Multilayer filter device

Abstract

To achieve a layered filter device that can be downsized while suppressing the generation of spurious signals.SOLUTION: The filter device 1 includes first to third resonators 10, 20, 30. Each of the first to third resonators 10, 20, 30 includes a first line portion and a second line portion electrically connected to the first line portion and having a lower impedance than the first line portion. The impedance ratio on at least one of the first through third resonators 10, 20, 30 is 0.3 or less. The second line portion 12 of the first resonator 10 and the second line portion 22 of the second resonator 20 each have a shape that is long in a direction perpendicular to the layered direction and intersecting the longitudinal direction of the second line portion 32 of the third resonator 30.SELECTED DRAWING: Figure 6

Description

Technical Field

[0001] The present invention relates to a laminated filter device including a resonator composed of a distributed constant line.

Background Art

[0002] One of the electronic components used in communication devices is a band-pass filter including a plurality of resonators. Each of the plurality of resonators is configured by, for example, a distributed constant line. The distributed constant line is configured to have a predetermined line length.

[0003] In particular, miniaturization is required for a band-pass filter used in a particularly small communication device. However, in a band-pass filter including a resonator composed of a distributed constant line, the distributed constant line constituting the resonator becomes an obstacle, and it has been difficult to miniaturize the band-pass filter.

[0004] Patent Document 1 describes a short-circuited step impedance transmission line resonator (also referred to as a stepped impedance resonator (SIR)). In the technique described in Patent Document 1, the ratio of the line impedance of a relatively wide transmission line to the line impedance of a relatively narrow transmission line (hereinafter referred to as the impedance ratio) is set to be less than 1, thereby miniaturizing the dimensions of the resonator.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] In order to further miniaturize a band-pass filter equipped with a SIR, it is conceivable to reduce the impedance ratio and thereby reduce the size of the resonator. However, it has been found that in a conventional band-pass filter, a large number of spurs are generated in a frequency region higher than the passband.

[0007] The present invention has been made in view of such problems, and an object thereof is to provide a laminated filter device capable of miniaturization while suppressing the generation of spurs.

Means for Solving the Problems

[0008] The laminated filter device of the present invention includes a laminate including a plurality of laminated dielectric layers, and a first resonator, a second resonator, and a third resonator integrated with the laminate. The laminate has a first side surface and a second side surface located at both ends in a direction orthogonal to the lamination direction of the plurality of dielectric layers. The first resonator is disposed at a position closer to the first side surface than the second side surface. The second resonator is disposed at a position closer to the second side surface than the first side surface. At least a part of the third resonator is disposed between the first resonator and the second resonator when viewed from a direction parallel to the lamination direction.

[0009] Each of the first resonator, the second resonator, and the third resonator includes a first line portion and a second line portion having an impedance smaller than that of the first line portion. In at least one of the first resonator, the second resonator, and the third resonator, First With respect to the impedance of the line portion Second The impedance ratio, which is the ratio of the impedance of the line portion, is 0.3 or less.

[0010] The shape of the second line portion of the third resonator is a shape that is long in a direction orthogonal to the lamination direction. The shape of each of the second line portions of the first resonator and the second resonator is a shape that is long in a direction orthogonal to the lamination direction and intersecting the longitudinal direction of the second line portion of the third resonator.

[0011] In the laminated filter device of the present invention, the impedance ratio in each of the first resonator, the second resonator, and the third resonator may be 0.3 or less.

[0012] Also, in the laminated filter device of the present invention, the longitudinal direction of the second line portion of the first resonator and the longitudinal direction of the second line portion of the second resonator may be orthogonal to the longitudinal direction of the second line portion of the third resonator.

[0013] Also, in the laminated filter device of the present invention, the first line portion of the first resonator and the first line portion of the second resonator may each include portions extending in a plurality of directions orthogonal to the lamination direction and different from each other.

[0014] Also, in the laminated filter device of the present invention, the first line portion of the third resonator may have an asymmetric shape.

[0015] Also, the laminated filter device of the present invention may further include a first stub-type resonator electrically connected to the first line portion of the first resonator and a second stub-type resonator electrically connected to the first line portion of the second resonator.

[0016] Also, in the laminated filter device of the present invention, the third resonator may be arranged between the first resonator and the second resonator in terms of circuit configuration.

[0017] Also, in the laminated filter device of the present invention, in each of the first resonator, the second resonator, and the third resonator, the first line portion and the second line portion may be arranged at different positions in the lamination direction and electrically connected to each other.

[0018] Also, the laminated filter device of the present invention may further include a plurality of through holes connecting the first line portion and the second line portion of each of the first resonator, the second resonator, and the third resonator.

[0019] In addition, in the stacked filter device of the present invention, the first line portion of the first resonator and the first line portion of the second resonator may be arranged at the same position in the stacking direction. The first line portion of the third resonator may be arranged at a position different from the first line portion of each of the first resonator and the second resonator in the stacking direction.

[0020] Further, in the stacked filter device of the present invention, the second line portion of the first resonator and the second line portion of the second resonator may be arranged at the same position in the stacking direction. The second line portion of the third resonator may be arranged at a position different from the second line portion of each of the first resonator and the second resonator in the stacking direction.

Advantages of the Invention

[0021] In the stacked filter device of the present invention, the impedance ratio in at least one of the first resonator, the second resonator, and the third resonator is 0.3 or less. The shape of the second line portion of the first resonator and the shape of the second line portion of the second resonator are each a shape long in a direction orthogonal to the stacking direction, and the shape of the second line portion of the third resonator is a shape long in a direction orthogonal to the stacking direction and intersecting the longitudinal direction of the second line portion of the first resonator and the longitudinal direction of the second line portion of the second resonator. From these, according to the present invention, there is an effect that it is possible to realize a stacked filter device that can be miniaturized while suppressing the generation of spurious.

Brief Description of the Drawings

[0022]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

Figure 13

Figure 14

Figure 15

Embodiments for Carrying Out the Invention

[0023] [First Embodiment] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. First, referring to FIG. 1, the configuration of a stacked filter device (hereinafter simply referred to as a filter device) 1 according to the first embodiment of the present invention will be described. FIG. 1 is a circuit diagram showing the circuit configuration of the filter device 1. The filter device 1 is configured to function as a bandpass filter that selectively passes signals having frequencies within a predetermined passband.

