Filter

Abstract

To realize a sufficient bandwidth while realizing a steeply changing pass attenuation characteristic in a frequency region close to a cutoff frequency.SOLUTION: A first end L11a of an inductor L11 and a first end L12a of an inductor L12 are connected to each other and connected to an acoustic wave element 31. A first inductor conductor 110 of the inductor L11 includes a first portion 110A. A second inductor conductor 120 of the inductor L12 includes a second portion 120A disposed adjacent to the first portion 110A at a predetermined interval. A direction in the first portion 110A when moving from the first end L11a to the second end L11b of the inductor L11 and a direction in the second portion 120A when moving from the first end L12a to the second end L12b of the inductor L12 are opposite to each other.SELECTED DRAWING: Figure 11

Description

[Technical Field]

[0001] The present invention relates to a filter including an inductor and an acoustic wave element. [Background technology]

[0002] Electronic components used in wireless communication systems include filters such as low-pass filters, high-pass filters, and band-pass filters. These filters are constructed using multiple resonators. Examples of resonators used in these filters include LC resonators constructed using inductors and capacitors, and acoustic wave resonators constructed using acoustic wave elements. An acoustic wave element is an element that utilizes acoustic waves. Acoustic wave elements include surface acoustic wave elements that utilize surface acoustic waves and bulk acoustic wave elements that utilize bulk acoustic waves.

[0003] As a filter device configured using an acoustic wave resonator, for example, as disclosed in Patent Document 1, an acoustic wave filter device is known that includes an acoustic wave filter chip mounted on the upper surface of a laminated substrate and an inductance element formed within the laminated substrate. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] International Publication No. 2009 / 136472 Summary of the Invention [Problem to be solved by the invention]

[0005] In wireless communication systems, the effective use of radio waves is being promoted by increasing the number of newly allocable frequencies. In recent years, the formulation of new standards has progressed, resulting in the existence of multiple standards, both existing and new, in a relatively narrow frequency band. Therefore, filters used in wireless communication systems are required to extract signals of the corresponding standard while reliably blocking signals of adjacent standards. To achieve this, the insertion loss must change sharply in the frequency range close to the passband.

[0006] In general, an acoustic wave filter device such as that disclosed in Patent Document 1 is suitable for achieving a bandpass attenuation characteristic that changes sharply in a frequency range close to the passband. However, an acoustic wave filter device has a problem in that it is difficult to achieve a sufficient bandwidth.

[0007] The present invention has been made in view of the above problems, and an object of the present invention is to provide a filter that can achieve a sufficient bandwidth while achieving a bandpass attenuation characteristic that changes sharply in a frequency range close to the cutoff frequency. [Means for solving the problem]

[0008] The filter of the present invention includes a first inductor, a second inductor, and a first acoustic wave element. The first inductor and the second inductor each have a first end and a second end located opposite each other. The first end of the first inductor and the first end of the second inductor are connected to each other and to the first acoustic wave element. The first inductor includes a first inductor conductor. The second inductor includes a second inductor conductor. The first inductor conductor includes a first portion having a shape elongated in one direction. The second inductor conductor includes a second portion having a shape elongated in one direction and disposed adjacent to the first portion with a predetermined gap therebetween. The direction of the first portion when moving along the first inductor conductor from the first end to the second end of the first inductor is opposite to the direction of the second portion when moving along the second inductor conductor from the first end to the second end of the second inductor. [Effects of the Invention]

[0009] In the filter of the present invention, the direction in the first portion when moving along the first inductor conductor from the first end to the second end of the first inductor is opposite to the direction in the second portion when moving along the second inductor conductor from the first end to the second end of the second inductor, thereby achieving a sufficient bandwidth while achieving a bandpass attenuation characteristic that changes sharply in a frequency range close to the cutoff frequency. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is a circuit diagram showing a circuit configuration of a filter according to an embodiment of the present invention. [Figure 2] 1 is a perspective view showing a filter according to an embodiment of the present invention. [Figure 3] 1 is a perspective view showing a first main body of a filter according to an embodiment of the present invention. [Figure 4] 1 is a perspective view showing a first main body of a filter according to an embodiment of the present invention. [Figure 5] 5 is an explanatory diagram showing the pattern-forming surfaces of the first to third dielectric layers in the first main body shown in FIGS. 2 to 4. FIG. [Figure 6] 5 is an explanatory view showing the pattern-forming surfaces of the fourth to sixth dielectric layers in the first main body shown in FIGS. 2 to 4. FIG. [Figure 7] 5 is an explanatory view showing the pattern-forming surfaces of the seventh to fifteenth dielectric layers in the first main body shown in FIGS. 2 to 4. FIG. [Figure 8] 5 is an explanatory diagram showing the pattern-forming surfaces of the 16th to 18th dielectric layers in the first main body shown in FIGS. 2 to 4. FIG. [Figure 9] 5 is an explanatory view showing an electrode formation surface of the 18th dielectric layer in the first main body shown in FIGS. 2 to 4. FIG. [Figure 10] FIG. 2 is a perspective view showing the inside of a first main body according to an embodiment of the present invention. [Figure 11] FIG. 2 is a plan view showing a part of the inside of a first main body according to the embodiment of the present invention. [Figure 12] FIG. 10 is a characteristic diagram showing the pass attenuation characteristics of the first to third models. [Figure 13] 13 is a characteristic diagram showing an enlarged portion of the pass attenuation characteristic shown in FIG. 12. FIG. [Figure 14] 13 is a characteristic diagram showing an enlarged portion of the pass attenuation characteristic shown in FIG. 12. FIG. [Figure 15] FIG. 10 is a perspective view showing a first modified example of first and second inductor conductors in one embodiment of the present invention. [Figure 16] FIG. 10 is a perspective view showing a second modified example of the first and second inductor conductors in the embodiment of the present invention. [Figure 17] FIG. 10 is a perspective view showing a third modified example of the first and second inductor conductors in the embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. First, with reference to FIG. 1, a schematic configuration of a filter 1 according to an embodiment of the present invention will be described. The filter 1 according to this embodiment includes a first input / output port 2, a second input / output port 3, and a filter circuit 10 provided between the first input / output port 2 and the second input / output port 3 in terms of the circuit configuration. In this embodiment, the filter circuit 10 is a high-pass filter. Note that in this application, the expression "in terms of the circuit configuration" is used to refer to the arrangement on a circuit diagram, rather than the arrangement in a physical configuration.

[0012] Each of the first and second input / output ports 2 and 3 is a signal port for inputting or outputting a signal. That is, when a signal is input to the first input / output port 2, the signal is output from the second input / output port 3. When a signal is input to the second input / output port 3, the signal is output from the first input / output port 2.

[0013] The filter 1 further includes a first path 5 connecting the first input / output port 2 and the filter circuit 10, a second path 6 connecting the second input / output port 3 and the filter circuit 10, a first low-pass filter 20 provided on the first path 5, and a second low-pass filter 30 provided on the second path 6. The filter 1 is a band-pass filter configured with the filter circuit 10, which is a high-pass filter, and the first and second low-pass filters 20 and 30. In this embodiment in particular, the filter circuit 10 and the first and second low-pass filters 20 and 30 are connected in series from the first input / output port 2 to the second input / output port 3 in the order of the first low-pass filter 20, the filter circuit 10 (high-pass filter), and the second low-pass filter 30. The filter 1 is configured to selectively pass signals of frequencies within a predetermined pass band.

[0014] The filter 1 further includes a capacitor C1 provided in the first path 5 and a capacitor C4 provided in the second path 6. In terms of the circuit configuration, the capacitor C1 is provided between the first input / output port 2 and the first low-pass filter 20. In terms of the circuit configuration, the capacitor C4 is provided between the second low-pass filter 30 and the second input / output port 3.

[0015] Next, an example of the circuit configuration of each of the filter circuit 10, the first low-pass filter 20, and the second low-pass filter 30 will be described with reference to FIG. 1. First, the circuit configuration of the filter circuit 10 will be described. The filter circuit 10 includes inductors L11, L12, L13, and L14, and capacitors C2, C3, and C11. Each of the inductors L11 to L14 has a first end and a second end located opposite each other. Hereinafter, the first end and the second end of the inductor L11 will be represented by reference characters L11a and L11b, respectively; the first end and the second end of the inductor L12 will be represented by reference characters L12a and L12b, respectively; the first end and the second end of the inductor L13 will be represented by reference characters L13a and L13b, respectively; and the first end and the second end of the inductor L14 will be represented by reference characters L14a and L14b, respectively.

[0016] A first end L11a of the inductor L11 and a first end L12a of the inductor L12 are connected to each other. A second end L11b of the inductor L11 is connected to one end of the capacitor C2. A second end L12b of the inductor L12 is connected to one end of the capacitor C11.

