Bandpass filter

Abstract

A band-pass filter includes a first input-output port, a second input-output port, a first high-pass filter, a first low-pass filter, and a first stub resonator. The first stub resonator includes a first distributed constant line. The first low-pass filter is disposed between the first input-output port and the first high-pass filter in a circuit structure. The first distributed constant line has a first end connected to a first path connecting the first input-output port and the first low-pass filter, and a second end closest to a ground line in the circuit structure.

Description

Technical Field

[0001] This invention relates to a bandpass filter comprising a high-pass filter and a low-pass filter. Background Technology

[0002] In recent years, the market has demanded miniaturization and space-saving in small mobile communication devices, and also miniaturization of the bandpass filters used in these devices. As a bandpass filter suitable for miniaturization, bandpass filters using laminates comprising multiple dielectric layers and multiple conductor layers are known.

[0003] A bandpass filter can be constructed by connecting a high-pass filter, which forms an attenuation electrode on the low-frequency side of the passband of the bandpass filter, and a low-pass filter, which forms an attenuation electrode on the high-frequency side of the passband of the bandpass filter, in series. The high-pass filter and the low-pass filter can each be filters containing at least one inductor and at least one capacitor, respectively.

[0004] A bandpass filter that connects a high-pass filter and a low-pass filter in series is disclosed in Japanese Patent Application Publication No. Hei 9-181549 and Japanese Patent Application Publication No. 2009-267811.

[0005] Currently, communication services using the fifth-generation mobile communication system (hereinafter referred to as 5G) are being offered. In 5G, it is assumed that frequency bands above 10 GHz are utilized, particularly the 10–30 GHz submillimeter wave band or the 30–300 GHz millimeter wave band. Therefore, if higher frequency bands are used than before, the bandpass filter is also required to meet characteristics at higher frequency bands. For example, it is required to increase the pass-through attenuation of the bandpass filter on the high-frequency side of the passband. Summary of the Invention

[0006] The purpose of this invention is to provide a bandpass filter that can increase the pass attenuation on the high-frequency side of the passband.

[0007] The bandpass filter of the present invention selectively allows signals of frequencies within a specified passband to pass through. The bandpass filter includes: a first input / output port; a second input / output port; and a first high-pass filter, a first low-pass filter, and a first stub resonator, which are arranged in a circuit structure between the first and second input / output ports. The first high-pass filter and the first low-pass filter each include at least one first inductor and at least one first capacitor. The first stub resonator includes a first distributed constant line.

[0008] The first low-pass filter is positioned between the first input / output port and the first high-pass filter in the circuit structure. The first distributed constant line has a first end connected to the first path connecting the first input / output port and the first low-pass filter, and a second end that is closest to the ground line in the circuit structure.

[0009] In the bandpass filter of the present invention, the first stub resonator may further include a second capacitor, which is disposed in the circuit structure between the first distribution constant line and the ground line.

[0010] In addition, in the bandpass filter of the present invention, the first low-pass filter and the first stub resonator can also form attenuation poles on the high-frequency side of the passband, respectively.

[0011] In addition, in the bandpass filter of the present invention, the first distribution constant line can also be a 1 / 4 wavelength line.

[0012] Furthermore, the bandpass filter of the present invention may also include a stack comprising multiple stacked dielectric layers and multiple conductor layers, for integrating a first input / output port, a second input / output port, a first high-pass filter, a first low-pass filter, and a first stub-type resonator. In this case, the multiple conductor layers may also include a first conductor line constituting a first distribution constant line and a ground conductor layer connected to a ground line. A portion of the first conductor line may also be opposite to the ground conductor layer.

[0013] Furthermore, the bandpass filter of the present invention may also include a second high-pass filter, a second low-pass filter, and a second stub-type resonator, which are arranged in the circuit structure between the first high-pass filter and the second input / output port. In this case, the second high-pass filter and the second low-pass filter may each include at least one second inductor and at least one third capacitor, and the second stub-type resonator may also include a second distributed constant line. The second low-pass filter may also be arranged in the circuit structure between the second input / output port and the second high-pass filter. The second distributed constant line may also have a third terminal connected to the second path connecting the second input / output port and the second low-pass filter, and a fourth terminal that is closest to the ground line in the circuit structure.

[0014] In addition, in the bandpass filter of the present invention, the second stub resonator may also include a fourth capacitor, which is disposed between the second distribution constant line and the ground line in the circuit structure.

[0015] In addition, in the bandpass filter of the present invention, the second distribution constant line can also be a 1 / 4 wavelength line.