[0024] The filter device 1 according to the present embodiment includes a first resonator 10, a second resonator 20, and a third resonator 30 disposed between the first resonator 10 and the second resonator 20 in terms of circuit configuration. In the present application, the expression "in terms of circuit configuration" is used to refer to the arrangement on the circuit diagram rather than the arrangement in the physical configuration.

[0025] The first to third resonators 10, 20, 30 are configured such that the first resonator 10 and the third resonator 30 are adjacent to each other in terms of circuit configuration and are electromagnetically coupled, and the second resonator 20 and the third resonator 30 are adjacent to each other in terms of circuit configuration and are electromagnetically coupled. In FIG. 1, the curve marked with the symbol K13 represents the electric field coupling between the first resonator 10 and the third resonator 30, and the curve marked with the symbol K23 represents the electric field coupling between the second resonator 20 and the third resonator 30.

[0026] Further, the first resonator 10 is magnetically coupled to the second resonator 20 that is not adjacent to it in terms of circuit configuration. In this way, the electromagnetic coupling between two resonators that are not adjacent to each other in terms of circuit configuration is called skip coupling. In FIG. 1, the curve marked with the symbol K12 indicates the magnetic field coupling between the first resonator 10 and the second resonator 20.

[0027] The first resonator 10 includes a first line portion 11 and a second line portion 12 having an impedance smaller than that of the first line portion 11. The first line portion 11 and the second line portion 12 are electrically connected to each other. The first line portion 11 is connected to the ground. Further, each of the first line portion 11 and the second line portion 12 is a distributed constant line. In particular, in the present embodiment, the first line portion 11 is a distributed constant line with a small width, and the second line portion 12 is a distributed constant line with a width larger than that of the first line portion 11.

[0028] The first resonator 10 further includes a conductor portion 13 that electrically connects the first line portion 11 and the second line portion 12. The conductor portion 13 may include a distributed constant line having a width smaller than that of the second line portion 12. The width of the distributed constant line of the conductor portion 13 may be the same as or different from the width of the first line portion 11.

[0029] The configuration of the second resonator 20 is basically the same as that of the first resonator 10. That is, the second resonator 20 includes a first line portion 21 and a second line portion 22 having an impedance smaller than that of the first line portion 21. The first line portion 21 and the second line portion 22 are electrically connected to each other. The first line portion 21 is connected to the ground. Further, each of the first line portion 21 and the second line portion 22 is a distributed constant line. In particular, in the present embodiment, the first line portion 21 is a distributed constant line with a small width, and the second line portion 22 is a distributed constant line with a width larger than that of the first line portion 21.

[0030] The second resonator 20 further includes a conductor portion 23 that electrically connects the first line portion 21 and the second line portion 22. The conductor portion 23 may include a distributed constant line having a width smaller than that of the second line portion 22. The width of the distributed constant line of the conductor portion 23 may be the same as or different from the width of the first line portion 21.

[0031] The third resonator 30 includes a first line portion 31 and a second line portion 32 having an impedance smaller than that of the first line portion 31. The first line portion 31 and the second line portion 32 are electrically connected to each other. The first line portion 31 is connected to the ground. Also, each of the first line portion 31 and the second line portion 32 is a distributed constant line. In particular, in the present embodiment, the first line portion 31 is a distributed constant line with a small width, and the second line portion 32 is a distributed constant line with a width larger than that of the first line portion 31.

[0032] The first to third resonators 10, 20, 30 are all stepped impedance resonators each composed of a distributed constant line with a small width and a distributed constant line with a large width. Also, the first to third resonators 10, 20, 30 are all 1 / 4 wavelength resonators with one end short-circuited and the other end open.

[0033] The impedance of each of the first line portions 11, 21, 31 is, for example, within the range of 15 to 35 Ω. The impedance of each of the second line portions 12, 22, 32 is, for example, within the range of 1 to 5 Ω. Here, in each of the first to third resonators 10, 20, 30, First With respect to the impedance of the line portion Second The ratio of the impedance of the line portion to the impedance of the line portion is referred to as the impedance ratio. From the viewpoint of making the resonator small, it is preferable that the impedance ratio is small. For example, it is possible to adjust the impedance ratio by adjusting the width of each of the first line portion and the second line portion. As the impedance ratio becomes smaller, the width of the first line portion becomes relatively smaller, and the width of the second line portion becomes relatively larger.

[0034] In the present embodiment, the impedance ratio of at least one of the first to third resonators 10, 20, 30 is 0.3 or less. In particular, in the present embodiment, the impedance ratio in each of the first to third resonators 10, 20, 30 is set to 0.3 or less. In one example, each of the first and second resonators 10, 20 SecondThe impedance of the line portion is 2.87 Ω, and for each of the first and second resonators 10, 20 First The impedance of the line portion is 27 Ω. In this case, the impedance ratio for each of the first and second resonators 10, 20 is 0.106. Also, in one example, the Second line portion 32 impedance of the third resonator 30 is 2.55 Ω, and the First line portion 31 impedance of the third resonator 30 is 27 Ω. In this case, the impedance ratio for the third resonator 30 is 0.094.

[0035] However, if the impedance ratio is made too small, the desired characteristics may not be obtained. For example, in a stepped impedance resonator (quarter - wavelength resonator) with one end short - circuited and the other end open - circuited, if the impedance ratio is made too small, this resonator becomes a half - wavelength resonator consisting substantially only of a second line portion with both ends open - circuited. As a result, the desired characteristics cannot be obtained. To prevent this, in the present embodiment, the impedance ratio for each of the first to third resonators 10, 20, 30 is set to 0.06 or more.

[0036] The filter device 1 further includes a first port 2, a second port 3, and conductor portions 4, 5. The first to third resonators 10, 20, 30 are arranged between the first port 2 and the second port 3 in terms of circuit configuration.

[0037] The conductor portion 4 electrically connects the first port 2 and the first resonator 10. One end of the conductor portion 4 is connected to the first port 2. The other end of the conductor portion 4 is connected to the first resonator 10 between the first line portion 11 and the conductor portion 13.

[0038] The conductor portion 5 electrically connects the second port 3 and the second resonator 20. One end of the conductor portion 5 is connected to the second port 3. The other end of the conductor portion 5 is connected to the second resonator 20 between the first line portion 21 and the conductor portion 23.