[0017] A first end L13a of the inductor L13 and a first end L14a of the inductor L14 are connected to each other. A second end L13b of the inductor L13 is connected to the other end of the capacitor C11. A second end L14b of the inductor L14 is connected to one end of the capacitor C3.

[0018] Filter circuit 10 further includes acoustic wave elements 31 and 32 and an inductor L15. Each of acoustic wave elements 31 and 32 may be, for example, a bulk acoustic wave element or a surface acoustic wave element. One end of acoustic wave element 31 is connected to a first end L11a of inductor L11 and a first end L12a of inductor L12. One end of acoustic wave element 32 is connected to a first end L13a of inductor L13 and a first end L14a of inductor L14. The other ends of acoustic wave elements 31 and 32 are connected to one end of inductor L15. The other end of inductor L15 is connected to ground.

[0019] In the circuit configuration, inductor L11 is provided between the first input / output port 2 and the acoustic wave element 31. Inductor L12 is provided between the second input / output port 3 and the acoustic wave element 31. Inductor L13 is provided between the first input / output port 2 and the acoustic wave element 32. Inductor L14 is provided between the second input / output port 3 and the acoustic wave element 32.

[0020] Each of acoustic wave elements 31 and 32 is electrically connected to ground via inductor L15. In this application, the expression "electrically connected" includes electrical connection via a metal conductor (including an inductor), but does not include connection via a capacitor. Because capacitors C1 and C2 are interposed between acoustic wave element 31 and first input / output port 2, acoustic wave element 31 is not electrically connected to first input / output port 2. Furthermore, because capacitors C3, C4, and C11 are interposed between acoustic wave element 31 and second input / output port 3, acoustic wave element 31 is not electrically connected to second input / output port 3. Furthermore, because capacitors C1, C2, and C11 are interposed between acoustic wave element 32 and first input / output port 2, acoustic wave element 32 is not electrically connected to first input / output port 2. Furthermore, since capacitors C3 and C4 are interposed between acoustic wave element 32 and second input / output port 3, acoustic wave element 32 is not electrically connected to second input / output port 3.

[0021] Inductors L11 to L15, capacitors C2, C3, C11, and acoustic wave elements 31 and 32 are configured to form a high-pass filter.

[0022] Next, the circuit configuration of the first low-pass filter 20 will be described. The first low-pass filter 20 includes an inductor L21 and capacitors C21 and C22. One end of the inductor L21 is connected to the capacitor C1. The other end of the inductor L21 is connected to the other end of the capacitor C2.

[0023] The capacitor C21 is connected in parallel to the inductor L21. One end of the capacitor C22 is connected to the other end of the inductor L21. The other end of the capacitor C22 is connected to ground.

[0024] Next, the circuit configuration of the second low-pass filter 30 will be described. The second low-pass filter 30 includes an inductor L31 and capacitors C31 and C32. One end of the inductor L31 is connected to the other end of the capacitor C3. The other end of the inductor L31 is connected to the capacitor C4.

[0025] The capacitor C31 is connected in parallel to the inductor L31. One end of the capacitor C32 is connected to one end of the inductor L31. The other end of the capacitor C32 is connected to ground.

[0026] Next, the connection relationship between the capacitors C1 and C4 will be described. One end of the capacitor C1 is connected to the first input / output port 2. The other end of the capacitor C1 is connected to one end of the inductor L21. One end of the capacitor C4 is connected to the other end of the inductor L31. The other end of the capacitor C4 is connected to the second input / output port 3.

[0027] Next, other configurations of the filter 1 will be described with reference to Figures 2 to 4. Figure 2 is a perspective view showing the filter 1. Figures 3 and 4 are perspective views showing the first main body of the filter 1.

[0028] The filter 1 according to this embodiment includes a first body 50 and a second body 80 mounted on the first body 50. The first body 50 is formed of a laminate including a plurality of stacked dielectric layers and a plurality of conductors (a plurality of conductor layers and a plurality of through holes). Each of the plurality of dielectric layers is formed of a dielectric material. For example, low-temperature co-fired ceramics (LTCC) is used as the dielectric material.

[0029] First body 50 includes at least one first element. Second body 80 includes at least one second element. Filter 1 includes a circuit including at least one first element and at least one second element. In the present embodiment, first body 50 includes inductors L11 to L15 and capacitor C11 shown in FIG. 1 as at least one first element. Second body 80 includes acoustic wave elements 31 and 32 shown in FIG. 1 as at least one second element. Filter 1 includes filter circuit 10 as the above circuit, including inductors L11 to L15, capacitor C11, and acoustic wave elements 31 and 32.

[0030] First body 50 further includes inductors L21 and L31 and capacitors C1 to C4, C21, C22, C31, and C32 shown in Fig. 1. Inductors L11 to L15, L21, and L31 and capacitors C1 to C4, C11, C21, C22, C31, and C32 are provided inside first body 50, which is a laminate, and are configured using multiple dielectric layers and multiple conductors. Acoustic wave elements 31 and 32 are mounted on first body 50, which is a laminate.

[0031] The first body 50 has a first surface 50A and a second surface 50B located at both ends in the stacking direction T of the multiple dielectric layers, and four side surfaces 50C to 50F connecting the first surface 50A and the second surface 50B. The side surfaces 50C and 50D face in opposite directions from each other, and the side surfaces 50E and 50F also face in opposite directions from each other. The side surfaces 50C to 50F are perpendicular to the first surface 50A and the second surface 50B.

[0032] Here, the X direction, Y direction, and Z direction are defined as shown in FIGS. 2 to 4. The X direction, Y direction, and Z direction are perpendicular to each other. In this embodiment, a direction parallel to the stacking direction T is defined as the Z direction. The direction opposite to the X direction is defined as the -X direction, the direction opposite to the Y direction is defined as the -Y direction, and the direction opposite to the Z direction is defined as the -Z direction. The expression "when viewed from a predetermined direction (for example, the Z direction)" means that the object is viewed from a position away in the predetermined direction or in a direction parallel to the predetermined direction.

[0033] As shown in Figures 2 to 4, the first surface 50A is located at the end of the first main body 50 in the Z direction. The first surface 50A is both the top surface of the first main body 50 and the mounting surface for mounting the second main body 80. The second surface 50B is located at the end of the first main body 50 in the -Z direction. The second surface 50B is also the bottom surface of the first main body 50. Figure 3 shows the first main body 50 as viewed from the first surface 50A side. Figure 4 shows the first main body 50 as viewed from the second surface 50B side.

[0034] The side surface 50C is located at the end of the first main body 50 in the -X direction. The side surface 50D is located at the end of the first main body 50 in the X direction. The side surface 50E is located at the end of the first main body 50 in the -Y direction. The side surface 50F is located at the end of the first main body 50 in the Y direction.

[0035] The first body 50 further includes a plurality of electrodes 111, 112, 113, 114, 115, 116, 117, 118, and 119 provided on the second surface 50B of the first body 50. The electrodes 111, 112, and 113 are arranged in this order in the X direction at positions closer to the side surface 50E than to the side surface 50F. The electrodes 115, 116, and 117 are arranged in this order in the -X direction at positions closer to the side surface 50F than to the side surface 50E.

[0036] Electrode 114 is disposed between electrode 113 and electrode 115. Electrode 118 is disposed between electrode 111 and electrode 117. Electrode 119 is disposed between electrode 112 and electrode 116. Electrode 119 is disposed approximately in the center of second surface 50B.

[0037] The electrode 114 corresponds to the first input / output port 2. The electrode 118 corresponds to the second input / output port 3. Therefore, the first and second input / output ports 2 and 3 are provided on the second surface 50B of the first body 50. Each of the electrodes 111, 112, 113, 115, 116, 117, and 119 is connected to ground.

[0038] The first body 50 further includes a plurality of electrodes 121, 122, 123, and 124 provided on the first surface 50A of the first body 50. The electrodes 121 and 122 are arranged in this order in the -X direction at positions closer to the side surface 50F than to the side surface 50E. The electrodes 123 and 124 are arranged in this order in the -X direction at positions further ahead of the electrodes 121 and 122 in the Y direction.

[0039] The second body 80 further includes four electrodes 81, 82, 83, and 84. When the second body 80 is mounted on the first body 50, the four electrodes 81 to 84 face the electrodes 121 to 124 of the first body 50, respectively. The four electrodes 81 to 84 are physically connected to the electrodes 121 to 124 by, for example, solder bumps 7.

[0040] The filter 1 further includes a sealing portion (not shown) that seals the second main body 80. The sealing portion covers the periphery of the second main body 80 and at least a part of the first surface 50A of the first main body 50. The sealing portion may also cover the side surfaces 50C to 50F of the first main body 50. The sealing portion is made of, for example, resin.

