B.

[0387] The plurality of series arm resonator sections of the first filter 51A are a series arm resonator section S51, a series arm resonator section S52, and a series arm resonator section S53. In the present embodiment, the series arm resonator section S51 includes a series arm resonator S51a and a series arm resonator S51b. The series arm resonator S51a and the series arm resonator S51b are connected in series with each other. The series arm resonator section S53 includes a series arm resonator S53a and a series arm resonator S53b. The series arm resonator S53a and the series arm resonator S53b are connected in parallel with each other. On the other hand, the series arm resonator section S52 includes one series arm resonator.

[0388] A series arm resonator section S51 and a series arm resonator section S52 are connected between the first signal terminal 3A and the longitudinally coupled resonator type elastic wave filter 55. Of the series arm resonator section S51 and the series arm resonator section S52, the series arm resonator section S51 is located on the first signal terminal 3A side. A series arm resonator section S53 is connected between the longitudinally coupled resonator type elastic wave filter 55 and the second signal terminal 3B.

[0389] The plurality of parallel arm resonator sections of the first filter 51A are a parallel arm resonator section P51 and a parallel arm resonator section P52. The parallel arm resonator section P51 includes a parallel arm resonator P51a and a parallel arm resonator P51b. The parallel arm resonator P51a and the parallel arm resonator P51b are connected in series with each other. On the other hand, the parallel arm resonator section P52 includes one parallel arm resonator.

[0390] A parallel arm resonator section P51 is connected between a node D between the series arm resonator section S51 and the series arm resonator section S52 and the ground potential. A parallel arm resonator section P52 is connected between a node D between the longitudinally coupled resonator type elastic wave filter 55 and the series arm resonator section S53 and the ground potential. In the present embodiment, the resonator section located closest to the first signal terminal 3A among the plurality of resonator sections is the series arm resonator section S51.

[0391] Fig.32 is a circuit diagram for explaining the ladder section of the first filter in the fifth embodiment. Fig.32 In order to explain the trapezoidal portion, one parallel arm and a parallel arm resonator portion located in the parallel arm are shown by marking two parallel arms and two resonators for convenience.

[0392] In the first filter 51A, four-stage ladder sections are formed between the first signal terminal 3A and the second signal terminal 3B. The first to fourth-stage ladder sections are arranged in order from the first signal terminal 3A side to the second signal terminal 3B side. The third-stage ladder section is a ladder section that treats the longitudinally coupled resonator-type elastic wave filter 55 as one series arm resonator section.

[0393] In this embodiment, the first-stage trapezoidal portion and the second-stage trapezoidal portion are the first-half trapezoidal portion. The first-half resonator is Fig.31 The series arm resonator S51a, the series arm resonator S51b, the parallel arm resonator P51a, the parallel arm resonator P51b and the series arm resonator of the series arm resonator unit S52 are shown. All of these first half resonators are excitation angle variable resonators. Therefore, in all the first half resonators, it is possible to suppress unnecessary waves outside the frequency band. Therefore, it is possible to effectively suppress the influence of unnecessary waves in the multiplexer on filters other than the first filter 51A.

[0394] In the first to fifth embodiments, the resonator section includes a plurality of resonators, and when all of the plurality of resonators are excitation angle variable resonators, the plurality of resonators are configured in the same manner. However, the structures of the plurality of excitation angle variable resonators included in the same resonator section may be different from each other. This example is shown in the sixth embodiment. In addition, the circuit structure in the sixth embodiment is the same as that in the first embodiment. Therefore, the drawings and symbols used in the description of the first embodiment are sometimes cited in the description of the sixth embodiment.

[0395] Fig.33 It is a schematic plan view of a plurality of variable excitation angle resonators of the first filter in the sixth embodiment. Fig.33 A plurality of series arm resonators in a series arm resonator section S61 located closest to the first signal terminal 3A side among the plurality of series arm resonator sections are shown.

[0396] The present embodiment is different from the first embodiment in that the structures of the three series arm resonators in the series arm resonator portion S61 are different from each other. Except for the above point, the multiplexer of the present embodiment has the same structure as the multiplexer 1 of the first embodiment.

[0397] The series arm resonator unit S61 includes a series arm resonator S61a, a series arm resonator S61b, and a series arm resonator S61c. The series arm resonator S61a, the series arm resonator S61b, and the series arm resonator S61c are sequentially connected in series with each other.

[0398] The series arm resonator S61a, the series arm resonator S61b, and the series arm resonator S61c are connected to each other through wiring electrodes. Fig.33 In FIG. 1 , solid boundary lines are drawn between each bus bar and wiring electrode. Fig.33 In the figure, each bus bar and wiring electrode are schematically shown separately. In addition, in this embodiment, each bus bar and wiring electrode are made of the same material as a whole. However, each bus bar and wiring electrode can also be made of different materials. Alternatively, the stacking structure of each bus bar and wiring electrode can also be different from each other.

[0399] The series arm resonator S61a and the series arm resonator S61b are connected to Figure 5 The excitation angle variable resonator in the first embodiment shown in FIG. 1 is similarly configured. However, the duty ratios of the series arm resonator S61a and the series arm resonator S61b are different from each other. Furthermore, the series arm resonator S61a and the series arm resonator S61b are arranged to be 180° apart from each other. Specifically, the plurality of electrode fingers in the series arm resonator S61a are bent so as to face Fig.33The plurality of electrode fingers in the series arm resonator S61b are bent so as to protrude to the right. Fig.33 The left direction is protruding.

[0400] The series arm resonator S61c and Fig.13 The excitation angle variable resonator in the fifth modification example of the first embodiment shown is configured in the same manner. Fig.33 The double-dashed line N1 in accords with the above-mentioned reference line. Moreover, the angle formed by the extension line of the first envelope E1A and the reference line is the intersection angle θ C_AP1 The angle between the extension line of the second envelope E2A and the reference line is the intersection angle θ C_AP2 .

[0401] In the series arm resonator S61c, the duty cycle is determined according to the excitation angle θ C_prop The plurality of electrode fingers in the series arm resonator S61c are bent so that the resonant frequency or anti-resonant frequency is substantially the same in all the crossover regions. Fig.33 The right side of the figure is protruding.

[0402] In the first filter of this embodiment, it is possible to effectively suppress unnecessary waves outside the frequency band. This is because each series arm resonator of the series arm resonator unit S61 is an excitation angle variable resonator, and the frequency of unnecessary waves generated in each series arm resonator can be dispersed. This is shown below. The design parameters of the series arm resonator S61a are as follows. In addition, the design parameters are Fig. 9 The design parameters of the excitation angle variable resonator in the first embodiment according to the comparison shown are the same.

[0403] Support substrate: Material...Si, Surface orientation...(100), Euler angle ψ...45°

[0404] Intermediate layer 1: Material...SiN, thickness...0.514λ

[0405] Intermediate layer 2: Material...SiO2, thickness...0.384λ

[0406] Piezoelectric layer: Material... Rotated Y-cut 50°X-propagated LiTaO3, thickness... 0.343λ

[0407] IDT electrode: Material...Al, Thickness...0.05λ

[0408] Dielectric film: Material...SiO2, Thickness...0.02λ

[0409] Wavelength λ: at excitation angle θ C_propThe portion with a 0° angle is 1.7509 μm

[0410] Number of IDT electrode finger pairs: 100 pairs

[0411] Duty cycle: 0.5

[0412] Gap length: 0.135λ

[0413] Length of offset electrode: 3.5λ

[0414] The distance between the first envelope and the second envelope in the direction perpendicular to the propagation axis: 25λ

[0415] 1st envelope: absolute value of the inclination angle with respect to the propagation axis...20°, number of pairs of electrode fingers between bends V1...20 pairs

[0416] Second envelope: Absolute value of the tilt angle with respect to the propagation axis: 20°, Number of pairs of electrode fingers between bends V2: 20 pairs

[0417] Excitation angle on the first envelope line: θ C_AP1_1 =12°,θ C_AP1_2 =8°,θ C_AP1_3 =16°,θ C_AP1_4 =10°,θ C_AP1_5 =16°,θ C_AP1_6 =9°

[0418] Excitation angle on the second envelope line: θ C_AP2_1 =9°,θ C_AP2_2 =15°,θ C_AP2_3 =8°,θ C_AP2_4 =15.5°,θ C_AP2_5 =10°,θ C_AP2_6 =16°

[0419] Each reflector: Number of pairs of reflector electrode fingers...20 pairs

[0420] The design parameters of the series arm resonator S61b differ from those of the series arm resonator S61a only in that the duty ratio is 0.634.