[0039] Next, with reference to FIG. 2, other configurations of the filter device 1 will be described. FIG. 2 is a perspective view showing the appearance of the filter device 1.

[0040] The filter device 1 further includes a laminate 50. The laminate 50 includes a plurality of stacked dielectric layers, and a plurality of conductor layers and a plurality of through holes formed in the plurality of dielectric layers. The first to third resonators 10, 20, 30 are integrated with the laminate 50. The first to third resonators 10, 20, 30 are configured using a plurality of conductor layers.

[0041] The laminate 50 has a first surface 50A and a second surface 50B located at both ends in the stacking direction T of the plurality of 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 opposite sides, and the side surfaces 50E and 50F also face opposite sides. The side surfaces 50C to 50F are perpendicular to the first surface 50A and the second surface 50B.

[0042] Here, as shown in FIG. 2, the X direction, Y direction, and Z direction are defined. The X direction, Y direction, and Z direction are orthogonal to each other. In the present embodiment, one direction parallel to the stacking direction T is defined as the Z direction. Also, 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.

[0043] As shown in FIG. 2, the first surface 50A is located at the -Z direction end of the laminate 50. The first surface 50A is also the bottom surface of the laminate 50. The second surface 50B is located at the Z direction end of the laminate 50. The second surface 50B is also the upper surface of the laminate 50. The side surface 50C is located at the -X direction end of the laminate 50. The side surface 50D is located at the X direction end of the laminate 50. The side surface 50E is located at the -Y direction end of the laminate 50. The side surface 50F is located at the Y direction end of the laminate 50.

[0044] When viewed from the Z direction, the planar shape of the laminate 50, that is, the shape of the first surface 50A or the second surface 50B, is a shape elongated in one direction. In particular, in the present embodiment, the planar shape of the laminate 50 when viewed from the Z direction is a rectangular shape elongated in a direction parallel to the X direction.

[0045] The filter device 1 further includes a plurality of terminals 111, 112, 113, 114, 115, 116 provided on the first surface 50A of the laminate 50. The terminal 111 extends in the Y direction in the vicinity of the side surface 50C. The terminal 112 extends in the Y direction in the vicinity of the side surface 50D. The terminals 113 to 116 are arranged between the terminal 111 and the terminal 112. The terminals 113 and 114 are arranged in this order in the X direction in the vicinity of the side surface 50E. The terminals 115 and 116 are arranged in this order in the X direction in the vicinity of the side surface 50F.

[0046] The terminal 111 corresponds to the first port 2, and the terminal 112 corresponds to the second port 3. Therefore, the first and second ports 2 and 3 are provided on the first surface 50A of the laminate 50. The terminals 113 to 116 are connected to the ground. Hereinafter, the terminal 111 is also referred to as the first terminal 111, the terminal 112 is also referred to as the second terminal 112, and the terminals 113 to 116 are also referred to as the ground terminals 113 to 116.

[0047] Next, with reference to FIGS. 3 to 5, an example of a plurality of dielectric layers and a plurality of conductor layers constituting the laminate 50 will be described. In this example, the laminate 50 has nine stacked dielectric layers. Hereinafter, these nine dielectric layers are referred to as the first to ninth dielectric layers in order from the bottom. Also, the first to ninth dielectric layers are represented by reference numerals 51 to 59.

[0048] FIG. 3(a) shows the pattern formation surface of the first dielectric layer 51. The terminals 111, 112, 113, 114, 115, 116 are formed on the pattern formation surface of the dielectric layer 51. Further, through holes 51T1, 51T2, 51T3, 51T4, 51T5, 51T6 connected to the terminals 111, 112, 113, 114, 115, 116, respectively, are formed in the dielectric layer 51.

[0049] Figure 3(b) shows the pattern formation surface of the second dielectric layer 52. A conductor layer 521 is formed on the pattern formation surface of the dielectric layer 52. Further, through holes 52T1, 52T2, 52T3, 52T4, 52T5, 52T6 are formed in the dielectric layer 52. The through holes 51T1, 51T2 formed in the dielectric layer 51 are connected to the through holes 52T1, 52T2, respectively. The through holes 51T3 to 51T6 formed in the dielectric layer 51 and the through holes 52T3 to 52T6 are connected to the conductor layer 521.

[0050] Figure 3(c) shows the pattern formation surface of the third dielectric layer 53. Conductor layers 531, 532, 533, 534 are formed on the pattern formation surface of the dielectric layer 53. The conductor layer 532 is connected to the conductor layer 531. The conductor layer 534 is connected to the conductor layer 533. In Figure 3(c), the boundaries between the conductor layer 531 and the conductor layer 532 and between the conductor layer 533 and the conductor layer 534 are indicated by dotted lines, respectively.

[0051] Further, through holes 53T1, 53T2, 53T3, 53T4, 53T5, 53T6 are formed in the dielectric layer 53. The through hole 52T1 formed in the dielectric layer 52 and the through hole 53T1 are connected to the conductor layer 532. The through hole 52T2 formed in the dielectric layer 52 and the through hole 53T2 are connected to the conductor layer 534. The through holes 52T3 to 52T6 formed in the dielectric layer 52 are connected to the through holes 53T3 to 53T6, respectively.

[0052] Figure 4(a) shows the pattern formation surface of the fourth dielectric layer 54. A conductor layer 541 is formed on the pattern formation surface of the dielectric layer 54. Further, through holes 54T1, 54T2, 54T3, 54T4, 54T5, 54T6, 54T7 are formed in the dielectric layer 54. The through holes 53T1 to 53T6 formed in the dielectric layer 53 are connected to the through holes 54T1 to 54T6, respectively. The through hole 54T7 is connected to the conductor layer 541.

[0053] Figure 4(b) shows the pattern formation surface of the fifth dielectric layer 55. A conductor layer 551 is formed on the pattern formation surface of the dielectric layer 55. Further, through holes 55T1, 55T2, 55T7, 55T8 are formed in the dielectric layer 55. Through holes 54T1, 54T2, 54T7 formed in the dielectric layer 54 are respectively connected to through holes 55T1, 55T2, 55T7. Through holes 54T3 to 54T6 formed in the dielectric layer 54 and through hole 55T8 are connected to the conductor layer 551.