[0041] Next, an example of the plurality of dielectric layers, the plurality of conductor layers, and the plurality of through holes that make up the first main body 50 will be described with reference to Figures 5(a) to 9. In this example, the first main body 50 includes 18 laminated dielectric layers. Hereinafter, these 18 dielectric layers will be referred to as the 1st to 18th dielectric layers, in order from the bottom up. The 1st to 18th dielectric layers will be denoted by reference numerals 51 to 68.

[0042] In Figures 5(a) to 8(c), multiple circles represent multiple through holes. Multiple through holes are formed in each of the dielectric layers 51 to 68. The multiple through holes are formed by filling holes for the through holes with conductive paste. Each of the multiple through holes is connected to an electrode, a conductive layer, or another through hole.

[0043] 5(a) to 8(c), specific through holes among the plurality of through holes are assigned reference numerals. The connection relationship between each of the specific through holes and electrodes, conductor layers, or other through holes is explained with reference to the state in which the first to eighteenth dielectric layers 51 to 68 are stacked.

[0044] FIG. 5(a) shows the pattern-formed surface of the first dielectric layer 51. Electrodes 111 to 119 are formed on the pattern-formed surface of the dielectric layer 51. In FIG. 5(a), the through-hole labeled 51T7 is connected to the electrode 116. In the following description, the through-hole labeled 51T7 will be simply referred to as the through-hole 51T7. Furthermore, through-holes labeled with other symbols than the through-hole 51T7 will also be referred to in the same manner as the through-hole 51T7.

[0045] 5(b) shows the pattern-formed surface of the second dielectric layer 52. A conductor layer 521 is formed on the pattern-formed surface of the dielectric layer 52. The through-hole 51T7 and the through-holes 52T7a and 52T7b shown in FIG.

[0046] Fig. 5(c) shows the pattern formation surface of the third dielectric layer 53. Conductor layers 531 and 532 are formed on the pattern formation surface of the dielectric layer 53. The through holes 52T7a and 52T7b are connected to the through holes 53T7a and 53T7b shown in Fig. 5(c), respectively.

[0047] Fig. 6(a) shows the pattern formation surface of the fourth dielectric layer 54. Conductor layers 541, 542, 543, and 544 are formed on the pattern formation surface of the dielectric layer 54. The through holes 54T1a and 54T2a shown in Fig. 6(a) are connected to the conductor layers 541 and 544, respectively. The through holes 53T7a and 53T7b are connected to the through holes 54T7a and 54T7b shown in Fig. 6(a), respectively.

[0048] Fig. 6(b) shows the pattern formation surface of the fifth dielectric layer 55. Conductor layers 551, 552, 553, and 554 are formed on the pattern formation surface of the dielectric layer 55. Conductor layer 551 is connected to conductor layer 552. Conductor layer 553 is connected to conductor layer 554. In Fig. 6(b), the boundary between conductor layer 551 and conductor layer 552 and the boundary between conductor layer 553 and conductor layer 554 are indicated by dotted lines.

[0049] The through holes 55T1b and 55T2b shown in Fig. 6(b) are respectively connected to the conductor layers 552 and 554. The through holes 54T1a, 54T2a, 54T7a, and 54T7b are respectively connected to the through holes 55T1a, 55T2a, 55T7a, and 55T7b shown in Fig. 6(b).

[0050] FIG. 6(c) shows the pattern-formed surface of the sixth dielectric layer 56. Conductor layers 561, 562, 563, and 564 are formed on the pattern-formed surface of the dielectric layer 56. The through-hole 55T1a and the through-hole 56T1a shown in FIG. 6(c) are connected to the conductor layer 562. The through-hole 55T2a and the through-hole 56T2a shown in FIG. 6(c) are connected to the conductor layer 564. The through-holes 55T1b, 55T2b, 55T7a, and 55T7b are connected to the through-holes 56T1b, 56T2b, 56T7a, and 56T7b shown in FIG. 6(c), respectively.

[0051] 7(a) shows the pattern-forming surfaces of the seventh to thirteenth dielectric layers 57 to 63. Through holes 56T1a, 56T1b, 56T2a, 56T2b, 56T7a, and 56T7b are respectively connected to through holes 57T1a, 57T1b, 57T2a, 57T2b, 57T7a, and 57T7b formed in the dielectric layer 57. Furthermore, in the dielectric layers 57 to 63, adjacent through holes with the same reference numerals are connected to each other.

[0052] 7(b) shows the pattern formation surface of the 14th dielectric layer 64. A conductor layer 641 is formed on the pattern formation surface of the dielectric layer 64. Through holes 57T1a, 57T1b, 57T2a, 57T2b, 57T7a, and 57T7b formed in the dielectric layer 63 are connected to through holes 64T1a, 64T1b, 64T2a, 64T2b, 64T7a, and 64T7b shown in FIG. 7(b), respectively.

[0053] FIG. 7(c) shows the pattern formation surface of the 15th dielectric layer 65. Conductor layers 651, 652, 653, and 654 for inductors are formed on the pattern formation surface of the dielectric layer 65. The conductor layer 651 has a first end and a second end located opposite each other in the longitudinal direction of the conductor layer 651. The through-hole 65T3 shown in FIG. 7(c) is connected to a portion of the conductor layer 651 near the first end. The conductor layer 652 has a first end and a second end located opposite each other in the longitudinal direction of the conductor layer 652. The through-hole 65T4 shown in FIG. 7(c) is connected to a portion of the conductor layer 652 near the first end.

[0054] The conductor layer 653 has a first end and a second end located opposite to each other in the longitudinal direction of the conductor layer 653. The through-hole 65T5 shown in FIG. 7(c) is connected to a portion of the conductor layer 653 near the first end. The conductor layer 654 has a first end and a second end located opposite to each other in the longitudinal direction of the conductor layer 654. The through-hole 65T6 shown in FIG. 7(c) is connected to a portion of the conductor layer 654 near the first end.

[0055] The through holes 64T1a, 64T1b, 64T2a, 64T2b, 64T7a, and 64T7b are connected to the through holes 65T1a, 65T1b, 65T2a, 65T2b, 65T7a, and 65T7b shown in FIG. 7(c), respectively.

[0056] FIG. 8(a) shows the pattern formation surface of the 16th dielectric layer 66. Inductor conductor layers 661, 662, 663, and 664 are formed on the pattern formation surface of the dielectric layer 66. The conductor layer 661 has a first end and a second end located opposite each other in the longitudinal direction of the conductor layer 661. The through-hole 66T3 shown in FIG. 8(a) is connected to a portion of the conductor layer 661 near the first end. The through-hole 65T3 is connected to a portion of the conductor layer 661 near the second end. The conductor layer 662 has a first end and a second end located opposite each other in the longitudinal direction of the conductor layer 662. The through-hole 66T4 shown in FIG. 8(a) is connected to a portion of the conductor layer 662 near the first end. The through-hole 65T4 is connected to a portion of the conductor layer 662 near the second end.

[0057] The conductor layer 663 has a first end and a second end located opposite to each other in the longitudinal direction of the conductor layer 663. The through-hole 66T5 shown in FIG. 8(a) is connected to a portion of the conductor layer 663 near the first end. The through-hole 65T5 is connected to a portion of the conductor layer 663 near the second end. The conductor layer 664 has a first end and a second end located opposite to each other in the longitudinal direction of the conductor layer 664. The through-hole 66T6 shown in FIG. 8(a) is connected to a portion of the conductor layer 664 near the first end. The through-hole 65T6 is connected to a portion of the conductor layer 664 near the second end.

[0058] The through holes 65T1a, 65T1b, 65T2a, 65T2b, 65T7a, and 65T7b are connected to the through holes 66T1a, 66T1b, 66T2a, 66T2b, 66T7a, and 66T7b shown in FIG. 8(a), respectively.

[0059] 8(b) shows the pattern formation surface of the 17th dielectric layer 67. On the pattern formation surface of the dielectric layer 67, conductor layers 671, 672, 673, 674, 677, and 678 for inductors and conductor layers 675 and 676 are formed.

[0060] The conductor layer 671 has a first end and a second end located opposite each other in the longitudinal direction of the conductor layer 671. The conductor layer 672 has a first end and a second end located opposite each other in the longitudinal direction of the conductor layer 672. The first end of the conductor layer 671 and the first end of the conductor layer 672 are connected to the conductor layer 675. In FIG. 8(b), the boundary between the conductor layer 671 and the conductor layer 675 and the boundary between the conductor layer 672 and the conductor layer 675 are indicated by dotted lines. The through hole 67T3 shown in FIG. 8(b) is connected to the conductor layer 675.

[0061] The through hole 66T3 is connected to a portion of the conductor layer 671 near the second end. The through hole 66T4 is connected to a portion of the conductor layer 672 near the second end.