[0421] In the series arm resonator S61c, at the excitation angle θ C_prop The duty ratio is 0.5 for the 0° portion. C_prop The larger the absolute value of is, the smaller the duty cycle is. C_AP1 The crossing angle θ is 7.5°. C_AP2 It is -7.5°.

[0422] Fig.34is a diagram showing the phase characteristics of each excitation angle variable resonator in the sixth embodiment.

[0423] like Fig.34 As shown, in the series arm resonator S61a, the series arm resonator S61b, and the series arm resonator S61c as the excitation angle variable resonator, the unnecessary waves are fully suppressed. Furthermore, it can be seen that the frequencies of the unnecessary waves generated in these series arm resonators are different from each other. Therefore, the unnecessary waves can be effectively suppressed as a whole by the plurality of series arm resonators as the series arm resonator unit S61. Therefore, the influence of the unnecessary waves on the filters other than the first filter in the multiplexer can be effectively suppressed.

[0424] As described above, when an unwanted wave is generated in the resonator of the first half, the unwanted wave has a particularly large influence on other filters. Among them, when an unwanted wave is generated in a resonator in the resonator unit located closest to the first signal terminal 3A among the multiple resonator units, the unwanted wave has a greater influence on other filters. In this embodiment, the series arm resonator S61a and the series arm resonator S61c of the series arm resonator unit S61 located closest to the first signal terminal 3A have different shapes of electrode fingers when viewed from above. As a result, the frequencies of unwanted waves generated in the series arm resonators of both parties can be made different from each other.

[0425] In addition, in this specification, the type of shape of the electrode fingers when viewed from above refers to the type of shape such as a circular arc or an elliptical arc. The types of shapes of the electrode fingers when viewed from above are different, for example, one is in the shape of a circular arc and the other is in the shape of an elliptical arc, one is in the shape of an arc and the other is in the shape of a curve that can be approximated as an arc, etc. For example, when the shapes of the electrode fingers of both sides when viewed from above are in the shape of a curve that can be approximated as an arc and any fixed value parameter is different from each other, the types of shapes of the electrode fingers of both sides when viewed from above are the same. Or, for example, when the shapes of the electrode fingers of both sides when viewed from above are circular arcs and any parameter is changed according to the excitation angle θ. C_prop When the changing modes are different from each other, the shapes of the electrode fingers in plan view are the same. In the present embodiment, the shapes of the electrode fingers in plan view are the same in the series arm resonator S61a and the series arm resonator S61b.

[0426] The duty ratio is constant in the series arm resonator S61a and the series arm resonator S61b. In addition, the excitation angle θ is constant in both resonators. C_prop The duty ratios in the portion of 0° are different from each other. This makes it possible to more reliably make the frequencies at which unnecessary waves are generated different from each other in both resonators.

[0427] The effect of dispersing the frequency of the unnecessary wave generated in the sixth embodiment is further shown. In the first filter in the first embodiment, the sixth embodiment and the first comparative example, the return loss on the common connection terminal side is compared. Figure 3 In the series arm resonator section S1 shown, all the excitation angle variable resonators have the same shape.

[0428] Fig.35 It is a graph showing the return loss in the first embodiment, the sixth embodiment, and the first comparative example.

[0429] like Fig.35 As shown, in the first embodiment and the sixth embodiment, the unnecessary waves around 1725 MHz can be suppressed compared with the first comparative example. Furthermore, it can be seen that in the sixth embodiment, the unnecessary waves around 1725 MHz can be suppressed compared with the first embodiment.

[0430] In the following, when the resonator section located closest to the first signal terminal has a plurality of resonators, a preferred structure will be described regardless of whether the resonator section is a series arm resonator section or a parallel arm resonator section.

[0431] Preferably, the resonator portion located closest to the first signal terminal includes at least two excitation angle variable resonators, and the types of shapes of the electrode fingers in the plan view are different from each other in the at least two excitation angle variable resonators. As an example, for example, in at least one excitation angle variable resonator included in the resonator portion located closest to the first signal terminal, the shape of the electrode fingers in the plan view is an arc. In this case, in at least one other excitation angle variable resonator, the shape of the electrode fingers in the plan view is other than an arc. As a result, the frequencies of the unnecessary waves generated in the multiple resonators of the resonator portion can be dispersed more reliably, and the unnecessary waves can be suppressed more reliably and effectively.

[0432] More preferably, the resonator section located closest to the first signal terminal includes at least three excitation angle variable resonators, and the shapes of the electrode fingers in the at least three excitation angle variable resonators in the resonator section are different from each other in plan view. Thus, the frequencies of unnecessary waves generated in the plurality of resonators in the resonator section can be further reliably dispersed, and unnecessary waves can be further reliably and effectively suppressed.

[0433] In each of at least two variable excitation angle resonators in the resonator section located closest to the first signal terminal, at least the excitation angle θ C_prop The duty ratio in the portion where the excitation angle is 0° is fixed. In this case, it is preferred that the excitation angle θ of at least two excitation angle variable resonators in the resonator section isC_prop Alternatively, in each of at least three excitation angle variable resonators in the resonator section located closest to the first signal terminal, at least the excitation angle θ C_prop The duty ratio in the portion where the excitation angle is 0° is fixed. In this case, it is more preferable that the excitation angle θ of at least three excitation angle variable resonators in the resonator section is C_prop The duty ratios in the portion at 0° are different from each other. This makes it possible to more reliably disperse the frequencies of unnecessary waves generated in the plurality of resonators in the resonator section, and to more reliably and effectively suppress unnecessary waves.

[0434] Preferably, the resonant frequency or anti-resonant frequency in the cross region of at least two excitation angle variable resonators included in the resonator portion located closest to the first signal terminal is substantially consistent. These excitation angle variable resonators are equivalent to resonators that are split in series or in parallel. Large power is often applied to the resonator portion. In contrast, since the resonator having the desired resonant frequency or anti-resonant frequency is split in series or in parallel, the applied power can be dispersed. Therefore, the resonator having the desired resonant frequency or anti-resonant frequency is not easily damaged.

[0435] Fig.36 This is a circuit diagram of a multiplexer according to the seventh embodiment.

[0436] The multiplexer 71 includes a first filter 21A, a second filter 71B, a third filter 71C, and a fourth filter 71D. The passband of each filter is the same as that of the first embodiment and the second embodiment.

[0437] Moreover, the structure of the first filter 21A is the same as that of the second embodiment. Therefore, all the resonators of the series arm resonator unit S1 and the parallel arm resonator unit P21 located on the side closest to the common connection terminal 7 in the first filter 21A are excitation angle variable resonators. The same is true for each filter other than the first filter. That is, in this embodiment, all the resonators in the series arm resonator unit and the parallel arm resonator unit located on the side closest to the common connection terminal 7 of all filters commonly connected to the common connection terminal 7 are excitation angle variable resonators. As a result, in all filters in the multiplexer 71, the influence of useless waves can be effectively suppressed.

[0438] The circuit configurations of the second filter 71B, the third filter 71C, and the fourth filter 71D are described below. The second filter 71B, the third filter 71C, and the fourth filter 71D each include a signal terminal, a plurality of series arm resonator sections, and a plurality of parallel arm resonator sections.

[0439] The plurality of series arm resonator sections of the second filter 71B are a series arm resonator section S71B, a series arm resonator section S72B, a series arm resonator section S73B, and a series arm resonator section S74B. The series arm resonator section S71B includes three series arm resonators connected in series with each other. The series arm resonator section S72B and the series arm resonator section S74B each include two series arm resonators connected in series with each other. On the other hand, the series arm resonator section S73B includes one series arm resonator.

[0440] The series arm resonator section S71B, the series arm resonator section S72B, the series arm resonator section S73B and the series arm resonator section S74B are connected in series with each other in order from the common connection terminal 7 side. The series arm resonator section S71B among the plurality of series arm resonator sections is located closest to the common connection terminal 7 side.