[0054] Figure 4(c) shows the pattern formation surface of the sixth dielectric layer 56. Through holes 56T1, 56T2, 56T7, 56T8 are formed in the dielectric layer 56. Through holes 55T1, 55T2, 55T7, 55T8 formed in the dielectric layer 55 are respectively connected to through holes 56T1, 56T2, 56T7, 56T8.

[0055] Figure 5(a) shows the pattern formation surface of the seventh dielectric layer 57. Conductor layers 571, 572 are formed on the pattern formation surface of the dielectric layer 57. Each of the conductor layers 571, 572 has a first end and a second end located on opposite sides of each other. The first end of the conductor layer 571 and the first end of the conductor layer 572 are connected to each other. In Figure 5(a), the boundary between the conductor layer 571 and the conductor layer 572 is indicated by a dotted line. Through hole 56T1 formed in the dielectric layer 56 is connected to a vicinity portion of the second end of the conductor layer 571. Through hole 56T2 formed in the dielectric layer 56 is connected to a vicinity portion of the second end of the conductor layer 572.

[0056] Further, through holes 57T7, 57T8 are formed in the dielectric layer 57. Through hole 56T7 formed in the dielectric layer 56 is connected to through hole 57T7. Through hole 56T8 formed in the dielectric layer 56 and through hole 57T8 are connected to a vicinity portion of the first end of the conductor layer 571 and a vicinity portion of the first end of the conductor layer 572.

[0057] FIG. 5(b) shows the pattern formation surface of the eighth dielectric layer 58. A conductor layer 581 is formed on the pattern formation surface of the dielectric layer 58. The conductor layer 581 has a first end and a second end located on opposite sides of each other. The through hole 57T7 formed in the dielectric layer 57 is connected to a vicinity portion of the first end of the conductor layer 581.

[0058] Also, a through hole 58T8 is formed in the dielectric layer 58. The through hole 57T8 formed in the dielectric layer 57 and the through hole 58T8 are connected to a vicinity portion of the second end of the conductor layer 581.

[0059] FIG. 5(c) shows the pattern formation surface of the ninth dielectric layer 59. A conductor layer 591 is formed on the pattern formation surface of the dielectric layer 59. The through hole 58T8 formed in the dielectric layer 58 is connected to the conductor layer 591.

[0060] The laminate 50 shown in FIG. 2 is configured by laminating the first to ninth dielectric layers 51 to 59 such that the pattern formation surface of the first dielectric layer 51 becomes the first surface 50A of the laminate 50, and the surface opposite to the pattern formation surface of the ninth dielectric layer 59 becomes the second surface 50B of the laminate 50.

[0061] FIG. 6 shows the inside of the laminate 50 configured by laminating the first to ninth dielectric layers 51 to 59. As shown in FIG. 6, inside the laminate 50, a plurality of conductor layers and a plurality of through holes shown in FIGS. 3 to 5 are laminated.

[0062] Hereinafter, the correspondence between the circuit components of the filter device 1 shown in FIG. 1 and the components inside the laminate 50 shown in FIGS. 3 to 5 will be described. First, the first resonator 10 will be described. The first line portion 11 is constituted by the conductor layer 571. The second line portion 12 is constituted by the conductor layer 531. The conductor portion 13 is constituted by the conductor layer 532.

[0063] The conductor layer 532 (conductor portion 13) and the through holes 53T1, 54T1, 55T1, 56T1 connect the conductor layer 571 constituting the first line portion 11 and the conductor layer 531 constituting the second line portion 12. Further, the conductor layer 571 constituting the first line portion 11 is connected to the ground terminals 113 to 116 via the through holes 51T3 to 51T6, the conductor layer 521, the through holes 52T3 to 52T6, 53T3 to 53T6, the through holes 54T3 to 54T6, the conductor layer 551, and the through holes 55T8, 56T8.

[0064] Next, the second resonator 20 will be described. The first line portion 21 is constituted by the conductor layer 572. The second line portion 22 is constituted by the conductor layer 533. The conductor portion 23 is constituted by the conductor layer 534.

[0065] The conductor layer 534 (conductor portion 23) and the through holes 53T2, 54T2, 55T2, 56T2 connect the conductor layer 572 constituting the first line portion 21 and the conductor layer 533 constituting the second line portion 22. Further, the conductor layer 572 constituting the first line portion 21 is connected to the ground terminals 113 to 116 via the through holes 51T3 to 51T6, the conductor layer 521, the through holes 52T3 to 52T6, 53T3 to 53T6, the through holes 54T3 to 54T6, the conductor layer 551, and the through holes 55T8, 56T8.

[0066] Next, the third resonator 30 will be described. The first line portion 31 is constituted by the conductor layer 581. The second line portion 32 is constituted by the conductor layer 541.

[0067] The conductor layer 581 constituting the first line portion 31 is connected to the ground terminals 113 to 116 via the through holes 51T3 to 51T6, the conductor layer 521, the through holes 52T3 to 52T6, 53T3 to 53T6, the through holes 54T3 to 54T6, the conductor layer 551, and the through holes 55T8, 56T8, 57T8.

[0068] Next, the conductor parts 4 and 5 will be described. The conductor part 4 is composed of through-holes 51T1 and 52T1. The through-hole 51T1 is connected to the first terminal 111. The through-hole 52T1 is connected to the conductor layer 532 that constitutes the conductor part 13, and is also connected to the conductor layer 571 that constitutes the first line part 11 via through-holes 53T1, 54T1, 55T1, and 56T1.

[0069] The conductor part 5 is composed of through-holes 51T2 and 52T2. The through-hole 51T2 is connected to the second terminal 112. The through-hole 52T2 is connected to the conductor layer 534 that constitutes the conductor part 23, and is also connected to the conductor layer 572 that constitutes the first line part 21 via through-holes 53T2, 54T2, 55T2, and 56T2.

[0070] Next, with reference to FIGS. 2 to 8, the structural features of the filter device 1 according to the present embodiment will be described. FIGS. 7 and 8 are perspective views showing a part inside the laminate 50. FIG. 7 mainly shows a plurality of conductor layers and a plurality of through-holes that constitute the first and second resonators 10 and 20. FIG. 8 mainly shows a plurality of conductor layers and a plurality of through-holes that constitute the third resonator 30.