[0016] Furthermore, the bandpass filter of the present invention may also include a stack comprising multiple stacked dielectric layers and multiple conductor layers, for integrating a first input / output port, a second input / output port, a first high-pass filter, a first low-pass filter, a first stub resonator, a second high-pass filter, a second low-pass filter, and a second stub resonator. In this case, the multiple conductor layers may also include a first conductor line constituting a first distribution constant line, a second conductor line constituting a second distribution constant line, and a ground conductor layer connected to a ground line. A portion of the first conductor line and a portion of the second conductor line may also be respectively opposite to the ground line.

[0017] Furthermore, the bandpass filter of the present invention may also include at least one resonator, which is disposed in the circuit structure between the first high-pass filter and the second high-pass filter. In this case, the at least one resonator may also include a third inductor, which is disposed in the circuit structure between the third path connecting the first high-pass filter and the second high-pass filter and the ground line.

[0018] The bandpass filter of the present invention includes a first high-pass filter, a first low-pass filter, and a first stub resonator. The first stub resonator includes a first distributed constant line. The first low-pass filter is disposed between a first input / output port and the first high-pass filter in the circuit structure. The first distributed constant line is connected to a first path connecting the first input / output port and the first low-pass filter. Therefore, according to the present invention, the pass-through attenuation can be increased on the high-frequency side of the passband.

[0019] Other objects, features, and benefits of the present invention will become sufficiently clear from the following description. Attached Figure Description

[0020] Figure 1 This is a circuit diagram illustrating the circuit structure of a bandpass filter according to one embodiment of the present invention.

[0021] Figure 2 This is a perspective view showing the appearance of a bandpass filter according to one embodiment of the present invention.

[0022] Figures 3A to 3C This is an explanatory diagram showing the pattern formation surface of the first to third dielectric layers in a stack of a bandpass filter according to an embodiment of the present invention.

[0023] Figures 4A to 4C This is an explanatory diagram showing the pattern formation surface of the fourth to sixth dielectric layers in a stack of a bandpass filter according to an embodiment of the present invention.

[0024] Figures 5A to 5CThis is an explanatory diagram showing the pattern formation surface of the seventh to ninth dielectric layers in a stack of a bandpass filter according to an embodiment of the present invention.

[0025] Figures 6A to 6C This is an explanatory diagram showing the pattern formation surface of the tenth to twelfth dielectric layers in a stack of layers of a bandpass filter according to an embodiment of the present invention.

[0026] Figures 7A to 7C This is an explanatory diagram showing the pattern formation surface of the thirteenth to fifteenth dielectric layers in a stack of layers of a bandpass filter according to one embodiment of the present invention.

[0027] Figures 8A to 8C This is an explanatory diagram showing the pattern formation surface of the sixteenth to eighteenth dielectric layers in a stack of a bandpass filter according to an embodiment of the present invention.

[0028] Figure 9A and Figure 9B This is an explanatory diagram showing the pattern formation surfaces of the nineteenth and twentieth dielectric layers in a stack of a bandpass filter according to an embodiment of the present invention.

[0029] Figure 10 This is a perspective view of the interior of a stack of bandpass filters according to one embodiment of the present invention.

[0030] Figure 11 It means Figure 10 A three-dimensional view of a portion of the interior of the stacked body shown.

[0031] Figure 12 It means Figure 10 A cross-sectional view of a portion of the interior of the stacked body shown.

[0032] Figure 13 This is a characteristic diagram illustrating the attenuation characteristics of an example of the model in the embodiment and the model in the comparative example.

[0033] Figure 14 This is a characteristic diagram showing the insertion loss of the model in the embodiment and the model in the comparative example.

[0034] Figure 15 This is a characteristic diagram showing the reflection loss of the first input / output port of the model in the embodiment and the model in the comparative example.

[0035] Figure 16 This is a characteristic diagram showing the reflection loss of the second input / output port of the model in the embodiment and the model in the comparative example. Detailed Implementation

[0036] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. First, referring to... Figure 1A general description of the structure of a bandpass filter 1 according to one embodiment of the present invention will be provided. The bandpass filter 1 of this embodiment is a filter that selectively allows signals of frequencies within a defined passband to pass through. The bandpass filter 1 includes a first input / output port 2, a second input / output port 3, a first high-pass filter 12, a first low-pass filter 11, a second high-pass filter 22, a second low-pass filter 21, a resonator 31, a first stub resonator 41, and a second stub resonator 42. The first high-pass filter 12, the first low-pass filter 11, the second high-pass filter 22, the second low-pass filter 21, the resonator 31, the first stub resonator 41, and the second stub resonator 42 are arranged in the circuit structure between the first input / output port 2 and the second input / output port 3.

[0037] Furthermore, in this application, expressions such as "in terms of circuit structure" are not physical structural configurations, but are used to indicate configurations on a circuit diagram.

[0038] The first low-pass filter 11 is positioned between the first input / output port 2 and the first high-pass filter 12 in the circuit structure. Furthermore, the first low-pass filter 11 is connected to the first input / output port 2.