[0441] The plurality of parallel arm resonator sections of the second filter 71B are a parallel arm resonator section P71B, a parallel arm resonator section P72B, a parallel arm resonator section P73B, and a parallel arm resonator section P74B. The parallel arm resonator section P74B includes two parallel arm resonators connected in series with each other. On the other hand, the parallel arm resonator section P71B, the parallel arm resonator section P72B, and the parallel arm resonator section P73B each include one parallel arm resonator.

[0442] A parallel arm resonator section P71B is connected between a node D between the series arm resonator section S71B and the series arm resonator section S72B and the ground potential. A parallel arm resonator section P72B is connected between a node D between the series arm resonator section S72B and the series arm resonator section S73B and the ground potential. A parallel arm resonator section P73B is connected between a node D between the series arm resonator section S73B and the series arm resonator section S74B and the ground potential. A parallel arm resonator section P74B is connected between a node D between the series arm resonator section S74B and the signal terminal 73B and the ground potential. The parallel arm resonator section P71B among the plurality of parallel arm resonator sections is located closest to the common connection terminal 7.

[0443] The second filter 71B includes an inductor L1 and an inductor L2. The parallel arm resonator portion P72B and the parallel arm resonator portion P73B are connected to the inductor L1. The inductor L1 is connected to the ground potential. The inductor L2 is connected between the parallel arm resonator portion P74B and the ground potential.

[0444] The plurality of series arm resonator sections of the third filter 71C are a series arm resonator section S71C, a series arm resonator section S72C, a series arm resonator section S73C, a series arm resonator section S74C, and a series arm resonator section S75C. The series arm resonator section S71C, the series arm resonator section S72C, the series arm resonator section S73C, and the series arm resonator section S74C each include two series arm resonators connected in series with each other. On the other hand, the series arm resonator section S75C includes one series arm resonator.

[0445] The series arm resonator section S71C, the series arm resonator section S72C, the series arm resonator section S73C, the series arm resonator section S74C and the series arm resonator section S75C are connected in series with each other in order from the common connection terminal 7 side. The series arm resonator section S71C among the plurality of series arm resonator sections is located closest to the common connection terminal 7 side.

[0446] The plurality of parallel arm resonator sections of the third filter 71C are a parallel arm resonator section P71C, a parallel arm resonator section P72C, a parallel arm resonator section P73C, and a parallel arm resonator section P74C. Each parallel arm resonator section of the third filter 71C includes one parallel arm resonator.

[0447] A parallel arm resonator section P71C is connected between a node D between the series arm resonator section S71C and the series arm resonator section S72C and the ground potential. A parallel arm resonator section P72C is connected between a node D between the series arm resonator section S72C and the series arm resonator section S73C and the ground potential. A parallel arm resonator section P73C is connected between a node D between the series arm resonator section S73C and the series arm resonator section S74C and the ground potential. A parallel arm resonator section P74C is connected between a node D between the series arm resonator section S74C and the series arm resonator section S75C and the ground potential. The parallel arm resonator section P71C among the plurality of parallel arm resonator sections is located closest to the common connection terminal 7.

[0448] The third filter 71C includes a capacitive element C1 and a capacitive element C2. The capacitive element C1 and the capacitive element C2 are connected in parallel to the series arm resonator portion S71C. The capacitive element C1 and the capacitive element C2 are connected in series with each other in this order from the common connection terminal 7 side.

[0449] The plurality of series arm resonator sections of the fourth filter 71D are a series arm resonator section S71D, a series arm resonator section S72D, a series arm resonator section S73D, and a series arm resonator section S74D. The series arm resonator section S71D and the series arm resonator section S73D each include three series arm resonators connected in series with each other. The series arm resonator section S72D and the series arm resonator section S74D each include two series arm resonators connected in series with each other.

[0450] The series arm resonator section S71D, the series arm resonator section S72D, the series arm resonator section S73D, and the series arm resonator section S74D are connected in series with each other in this order from the common connection terminal 7 side. The series arm resonator section S71D among the plurality of series arm resonator sections is located closest to the common connection terminal 7 side.

[0451] The plurality of parallel arm resonator sections of the fourth filter 71D are a parallel arm resonator section P71D, a parallel arm resonator section P72D, a parallel arm resonator section P73D, and a parallel arm resonator section P74D. The parallel arm resonator section P74D includes three parallel arm resonators connected in series with each other. On the other hand, the parallel arm resonator section P71D, the parallel arm resonator section P72D, and the parallel arm resonator section P73D each include one parallel arm resonator.

[0452] A parallel arm resonator section P71D is connected between a node D between the series arm resonator section S71D and the series arm resonator section S72D and the ground potential. A parallel arm resonator section P72D is connected between a node D between the series arm resonator section S72D and the series arm resonator section S73D and the ground potential. A parallel arm resonator section P73D is connected between a node D between the series arm resonator section S73D and the series arm resonator section S74D and the ground potential. A parallel arm resonator section P74D is connected between a node D between the series arm resonator section S74D and the signal terminal 73D and the ground potential. The parallel arm resonator section P71D among the plurality of parallel arm resonator sections is located closest to the common connection terminal 7 side.

[0453] The fourth filter 71D includes an inductor L3 and an inductor L4. The inductor L3 is connected between the parallel arm resonator section P71D and the ground potential. The inductor L4 is connected between the parallel arm resonator section P73D and the ground potential.

[0454] In this embodiment, all filters of the multiplexer 71 are mounted on the same mounting substrate. The communication frequency bands of the multiplexer 71 are Band 1 and Band 3. Specifically, the first filter 21A is a receiving filter of Band 1. The second filter 71B is a transmitting filter of Band 3. The third filter 71C is a receiving filter of Band 3. The fourth filter 71D is a transmitting filter of Band 1. However, the multiplexer 71 may also include filters that are not mounted on the same mounting substrate.

[0455] In this case, for example, the multiplexer 71 may also have a module substrate on which a mounting substrate is mounted. Furthermore, a filter that does not share a mounting substrate with the first filter 21A, the second filter 71B, the third filter 71C, and the fourth filter 71D may be mounted on the module substrate. It is sufficient that the first filter 21A, the second filter 71B, the third filter 71C, and the fourth filter 71D are connected to the common connection terminal 7 together with other filters. The common connection terminal 7 may also be provided on the module substrate.

[0456] The multiplexer 71 may include, for example, a reception filter of Band 32 in addition to the transmission filter and reception filter of Band 1 and the transmission filter and reception filter of Band 3. The passband of the reception filter is 1452 MHz to 1496 MHz.

[0457] The frequency of Rayleigh waves generated in the resonator of the transmission filter of Band 1 is often within the passband of the reception filter. However, in the fourth filter 71D as the resonator of the transmission filter of Band 1, the influence of Rayleigh waves as unnecessary waves on other filters can be suppressed.

[0458] Multiplexer 71 may also have a transmission filter of Band7, Band41, n77 or n78, for example. Alternatively, multiplexer 71 may also have a reception filter of n77 or n78. The passband of the transmission filter of Band7 is 2500MHz to 2570MHz. The passband of the transmission filter of Band41 is 2496MHz to 2690MHz. The frequency band of n77 is 3300MHz to 4800MHz. The frequency band of n78 is 3300MHz to 4200MHz.

[0459] The frequency of unnecessary waves generated in the resonators of other filters may be within the passband of these transmission filters or reception filters. However, in the first filter 21A, the second filter 71B, the third filter 71C and the fourth filter 71D, the influence of unnecessary waves generated on the high frequency side of the anti-resonance frequency of the resonator on other filters can be suppressed.

[0460] In the first filter as the filter device according to the present invention, the stacked structure of the piezoelectric substrate is not limited to Figure 4 The eighth embodiment shows an example in which the first filter has a piezoelectric substrate different from that of the first embodiment.

[0461] Fig.37 It is a schematic front cross-sectional view of the excitation angle variable resonator of the first filter in the eighth embodiment.