[0071] The first resonator 10 is arranged in the region on the -X direction side within the laminate 50. That is, the first resonator 10 is arranged at a position closer to the side surface 50C than the side surface 50D. As shown in FIG. 7, the first line part 11 (conductor layer 571) and the second line part 12 (conductor layer 531) of the first resonator 10 are arranged at different positions in the stacking direction T. The second line part 12 is arranged between the first surface 50A where a plurality of terminals 111 to 116 are arranged and the first line part 11.

[0072] The first circuit portion 11 (conductor layer 571) includes a plurality of portions extending in a plurality of directions orthogonal to the stacking direction T. In particular, in the present embodiment, the first circuit portion 11 (conductor layer 571) includes four portions extending in a direction parallel to the X direction and three portions extending in a direction parallel to the Y direction.

[0073] The shape of the second circuit portion 12 (conductor layer 531) is long in a direction intersecting the longitudinal direction of the laminate 50. In particular, in the present embodiment, the shape of the second circuit portion 12 (conductor layer 531) is a rectangular shape that is long in a direction parallel to the Y direction.

[0074] The second resonator 20 is disposed in the region on the X-direction side within the laminate 50. That is, the second resonator 20 is disposed at a position closer to the side surface 50D than the side surface 50C. As shown in FIG. 7, the first circuit portion 21 (conductor layer 572) and the second circuit portion 22 (conductor layer 533) of the second resonator 20 are disposed at different positions in the stacking direction T. The second circuit portion 22 is disposed between the first surface 50A on which the plurality of terminals 111 to 116 are disposed and the first circuit portion 21.

[0075] The first circuit portion 21 (conductor layer 572) includes a plurality of portions extending in a plurality of directions orthogonal to the stacking direction T. In particular, in the present embodiment, the first circuit portion 21 (conductor layer 572) includes four portions extending in a direction parallel to the X direction and three portions extending in a direction parallel to the Y direction.

[0076] The shape of the second circuit portion 22 (conductor layer 533) is long in a direction intersecting the longitudinal direction of the laminate 50. In particular, in the present embodiment, the shape of the second circuit portion 22 (conductor layer 533) is a rectangular shape that is long in a direction parallel to the Y direction.

[0077] At least a part of the third resonator 30 is disposed between the first resonator 10 and the second resonator 20 when viewed from the Z direction. In particular, in the present embodiment, a part of the third resonator 30 is disposed between the first resonator 10 and the second resonator 20.

[0078] As shown in FIG. 8, the first line portion 31 (conductor layer 581) and the second line portion 32 (conductor layer 541) of the third resonator 30 are arranged at different positions from each other in the stacking direction T. The second line portion 32 is arranged between the first surface 50A where a plurality of terminals 111 to 116 are arranged and the first line portion 31.

[0079] The first line portion 31 (conductor layer 581) includes a plurality of portions extending in a plurality of directions orthogonal to the stacking direction T. In particular, in the present embodiment, the first line portion 31 (conductor layer 581) includes three portions extending in a direction parallel to the X direction and four portions extending in a direction parallel to the Y direction.

[0080] The first line portion 31 (conductor layer 581) has a shape that is asymmetric with respect to any XZ plane intersecting the first line portion 31 and also has a shape that is asymmetric with respect to any YZ plane intersecting the first line portion 31. Hereinafter, any XZ plane intersecting the first line portion 31 is referred to as a first virtual plane, and any YZ plane intersecting the first line portion 31 is referred to as a second virtual plane. The first virtual plane may intersect the center of the laminate 50 in a direction parallel to the Y direction. The second virtual plane may intersect the center of the laminate 50 in a direction parallel to the X direction.

[0081] The shape of the second line portion 32 (conductor layer 541) is a shape that is long in the longitudinal direction of the laminate 50. In particular, in the present embodiment, the shape of the second line portion 32 (conductor layer 541) is a rectangular shape that is long in a direction parallel to the X direction.

[0082] As shown in FIGS. 5(a) and 6, the first line portion 11 (conductor layer 571) of the first resonator 10 and the first line portion 21 (conductor layer 572) of the second resonator 20 are arranged at the same position in the stacking direction T. As shown in FIGS. 5(a), 5(b) and 6, the first line portion 31 (conductor layer 581) of the third resonator 30 is arranged at a position different from the first line portions 11 and 21 in the stacking direction T. Also, a part of the first line portion 11 and a part of the first line portion 21 overlap the first line portion 31 when viewed from the Z direction. Also, the shape of the first line portion 31 is different from the shape of the first line portion 11 and the shape of the first line portion 21.

[0083] Also, as shown in FIGS. 3(c) and 6, the second line portion 12 (conductor layer 531) of the first resonator 10 and the second line portion 22 (conductor layer 533) of the second resonator 20 are arranged at the same position in the stacking direction T. As shown in FIGS. 3(c), 4(a) and 6, the second line portion 32 (conductor layer 541) of the third resonator 30 is arranged at a position different from the second line portions 12 and 22 in the stacking direction T. Also, a part of the second line portion 12 and a part of the second line portion 22 overlap the second line portion 32 when viewed from the Z direction. Also, the shape of the second line portion 32 is different from the shape of the second line portion 12 and the shape of the second line portion 22.

[0084] Also, as shown in FIGS. 3(c), 4(a), 7 and 8, the shape of the second line portion 32 of the third resonator 30 is a shape long in a direction orthogonal to the stacking direction T, and the shape of each of the second line portion 12 of the first resonator 10 and the second line portion 22 of the second resonator 20 is a shape long in a direction orthogonal to the stacking direction T and intersecting the longitudinal direction of the second line portion 32.

[0085] As described above, in particular in this embodiment, the shapes of both the second line portion 12 and the second line portion 22 are rectangular shapes that are long in a direction parallel to the Y direction, and the shape of the second line portion 32 is a rectangular shape that is long in a direction parallel to the X direction. Therefore, the longitudinal directions of the second line portion 12 and the second line portion 22 are orthogonal to the longitudinal direction of the second line portion 32 (the direction parallel to the X direction).