[0062] The conductor layer 673 has a first end and a second end located opposite each other in the longitudinal direction of the conductor layer 673. The conductor layer 674 has a first end and a second end located opposite each other in the longitudinal direction of the conductor layer 674. The first end of the conductor layer 673 and the first end of the conductor layer 674 are connected to the conductor layer 676. In FIG. 8(b), the boundary between the conductor layer 673 and the conductor layer 676 and the boundary between the conductor layer 674 and the conductor layer 676 are indicated by dotted lines. The through hole 67T4 shown in FIG. 8(b) is connected to the conductor layer 676.

[0063] The through hole 66T5 is connected to a portion of the conductor layer 673 near the second end. The through hole 66T6 is connected to a portion of the conductor layer 674 near the second end.

[0064] The conductor layer 677 has a first end and a second end located on opposite sides in the longitudinal direction of the conductor layer 677. The through-hole 66T1a is connected to a portion of the conductor layer 677 near the first end. The through-hole 66T1b is connected to a portion of the conductor layer 677 near the second end.

[0065] The conductor layer 678 has a first end and a second end located opposite each other in the longitudinal direction of the conductor layer 678. The through-hole 66T2a is connected to a portion of the conductor layer 678 near the first end. The through-hole 66T2b is connected to a portion of the conductor layer 678 near the second end.

[0066] The through holes 66T7a and 66T7b are connected to the through holes 67T7a and 67T7b shown in FIG. 8(b), respectively.

[0067] Fig. 8(c) shows the patterned surface of the 18th dielectric layer 68. The through holes 67T3, 67T4, 67T7a, and 67T7b are connected to the through holes 68T3, 68T4, 68T7a, and 68T7b shown in Fig. 8(c), respectively.

[0068] 9 shows the surface of the 18th dielectric layer 68 opposite to the pattern-forming surface. Hereinafter, the surface of the dielectric layer 68 opposite to the pattern-forming surface will be referred to as the electrode-forming surface of the dielectric layer 68. Electrodes 121, 122, 123, and 124 are formed on the electrode-forming surface of the dielectric layer 68. Through holes 68T3, 68T4, 68T7a, and 68T7b are connected to the electrodes 121, 122, 123, and 124, respectively.

[0069] The first body 50 is constructed by stacking the first to eighteenth dielectric layers 51 to 68 so that the pattern-forming surface of the first dielectric layer 51 becomes the second surface 50B of the first body 50, and the electrode-forming surface of the eighteenth dielectric layer 68 becomes the first surface 50A of the first body 50.

[0070] Each of the multiple through holes shown in Figures 5(a) to 8(c) is connected to a conductor layer that overlaps it in the stacking direction T when the 1st to 18th dielectric layers 51 to 68 are stacked, or to another through hole that overlaps it in the stacking direction T. Furthermore, of the multiple through holes shown in Figures 5(a) to 8(c), a through hole located within an electrode or a conductor layer is connected to that electrode or that conductor layer.

[0071] Fig. 10 shows the inside of the first main body 50, which is configured by laminating the 1st to 18th dielectric layers 51 to 68. As shown in Fig. 10, inside the first main body 50, the multiple conductor layers and multiple through holes shown in Figs. 5(a) to 9 are laminated.

[0072] The following describes the correspondence between the circuit components of the filter 1 shown in FIG. 1 and the internal components of the first main body 50 shown in FIGS. 5(a) to 9.

[0073] First, a description will be given of the filter circuit 10. The inductor L11 is formed by inductor conductor layers 651, 661, and 671 and through holes 65T3 and 66T3. The inductor L12 is formed by inductor conductor layers 652, 662, and 672 and through holes 65T4 and 66T4.

[0074] The inductor L13 is formed by inductor conductor layers 653, 663, and 673 and through holes 65T5 and 66T5. The inductor L14 is formed by inductor conductor layers 654, 664, and 674 and through holes 65T6 and 66T6.

[0075] Inductor L15 is formed by through-hole 51T7. Capacitor C2 is formed by conductor layers 551 and 561 and a dielectric layer 55 between these conductor layers. Capacitor C3 is formed by conductor layers 553 and 563 and a dielectric layer 55 between these conductor layers. Capacitor C11 is formed by conductor layers 641, 652, and 653 and a dielectric layer 64 between these conductor layers.

[0076] Next, we will explain the first low-pass filter 20. The inductor L21 is composed of an inductor conductor layer 677, a conductor layer 562, and through holes 54T1a, 55T1a, 55T1b, 56T1a, 56T1b, 57T1a, 57T1b, 64T1a, 64T1b, 65T1a, 65T1b, 66T1a, and 66T1b.

[0077] Capacitor C21 is composed of conductor layers 541 and 551 and a dielectric layer 54 between these conductor layers. Capacitor C22 is composed of conductor layers 542 and 552 and a dielectric layer 54 between these conductor layers.

[0078] Next, we will explain the second low-pass filter 30. The inductor L31 is composed of an inductor conductor layer 678, a conductor layer 564, and through holes 54T2a, 55T2a, 55T2b, 56T2a, 56T2b, 57T2a, 57T2b, 64T2a, 64T2b, 65T2a, 65T2b, 66T2a, and 66T2b.

[0079] Capacitor C31 is composed of conductor layers 544 and 553 and a dielectric layer 54 between these conductor layers. Capacitor C32 is composed of conductor layers 543 and 554 and a dielectric layer 54 between these conductor layers.

[0080] Next, capacitors C1 and C4 will be described. Capacitor C1 is composed of conductor layers 531 and 541 and a dielectric layer 53 between these conductor layers. Capacitor C4 is composed of conductor layers 532 and 544 and a dielectric layer 53 between these conductor layers.

[0081] Next, structural features of the filter 1 according to this embodiment will be described with reference to FIGS. 2 to 11. FIG. 11 is a plan view showing a portion of the interior of the first body 50. First, structural features of each of the inductors L11 to L14 of the filter circuit 10 will be described. As shown in FIG. 10, the inductors L11 and L12 are aligned in a direction perpendicular to the stacking direction T. In this embodiment, in particular, the inductors L11 and L12 are aligned in this order in the -Y direction. Furthermore, the inductors L13 and L14 are aligned in a direction perpendicular to the stacking direction T. In this embodiment, in particular, the inductors L13 and L14 are aligned in this order in the Y direction.

[0082] The inductor L11 includes a first inductor conductor 110. The first inductor conductor 110 is a single continuous conductor formed by the conductor layers 651, 661, and 671 and the through holes 65T3 and 66T3. The first inductor conductor 110 is wound around an axis extending in a direction parallel to the lamination direction T.

[0083] The inductor L12 includes a second inductor conductor 120. The second inductor conductor 120 is a single continuous conductor formed by the conductor layers 652, 662, and 672 and the through holes 65T4 and 66T4. The second inductor conductor 120 is wound around an axis extending in a direction parallel to the lamination direction T.

[0084] The inductor L13 includes a third inductor conductor 130. The third inductor conductor 130 is a single continuous conductor formed by the conductor layers 653, 663, and 673 and the through holes 65T5 and 66T5. The third inductor conductor 130 is wound around an axis extending in a direction parallel to the lamination direction T.

[0085] The inductor L14 includes a fourth inductor conductor 140. The fourth inductor conductor 140 is a single continuous conductor formed by the conductor layers 654, 664, and 674 and the through holes 65T6 and 66T6. The fourth inductor conductor 140 is wound around an axis extending in a direction parallel to the stacking direction T.

[0086] 11 shows a portion of each of the first to fourth inductor conductors 110, 120, 130, and 140. The first inductor conductor 110 has a first end 110a corresponding to the first end L11a of the inductor L11 and a second end corresponding to the second end L11b of the inductor L11. The first end 110a is specifically a first end of the conductor layer 671 and is located at the boundary between the conductor layer 671 and the conductor layer 675. The second end is specifically a portion near the second end of the conductor layer 651 and connected to a through hole formed in the dielectric layer 64.

[0087] A first end 110a of the first inductor conductor 110 is connected to the acoustic wave element 31 (see FIG. 1) via the conductor layer 675, through holes 67T3 and 68T3, and electrodes 121 and 81. A second end of the first inductor conductor 110 is connected to the conductor layer 561 that constitutes the capacitor C2 via a plurality of through holes.

[0088] The second inductor conductor 120 has a first end 120a corresponding to the first end L12a of the inductor L12 and a second end corresponding to the second end L12b of the inductor L12. The first end 120a is specifically a first end of the conductor layer 672 and is located at the boundary between the conductor layer 672 and the conductor layer 675. The second end is specifically a portion near the second end of the conductor layer 652 and facing the conductor layer 641 formed on the pattern formation surface of the dielectric layer 64.

[0089] First end 120a of second inductor conductor 120 is connected to acoustic wave element 31 (see FIG. 1) via conductor layer 675, through holes 67T3 and 68T3, and electrodes 121 and 81.