[0462] This embodiment is different from the first embodiment in the stacked structure of the piezoelectric substrate 82. This embodiment is also different from the first embodiment in that the dielectric film 8 is not provided on the piezoelectric substrate 82. Except for the above-mentioned points, the multiplexer of this embodiment has the same structure as the multiplexer 1 of the first embodiment.

[0463] The piezoelectric substrate 82 includes a supporting substrate 4, an intermediate layer 85, and a piezoelectric layer 6. The intermediate layer 85 is provided on the supporting substrate 4. The piezoelectric layer 6 is provided on the intermediate layer 85. In the present embodiment, the intermediate layer 85 has a frame-like shape. That is, the intermediate layer 85 has a through hole. The supporting substrate 4 blocks one side of the through hole of the intermediate layer 85. The piezoelectric layer 6 blocks the other side of the through hole of the intermediate layer 85. Thus, a hollow portion 82c is formed in the piezoelectric substrate 82. A portion of the piezoelectric layer 6 and a portion of the supporting substrate 4 are opposed to each other with the hollow portion 82c sandwiched therebetween. At least a portion of the IDT electrode 18 overlaps with the hollow portion 82c when viewed from above.

[0464] In this embodiment, the main mode can be reflected toward the piezoelectric layer 6. Therefore, the energy of the elastic wave can be effectively confined in the piezoelectric layer 6. Also, similarly to the first embodiment, the influence of unnecessary waves can be suppressed in the multiplexer.

[0465] In addition, the piezoelectric substrate 82 may have a plurality of hollow portions 82c. Furthermore, the plurality of IDT electrodes in the first filter may overlap with different hollow portions 82c in a plan view. Alternatively, the plurality of IDT electrodes may overlap with the same hollow portion 82c in a plan view.

[0466] The following is a first variant and a second variant of the eighth embodiment, in which only the stacked structure of the piezoelectric substrate is different from that of the eighth embodiment. In the first variant and the second variant, the influence of the useless waves in the multiplexer can be suppressed as in the eighth embodiment. Furthermore, in the first filter, the energy of the elastic wave can be effectively confined on the piezoelectric layer 6 side.

[0467] exist Fig.38In the first modified example shown, the piezoelectric substrate 82A includes a supporting substrate 4, an acoustic reflection film 87, an intermediate layer 85A, and a piezoelectric layer 6. The acoustic reflection film 87 is provided on the supporting substrate 4. The intermediate layer 85A is provided on the acoustic reflection film 87. The piezoelectric layer 6 is provided on the intermediate layer 85A. The intermediate layer 85A is a low acoustic velocity film.

[0468] The acoustic reflection film 87 is a laminate of multiple acoustic impedance layers. Specifically, the acoustic reflection film 87 has multiple low acoustic impedance layers and multiple high acoustic impedance layers. The high acoustic impedance layer is a layer with relatively high acoustic impedance. More specifically, the multiple high acoustic impedance layers of the acoustic reflection film 87 are high acoustic impedance layer 87a, high acoustic impedance layer 87c, and high acoustic impedance layer 87e. On the other hand, the low acoustic impedance layer is a layer with relatively low acoustic impedance. More specifically, the multiple low acoustic impedance layers of the acoustic reflection film 87 are low acoustic impedance layer 87b and low acoustic impedance layer 87d. The low acoustic impedance layer and the high acoustic impedance layer are alternately laminated. In addition, the high acoustic impedance layer 87a is the layer located closest to the piezoelectric layer 6 in the acoustic reflection film 87.

[0469] The acoustic reflective film 87 has two low acoustic impedance layers and three high acoustic impedance layers. However, the acoustic reflective film 87 only needs to have at least one low acoustic impedance layer and one high acoustic impedance layer.

[0470] As the material of the low acoustic impedance layer, for example, silicon oxide or aluminum can be used. As the material of the high acoustic impedance layer, for example, metals such as platinum or tungsten, and dielectrics such as aluminum nitride or silicon nitride can be used. In addition, the material of the intermediate layer 85A can also be the same as the material of the low acoustic impedance layer.

[0471] exist Fig.39 In the second variation shown, the piezoelectric substrate 82B has a support substrate 84 and a piezoelectric layer 6. The piezoelectric layer 6 is directly provided on the support substrate 84. More specifically, the support substrate 84 has a recess. The piezoelectric layer 6 is provided on the support substrate 84 so as to block the recess. Thus, a hollow portion is provided in the piezoelectric substrate 82B. The hollow portion overlaps with at least a portion of the IDT electrode 18 when viewed from above.

[0472] Fig.40 It is a schematic front cross-sectional view of the excitation angle variable resonator of the first filter in the ninth embodiment.

[0473] This embodiment differs from the first embodiment in that the IDT electrode 18 is embedded in the protective film 99. Although not shown, other IDT electrodes in the first filter are also embedded in the protective film 99. Except for the above, the multiplexer of this embodiment has the same structure as the multiplexer 1 of the first embodiment.

[0474] Specifically, the protective film 99 is provided on the piezoelectric layer 6 so as to cover the IDT electrode 18. The thickness of the protective film 99 is thicker than the thickness of the IDT electrode 18. The IDT electrode 18 is embedded in the protective film 99. Thus, the IDT electrode 18 is not easily damaged.

[0475] The protective film 99 has a first protective layer 99a and a second protective layer 99b. The IDT electrode 18 is embedded in the first protective layer 99a. The second protective layer 99b is provided on the first protective layer 99a. Thus, multiple effects can be obtained by the protective film 99. Specifically, in the present embodiment, silicon oxide is used as the material of the first protective layer 99a. Thus, the absolute value of the temperature coefficient of frequency (TCF) in each resonator can be reduced. Therefore, the temperature characteristics of each resonator can be improved. Silicon nitride is used for the second protective layer 99b. Thus, moisture resistance can be improved.

[0476] Furthermore, in this embodiment, as in the first embodiment, the influence of unnecessary waves in the multiplexer can be suppressed.

[0477] The materials of the first protective layer 99a and the second protective layer 99b are not limited to those described above. The protective film 99 may be a single layer or a laminate of three or more layers.

[0478] Fig.41 It is a schematic front cross-sectional view of the excitation angle variable resonator of the first filter in the tenth embodiment.

[0479] The difference between this embodiment and the first embodiment is that an IDT electrode 18 is provided on both the first principal surface 6a and the second principal surface 6b of the piezoelectric layer 6. In addition, the IDT electrode 18 provided on the second principal surface 6b is embedded in the second layer 5b of the intermediate layer 5. The difference between this embodiment and the first embodiment is that the dielectric film 8 is not provided on the first principal surface 6a. Except for the above aspects, the multiplexer of this embodiment has the same structure as the multiplexer 1 of the first embodiment.

[0480] The IDT electrode 18 provided on the first principal surface 6a of the piezoelectric layer 6 and the IDT electrode 18 provided on the second principal surface 6b face each other across the piezoelectric layer 6. In this embodiment, as in the first embodiment, the influence of unnecessary waves in the multiplexer can be suppressed.

[0481] Furthermore, the IDT electrodes 18 provided on the first principal surface 6 a and the second principal surface 6 b of the piezoelectric layer 6 may have different design parameters, for example.

[0482] Alternatively, on the second main surface 6b of the piezoelectric layer 6, Fig.41 IDT electrodes are also provided in addition to the parts shown. For example, in the first filter, Fig.41 In addition to the portions shown, the IDT electrodes are also opposed to each other with the piezoelectric layer 6 interposed therebetween.

[0483] The following describes the first to third variations of the tenth embodiment in which at least one of the structure of the electrode provided only on the second main surface of the piezoelectric layer and the stacked structure of the piezoelectric substrate is different from the tenth embodiment. In the first to third variations, the influence of useless waves can be suppressed in the multiplexer as in the tenth embodiment.

[0484] exist Fig.42 In the first modification shown, the piezoelectric substrate 82 is configured similarly to the eighth embodiment. Specifically, the piezoelectric substrate 82 includes a support substrate 4, an intermediate layer 85, and a piezoelectric layer 6. The IDT electrode 18 provided on the second principal surface 6b of the piezoelectric layer 6 is located in the hollow portion 82c.