[0039] The second high-pass filter 22 is disposed between the first high-pass filter 12 and the second input / output port 3 in the circuit structure. The second low-pass filter 21 is disposed between the second input / output port 3 and the second high-pass filter 22 in the circuit structure. In addition, the second low-pass filter 21 is connected to the second input / output port 3.

[0040] The resonator 31 is positioned in the circuit structure between the first high-pass filter 12 and the second high-pass filter 22.

[0041] The first high-pass filter 12, the first low-pass filter 11, the second high-pass filter 22, and the second low-pass filter 21 are each composed of an LC resonant circuit containing an inductor and a capacitor.

[0042] The resonator 31 includes an inductor that is positioned in the circuit structure between the path 4 connecting the first high-pass filter 12 and the second low-pass filter 21 and the ground wire.

[0043] The first stub-type resonator 41 includes a first distribution constant line 41A and a capacitor C41. The first distribution constant line 41A is a quarter-wavelength line. The first distribution constant line 41A has a first terminal 41Aa connected to a first path 5 that connects the first input / output port 2 and the first low-pass filter 11, and a second terminal 41Ab that is structurally closest to ground. The capacitor C41 is structurally positioned between the first distribution constant line 41A and ground.

[0044] The second stub-type resonator 42 includes a second distribution constant line 42A and a capacitor C42. The second distribution constant line 42A is a quarter-wavelength line. The second distribution constant line 42A has a first terminal 42Aa connected to the second path 6 that connects the second input / output port 3 and the second low-pass filter 21, and a second terminal 42Ab that is structurally closest to ground. The capacitor C42 is structurally positioned between the second distribution constant line 42A and ground.

[0045] Next, refer to Figure 1 An example of the structure of the first high-pass filter 12, the first low-pass filter 11, the second high-pass filter 22, the second low-pass filter 21, and the resonator 31 will be described.

[0046] The first low-pass filter 11 includes an inductor L11 and capacitors C11 and C12. One end of the inductor L11 is connected to the first input / output port 2. Capacitor C11 is connected in parallel with inductor L11. One end of capacitor C12 is connected to the other end of inductor L11. The other end of capacitor C12 is connected to ground.

[0047] The first high-pass filter 12 includes an inductor L12 and capacitors C13, C14, C15, and C16. One end of capacitor C13 is connected to the other end of inductor L11 of the first low-pass filter 11. One end of capacitor C14 is connected to the other end of capacitor C13. One end of capacitor C15 is connected to one end of capacitor C13. The other end of capacitor C15 is connected to the other end of capacitor C14.

[0048] One end of inductor L12 is connected to the junction of capacitors C13 and C14. The other end of inductor L12 is connected to ground. Capacitor C16 is connected in parallel with inductor L12.

[0049] The second low-pass filter 21 includes an inductor L21 and a capacitor C21. One end of the inductor L21 is connected to the second input / output port 3. The capacitor C21 is connected in parallel with the inductor L21.

[0050] The second high-pass filter 22 includes an inductor L22 and capacitors C23, C24, C25, and C26. One end of capacitor C23 is connected to the other end of inductor L21 of the second low-pass filter 21. One end of capacitor C24 is connected to the other end of capacitor C23. One end of capacitor C25 is connected to one end of capacitor C23. The other end of capacitor C25 is connected to the other end of capacitor C24.

[0051] One end of inductor L22 is connected to the junction of capacitors C23 and C24. The other end of inductor L22 is connected to ground. Capacitor C26 is connected in parallel with inductor L22.

[0052] Path 4, which connects the first high-pass filter 12 and the second high-pass filter 22, connects the other end of capacitor C14 of the first high-pass filter 12 and the other end of capacitor C24 of the second high-pass filter 22.

[0053] The resonator 31 includes an inductor L31 and a capacitor C31. One end of the inductor L31 is connected to path 4 in the circuit structure, closer to the first high-pass filter 12 than the second high-pass filter 22. One end of the capacitor C31 is connected to the other end of the inductor L31. The other end of the capacitor C31 is connected to ground.

[0054] Next, refer to Figure 2 The other structures of bandpass filter 1 will be described. Figure 2 This is a three-dimensional view showing the appearance of bandpass filter 1.

[0055] The bandpass filter 1 also includes a stack 50 comprising multiple dielectric layers and multiple conductor layers. The stack 50 integrates the first input / output port 2, the second input / output port 3, the first high-pass filter 12, the first low-pass filter 11, the second high-pass filter 22, the second low-pass filter 21, the resonator 31, the first stub resonator 41, and the second stub resonator 42. The first high-pass filter 12, the first low-pass filter 11, the second high-pass filter 22, the second low-pass filter 21, the resonator 31, the first stub resonator 41, and the second stub resonator 42 are constructed using multiple conductor layers.