[0090] The third inductor conductor 130 has a first end 130a corresponding to the first end L13a of the inductor L13 and a second end corresponding to the second end L13b of the inductor L13. The first end 130a is specifically a first end of the conductor layer 673 and is located at the boundary between the conductor layer 673 and the conductor layer 676. The second end is specifically a portion near the second end of the conductor layer 653 and facing the conductor layer 641 formed on the pattern formation surface of the dielectric layer 64.

[0091] A first end 130a of the third inductor conductor 130 is connected to the acoustic wave element 32 (see FIG. 1) via the conductor layer 676, through holes 67T4 and 68T4, and electrodes 122 and 82.

[0092] The fourth inductor conductor 140 has a first end 140a corresponding to the first end L14a of the inductor L14 and a second end corresponding to the second end L14b of the inductor L14. The first end 140a is specifically the first end of the conductor layer 674 and is located at the boundary between the conductor layer 674 and the conductor layer 676. The second end is specifically a portion near the second end of the conductor layer 654 and connected to a through hole formed in the dielectric layer 64.

[0093] A first end 140a of the fourth inductor conductor 140 is connected to the acoustic wave element 32 (see FIG. 1) via the conductor layer 676, through holes 67T4 and 68T4, and electrodes 122 and 82. A second end of the fourth inductor conductor 140 is connected to the conductor layer 563 that constitutes the capacitor C3 via multiple through holes.

[0094] Next, we will explain the features of the first inductor conductor 110 and the second inductor conductor 120. When viewed from the Z direction, the first inductor conductor 110 extends clockwise in Fig. 11 from the first end 110a to the second end. When viewed from the Z direction, the second inductor conductor 120 extends clockwise in Fig. 11 from the first end 120a to the second end.

[0095] The first inductor conductor 110 is part of the conductor layer 671 and includes a first portion 110A that is elongated in one direction. The second inductor conductor 120 is part of the conductor layer 672 and includes a second portion 120A that is elongated in one direction and is disposed adjacent to the first portion 110A with a predetermined gap between them. The first portion 110A and the second portion 120A may extend in the same direction.

[0096] The first portion 110A and the second portion 120A may have one or more pairs. FIG. 11 shows an example of a pair of the first portion 110A and the second portion 120A. In the example shown in FIG. 11, the first portion 110A and the second portion 120A extend in a direction parallel to the X direction. Alternatively, one of the first portion 110A and the second portion 120A may extend in a direction tilted at a predetermined angle from the direction in which the other of the first portion 110A and the second portion 120A extends.

[0097] Here, consider the direction in the first portion 110A when moving along the first inductor conductor 110 from the first end L11a to the second end L11b of the inductor L11 (hereinafter referred to as the first direction). The first direction is the same as the direction in the first portion 110A when moving along the first inductor conductor 110 from the first end 110a to the second end of the first inductor conductor 110. As described above, the first inductor conductor 110 extends clockwise in FIG. 11 from the first end 110a to the second end when viewed from the Z direction. In the example shown in FIG. 11, the first direction is the −X direction. In FIG. 11, the arrow labeled D1 indicates the first direction.

[0098] Next, consider the direction in the second portion 120A when traveling along the second inductor conductor 120 from the first end L12a to the second end L12b of the inductor L12 (hereinafter referred to as the second direction). The second direction is the same as the direction in the second portion 120A when traveling along the second inductor conductor 120 from the first end 120a to the second end of the second inductor conductor 120. As described above, the second inductor conductor 120 extends clockwise in FIG. 11 from the first end 120a to the second end when viewed from the Z direction. In the example shown in FIG. 11, the second direction is the X direction. In FIG. 11, the arrow labeled D2 indicates the second direction.

[0099] As shown in FIG. 11, the first direction D1 and the second direction D2 are opposite to each other.

[0100] Next, we will explain the features of the third inductor conductor 130 and the fourth inductor conductor 140. When viewed from the Z direction, the third inductor conductor 130 extends counterclockwise in Fig. 11 from the first end 130a to the second end. When viewed from the Z direction, the fourth inductor conductor 140 extends counterclockwise in Fig. 11 from the first end 140a to the second end.

[0101] The third inductor conductor 130 is part of the conductor layer 673 and includes a third portion 130A elongated in one direction. The fourth inductor conductor 140 is part of the conductor layer 674 and includes a fourth portion 140A elongated in one direction and disposed adjacent to the third portion 130A with a predetermined gap therebetween. The third portion 130A and the fourth portion 140A may extend in the same direction. In the example shown in FIG. 11 , the third portion 130A and the fourth portion 140A extend in a direction parallel to the X direction. Alternatively, one of the third portion 130A and the fourth portion 140A may extend in a direction inclined at a predetermined angle from the direction in which the other of the third portion 130A and the fourth portion 140A extends.

[0102] Here, consider the direction in the third portion 130A when moving from the first end L13a to the second end L13b of the inductor L13 along the third inductor conductor 130 (hereinafter referred to as the third direction). The third direction is the same as the direction in the third portion 130A when moving from the first end 130a to the second end of the third inductor conductor 130 along the third inductor conductor 130. As described above, the third inductor conductor 130 extends counterclockwise in FIG. 11 from the first end 130a to the second end when viewed from the Z direction. In the example shown in FIG. 11, the third direction is the −X direction. In FIG. 11, the arrow labeled D3 indicates the third direction.

[0103] Next, consider the direction in the fourth portion 140A when moving from the first end L14a to the second end L14b of the inductor L14 along the fourth inductor conductor 140 (hereinafter referred to as the fourth direction). The fourth direction is the same as the direction in the fourth portion 140A when moving from the first end 140a to the second end of the fourth inductor conductor 140 along the fourth inductor conductor 140. As described above, the fourth inductor conductor 140 extends counterclockwise in FIG. 11 from the first end 140a to the second end when viewed from the Z direction. In the example shown in FIG. 11, the fourth direction is the X direction. In FIG. 11, an arrow labeled D4 indicates the fourth direction.

[0104] As shown in FIG. 11, the third direction D3 and the fourth direction D4 are opposite to each other.

[0105] Next, features of acoustic wave elements 31 and 32 will be described. One end of acoustic wave element 31 is connected to first end 110a of first inductor conductor 110 via conductor layer 675, through holes 67T3 and 68T3, and electrodes 121 and 81, and is also connected to first end 120a of second inductor conductor 120 via conductor layer 675, through holes 67T3 and 68T3, and electrodes 121 and 81. The other end of acoustic wave element 31 is connected to through hole 51T7 constituting inductor L15 via conductor layer 521, through holes 52T7a, 53T7a, 54T7a, 55T7a, 56T7a, 57T7a, 64T7a, 65T7a, 66T7a, 67T7a, and 68T7a, and electrodes 123 and 83.

[0106] Here, a columnar structure formed by connecting multiple through holes in series is referred to as a columnar conductor. The columnar conductor extends in a direction parallel to the stacking direction T. Columnar conductor T7a shown in FIG. 10 is formed by through holes 52T7a, 53T7a, 54T7a, 55T7a, 56T7a, 57T7a, 64T7a, 65T7a, 66T7a, 67T7a, and 68T7a. The other end of acoustic wave element 31 is connected to through hole 51T7, which constitutes inductor L15, via conductor layer 521, columnar conductor T7a, and electrodes 123 and 83.

[0107] One end of the acoustic wave element 32 is connected to a first end 130a of the third inductor conductor 130 via the conductor layer 676, through holes 67T4 and 68T4, and electrodes 122 and 82, and is also connected to a first end 140a of the fourth inductor conductor 140 via the conductor layer 676, through holes 67T4 and 68T4, and electrodes 122 and 82. The columnar conductor T7b shown in FIG. 10 is composed of through holes 52T7b, 53T7b, 54T7b, 55T7b, 56T7b, 57T7b, 64T7b, 65T7b, 66T7b, 67T7b, and 68T7b. The other end of the acoustic wave element 32 is connected to the through hole 51T7 constituting the inductor L15 via the conductor layer 521, the columnar conductor T7b, and electrodes 124 and 84.

[0108] Next, the operation and effect of the filter 1 according to this embodiment will be described. In this embodiment, the shapes and arrangement of the first inductor conductor 110 and the second inductor conductor 120 are defined so that the first direction D1 in the first portion 110A and the second direction D2 in the second portion 120A are opposite to each other, and the shapes and arrangement of the third inductor conductor 130 and the fourth inductor conductor 140 are defined so that the third direction D3 in the third portion 130A and the fourth direction D4 in the fourth portion 140A are opposite to each other. As a result, this embodiment can achieve a sufficient bandwidth while achieving a bandpass attenuation characteristic that changes sharply in a frequency range close to the cutoff frequency. This effect will be described below with reference to simulation results.

[0109] The simulation uses first to third models of the filter circuit. The first model is a model of the filter circuit 10 in this embodiment. In the first model, the magnetic coupling coefficient between inductors L11 and L12 and the magnetic coupling coefficient between inductors L13 and L14 are both negative values.