[0485] exist Fig.43 In the second modification shown in the figure, a plate-shaped electrode 118 is provided on the second main surface 6b of the piezoelectric layer 6. The electrode 118 is embedded in the second layer 5b of the intermediate layer 5. The IDT electrode 18 and the electrode 118 are opposed to each other with the piezoelectric layer 6 sandwiched therebetween. Fig.43 Other electrodes 118 are also provided in addition to the portion shown. For example, in the first filter, Fig.43 In addition to the illustrated portion, the IDT electrode and the electrode 118 are also opposed to each other with the piezoelectric layer 6 interposed therebetween.

[0486] exist Fig.44 In the third modification shown, the piezoelectric substrate 82 is configured similarly to the first modification, and an electrode 118 similar to the second modification is provided on the second principal surface 6b of the piezoelectric layer 6. The electrode 118 is located in the hollow portion 82c. The IDT electrode 18 and the electrode 118 face each other with the piezoelectric layer 6 interposed therebetween.

[0487] Examples of aspects of the elastic wave device according to the present invention are summarized below.

[0488] <1> A filter device comprises: a first signal terminal and a second signal terminal; and a plurality of resonators including a plurality of series arm resonators and a plurality of parallel arm resonators, at least one of the plurality of series arm resonators and the plurality of parallel arm resonators being an excitation angle variable resonator, the excitation angle variable resonator comprising: a piezoelectric substrate including a piezoelectric layer; and an IDT electrode including a plurality of electrode fingers arranged on the piezoelectric substrate, the piezoelectric layer having a propagation axis, the plurality of electrode fingers being bent, the excitation direction of elastic waves in any portion of any electrode finger among the plurality of electrode fingers being any one of a first direction to a third direction, the first direction being a direction perpendicular to the direction in which the electrode finger extends, the second direction being a direction connecting the shortest distance between the electrode finger and the electrode finger adjacent to the electrode finger, the third direction being a direction of an electric field vector generated between the electrode finger and the electrode finger adjacent to the electrode finger, and the excitation direction and the third direction being a direction of an electric field vector generated between the electrode finger and the electrode finger adjacent to the electrode finger. When the angle formed by the direction in which the propagation axis extends is set as the excitation angle, the excitation angle is different in the IDT electrode of the excitation angle variable resonator, and when an adjacent group of the series arm resonators and the parallel arm resonators are set as a trapezoidal portion, a plurality of the trapezoidal portions are formed between the first signal terminal and the second signal terminal, and in the adjacent trapezoidal portions, at least one of the series arm resonators and the parallel arm resonators is a mutually different resonator, and the half of the trapezoidal portions located on the first signal terminal side among all the trapezoidal portions are set as the front half of the trapezoidal portions, and the series arm resonators and the parallel arm resonators from the resonator located closest to the first signal terminal to the trapezoidal portion located closest to the second signal terminal among the plurality of resonators in the front half of the trapezoidal portions are set as the front half of the resonators, and at this time, at least one of the resonators in the front half is the excitation angle variable resonator.

[0489] <2> according to <1> In the filter device, the first signal terminal is connected to an antenna.

[0490] <3> according to <1> or <2> In the filter device, in the IDT electrode of at least one of the variable excitation angle resonators, the shape of the plurality of electrode fingers in a plan view includes a circular arc or an elliptical arc.

[0491] <4> according to <1> or <2> The filter device described above, wherein the plurality of electrode fingers in the IDT electrode of at least one of the excitation angle-variable resonators include a plurality of first electrode fingers and a plurality of second electrode fingers that are interlaced with each other, a virtual line formed by connecting the front ends of the front ends of the plurality of second electrode fingers is set as a first envelope, a virtual line formed by connecting the front ends of the front ends of the plurality of first electrode fingers is set as a second envelope, an area between the first envelope and the second envelope in the IDT electrode is a crossing area, a portion of the first electrode finger including a portion located on the first envelope and adjacent to the front end of any of the second electrode fingers is an adjacent portion of the first electrode finger, and a portion of the second electrode finger including a portion located on the first envelope and adjacent to the front end of any of the second electrode fingers is an adjacent portion of the first electrode finger. The portion located on the second envelope and adjacent to the front end portion of any one of the first electrode fingers is an adjacent portion of the second electrode finger, the intersection region includes at least one curved region in which the shapes of the plurality of first electrode fingers and the plurality of second electrode fingers are curved when viewed from above, the at least one curved region includes a curved region whose end edge is the first envelope, in the curved region, the curvature of each of the first electrode fingers and the second electrode fingers is not fixed, and the curvatures of the front ends located on the first envelope side in at least one group of electrode fingers among the plurality of first electrode fingers and the plurality of second electrode fingers are different from each other, between the adjacent portions, or between the front end portion and the adjacent portion.

[0492] <5> according to <3> or <4> The filter device described above, wherein at least one of the excitation angle-variable resonators has a pair of reflectors arranged on the piezoelectric layer to face each other with the IDT electrode sandwiched therebetween and each having a plurality of reflector electrode fingers, wherein the shapes of the plurality of reflector electrode fingers in a plan view include a curved shape.

[0493] <6> according to <1> or <2> The filter device described above, wherein the plurality of electrode fingers in the IDT electrode of at least one of the excitation angle-variable resonators include a plurality of first electrode fingers and a plurality of second electrode fingers that are interlaced with each other, a virtual line formed by connecting the front ends of the plurality of second electrode fingers is set as a first envelope, and a virtual line formed by connecting the front ends of the plurality of first electrode fingers is set as a second envelope, and a region between the first envelope and the second envelope in the IDT electrode is an intersection region, the intersection region includes a plurality of parallel regions in which the plurality of first electrode fingers and the plurality of second electrode fingers extend in parallel, and a non-parallel region in which the directions in which the plurality of first electrode fingers and the plurality of second electrode fingers extend intersect with each other, and in at least a portion of the intersection region, the parallel regions and the non-parallel regions are alternately arranged, and the plurality of first electrode fingers and the second electrode fingers extend linearly in the plurality of parallel regions and the non-parallel regions, respectively, and are bent at the boundaries between the parallel regions and the non-parallel regions.

[0494] <7> according to <6> The filter device described above, wherein at least one of the excitation angle-variable resonators has a pair of reflectors arranged on the piezoelectric layer and facing each other with the IDT electrode sandwiched therebetween and each having a plurality of reflector electrode fingers, wherein the shapes of the plurality of reflector electrode fingers in a plan view include shapes bent at a plurality of nodes.

[0495] <8> according to <1> ~ <7> The filter device according to any one of claims 1 to 5, wherein at least one of an electrode finger pitch and a duty ratio is constant in a portion where the excitation angle of the IDT electrode of at least one of the excitation angle variable resonators is the same.

[0496] <9> according to <1> ~ <8> A filter device as described in any one of the items, wherein the plurality of electrode fingers in the IDT electrode of the excitation angle variable resonator include a plurality of first electrode fingers and a plurality of second electrode fingers that are interlaced with each other, a virtual line formed by connecting the front ends of the front ends of the plurality of second electrode fingers is set as a first envelope, and a virtual line formed by connecting the front ends of the front ends of the plurality of first electrode fingers is set as a second envelope, and an area between the first envelope and the second envelope in the IDT electrode is an intersection area, and in the intersection area of ​​at least one of the excitation angle variable resonators, the resonant frequency or the anti-resonant frequency is substantially consistent.

[0497] <10> according to <1> ~ <9> The filter device according to any one of the preceding claims, wherein a path connecting the first signal terminal and the second signal terminal is a series arm, paths branching from the series arm to a ground potential are parallel arms, connection points of the series arm and the parallel arms are nodes, and when one of the series arm resonators or a group of a plurality of the series arm resonators connected in series with each other without passing through the node is set as a series arm resonator section, a plurality of the series arm resonator sections are formed in the series arm, and a path between the first signal terminal and the series arm resonator section and between the second signal terminal and the series arm resonator section is connected. When intervals are set between the parts and between adjacent series arm resonator parts respectively, at least one of the nodes is located at least in each of the intervals between adjacent series arm resonator parts, and when the parallel arm resonator located in the parallel arm connected to the node located in the same interval is set as one parallel arm resonator part, a plurality of parallel arm resonator parts are constituted, and at least one of the series arm resonator part located closest to the first signal terminal and the parallel arm resonator part located closest to the first signal terminal is the excitation angle variable resonator.