[0086] As described above, in this embodiment, the first line portion 11 and the second line portion 12 of the first resonator 10 are arranged at different positions from each other in the stacking direction T. Thereby, according to this embodiment, it becomes possible to arrange the first line portion 11 and the second line portion 12 in an overlapping manner. Thereby, according to this embodiment, compared with the case where the first line portion 11 and the second line portion 12 are formed in the same dielectric layer and arranged at the same position in the stacking direction T, the area for arranging the first resonator 10 can be substantially reduced.

[0087] The above description of the first resonator 10 also applies to the second and third resonators 20 and 30. From these facts, according to this embodiment, the filter device 1 can be miniaturized.

[0088] Also, in this embodiment, each of the first line portions 11, 21, and 31 includes a plurality of portions extending in a plurality of different directions from each other. Thereby, according to this embodiment, compared with the case where each of the first line portions 11, 21, and 31 extends in one direction, the area for arranging each of the first line portions 11, 21, and 31 can be substantially reduced.

[0089] Also, in this embodiment, the first line portion 31 has the asymmetric shape as described above. Thereby, according to this embodiment, the interaction generated between the first line portion 11 and the first line portion 31 and the interaction generated between the first line portion 21 and the first line portion 31 can be made different. Thereby, for example, it becomes possible to suppress spurious signals generated in a frequency region higher than the passband.

[0090] Also, in the present embodiment, the conductor layer 591 is connected to the ground terminals 113 to 116 via the through holes 51T3 to 51T6, the conductor layer 521, the through holes 52T3 to 52T6, 53T3 to 53T6, the through holes 54T3 to 54T6, the conductor layer 551, and the through holes 55T8, 56T8, 57T8, 58T8. The first to third resonators 10, 20, 30 are disposed between the conductor layer 521 and the conductor layer 591. Each of the conductor layers 521 and 591 overlaps the first to third resonators 10, 20, 30 when viewed from the Z direction. The conductor layers 521 and 591 function as shields.

[0091] Also, in the present embodiment, the shape of each of the second line portions 12 of the first resonator 10 and the second line portions 22 of the second resonator 20 is long in a direction intersecting the longitudinal direction of the second line portion 32 of the third resonator 30. Thus, according to the present embodiment, the generation of spurious can be suppressed. Hereinafter, this effect will be described with reference to the results of simulation.

[0092] First, the models of the comparative example used in the simulation and the models of the first and second embodiments will be described. The model of the comparative example is a model of the filter device of the comparative example. The configuration of the filter device of the comparative example is substantially the same as the configuration of the filter device 1 according to the present embodiment except for the shapes of the second line portions 12 of the first resonator 10 and the second line portions 22 of the second resonator 20. In the filter device of the comparative example, each of the second line portions 12 and 22 has a rectangular shape that is long in a direction parallel to the X direction, similar to the second line portion 32 of the third resonator 30. In the model of the comparative example, the impedance ratio in each of the first and second resonators 10 and 20 was set to 0.106, and the impedance ratio in the third resonator 30 was set to 0.094.

[0093] The model of the first embodiment is a model of the filter device of the first embodiment. The configuration of the filter device of the first embodiment is substantially the same as the configuration of the filter device 1 according to the present embodiment, except for the shapes of the second line portions 12 of the first resonator 10 and the second line portions 22 of the second resonator 20. In the filter device of the first embodiment, each of the second line portions 12 and 22 has a shape that is long in a direction intersecting the longitudinal direction, i.e., the X direction, of the planar shape of the laminate 50. When the second line portion 12 is viewed from a position at the front in the Z direction, the second line portion 12 extends in a direction parallel to a direction rotated 115° clockwise from the Y direction to the -Y direction (a direction rotated 25° from the X direction to the -Y direction). When the second line portion 22 is viewed from a position at the front in the Z direction, the second line portion 22 extends in a direction parallel to a direction rotated 115° counterclockwise from the Y direction to the -Y direction (a direction rotated 25° from the -X direction to the -Y direction). In the model of the first embodiment, the impedance ratio in each of the first and second resonators 10 and 20 is set to 0.106, and the impedance ratio in the third resonator 30 is set to 0.094.

[0094] The model of the second embodiment is a model of the filter device 1 according to the present embodiment. In the model of the second embodiment, the impedance ratio in each of the first and second resonators 10 and 20 is set to 0.106, and the impedance ratio in the third resonator 30 is set to 0.094.

[0095] In the simulation, for each of the models of the comparative example and the first and second embodiments, they were designed to function as a band-pass filter. Then, the pass attenuation characteristics of each of the models of the comparative example and the first and second embodiments were obtained.

[0096] FIG. 9 is a characteristic diagram showing the passing attenuation characteristics of the model of the comparative example. In FIG. 9, the horizontal axis represents the frequency, and the vertical axis represents the attenuation amount. As shown in FIG. 9, in the model of the comparative example, many spurs occur in the frequency region higher than the passing band (for example, the region where the frequency is 15 to 40 GHz). As a result, the absolute value of the attenuation amount in this frequency region becomes small.

[0097] FIG. 10 is a characteristic diagram showing the passing attenuation characteristics of the model of the first embodiment. In FIG. 10, the horizontal axis represents the frequency, and the vertical axis represents the attenuation amount. As shown in FIG. 10, in the model of the first embodiment, compared with the model of the comparative example, the number of spurs decreases, and in the frequency region higher than the passing band (for example, the region where the frequency is 15 to 40 GHz), the frequency region where the absolute value of the attenuation amount becomes large (for example, the frequency region where the absolute value of the attenuation amount is 10 dB or more) expands.

[0098] FIG. 11 is a characteristic diagram showing the passing attenuation characteristics of the model of the second embodiment. In FIG. 11, the horizontal axis represents the frequency, and the vertical axis represents the attenuation amount. As shown in FIG. 11, in the model of the second embodiment, compared with the models of the comparative example and the first embodiment, the number of spurs decreases, and as a result, the absolute value of the attenuation amount in the frequency region higher than the passing band becomes large.

[0099] The reason why the number of spurs decreases in the model of the second embodiment is considered as follows. In the model of the comparative example, the longitudinal direction of the second line portion 12 of the first resonator 10 and the longitudinal direction of the second line portion 22 of the second resonator 20 each coincide with the longitudinal direction of the second line portion 32 of the third resonator 30. Thereby, it is considered that the interaction between the second line portion 12 and the second line portion 32 and the interaction between the second line portion 22 and the second line portion 32 are strengthened, and spurs are generated.