[0110] The second model is a model of the filter circuit of the first comparative example. The circuit configuration of the filter circuit of the first comparative example is the same as the circuit configuration of the filter circuit 10 of the present embodiment. In the filter circuit of the first comparative example, the magnetic coupling coefficient between inductors L11 and L12 and the magnetic coupling coefficient between inductors L13 and L14 are both zero.

[0111] The third model is a model of a filter circuit of a second comparative example. The circuit configuration of the filter circuit of the second comparative example is the same as the circuit configuration of the filter circuit 10 of the present embodiment. In the filter circuit of the second comparative example, the winding direction of one of the first and second inductor conductors 110, 120 and the winding direction of one of the third and fourth inductor conductors 130, 140 are different from those of the filter circuit 10 of the present embodiment. In the second comparative example, the winding direction of one of the first and second inductor conductors 110, 120 from the first end to the second end is opposite to that of the filter circuit 10 of the present embodiment. Similarly, in the second comparative example, the winding direction of one of the third and fourth inductor conductors 130, 140 from the first end to the second end is opposite to that of the filter circuit 10 of the present embodiment.

[0112] In the second comparative example, the direction in the first portion 110A along the first inductor conductor 110 from the first end L11a to the second end L11b of the inductor L11 is the same as the direction in the second portion 120A along the second inductor conductor 120 from the first end L12a to the second end L12b of the inductor L12. Similarly, in the second comparative example, the direction in the third portion 130A along the third inductor conductor 130 from the first end L13a to the second end L13b of the inductor L13 is the same as the direction in the fourth portion 140A along the fourth inductor conductor 140 from the first end L14a to the second end L14b of the inductor L14.

[0113] In the filter circuit of the second comparative example, the magnetic coupling coefficient between the inductors L11 and L12 and the magnetic coupling coefficient between the inductors L13 and L14 are both positive values.

[0114] 12 to 14 are characteristic diagrams showing the pass attenuation characteristics of the first to third models obtained by simulation. FIG. 13 shows an enlarged view of the frequency region including the pass band. FIG. 14 shows an enlarged view of the frequency region near the cutoff frequency on the lower side of the pass band. In FIGS. 12 to 14, the horizontal axis represents frequency and the vertical axis represents attenuation. In addition, in FIGS. 12 to 14, reference numeral 91 represents the pass attenuation characteristics of the first model, reference numeral 92 represents the pass attenuation characteristics of the second model, and reference numeral 93 represents the third model.

[0115] As shown in Figures 12 and 13, it can be seen that the first model has a wider frequency range in which the absolute value of the attenuation is smaller than the second and third models. It can also be seen that the first model has a smaller absolute value of the attenuation in the passband, i.e., a smaller insertion loss, than the second and third models. As can be seen from these results, this embodiment can achieve a sufficient bandwidth. It can also be seen from Figures 12 and 13 that a sufficient bandwidth can be achieved by reducing the magnetic coupling coefficient.

[0116] 12 and 14, it can be seen that the attenuation of the first model changes more sharply in the frequency region near the cutoff frequency on the lower side of the passband than that of the second and third models. As can be seen from these results, according to this embodiment, it is possible to realize a pass attenuation characteristic that changes sharply in the frequency region near the cutoff frequency. Furthermore, it can be seen from FIGS. 12 and 14 that by reducing the magnetic coupling coefficient, it is possible to realize a pass attenuation characteristic that changes sharply in the frequency region near the cutoff frequency.

[0117] As described above, according to this embodiment, it is possible to realize a sufficient bandwidth while realizing a pass attenuation characteristic that changes sharply in the frequency range close to the cutoff frequency.

[0118] The shapes and arrangement of the first inductor conductor 110 and the second inductor conductor 120 are not limited to the example shown in Fig. 11. By defining the shapes and arrangement of the first inductor conductor 110 and the second inductor conductor 120 so that the magnetic coupling coefficient between the inductors L11 and L12 is negative, it is possible to achieve a sufficient bandwidth while realizing bandpass attenuation characteristics that change sharply in a frequency range close to the cutoff frequency. Similarly, the shapes and arrangement of the third inductor conductor 130 and the fourth inductor conductor 140 are not limited to the example shown in Fig. 11. By defining the shapes and arrangement of the third inductor conductor 130 and the fourth inductor conductor 140 so that the magnetic coupling coefficient between the inductors L13 and L14 is negative, it is possible to achieve a sufficient bandwidth while realizing bandpass attenuation characteristics that change sharply in a frequency range close to the cutoff frequency.

[0119] [Variations] Next, first to third modified examples of the first and second inductor conductors in this embodiment will be described. First, the first modified example of the first and second inductor conductors will be described with reference to Fig. 15. Fig. 15 is a perspective view showing the first modified example of the first and second inductor conductors.

[0120] In the first modification, the inductor L11 includes a first inductor conductor 210 instead of the first inductor conductor 110. The first inductor conductor 210 is a single continuous conductor formed by the conductor layer 41. The first inductor conductor 210 (conductor layer 41) is wound around an axis extending in a direction parallel to the stacking direction T.

[0121] The conductor layer 41 has a first end and a second end located on opposite sides in the longitudinal direction of the conductor layer 41. A through hole is connected to a portion of the conductor layer 41 near the first end and a portion of the conductor layer 41 near the second end, respectively.

[0122] The first inductor conductor 210 has a first end 210a corresponding to the first end L11a of the inductor L11 and a second end 210b corresponding to the second end L11b of the inductor L11. The first end 210a is specifically a portion near the first end of the conductor layer 41 and connected to a through-hole. The second end 210b is specifically a portion near the second end of the conductor layer 41 and connected to a through-hole.

[0123] Moreover, in the first modified example, the inductor L12 includes a second inductor conductor 220 instead of the second inductor conductor 120. The second inductor conductor 220 is a single continuous conductor formed by conductor layers 42. The second inductor conductor 220 (conductor layer 42) is wound around an axis extending in a direction parallel to the stacking direction T. Particularly in the first modified example, the first inductor conductor 210 (conductor layer 41) and the second inductor conductor 120 (conductor layer 42) are arranged to overlap each other when viewed from the Z direction, and are wound around the same axis.

[0124] The conductor layer 42 has a first end and a second end located opposite to each other in the longitudinal direction of the conductor layer 42. A through hole is connected to a portion of the conductor layer 42 near the first end and a portion of the conductor layer 42 near the second end, respectively.

[0125] The second inductor conductor 220 has a first end 220a corresponding to the first end L12a of the inductor L12 and a second end 220b corresponding to the second end L12b of the inductor L12. The first end 220a is specifically a portion near the first end of the conductor layer 42 and connected to a through-hole. The second end 220b is specifically a portion near the second end of the conductor layer 41 and connected to a through-hole.

[0126] The first end 210a of the first inductor conductor 210 and the first end 220a of the second inductor conductor 220 are each connected to the conductor layer 43 via a through hole. The conductor layer 43 may be provided, for example, between the conductor layer 41 and the conductor layer 42 in the stacking direction T. The first end 210a of the first inductor conductor 210 and the first end 220a of the second inductor conductor 220 are connected to the acoustic wave element 31 (see FIG. 1 ) via a plurality of through holes, the conductor layer 43, and a plurality of conductors (not shown).

[0127] When viewed from the Z direction, the first inductor conductor 210 extends counterclockwise in Fig. 15 from the first end 210a to the second end 210b. When viewed from the Z direction, the second inductor conductor 220 extends clockwise in Fig. 15 from the first end 220a to the second end 220b.

[0128] The first inductor conductor 210 is part of the conductor layer 41 and includes a first portion 210A that is elongated in one direction. The second inductor conductor 220 is part of the conductor layer 42 and includes a second portion 220A that is elongated in one direction and is disposed adjacent to the first portion 210A with a predetermined gap therebetween. In the example shown in FIG. 15, there are multiple pairs of the first portion 210A and the second portion 220A. In FIG. 15, one of the pairs of the first portion 210A and the second portion 220A is hatched for convenience.

[0129] Here, consider the direction (first direction) in the first portion 210A when traveling along the first inductor conductor 210 from the first end L11a to the second end L11b of the inductor L11. The first direction is the same as the direction in the first portion 210A when traveling along the first inductor conductor 210 from the first end 210a to the second end 210b. As described above, the first inductor conductor 210 extends counterclockwise in FIG. 15 from the first end 210a to the second end 210b when viewed from the Z direction. In the first portion 210A shown in FIG. 15, the first direction is the −X direction. In FIG. 15, the arrow labeled D1 indicates the first direction.