[0498] <11> according to <10> The filter device described above, wherein when the plurality of series arm resonator sections and the plurality of parallel arm resonator sections are provided as a plurality of resonator sections, at least one of the resonators of the resonator sections located closest to the first signal terminal is the excitation angle variable resonator.

[0499] <12> according to <11> In the filter device, the resonator section located closest to the first signal terminal includes a plurality of the resonators, and more than half of the resonators among the plurality of resonators are the excitation angle variable resonators.

[0500] <13> according to <10> ~ <12> A filter device as described in any one of the above, wherein, when the plurality of series arm resonator sections and the plurality of parallel arm resonator sections are set as a plurality of resonator sections, the resonator section located closest to the first signal terminal includes a plurality of resonators, at least two of the plurality of resonators are excitation angle variable resonators, and in at least two of the excitation angle variable resonators in the resonator section located closest to the first signal terminal, the types of shapes of the electrode fingers in a plan view are different from each other.

[0501] <14> according to <10> ~ <13> A filter device as described in any one of the claims , wherein, when the plurality of series arm resonator sections and the plurality of parallel arm resonator sections are set as a plurality of resonator sections, the resonator section located closest to the first signal terminal includes a plurality of resonators, at least two of the plurality of resonators are excitation angle variable resonators, and in each of at least two of the excitation angle variable resonators in the resonator section located closest to the first signal terminal, at least a duty ratio in a portion where the excitation angle is 0° is fixed, and in at least two of the excitation angle variable resonators in the resonator section located closest to the first signal terminal, duty ratios in a portion where the excitation angle is 0° are different from each other.

[0502] <15> according to <13> or <14> The filter device described above, wherein the resonator section located closest to the first signal terminal includes a plurality of the resonators, at least three of the plurality of resonators are variable excitation angle resonators, and the shapes of the electrode fingers in a plan view are different from each other in at least three of the variable excitation angle resonators in the resonator section located closest to the first signal terminal.

[0503] <16> according to <13> ~ <15> A filter device as described in any one of the above, wherein the resonator section located closest to the first signal terminal includes a plurality of resonators, at least three of the plurality of resonators are excitation angle variable resonators, and in each of the at least three excitation angle variable resonators in the resonator section located closest to the first signal terminal, at least a duty ratio in a portion where the excitation angle is 0° is fixed, and in the at least three excitation angle variable resonators in the resonator section located closest to the first signal terminal, the duty ratios in the portion where the excitation angle is 0° are different from each other.

[0504] <17> according to <13> or <15> The filter device described above, wherein, in at least one of the variable excitation angle resonators included in the resonator portion located closest to the first signal terminal, the shape of the electrode finger when viewed from above is an arc, and in at least one of the other variable excitation angle resonators, the shape of the electrode finger when viewed from above is other than an arc.

[0505] <18> according to <10> ~ <17> The filter device according to any one of the preceding claims, wherein, when the plurality of series arm resonator sections and the plurality of parallel arm resonator sections are set as a plurality of resonator sections, the resonator section located closest to the first signal terminal includes a plurality of resonators, at least two of the plurality of resonators are excitation angle variable resonators, the plurality of electrode fingers in the IDT electrode of each of the excitation angle variable resonators include a plurality of first electrode fingers and a plurality of second electrode fingers that are interlaced with each other, and in each of the excitation angle variable resonators, the plurality of electrode fingers connected by the IDT electrode are connected by the first electrode fingers. A virtual line formed by the front ends of the front ends of the plurality of second electrode fingers is set as the first envelope, and a virtual line formed by connecting the front ends of the plurality of first electrode fingers is set as the second envelope. An area between the first envelope and the second envelope in the IDT electrode is an intersection area, and in the intersection area, the resonant frequency or the anti-resonant frequency is substantially consistent, and in at least two of the excitation angle variable resonators included in the resonator portion located closest to the first signal terminal, the resonant frequency or the anti-resonant frequency in the intersection area is substantially consistent.

[0506] <19> according to <1> ~ <18> A filter device as described in any one of the above, wherein the plurality of electrode fingers in the IDT electrode of the excitation angle variable resonator include a plurality of first electrode fingers and a plurality of second electrode fingers which are interlaced with each other, a virtual line formed by connecting the front ends of the front ends of the plurality of second electrode fingers is set as a first envelope, and a virtual line formed by connecting the front ends of the front ends of the plurality of first electrode fingers is set as a second envelope, and an area between the first envelope and the second envelope in the IDT electrode is an intersection area, and in at least one of the excitation angle variable resonators, at least one of the first envelope and the second envelope has at least one bend portion whose extending direction changes.

[0507] <20> according to <1> ~ <18> A filter device as described in any one of the above, wherein the plurality of electrode fingers in the IDT electrode of the excitation angle variable resonator include a plurality of first electrode fingers and a plurality of second electrode fingers which are interlaced with each other, a virtual line formed by connecting the front ends of the front ends of the plurality of second electrode fingers is set as a first envelope, and a virtual line formed by connecting the front ends of the front ends of the plurality of first electrode fingers is set as a second envelope, an area between the first envelope and the second envelope in the IDT electrode is a crossing area, and in at least one of the excitation angle variable resonators, at least one of the first envelope and the second envelope is a straight line.

[0508] <21> according to <1> ~ <20> A filter device as described in any one of the above, wherein the plurality of electrode fingers in the IDT electrode of the excitation angle variable resonator include a plurality of first electrode fingers and a plurality of second electrode fingers that are interlaced with each other, a virtual line formed by connecting the front ends of the front ends of the plurality of second electrode fingers is set as a first envelope, and a virtual line formed by connecting the front ends of the front ends of the plurality of first electrode fingers is set as a second envelope, and a region between the first envelope and the second envelope in the IDT electrode is a cross region, and the cross region has a first edge region including the first envelope, a second edge region including the second envelope, and a central region sandwiched by the first edge region and the second edge region, and in at least one of the excitation angle variable resonators, at least a portion of at least one of the first edge region and the second edge region constitutes a low sound velocity region having a sound velocity lower than that in the central region.

[0509] <22> according to <21> The filter device described above, wherein in at least one of the first edge region and the second edge region, at least one of the electrode fingers has a wide portion having a width wider than that in the central region, thereby constituting the low acoustic velocity region.

[0510] <23> according to <21> or <22> The filter device, wherein at least one of the first edge region and the second edge region, further comprises a mass-added film, wherein the mass-added film is arranged to overlap with at least one of the plurality of first electrode fingers and the plurality of second electrode fingers when viewed from above, and by arranging the mass-added film, the low acoustic velocity region is formed.

[0511] <24> according to <21> ~ <23> A filter device as described in any one of the items, wherein in at least one of the first edge region and the second edge region, the thickness of at least one of the electrode fingers is thicker than the thickness of the electrode finger in the central region, thereby constituting the low acoustic velocity region.

[0512] <25> according to <21> ~ <24> The filter device described in any one of claims , wherein the low acoustic velocity region is constituted in the entirety of both the first edge region and the second edge region.

[0513] <26> according to <1> ~ <25> The filter device according to any one of claims , wherein a path connecting the first signal terminal and the second signal terminal is a series arm, and the plurality of resonators include a longitudinally coupled resonator-type elastic wave filter located in the series arm.

[0514] <27> according to <1> ~ <26> The filter device described in any one of claims , wherein the piezoelectric substrate has a supporting substrate, and the piezoelectric layer is provided on the supporting substrate.

[0515] <28> according to <27> In the filter device, the piezoelectric substrate includes an intermediate layer provided between the supporting substrate and the piezoelectric layer.

[0516] <29> according to <28> In the filter device, a hollow portion is formed in the piezoelectric substrate, and a portion of the support substrate and a portion of the piezoelectric layer are opposed to each other with the hollow portion interposed therebetween.

[0517] <30> according to <1> ~ <26> A filter device as described in any one of claims , wherein the piezoelectric substrate includes only the piezoelectric layer.

[0518] <31> according to <1> ~ <30> The filter device described in any one of claims 1 to 5, wherein all of the resonators share the same piezoelectric substrate.