[0100] In contrast, in the model of the second embodiment, the longitudinal direction of each of the second line portions 12 and 22 is made orthogonal to the longitudinal direction of the second line portion 32 to change the above interaction. Thereby, in the model of the second embodiment, it is considered that the number of spurs has decreased.

[0101] As described above, in the model of the first embodiment, the frequency region where the absolute value of the attenuation amount becomes larger is expanded compared to the model of the comparative example. The result of this simulation shows that if the above interaction can be changed, spurs can be suppressed not only when the longitudinal direction of each of the second line portions 12 and 22 is orthogonal to the longitudinal direction of the second line portion 32. Therefore, even when the longitudinal direction of each of the second line portions 12 and 22 intersects at an angle other than 90° with respect to the longitudinal direction of the second line portion 32, spurs can be suppressed.

[0102] [Second Embodiment] Next, with reference to FIGS. 12 to 14, a second embodiment of the present invention will be described. FIG. 12 is a circuit diagram showing the circuit configuration of the laminated filter device according to the present embodiment. FIG. 13 is an explanatory diagram showing the pattern formation surface of the seventh dielectric layer in the present embodiment. FIG. 14 is a perspective view showing the inside of the laminate of the laminated filter device according to the present embodiment.

[0103] The filter device 1 according to the present embodiment is different from the first embodiment in the following points. The filter device 1 according to the present embodiment includes a first stub-type resonator 91 electrically connected to the first line portion 11 of the first resonator 10, and a second stub-type resonator 92 electrically connected to the first line portion 21 of the second resonator 20. Each of the first and second stub-type resonators 91 and 92 is a distributed constant line.

[0104] The first stub-type resonator 91 is connected in the middle of the first line portion 11. In FIG. 12, among the first line portion 11, the portion located between the connection point with the first stub-type resonator 91 and the second line portion 12 in terms of circuit configuration is indicated by reference numeral 11A, and the portion located between the connection point with the first stub-type resonator 91 and the ground in terms of circuit configuration is indicated by reference numeral 11B.

[0105] The second stub-type resonator 92 is connected in the middle of the first line portion 21. In FIG. 12, among the first line portion 21, the portion located between the connection point with the second stub-type resonator 92 and the second line portion 22 in terms of circuit configuration is indicated by reference numeral 21A, and the portion located between the connection point with the second stub-type resonator 92 and the ground in terms of circuit configuration is indicated by reference numeral 21B.

[0106] Also, in the present embodiment, the laminate 50 includes a dielectric layer 157 shown in FIG. 13 instead of the seventh dielectric layer 57 in the first embodiment. Conductor layers 571 and 572 are formed on the pattern formation surface of the dielectric layer 157, similar to the dielectric layer 57. Further, conductor layers 573 and 574 are formed on the pattern formation surface of the dielectric layer 157. The conductor layer 573 is connected in the middle of the conductor layer 571. The conductor layer 574 is connected in the middle of the conductor layer 572. In FIG. 13, the boundaries between the conductor layer 571 and the conductor layer 573, and between the conductor layer 572 and the conductor layer 574 are each indicated by a dotted line.

[0107] The first stub-type resonator 91 is constituted by the conductor layer 572. The second stub-type resonator 92 is constituted by the conductor layer 574. The shape of the conductor layer 572 and the shape of the conductor layer 574 may be the same as each other or different from each other. In the example shown in FIG. 13, the shape of the conductor layer 572 and the shape of the conductor layer 574 are different from each other.

[0108] The first and second stub resonators 91 and 92 are used, for example, to control spurious signals generated in a frequency region higher than the passband. The first and second stub resonators 91 and 92 may each be an open stub with one end open or a short stub with one end connected to ground.

[0109] Other configurations, operations, and effects in this embodiment are the same as those in the first embodiment.

[0110] [Third Embodiment] Next, with reference to FIG. 15, a third embodiment of the present invention will be described. FIG. 15 is a circuit diagram showing the circuit configuration of the stacked filter device according to this embodiment.

[0111] The filter device 1 according to this embodiment is different from the second embodiment in the following points. The filter device 1 according to this embodiment includes a fourth resonator 40. The fourth resonator 40 is arranged between the second resonator 20 and the third resonator 30 in terms of circuit configuration. In this embodiment, the first to fourth resonators 10, 20, 30, and 40 are configured such that the first resonator 10 and the third resonator 30 are adjacent to each other in the circuit configuration and are electromagnetically coupled, the third resonator 30 and the fourth resonator 40 are adjacent to each other in the circuit configuration and are electromagnetically coupled, and the second resonator 20 and the fourth resonator 40 are adjacent to each other in the circuit configuration and are electromagnetically coupled. In FIG. 15, the curve marked with the symbol K13 represents the electric field coupling between the first resonator 10 and the third resonator 30, the curve marked with the symbol K34 represents the magnetic field coupling between the third resonator 30 and the fourth resonator 40, and the curve marked with the symbol K24 represents the electric field coupling between the second resonator 20 and the fourth resonator 40.

[0112] The configuration of the fourth resonator 40 is basically the same as that of the third resonator 30. That is, the fourth resonator 40 includes a first line portion 41 and a second line portion 42 having an impedance smaller than that of the first line portion 41. The first line portion 41 and the second line portion 42 are electrically connected to each other. The first line portion 41 is connected to the ground. Further, each of the first line portion 41 and the second line portion 42 is a distributed constant line. In particular, in the present embodiment, the first line portion 41 is a distributed constant line having a small width, and the second line portion 42 is a distributed constant line having a width larger than that of the first line portion 41.

[0113] Similar to the first to third resonators 10, 20, and 30, the fourth resonator 40 is a stepped impedance resonator composed of a distributed constant line with a small width and a distributed constant line with a large width.

[0114] Although not shown, the first line portion 41 and the second line portion 42 of the fourth resonator 40 are arranged at different positions from each other in the stacking direction T, similar to the first line portion 31 and the second line portion 32 of the third resonator 30. The first line portion 31 and the first line portion 41 may be arranged at the same position in the stacking direction T, or may be arranged at different positions in the stacking direction T. Similarly, the second line portion 32 and the second line portion 42 may be arranged at the same position in the stacking direction T, or may be arranged at different positions in the stacking direction T.