[0056] The laminate 50 has a bottom surface 50A and a top surface 50B located at both ends of the lamination direction T of the plurality of dielectric layers, and four side surfaces 50C to 50F connecting the bottom surface 50A and the top surface 50B. Side surfaces 50C and 50D face opposite sides to each other, and side surfaces 50E and 50F also face opposite sides to each other. Side surfaces 50C to 50F are perpendicular to the top surface 50B and the bottom surface 50A.

[0057] Here, as Figure 2 As shown, the X, Y, and Z directions are defined. The X, Y, and Z directions are orthogonal to each other. In this embodiment, the direction parallel to the stacking direction T is designated as the Z direction. Furthermore, the direction opposite to the X direction is designated as the -X direction, the direction opposite to the Y direction as the -Y direction, and the direction opposite to the Z direction as the -Z direction.

[0058] like Figure 2As shown, bottom surface 50A is located at one end of the laminate 50 in the -Z direction. Top surface 50B is located at one end of the laminate 50 in the Z direction. Both bottom surface 50A and top surface 50B are rectangular shapes that are longer in the X direction. Side surface 50C is located at one end of the laminate 50 in the -X direction. Side surface 50D is located at one end of the laminate 50 in the X direction. Side surface 50E is located at one end of the laminate 50 in the -Y direction. Side surface 50F is located at one end of the laminate 50 in the Y direction.

[0059] The bandpass filter 1 also includes a plurality of terminals 111, 112, 113, 114, 115, and 116 disposed on the bottom surface 50A of the laminate 50. Terminal 111 extends along the Y direction near side surface 50C. Terminal 112 extends along the Y direction near side surface 50D. Terminals 113 to 116 are disposed between terminals 111 and 112. Terminals 113 and 114 are arranged sequentially along the X direction at a position closer to side surface 50E than side surface 50F. Terminals 115 and 116 are arranged sequentially along the X direction at a position closer to side surface 50F than side surface 50E.

[0060] Terminal 111 corresponds to the first input / output port 2, and terminal 112 corresponds to the second input / output port 3. Therefore, the first and second input / output ports 2 and 3 are disposed on the bottom surface 50A of the laminate 50. Terminals 113 to 116 are each connected to the ground wire.

[0061] Next, refer to Figures 3A to 9B An example of the plurality of dielectric layers and the plurality of conductor layers constituting the laminate 50 will be described. In this example, the laminate 50 has twenty dielectric layers stacked together. Hereinafter, these twenty dielectric layers will be referred to as the first to the twentieth dielectric layers from bottom to top. In addition, the first to the twentieth dielectric layers will be represented by the symbols 51 to 70.

[0062] Figure 3A This indicates the patterned surface of the first dielectric layer 51. Terminals 111, 112, 113, 114, 115, and 116 are formed on the patterned surface of the dielectric layer 51. Additionally, through-holes 51T1, 51T2, 51T3, 51T4, 51T5, 51T6, and 51T7 are formed on the dielectric layer 51. Through-hole 51T1 is connected to terminal 111. Through-holes 51T2 and 51T3 are connected to terminal 112. Through-holes 51T4 to 51T7 are connected to terminals 113 to 116, respectively.

[0063] Figure 3BThis indicates the patterned surface of the second dielectric layer 52. Conductor layers 521 and 522 and a ground conductor layer 523 are formed on the patterned surface of the dielectric layer 52. Additionally, vias 52T1, 52T2, 52T3, 52T4, and 52T5 are formed on the dielectric layer 52. Vias 51T1 and 52T1 formed in the dielectric layer 51 are connected to the conductor layer 521. Vias 51T2, 51T3, and 52T2 and 52T5 formed in the dielectric layer 51 are connected to the conductor layer 522. Vias 51T4 to 51T7 and 52T3 and 52T4 formed in the dielectric layer 51 are connected to the ground conductor layer 523.

[0064] Figure 3C This indicates the patterned surface of the third dielectric layer 53. A first conductor line 531 constituting a first distribution constant line and a second conductor line 532 constituting a second distribution constant line are formed on the patterned surface of the dielectric layer 53. Additionally, vias 53T1, 53T2, 53T3, and 53T4 are formed on the dielectric layer 53. Vias 52T1 and 53T1 formed in the dielectric layer 52 are connected to the first conductor line 531. Vias 52T2 to 52T4 formed in the dielectric layer 52 are connected to vias 53T2 to 53T4, respectively. Via 52T5 formed in the dielectric layer 52 is connected to the second conductor line 532.