[0519] <32> A multiplexer comprising: a common connection terminal; and a plurality of filters commonly connected to the common connection terminal, including a first filter and a second filter, wherein at least the first filter among the plurality of filters is <1> ~ <31> The filter device as described above.

[0520] <33> according to <32> The multiplexer, wherein the multiple filters share the same piezoelectric substrate.

[0521] <34> according to <32> The multiplexer described above further includes a mounting substrate, at least the second filter among the plurality of filters has a substrate different from the piezoelectric substrate of the first filter, and the plurality of filters are mounted on the mounting substrate.

[0522] <35> according to <32> ~ <34> A multiplexer as described in any one of the items, wherein the passband of the first filter is located on the high-frequency side than the passband of the second filter, and the passband of the second filter includes at least a portion of the frequencies that are greater than 0.5 times and less than 0.9 times the resonant frequency of at least one of the excitation angle-variable resonators in the first filter.

[0523] <36> according to <32> ~ <34> A multiplexer as described in any one of claims , wherein a passband of the first filter is located on a lower frequency side than a passband of the second filter.

Claims

1. A filter device comprising: a first signal terminal and a second signal terminal; and a plurality of resonators including a plurality of series-arm resonators and a plurality of parallel-arm resonators, At least one of the plurality of series arm resonators and the plurality of parallel arm resonators is an excitation angle variable resonator, The excitation angle variation type resonator comprises: a piezoelectric substrate including a piezoelectric layer; and an IDT electrode including a plurality of electrode fingers provided on the piezoelectric substrate. The piezoelectric layer has a propagation axis, and the plurality of electrode fingers are bent. The excitation direction of the elastic wave in any part of any electrode finger among the plurality of electrode fingers is any one of a first direction to a third direction, wherein the first direction is a direction perpendicular to the direction in which the electrode finger extends, the second direction is a direction connecting the electrode finger with the shortest distance between the electrode finger and the electrode finger adjacent to the electrode finger, and the third direction is a direction of an electric field vector generated between the electrode finger and the electrode finger adjacent to the electrode finger. When the angle between the excitation direction and the direction in which the propagation axis extends is defined as an excitation angle, the excitation angle varies in the IDT electrode of the excitation angle-variable resonator. When an adjacent set of the series arm resonators and the parallel arm resonators is set as a trapezoidal portion, a plurality of the trapezoidal portions are formed between the first signal terminal and the second signal terminal, and in the adjacent trapezoidal portions, at least one of the series arm resonators and the parallel arm resonators is a different resonator from each other. The half of the trapezoidal portions located on the first signal terminal side among all the trapezoidal portions is set as the first half of the trapezoidal portions, and the series arm resonators and the parallel arm resonators from the resonator located closest to the first signal terminal to the trapezoidal portion located closest to the second signal terminal among the plurality of resonators in the first half of the trapezoidal portions are set as the first half of the resonators, and at this time, at least one of the resonators in the first half is the excitation angle variable resonator.

2. The filter device according to claim 1, wherein The first signal terminal is connected to an antenna.

3. The filter device according to claim 1 or 2, wherein: In at least one of the IDT electrodes of the variable excitation angle resonator, a shape of the plurality of electrode fingers in a plan view includes a circular arc shape or an elliptical arc shape.

4. The filter device according to claim 1 or 2, wherein: The plurality of electrode fingers in the IDT electrode of at least one of the excitation angle-variable resonators include a plurality of first electrode fingers and a plurality of second electrode fingers that are interlaced with each other. a virtual line formed by connecting the front ends of the front ends of the plurality of second electrode fingers as a first envelope, a virtual line formed by connecting the front ends of the plurality of first electrode fingers as a second envelope, and a region between the first envelope and the second envelope in the IDT electrode as a crossing region, A portion of the first electrode finger including a portion located on the first envelope and adjacent to the front end portion of any of the second electrode fingers is an adjacent portion of the first electrode finger, and a portion of the second electrode finger including a portion located on the second envelope and adjacent to the front end portion of any of the first electrode fingers is an adjacent portion of the second electrode finger. The intersection region includes at least one curved region in which the shapes of the plurality of first electrode fingers and the plurality of second electrode fingers are curved in a plan view, and the at least one curved region includes the curved region whose end edge is the first envelope. In the curved area, the curvatures of each of the first electrode fingers and the second electrode fingers are not fixed, and the curvatures of at least one group of electrode fingers among the plurality of first electrode fingers and the plurality of second electrode fingers are different between the front end portions located on the first envelope side, between the adjacent portions, or between the front end portions and the adjacent portions.

5. The filter device according to claim 3 or 4, wherein: At least one of the excitation angle-variable resonators includes a pair of reflectors disposed on the piezoelectric layer so as to face each other with the IDT electrode interposed therebetween and each of which includes a plurality of reflector electrode fingers. The shapes of the plurality of reflector electrode fingers in a plan view include curved shapes.

6. The filter device according to claim 1 or 2, wherein: The plurality of electrode fingers in the IDT electrode of at least one of the excitation angle-variable resonators include a plurality of first electrode fingers and a plurality of second electrode fingers that are interlaced with each other. A virtual line formed by connecting the front ends of the plurality of second electrode fingers is set as a first envelope, a virtual line formed by connecting the front ends of the plurality of first electrode fingers is set as a second envelope, and a region between the first envelope and the second envelope in the IDT electrode is a crossing region, The intersection region includes a plurality of parallel regions in which the plurality of first electrode fingers and the plurality of second electrode fingers extend in parallel, and a non-parallel region in which the directions in which the plurality of first electrode fingers and the plurality of second electrode fingers extend intersect with each other. In at least a portion of the intersection region, the parallel regions and the non-parallel regions are alternately arranged, and the plurality of first electrode fingers and the second electrode fingers extend linearly in the plurality of parallel regions and the non-parallel regions, respectively, and are bent at boundaries between the parallel regions and the non-parallel regions.

7. The filter device according to claim 6, wherein: At least one of the excitation angle-variable resonators includes a pair of reflectors disposed on the piezoelectric layer so as to face each other with the IDT electrode interposed therebetween and each of which includes a plurality of reflector electrode fingers. The shapes of the plurality of reflector electrode fingers in a plan view include shapes that are bent at a plurality of nodes.

8. The filter device according to any one of claims 1 to 7, wherein: In a portion where the excitation angle of the IDT electrode of at least one of the excitation angle-variable resonators is the same, at least one of an electrode finger pitch and a duty ratio is constant.

9. The filter device according to any one of claims 1 to 8, wherein: The plurality of electrode fingers in the IDT electrode of the variable excitation angle resonator include a plurality of first electrode fingers and a plurality of second electrode fingers that are interlaced with each other. a virtual line formed by connecting the front ends of the front ends of the plurality of second electrode fingers as a first envelope, a virtual line formed by connecting the front ends of the plurality of first electrode fingers as a second envelope, and a region between the first envelope and the second envelope in the IDT electrode as a crossing region, In the intersection region of at least one of the excitation angle-variable resonators, the resonant frequency or the antiresonant frequency substantially matches.

10. The filter device according to any one of claims 1 to 9, wherein: A path connecting the first signal terminal and the second signal terminal is a series arm, paths branching from the series arm to the ground potential are parallel arms, and connection points of the series arm and the parallel arm are nodes. When one of the series arm resonators or a group of a plurality of the series arm resonators connected in series with each other without passing through the node is set as a series arm resonator unit, a plurality of the series arm resonator units are configured in the series arm. When the area between the first signal terminal and the series arm resonator section, the area between the second signal terminal and the series arm resonator section, and the area between adjacent series arm resonator sections are respectively defined as sections, at least one of the nodes is located at least in each of the sections between adjacent series arm resonator sections. When the parallel arm resonator located in the parallel arm connected to the node located in the same section is set as one parallel arm resonator unit, a plurality of parallel arm resonator units are configured. At least one of the series arm resonator portion located closest to the first signal terminal and the parallel arm resonator portion located closest to the first signal terminal is the excitation angle variable resonator.

11. The filter device according to claim 10, wherein: When the plurality of series arm resonator sections and the plurality of parallel arm resonator sections are provided as a plurality of resonator sections, at least one resonator of the resonator section located closest to the first signal terminal is the excitation angle variable resonator.