[0130] Next, consider the direction (second direction) in the second portion 220A when traveling along the second inductor conductor 220 from the first end L12a to the second end L12b of the inductor L12. The second direction is the same as the direction in the second portion 220A when traveling along the second inductor conductor 220 from the first end 220a to the second end 220b. As described above, the second inductor conductor 220 extends clockwise in FIG. 15 from the first end 220a to the second end 220b when viewed from the Z direction. In the second portion 220A shown in FIG. 15, the second direction is the X direction. In FIG. 15, the arrow labeled D2 indicates the second direction.

[0131] As shown in FIG. 15, the first direction D1 and the second direction D2 are opposite to each other.

[0132] When the conductor layer 43 for connecting to the acoustic wave element 31 is not connected to the conductor layers 41 and 42, the conductor layers 41 and 42 and the multiple through holes connected to the conductor layers 41 and 42 can form a single inductor. This single inductor is wound around an axis extending in a direction parallel to the stacking direction T. When viewed from the Z direction, the inductor conductors (the conductor layers 41 and 42 and the multiple through holes connected to the conductor layers 41 and 42) forming this single inductor extend in the clockwise direction in FIG. 15 from the second end of the conductor layer 41 to the second end of the conductor layer 42. When the conductor layer 43 for connecting to the acoustic wave element 31 is not connected, the single inductor is referred to as a single virtual inductor. In particular, in the first modification, the inductor L11 is formed by a part of the single virtual inductor, and the inductor L12 is formed by another part of the single virtual inductor.

[0133] In addition, in the first modification, it can be said that conductor layer 43 for connection to acoustic wave element 31 is connected midway through one virtual inductor.

[0134] Next, a second modified example of the first and second inductor conductors will be described with reference to Fig. 16. Fig. 16 is a perspective view showing the second modified example of the first and second inductor conductors.

[0135] In the second modification, the inductor L11 includes a first inductor conductor 310 instead of the first inductor conductor 110. The first inductor conductor 310 includes two columnar conductors T11a and T11b arranged at a predetermined interval, and a conductor layer 141 connecting the two columnar conductors T11a and T11b. The first inductor conductor 310 is wound around an axis extending in a direction perpendicular to the stacking direction T.

[0136] The first inductor conductor 310 has a first end 310a corresponding to the first end L11a of the inductor L11 and a second end 310b corresponding to the second end L11b of the inductor L11. The first end 310a is specifically an end of the columnar conductor T11a located on the opposite side to the conductor layer 141. The second end 310b is specifically an end of the columnar conductor T11b located on the opposite side to the conductor layer 141.

[0137] In the second modification, the inductor L12 includes a second inductor conductor 320 instead of the second inductor conductor 120. The second inductor conductor 320 includes two columnar conductors T12a and T12b arranged at a predetermined interval and a conductor layer 142 connecting the two columnar conductors T12a and T12b. The second inductor conductor 320 is wound around an axis extending in a direction perpendicular to the stacking direction T.

[0138] The second inductor conductor 320 has a first end 320a corresponding to the first end L12a of the inductor L12 and a second end 320b corresponding to the second end L12b of the inductor L12. The first end 320a is specifically an end of the columnar conductor T12a located on the opposite side to the conductor layer 142. The second end 320b is specifically an end of the columnar conductor T12b located on the opposite side to the conductor layer 142.

[0139] In particular, in the second modification, the first inductor conductor 310 and the second inductor conductor 320 are arranged to overlap each other when viewed from the X direction and are wound around the same axis. The columnar conductors T11a and T12b are adjacent to each other with a predetermined gap therebetween. The columnar conductors T11b and T12a are adjacent to each other with a predetermined gap therebetween. The conductor layer 141 and the conductor layer 142 are adjacent to each other with a predetermined gap therebetween.

[0140] The first end 310a of the first inductor conductor 310 and the first end 320a of the second inductor conductor 320 are each connected to the conductor layer 143. The conductor layer 143 connects the columnar conductors T11a and T12a. The first end 310a of the first inductor conductor 310 and the first end 320a of the second inductor conductor 320 are connected to the acoustic wave element 31 (see FIG. 1) via the conductor layer 143 and multiple conductors (not shown).

[0141] The first inductor conductor 310 includes a first portion having a shape elongated in one direction. The second inductor conductor 320 includes a second portion having a shape elongated in one direction and arranged adjacent to the first portion with a predetermined gap therebetween. In the second modification, the two columnar conductors T11a and T11b and the conductor layer 141 each correspond to the first portion. When the first portion is the columnar conductor T11a, the second portion corresponds to the columnar conductor T12b. When the first portion is the columnar conductor T11b, the second portion corresponds to the columnar conductor T12a. When the first portion is the conductor layer 141, the second portion corresponds to the conductor layer 142.

[0142] Here, taking the case where the first portion is the conductor layer 141 as an example, consider the direction (first direction) in the first portion when traveling along the first inductor conductor 310 from the first end L11a to the second end L11b of the inductor L11. The first direction is the same as the direction in the first portion when traveling along the first inductor conductor 310 from the first end 310a to the second end 310b of the first inductor conductor 310. In the conductor layer 141, the first direction is the Y direction. In FIG. 16, the arrow labeled D1 indicates the first direction.

[0143] Also, taking the example of the case where the first portion is the conductor layer 141, i.e., the second portion is the conductor layer 142, let us consider the direction (second direction) in the second portion along the second inductor conductor 320 from the first end L12a to the second end L12b of the inductor L12. The second direction is the same as the direction in the second portion along the second inductor conductor 320 from the first end 320a to the second end 320b of the second inductor conductor 320. In the conductor layer 142, the second direction is the -Y direction. In FIG. 16, the arrow labeled D2 indicates the second direction.

[0144] As shown in FIG. 16, the first direction D1 and the second direction D2 are opposite to each other.

[0145] When a conductor (not shown) for connection to acoustic wave element 31 is not connected to conductor layer 143, columnar conductors T11a, T11b, T12a, and T12b and conductor layers 141, 142, and 143 can form a single inductor. This single inductor is wound around an axis extending in a direction perpendicular to stacking direction T. When it is assumed that multiple conductors for connection to acoustic wave element 31 are not connected, this single inductor becomes a single virtual inductor. In particular, in the second modification, inductor L11 is formed by a part of the single virtual inductor, and inductor L12 is formed by another part of the single virtual inductor.

[0146] In addition, in the second modification, it can also be said that a conductor (not shown) for connection to acoustic wave element 31 is connected midway through one virtual inductor.

[0147] Next, a third modified example of the first and second inductor conductors will be described with reference to Fig. 17. Fig. 17 is a perspective view showing the third modified example of the first and second inductor conductors.

[0148] In the third modification, the inductor L11 includes a first inductor conductor 410 instead of the first inductor conductor 110. The first inductor conductor 410 includes three columnar conductors T21a, T21b, and T21c arranged at a predetermined interval, a conductor layer 241A connecting two of the columnar conductors T21a and T21b, and a conductor layer 241B connecting two of the columnar conductors T21b and T21c. The first inductor conductor 410 is wound around an axis extending in a direction perpendicular to the stacking direction T.

[0149] The first inductor conductor 410 has a first end 410a corresponding to the first end L11a of the inductor L11 and a second end 410b corresponding to the second end L11b of the inductor L11. The first end 410a is specifically an end of the columnar conductor T21a located on the opposite side to the conductor layer 241A. The second end 410b is specifically an end of the columnar conductor T21c located on the opposite side to the conductor layer 241B.

[0150] In the third modification, the inductor L12 includes a second inductor conductor 420 instead of the second inductor conductor 120. The second inductor conductor 420 includes three columnar conductors T22a, T22b, and T22c arranged at a predetermined interval, a conductor layer 242A connecting two of the columnar conductors T22a and T22b, and a conductor layer 242B connecting two of the columnar conductors T22b and T22c. The second inductor conductor 320 is wound around an axis extending in a direction perpendicular to the stacking direction T.

[0151] The second inductor conductor 420 has a first end 420a corresponding to the first end L12a of the inductor L12 and a second end 420b corresponding to the second end L12b of the inductor L12. The first end 420a is specifically an end of the columnar conductor T12a located on the opposite side to the conductor layer 242A. The second end 420b is specifically an end of the columnar conductor T12b located on the opposite side to the conductor layer 242B.

[0152] In particular, in the third modification, the first inductor conductor 410 and the second inductor conductor 420 are wound around different axes, and the columnar conductor T21b of the first inductor conductor 410 and the columnar conductor T22a of the second inductor conductor 420 are adjacent to each other with a predetermined gap therebetween.

[0153] The first end 410a of the first inductor conductor 410 and the first end 420a of the second inductor conductor 420 are each connected to the conductor layer 243. The conductor layer 243 connects the columnar conductors T21a and T22a. The first end 410a of the first inductor conductor 410 and the first end 420a of the second inductor conductor 420 are connected to the acoustic wave element 31 (see FIG. 1) via the conductor layer 243 and multiple conductors (not shown).