[0065] Figure 4A This indicates the patterned surface of the fourth dielectric layer 54. Conductor layers 541, 542, and 543 are formed on the patterned surface of the dielectric layer 54. Additionally, vias 54T1, 54T2, 54T3, 54T4, 54T5, 54T6, and 54T7 are formed on the dielectric layer 54. Vias 53T1 to 53T4 formed in the dielectric layer 53 are connected to each other. Via 54T5 is connected to conductor layer 541. Via 54T6 is connected to conductor layer 543. Via 54T7 is connected to conductor layer 542.

[0066] Figure 4B This indicates the patterned surface of the fifth dielectric layer 55. Conductor layers 551 and 552 are formed on the patterned surface of the dielectric layer 55. Additionally, vias 55T1, 55T2, 55T3, 55T4, 55T5, 55T6, 55T7, 55T8, and 55T9 are formed on the dielectric layer 55. Vias 54T1 to 54T7 formed in the dielectric layer 54 are connected to vias 55T1 to 55T7, respectively. Via 55T8 is connected to conductor layer 552. Via 55T9 is connected to conductor layer 551.

[0067] Figure 4CThis indicates the patterned surface of the sixth dielectric layer 56. Conductor layers 561, 562, and 563 are formed on the patterned surface of the dielectric layer 56. Additionally, vias 56T1, 56T2, 56T3, 56T4, 56T5, 56T6, 56T7, 56T8, 56T9, and 56T10 are formed on the dielectric layer 56. Vias 55T1–55T5, 55T8, and 55T9 formed in the dielectric layer 55 are connected to vias 56T1–56T5, 56T8, and 56T9, respectively. Vias 55T6 and 56T6 formed in the dielectric layer 55 are connected to conductor layer 562. Vias 55T7 and 56T7 formed in the dielectric layer 55 are connected to conductor layer 561. Via 56T10 is connected to conductor layer 563.

[0068] Figure 5A This indicates the patterned surface of the seventh dielectric layer 57. Conductor layers 571 and 572 are formed on the patterned surface of the dielectric layer 57. Conductor layer 571 has a first end and a second end located on opposite sides of each other. Additionally, vias 57T1, 57T2, 57T3, 57T4, 57T5, 57T6, 57T7, 57T8, 57T9, and 57T10 are formed on the dielectric layer 57. The vias 56T1–56T4, 56T7, 56T8, and 56T10 formed in the dielectric layer 56 are connected to the vias 57T1–57T4, 57T7, 57T8, and 57T10, respectively. The via 56T6 formed in the dielectric layer 56 is connected to the via 57T9. The via 56T9 formed in the dielectric layer 56 is connected to the conductor layer 572. Vias 56T5 and 57T5 formed in dielectric layer 56 are connected to the portion near the first end of conductor layer 571. Via 57T6 is connected to the portion near the second end of conductor layer 571.

[0069] Figure 5B This indicates the patterned surface of the eighth dielectric layer 58. Conductor layers 581 and 582 are formed on the patterned surface of the dielectric layer 58. Conductor layer 581 has a first end and a second end located on opposite sides of each other. Additionally, vias 58T1, 58T2, 58T3, 58T4, 58T5, 58T6, 58T7, and 58T8 are formed on the dielectric layer 58. Vias 57T1 to 57T4 and 57T7 formed in the dielectric layer 57 are connected to vias 58T1 to 58T4 and 58T7, respectively. Via 57T5 formed in the dielectric layer 57 is connected to a portion near the first end of conductor layer 581. Vias 57T6 and 58T6 formed in the dielectric layer 57 are connected to a portion near the second end of conductor layer 581. Via 57T9 formed in the dielectric layer 57 is connected to via 58T5. The via 57T10 formed in the dielectric layer 57 is connected to the conductor layer 582.

[0070] Figure 5C This indicates the patterned surface of the ninth dielectric layer 59. Conductor layers 591 and 592 are formed on the patterned surface of the dielectric layer 59. Conductor layers 591 and 592 each have a first end and a second end located on opposite sides of each other. Additionally, vias 59T1, 59T2, 59T3, 59T4, 59T5, 59T6, 59T7, 59T8, and 59T9 are formed on the dielectric layer 59. Via 58T1 and 59T1 formed in the dielectric layer 58 are connected to the portion near the first end of the conductor layer 591. Via 58T2 to 58T4, 58T7, and 58T8 formed in the dielectric layer 58 are connected to vias 59T2 to 59T4, 59T7, and 59T8, respectively. Via 58T5 and 59T5 formed in the dielectric layer 58 are connected to the portion near the first end of the conductor layer 592. Through-holes 58T6 and 59T6 formed in dielectric layer 58 are connected to the portion near the second end of conductor layer 591. Through-hole 59T9 is connected to the portion near the second end of conductor layer 592.