12. The filter device according to claim 11, wherein The resonator section located closest to the first signal terminal includes a plurality of the resonators, and more than half of the resonators among the plurality of resonators are the excitation angle variation type resonators.

13. The filter device according to any one of claims 10 to 12, wherein: When the plurality of series arm resonator sections and the plurality of parallel arm resonator sections are set as a plurality of resonator sections, the resonator section located closest to the first signal terminal includes a plurality of the resonators, at least two of the plurality of resonators are the excitation angle variable resonators, In at least two of the variable excitation angle resonators in the resonator section located closest to the first signal terminal, the shapes of the electrode fingers in a plan view are different from each other.

14. The filter device according to any one of claims 10 to 13, wherein: When the plurality of series arm resonator sections and the plurality of parallel arm resonator sections are set as a plurality of resonator sections, the resonator section located closest to the first signal terminal includes a plurality of the resonators, at least two of the plurality of resonators are the excitation angle variable resonators, In each of at least two of the variable excitation angle resonators in the resonator section located closest to the first signal terminal, at least the duty ratio in a portion where the excitation angle is 0° is constant, At least two of the variable excitation angle resonators in the resonator section located closest to the first signal terminal have different duty ratios in a portion where the excitation angle is 0°.

15. The filter device according to claim 13 or 14, wherein: The resonator section located closest to the first signal terminal includes a plurality of the resonators, at least three of the plurality of resonators are the excitation angle variable resonators, In at least three of the variable excitation angle resonators in the resonator section located closest to the first signal terminal, the shapes of the electrode fingers in a plan view are different from each other.

16. The filter device according to any one of claims 13 to 15, wherein: The resonator section located closest to the first signal terminal includes a plurality of the resonators, at least three of the plurality of resonators are the excitation angle variable resonators, In each of at least three of the variable excitation angle resonators in the resonator section located closest to the first signal terminal, at least the duty ratio in a portion where the excitation angle is 0° is constant. At least three of the variable excitation angle resonators in the resonator portion located closest to the first signal terminal have different duty ratios in a portion where the excitation angle is 0°.

17. The filter device according to claim 13 or 15, wherein: In at least one of the variable excitation angle resonators included in the resonator portion located closest to the first signal terminal, the shape of the electrode finger in a plan view is an arc, and in at least one of the other variable excitation angle resonators, the shape of the electrode finger in a plan view is other than an arc.

18. The filter device according to any one of claims 10 to 17, wherein: When the plurality of series arm resonator sections and the plurality of parallel arm resonator sections are set as a plurality of resonator sections, the resonator section located closest to the first signal terminal includes a plurality of the resonators, at least two of the plurality of resonators are the excitation angle variable resonators, The plurality of electrode fingers in the IDT electrode of each of the variable excitation angle resonators include a plurality of first electrode fingers and a plurality of second electrode fingers that are interlaced with each other. In each of the excitation angle-variable resonators, a virtual line formed by connecting the front ends of the front ends of the plurality of second electrode fingers is set as a first envelope, and a virtual line formed by connecting the front ends of the front ends of the plurality of first electrode fingers is set as a second envelope, a region between the first envelope and the second envelope in the IDT electrode is a crossover region, and in the crossover region, the resonant frequency or the antiresonant frequency is substantially consistent, In at least two of the variable excitation angle resonators included in the resonator section located closest to the first signal terminal, the resonant frequencies or antiresonant frequencies in the intersection region are substantially identical to each other.

19. The filter device according to any one of claims 1 to 18, wherein: The plurality of electrode fingers in the IDT electrode of the variable excitation angle resonator include a plurality of first electrode fingers and a plurality of second electrode fingers that are interlaced with each other. a virtual line formed by connecting the front ends of the front ends of the plurality of second electrode fingers as a first envelope, a virtual line formed by connecting the front ends of the plurality of first electrode fingers as a second envelope, and a region between the first envelope and the second envelope in the IDT electrode as a crossing region, In at least one of the variable excitation angle resonators, at least one of the first envelope and the second envelope has at least one bend where the extending direction changes.

20. The filter device according to any one of claims 1 to 18, wherein: The plurality of electrode fingers in the IDT electrode of the variable excitation angle resonator include a plurality of first electrode fingers and a plurality of second electrode fingers that are interlaced with each other. a virtual line formed by connecting the front ends of the front ends of the plurality of second electrode fingers as a first envelope, a virtual line formed by connecting the front ends of the plurality of first electrode fingers as a second envelope, and a region between the first envelope and the second envelope in the IDT electrode as a crossing region, In at least one of the variable excitation angle resonators, at least one of the first envelope and the second envelope is linear.

21. The filter device according to any one of claims 1 to 20, wherein: The plurality of electrode fingers in the IDT electrode of the variable excitation angle resonator include a plurality of first electrode fingers and a plurality of second electrode fingers that are interlaced with each other. a virtual line formed by connecting the front ends of the front ends of the plurality of second electrode fingers as a first envelope, a virtual line formed by connecting the front ends of the plurality of first electrode fingers as a second envelope, and a region between the first envelope and the second envelope in the IDT electrode as a crossing region, The intersection region includes a first edge region including the first envelope, a second edge region including the second envelope, and a central region sandwiched by the first edge region and the second edge region. In at least one of the variable excitation angle resonators, at least a portion of at least one of the first edge region and the second edge region forms a low sound velocity region having a sound velocity lower than that in the central region.

22. The filter device according to claim 21, wherein In at least one of the first edge region and the second edge region, at least one of the electrode fingers has a wide portion having a width greater than that in the central region, thereby constituting the low acoustic velocity region.

23. A filter device according to claim 21 or 22, wherein: At least one of the first edge region and the second edge region further comprises a mass adding film, the mass adding film being provided so as to overlap with at least one of the plurality of first electrode fingers and the plurality of second electrode fingers in a plan view. The mass addition membrane is provided to form the low sound velocity region.

24. The filter device according to any one of claims 21 to 23, wherein: In at least one of the first edge region and the second edge region, the thickness of at least one of the electrode fingers is thicker than the thickness of the electrode finger in the central region, thereby forming the low acoustic velocity region.

25. The filter device according to any one of claims 21 to 24, wherein: The low sound velocity region is formed in the entirety of both the first edge region and the second edge region.

26. The filter device according to any one of claims 1 to 25, wherein: A path connecting the first signal terminal and the second signal terminal is a series arm, The plurality of resonators include a longitudinally coupled resonator-type elastic wave filter located in the series arm.

27. The filter device according to any one of claims 1 to 26, wherein: The piezoelectric substrate has a supporting substrate. The piezoelectric layer is provided on the supporting substrate.

28. The filter device according to claim 27, wherein The piezoelectric substrate includes an intermediate layer provided between the supporting substrate and the piezoelectric layer.

29. The filter device according to claim 28, wherein A hollow portion is formed in the piezoelectric substrate, and a portion of the support substrate and a portion of the piezoelectric layer face each other with the hollow portion interposed therebetween.

30. The filter device according to any one of claims 1 to 26, wherein: The piezoelectric substrate includes only the piezoelectric layer.

31. The filter device according to any one of claims 1 to 30, wherein: All of the resonators share the same piezoelectric substrate.

32. A multiplexer comprising: a common connection terminal; and A plurality of filters are commonly connected to the common connection terminal, including a first filter and a second filter, At least the first filter among the plurality of filters is the filter device according to any one of claims 1 to 31.

33. The multiplexer according to claim 32, wherein: The plurality of filters share the same piezoelectric substrate.

34. The multiplexer according to claim 32, wherein: The multiplexer further comprises a mounting substrate. At least the second filter among the plurality of filters has a substrate different from the piezoelectric substrate of the first filter, The plurality of filters are mounted on the mounting substrate.

35. The multiplexer according to any one of claims 32 to 34, wherein: The passband of the first filter is located on the high frequency side than the passband of the second filter. The passband of the second filter includes at least a portion of frequencies that are 0.5 times or more and 0.9 times or less the resonant frequency of at least one of the excitation angle variable resonators in the first filter.

36. The multiplexer according to any one of claims 32 to 34, wherein: The passband of the first filter is located on the lower frequency side than the passband of the second filter.

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