[0154] The first inductor conductor 410 includes a first portion that is elongated in one direction. The second inductor conductor 420 includes a second portion that is elongated in one direction and is arranged adjacent to the first portion with a predetermined gap between them. In the third modification, the columnar conductor T21b of the first inductor conductor 410 corresponds to the first portion, and the columnar conductor T22a of the second inductor conductor 420 corresponds to the second portion.

[0155] Here, consider the direction (first direction) in the first portion, i.e., the columnar conductor T21b, along the first inductor conductor 410 from the first end L11a to the second end L11b of the inductor L11. The first direction is the same as the direction in the columnar conductor T21b along the first inductor conductor 410 from the first end 410a to the second end 410b. In the columnar conductor T21b, the first direction is the Z direction. In FIG. 17, the arrow labeled D1 indicates the first direction.

[0156] Also, consider the direction (second direction) of the second portion, i.e., the columnar conductor T22a, along the second inductor conductor 420 from the first end L12a to the second end L12b of the inductor L12. The second direction is the same as the direction of the second portion along the second inductor conductor 420 from the first end 420a to the second end 420b. In the columnar conductor T22a, the second direction is the -Z direction. In FIG. 17, the arrow labeled D2 indicates the second direction.

[0157] As shown in FIG. 17, the first direction D1 and the second direction D2 are opposite to each other.

[0158] The inductor L13 may include an inductor conductor having a configuration similar to that of the second inductor conductor of any one of the first to third modified examples, instead of the third inductor conductor 130. Similarly, the inductor L14 may include an inductor conductor having a configuration similar to that of the first inductor conductor of any one of the first to third modified examples, instead of the fourth inductor conductor 140.

[0159] The present invention is not limited to the above-described embodiment, and various modifications are possible. For example, the filter of the present invention is not limited to a band-pass filter, and can be applied to other filters such as low-pass filters and high-pass filters, and electronic components including multiple resonators, such as a branching filter that separates multiple signals of different frequency bands.

[0160] Second body 80 may include only one acoustic wave element, or may include three or more. Second body 80 may include any passive element such as a capacitor in addition to acoustic wave elements 31 and 32. In this case, the passive element may be connected to acoustic wave element 31 or 32. Second body 80 may include any active element including a semiconductor such as a high-frequency switch instead of or in addition to acoustic wave elements 31 and 32.

[0161] Furthermore, each of the first portion of the first inductor conductor, the second portion of the second inductor conductor, the third portion of the third inductor conductor and the fourth portion of the fourth inductor conductor may have a shape extending along a predetermined direction, and may not be limited to a linear direction but may also have a shape extending along a curved direction (for example, a direction around an axis).

[0162] As described above, a filter of the present invention includes a first inductor, a second inductor, and a first acoustic wave element. The first inductor and the second inductor each have a first end and a second end located opposite each other. The first end of the first inductor and the first end of the second inductor are connected to each other and to the first acoustic wave element. The first inductor includes a first inductor conductor. The second inductor includes a second inductor conductor. The first inductor conductor includes a first portion having a shape elongated in one direction. The second inductor conductor includes a second portion having a shape elongated in one direction and disposed adjacent to the first portion with a predetermined gap therebetween. The direction of the first portion when moving along the first inductor conductor from the first end to the second end of the first inductor is opposite to the direction of the second portion when moving along the second inductor conductor from the first end to the second end of the second inductor.

[0163] In the filter of the present invention, the first inductor, the second inductor, and the first acoustic wave element may form a high-pass filter.

[0164] In the filter of the present invention, the first acoustic wave element may be connected to ground.

[0165] The filter of the present invention may further include a first input / output port and a second input / output port. The first inductor may be arranged between the first input / output port and the first acoustic wave element in terms of the circuit configuration. The second inductor may be arranged between the second input / output port and the first acoustic wave element in terms of the circuit configuration. The filter of the present invention may further include a low-pass filter arranged between the first inductor and the first input / output port in terms of the circuit configuration.

[0166] The filter of the present invention may further include a third inductor, a fourth inductor, and a second acoustic wave element. The third inductor and the fourth inductor may each have a third end and a fourth end located opposite each other. The third end of the third inductor and the third end of the fourth inductor may be connected to each other and to the second acoustic wave element. The third inductor may include a third inductor conductor. The fourth inductor may include a fourth inductor conductor. The third inductor conductor may include a third portion having a shape elongated in one direction. The fourth inductor conductor may include a fourth portion having a shape elongated in one direction and disposed adjacent to the third portion with a predetermined interval therebetween. The direction in the third portion when traveling along the third inductor conductor from the third end to the fourth end of the third inductor and the direction in the fourth portion when traveling along the fourth inductor conductor from the third end to the fourth end of the fourth inductor may be opposite to each other. The filter of the present invention may further include a capacitor provided between the second inductor and the third inductor in the circuit configuration.

[0167] The filter of the present invention may further include a laminate including a plurality of stacked dielectric layers. The first inductor and the second inductor may be provided inside the laminate. The first inductor and the second inductor may be aligned in a direction perpendicular to the stacking direction of the dielectric layers. Alternatively, the first inductor may be formed by a part of one virtual inductor, and the second inductor may be formed by another part of the one virtual inductor. The first acoustic wave element may be mounted on the laminate. [Explanation of symbols]

[0168] REFERENCE SIGNS LIST 1...filter, 2...first input / output port, 3...second input / output port, 5...first path, 6...second path, 7...solder bump, 10...filter circuit, 20...first low-pass filter, 30...second low-pass filter, 31, 32...acoustic wave element, 50...first body, 50A...first surface, 50B...second surface, 50C to 50F...side surface, 51 to 68...dielectric layer, 80...second body, 81 to 84, 11 1 to 119, 121 to 124...electrodes, 110...first inductor conductor, 110A...first part, 120...second inductor conductor, 120A...second part, 130...third inductor conductor, 130A...third part, 140...fourth inductor conductor, 140A...fourth part, C1 to C4, C11, C21, C22, C31, C32...capacitors, L11 to L15, L21, L31...inductors.

Claims

1. a first inductor; a second inductor; a first acoustic wave element; each of the first inductor and the second inductor having a first end and a second end located opposite each other; the first end of the first inductor and the first end of the second inductor are connected to each other and to the first acoustic wave element; the first inductor includes a first inductor conductor; the second inductor includes a second inductor conductor; the first inductor conductor includes a first portion having a shape that is elongated in one direction; the second inductor conductor has a shape that is elongated in one direction and includes a second portion that is disposed adjacent to the first portion with a predetermined gap therebetween; a direction in the first portion along the first inductor conductor from the first end to the second end of the first inductor and a direction in the second portion along the second inductor conductor from the first end to the second end of the second inductor are opposite to each other.

2. 2. The filter according to claim 1, wherein the first inductor, the second inductor, and the first acoustic wave element form a high-pass filter.

3. 2. The filter according to claim 1, wherein the first acoustic wave element is connected to ground.

4. further comprising a first input / output port; a second input / output port; the first inductor is arranged between the first input / output port and the first acoustic wave element in a circuit configuration; 2. The filter according to claim 1, wherein the second inductor is arranged between the second input / output port and the first acoustic wave element in terms of circuit configuration.

5. 5. The filter according to claim 4, further comprising a low-pass filter provided between said first inductor and said first input / output port in terms of circuit configuration.

6. further comprising a third inductor; a fourth inductor; and a second acoustic wave element; each of the third inductor and the fourth inductor has a third end and a fourth end located opposite to each other; 2. The filter according to claim 1, wherein the third end of the third inductor and the third end of the fourth inductor are connected to each other and to the second acoustic wave element.

7. the third inductor includes a third inductor conductor; the fourth inductor includes a fourth inductor conductor; the third inductor conductor includes a third portion having a shape elongated in one direction; the fourth inductor conductor has a shape that is elongated in one direction and includes a fourth portion that is disposed adjacent to the third portion with a predetermined interval therebetween; 7. The filter according to claim 6, wherein a direction in the third portion when traveling along the third inductor conductor from the third end to the fourth end of the third inductor and a direction in the fourth portion when traveling along the fourth inductor conductor from the third end to the fourth end of the fourth inductor are opposite to each other.

8. 7. The filter according to claim 6, further comprising a capacitor provided between the second inductor and the third inductor in the circuit configuration.

9. Further, a laminate including a plurality of laminated dielectric layers is provided, 2. The filter according to claim 1, wherein the first inductor and the second inductor are provided inside the laminate.

10. 10. The filter according to claim 9, wherein the first inductor and the second inductor are arranged in a direction perpendicular to the lamination direction of the dielectric layers.

11. the first inductor is configured by a part of one virtual inductor, 10. The filter according to claim 9, wherein the second inductor is formed by another part of the one virtual inductor.

12. 10. The filter according to claim 9, wherein the first acoustic wave element is mounted on the laminate.

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