[0071] Figure 6A This indicates the patterned surface of the tenth dielectric layer 60. Conductor layers 601 and 602 are formed on the patterned surface of the dielectric layer 60. Conductor layers 601 and 602 each have a first end and a second end located on opposite sides of each other. Additionally, vias 60T1, 60T2, 60T3, 60T4, 60T5, and 60T6 are formed on the dielectric layer 60. Via 59T1 formed in the dielectric layer 59 is connected to a portion near the first end of the conductor layer 601. Via 59T2 to 59T4 formed in the dielectric layer 59 are connected to vias 60T2 to 60T4, respectively. Via 59T5 formed in the dielectric layer 59 is connected to a portion near the first end of the conductor layer 602. Via 59T6 formed in the dielectric layer 59 is connected to a portion near the second end of the conductor layer 601. Via 59T7 formed in the dielectric layer 59 is connected to via 60T1. Through-hole 59T8 formed in dielectric layer 59 is connected to through-hole 60T6. Through-hole 59T9 and through-hole 60T5 formed in dielectric layer 59 are connected to the portion near the second end of conductor layer 602.

[0072] Figure 6BThis indicates the patterned surface of the eleventh dielectric layer 61. A conductor layer 611 is formed on the patterned surface of the dielectric layer 61. The conductor layer 611 has a first end and a second end located on opposite sides of each other. Furthermore, vias 61T1, 61T2, 61T3, 61T4, 61T5, and 61T6 are formed on the dielectric layer 61. The vias 60T1, 60T3, 60T4, and 60T6 formed in the dielectric layer 60 are connected to the vias 61T1, 61T3, 61T4, and 61T6, respectively. The vias 60T2 and 61T2 formed in the dielectric layer 60 are connected to the portion near the first end of the conductor layer 611. The vias 60T5 and 61T5 formed in the dielectric layer 60 are connected to the portion near the second end of the conductor layer 611.

[0073] Figure 6C This indicates the patterned surface of the twelfth dielectric layer 62. A conductor layer 621 is formed on the patterned surface of the dielectric layer 62. The conductor layer 621 has a first end and a second end located on opposite sides of each other. Furthermore, vias 62T1, 62T2, 62T3, and 62T4 are formed on the dielectric layer 62. The vias 61T1, 61T3, and 61T4 formed in the dielectric layer 61 are connected to the vias 62T1, 62T3, and 62T4, respectively. The via 61T2 formed in the dielectric layer 61 is connected to a portion near the first end of the conductor layer 621. The via 61T5 formed in the dielectric layer 61 is connected to a portion near the second end of the conductor layer 621. The via 61T6 formed in the dielectric layer 61 is connected to the via 62T2.

[0074] Figure 7A This indicates the pattern formation surface of the thirteenth dielectric layer 63. Through-holes 63T1, 63T2, 63T3, and 63T4 are formed on the dielectric layer 63. Through-holes 62T1 to 62T4 formed in the dielectric layer 62 are respectively connected to through-holes 63T1 to 63T4.

[0075] Figure 7B This indicates the patterned surface of the fourteenth dielectric layer 64. A conductor layer 641 is formed on the patterned surface of the dielectric layer 64. The conductor layer 641 has a first end and a second end located on opposite sides of each other. Furthermore, vias 64T1, 64T2, 64T3, 64T4, and 64T5 are formed on the dielectric layer 64. Vias 63T1 and 64T1 formed in the dielectric layer 63 are connected to the portion near the first end of the conductor layer 641. Vias 63T2 to 63T4 formed in the dielectric layer 63 are connected to vias 64T2 to 64T4, respectively. Via 64T5 is connected to the portion near the second end of the conductor layer 641.

[0076] Figure 7CThis indicates the patterned surface of the fifteenth dielectric layer 65. A conductor layer 651 is formed on the patterned surface of the dielectric layer 65. The conductor layer 651 has a first end and a second end located on opposite sides of each other. Furthermore, vias 65T1, 65T2, 65T3, and 65T4 are formed on the dielectric layer 65. The via 64T1 formed in the dielectric layer 64 is connected to a portion near the first end of the conductor layer 651. The vias 64T2 to 64T4 formed in the dielectric layer 64 are connected to the vias 65T2 to 65T4, respectively. The vias 64T5 and 65T1 formed in the dielectric layer 64 are connected to a portion near the second end of the conductor layer 651.

[0077] Figure 8A This indicates the patterned surface of the sixteenth dielectric layer 66. A conductor layer 661 is formed on the patterned surface of the dielectric layer 66. The conductor layer 661 has a first end and a second end located on opposite sides of each other. Furthermore, vias 66T1, 66T2, 66T3, 66T4, and 66T5 are formed on the dielectric layer 66. The vias 65T1, 65T3, and 65T4 formed in the dielectric layer 65 are connected to the vias 66T1, 66T3, and 66T4, respectively. The vias 65T2 and 66T2 formed in the dielectric layer 65 are connected to the portion near the first end of the conductor layer 661. The via 66T5 is connected to the portion near the second end of the conductor layer 661.