[0115] In the present embodiment, at least a part of the third resonator 30 and at least a part of the fourth resonator 40 are arranged between the first resonator 10 and the second resonator 20 when viewed from the Z direction (see FIG. 2).

[0116] Further, in the present embodiment, a part of the first line portion 11 of the first resonator 10 may overlap with the first line portion 31 of the third resonator 30 when viewed from the Z direction. In this case, a part of the first line portion 21 of the second resonator 20 may overlap with the first line portion 41 of the fourth resonator 40 when viewed from the Z direction.

[0117] Also, in the present embodiment, a part of the second line portion 12 of the first resonator 10 may overlap with the second line portion 32 of the third resonator 30 when viewed from the Z direction. In this case, a part of the second line portion 22 of the second resonator 20 may overlap with the second line portion 42 of the fourth resonator 40 when viewed from the Z direction.

[0118] The filter device 1 according to the present embodiment further includes a third stub type resonator 93 electrically connected to the first line portion 31 of the third resonator 30 and a fourth stub type resonator 94 electrically connected to the first line portion 41 of the fourth resonator 40. Each of the third and fourth stub type resonators 93 and 94 is a distributed constant line.

[0119] The third stub type resonator 93 is connected in the middle of the first line portion 31. In FIG. 15, a portion of the first line portion 31 located between the connection point with the third stub type resonator 93 and the second line portion 32 in terms of circuit configuration is denoted by reference numeral 31A, and a portion of the first line portion 31 located between the connection point with the third stub type resonator 93 and the ground is denoted by reference numeral 31B.

[0120] The fourth stub type resonator 94 is connected in the middle of the first line portion 41. In FIG. 15, a portion of the first line portion 41 located between the connection point with the fourth stub type resonator 94 and the second line portion 42 in terms of circuit configuration is denoted by reference numeral 41A, and a portion of the first line portion 41 located between the connection point with the fourth stub type resonator 94 and the ground is denoted by reference numeral 41B.

[0121] The third and fourth stub type resonators 93 and 94 are used, for example, to control spurious generated in a frequency region higher than the passband. Each of the third and fourth stub type resonators 93 and 94 may be an open stub with one end open or a short stub with one end connected to the ground.

[0122] Other configurations, operations, and effects in this embodiment are the same as those in the second embodiment.

[0123] Note that the present invention is not limited to the above-described embodiments, and various modifications are possible. For example, the number and configuration of the resonators are not limited to those shown in each embodiment, and any configuration may be used as long as it satisfies the claims. The number of resonators may be one, two, or five or more.

Description of Reference Numerals

[0124] 1... filter device, 2... first port, 3... second port, 4, 5... conductor parts, 10... first resonator, 11... first line part, 12... second line part, 13... conductor part, 20... second resonator, 21... first line part, 22... second line part, 23... conductor part, 30... third resonator, 31... first line part, 32... second line part, 50... laminate, 50A... first surface, 50B... second surface, 50C to 50F... side surfaces, 111... first terminal, 112... second terminal, 113 to 116... ground terminals.

Claims

1. A laminate including a plurality of stacked dielectric layers, and a first resonator, a second resonator, and a third resonator integrated with the laminate, wherein the laminate has a first side surface and a second side surface located at both ends in a direction orthogonal to the stacking direction of the plurality of dielectric layers, the first resonator is disposed closer to the first side surface than to the second side surface, the second resonator is disposed closer to the second side surface than to the first side surface, at least a part of the third resonator is disposed between the first resonator and the second resonator when viewed from a direction parallel to the stacking direction, each of the first resonator, the second resonator, and the third resonator includes a first line portion and a second line portion having an impedance smaller than that of the first line portion, an impedance ratio, which is a ratio of the impedance of the second line portion to the impedance of the first line portion in at least one of the first resonator, the second resonator, and the third resonator, is 0.3 or less, a shape of the second line portion of the third resonator is a rectangular shape that is long in a direction orthogonal to the stacking direction, a stacked filter device, wherein shapes of the second line portion of the first resonator and the second line portion of the second resonator are each long in a direction orthogonal to the stacking direction and intersecting a longitudinal direction of the second line portion of the third resonator.

2. The stacked filter device according to claim 1, wherein the impedance ratio in each of the first resonator, the second resonator, and the third resonator is 0.3 or less.

3. The stacked filter device according to claim 1 or 2, wherein a longitudinal direction of the second line portion of the first resonator and a longitudinal direction of the second line portion of the second resonator are orthogonal to a longitudinal direction of the second line portion of the third resonator.

4. The stacked filter device according to any one of claims 1 to 3, wherein the first line portion of the first resonator and the first line portion of the second resonator each include portions extending in a plurality of directions that are orthogonal to the stacking direction and different from each other.

5. The stacked filter device according to any one of claims 1 to 4, wherein the first line portion of the third resonator has an asymmetric shape.

6. Furthermore, a first stub type resonator electrically connected to the first line portion of the first resonator, and a second stub type resonator electrically connected to the first line portion of the second resonator, wherein the laminated filter device according to any one of claims 1 to 5 is provided.

7. The third resonator is arranged between the first resonator and the second resonator in terms of circuit configuration, wherein the laminated filter device according to any one of claims 1 to 6 is provided.

8. In each of the first resonator, the second resonator, and the third resonator, the first line portion and the second line portion are arranged at different positions from each other in the stacking direction and are electrically connected to each other, wherein the laminated filter device according to any one of claims 1 to 7 is provided.

9. Furthermore, a plurality of through holes connecting the first line portion and the second line portion of each of the first resonator, the second resonator, and the third resonator are provided, wherein the laminated filter device according to claim 8 is provided.

10. The first line portion of the first resonator and the first line portion of the second resonator are arranged at the same position in the stacking direction, the first line portion of the third resonator is arranged at a position different from the first line portions of each of the first resonator and the second resonator in the stacking direction, wherein the laminated filter device according to claim 8 or 9 is provided.

11. The second line portion of the first resonator and the second line portion of the second resonator are arranged at the same position in the stacking direction, the second line portion of the third resonator is arranged at a position different from the second line portions of each of the first resonator and the second resonator in the stacking direction, wherein the laminated filter device according to any one of claims 8 to 10 is provided.

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