[0078] Figure 8B This indicates the patterned surface of the seventeenth dielectric layer 67. A conductor layer 671 is formed on the patterned surface of the dielectric layer 67. The conductor layer 671 has a first end and a second end located on opposite sides of each other. Furthermore, vias 67T1, 67T2, 67T3, and 67T4 are formed on the dielectric layer 67. The vias 66T1, 66T3, and 66T4 formed in the dielectric layer 66 are connected to the vias 67T1, 67T3, and 67T4, respectively. The via 66T2 formed in the dielectric layer 66 is connected to the portion near the first end of the conductor layer 671. The vias 66T5 and 67T2 formed in the dielectric layer 66 are connected to the portion near the second end of the conductor layer 671.

[0079] Figure 8CThis indicates the patterned surface of the eighteenth dielectric layer 68. Conductor layers 681 and 682 are formed on the patterned surface of the dielectric layer 68. Conductor layers 681 and 682 each have a first end and a second end located on opposite sides of each other. Additionally, vias 68T1, 68T2, 68T3, and 68T4 are formed on the dielectric layer 68. Via 67T1 and 68T1 formed in the dielectric layer 67 are connected to the vicinity of the first end of conductor layer 681. Via 67T2 and 68T2 formed in the dielectric layer 67 are connected to the vicinity of the first end of conductor layer 682. Via 67T3 and 68T3 formed in the dielectric layer 67 are connected to the vicinity of the second end of conductor layer 681. Via 67T4 and 68T4 formed in the dielectric layer 67 are connected to the vicinity of the second end of conductor layer 682.

[0080] Figure 9A This indicates the patterned surface of the nineteenth dielectric layer 69. Conductor layers 691 and 692 are formed on the patterned surface of dielectric layer 69. Conductor layers 691 and 692 each have a first end and a second end located on opposite sides of each other. A via 68T1 formed in dielectric layer 68 connects to a portion near the first end of conductor layer 691. A via 68T2 formed in dielectric layer 68 connects to a portion near the first end of conductor layer 692. A via 68T3 formed in dielectric layer 68 connects to a portion near the second end of conductor layer 691. A via 68T4 formed in dielectric layer 68 connects to a portion near the second end of conductor layer 692.

[0081] Figure 9B This indicates the patterning surface of the twentieth dielectric layer 70. A mark 701 composed of a conductor layer is formed on the patterning surface of the dielectric layer 70.

[0082] Figure 2 The stack 50 shown is constructed by stacking the first to twentieth dielectric layers 51 to 70 in such a way that the pattern-forming surface of the first dielectric layer 51 becomes the bottom surface 50A of the stack 50, and the surface of the twentieth dielectric layer 70 opposite to the pattern-forming surface becomes the upper surface 50B of the stack 50.

[0083] Figure 10 This refers to the interior of the laminate 50, which is formed by stacking the first to twentieth dielectric layers 51 to 70. For example... Figure 10 As shown, the following are stacked inside the laminate 50: Figures 3A to 9B Multiple conductor layers and multiple through-holes are shown. Furthermore, in... Figure 10 The marker 701 has been omitted. Additionally, Figure 11 express Figure 10 A portion of the interior of the stacked body 50 shown. Specifically, Figure 11It mainly represents the ground conductor layer 523, the first conductor line 531, and the second conductor line 532.

[0084] Below, on Figure 1 The components of the bandpass filter 1 circuit shown are... Figures 3A to 9B The correspondence of the internal components of the stacked body 50 shown will be explained. First, the components of the first low-pass filter 11 will be explained. The inductor L11 consists of... Figures 5A to 6A The conductor layers 571, 581, 591, and 601 shown are constituted, along with a plurality of through-holes connected to these conductor layers. Here, the shape of the conductor layer when viewed from a direction parallel to the stacking direction T (Z direction) is referred to as the planar shape of the conductor layer. In this embodiment, in particular, the planar shape of conductor layer 571 is the same as or substantially the same as the planar shape of conductor layer 581. Furthermore, the planar shape of conductor layer 591 is the same as or substantially the same as the planar shape of conductor layer 601. Conductor layers 571 and 581 are connected in parallel via through-holes 57T5 and 57T6. Conductor layers 591 and 601 are connected in parallel via through-holes 59T1 and 59T6.

[0085] Capacitor C11 is made of Figure 3A Terminal 111 shown Figure 4A The conductor layer 541, the terminal 111, and the dielectric layers 51 to 53 between the conductor layer 541 are shown.

[0086] Capacitor C12 is made of Figure 3B The ground wire uses conductor layer 523. Figure 4A The conductor layer 541 shown is composed of dielectric layers 52 and 53 between these conductor layers.

[0087] Next, the constituent elements of the first high-pass filter 12 will be explained. The inductor L12 consists of... Figure 7B , Figure 7C , Figure 8C and Figure 9A The conductor layers 641, 651, 681, and 691 shown are constituted, along with a plurality of through-holes connected to these conductor layers. In this embodiment, in particular, the planar shape of conductor layer 641 is the same as or substantially the same as the planar shape of conductor layer 651. Furthermore, the planar shape of conductor layer 681 is the same as or substantially the same as the planar shape of conductor layer 691. Conductor layers 641 and 651 are connected in parallel via through-holes 64T1 and 64T5. Conductor layers 681 and 691 are connected in parallel via through-holes 68T1 and 68T3.

[0088] Capacitor C13 is made of Figure 4A The conductor layers 541 and 542 shown are formed.

[0089] Capacitor C14 is made of Figures 4B to 5AThe conductor layers 551, 561, and 572 shown, and the dielectric layers 55 and 56 between these conductor layers, constitute the structure.

[0090] Capacitor C15 is made of Figure 4A and Figure 4B The conductor layers 541 and 551 shown are composed of the dielectric layer 54 between these conductor layers.

[0091] Capacitor C16 is made of Figure 3B The ground wire uses conductor layer 523. Figure 4A The conductor layer 542 shown, and the dielectric layers 52 and 53 between these conductor layers constitute the structure.

[0092] Next, the constituent elements of the second low-pass filter 21 will be explained. The inductor L21 consists of... Figures 5C to 6C The conductor layers 592, 602, 611, and 621 shown are constituted, along with a plurality of through-holes connected to these conductor layers. In this embodiment, in particular, the planar shape of conductor layer 592 is the same as or substantially the same as the planar shape of conductor layer 602. Furthermore, the planar shape of conductor layer 611 is the same as or substantially the same as the planar shape of conductor layer 621. Conductor layers 592 and 602 are connected in parallel via through-holes 59T5 and 59T9. Conductor layers 611 and 621 are connected in parallel via through-holes 61T2 and 61T5.

[0093] Capacitor C21 is made of Figure 3B and Figure 4A The conductor layers 522 and 543 shown are composed of dielectric layers 52 and 53 between these conductor layers.

[0094] Next, the constituent elements of the second high-pass filter 22 will be explained. The inductor L22 consists of... Figures 8A to 9A The conductor layers 661, 671, 682, and 692 shown are constituted, along with a plurality of through-holes connected to these conductor layers. In this embodiment, in particular, the planar shape of conductor layer 661 is the same as or substantially the same as the planar shape of conductor layer 671. Furthermore, the planar shape of conductor layer 682 is the same as or substantially the same as the planar shape of conductor layer 692. Conductor layers 661 and 671 are connected in parallel via through-holes 66T2 and 66T5. Conductor layers 682 and 692 are connected in parallel via through-holes 68T2 and 68T4.

[0095] Capacitor C23 is made of Figures 4A to 5C The conductor layers 543, 552, 562, 582, and 592 shown, and the dielectric layers 54 to 58 between these conductor layers, constitute the structure.

[0096] Capacitor C24 is made of Figures 4B to 5B The conductor layers 551, 563, 572, and 582 shown, and the dielectric layers 55 to 57 between these conductor layers, constitute the structure.

[0097] Capacitor C25 is made of Figures 4A to 5A The conductor layers 543, 551, 562, and 572 shown, and the dielectric layers 54 to 56 between these conductor layers, constitute the structure.

[0098] Capacitor C26 is made of Figure 8B and Figure 8C The conductor layers 671 and 682 shown are formed by the dielectric layer 68 between these conductor layers.

[0099] Next, the constituent elements of resonator 31 will be explained. Inductor L31 consists of... Figure 4B and Figure 4C The conductor layer 551 and through holes 55T9 and 56T9 shown are constituted.

[0100] Capacitor C31 is made of Figure 3B The ground wire uses conductor layer 523. Figure 4B The conductor layer 551 shown is composed of dielectric layers 52 to 54 between these conductor layers.

[0101] Next, the constituent elements of the first stubular resonator 41 will be described. The first distributed constant line 41A is composed of... Figure 3C The first conductor line 531 shown is configured as follows. Additionally, as... Figure 11 As shown, a portion of the first conductor line 531 is connected to... Figure 3B The ground conductor layer 523 is shown opposite to the ground conductor layer 523. The capacitor C41 is composed of the ground conductor layer 523, the first conductor line 531, and the dielectric layer 52.

[0102] Next, the constituent elements of the second stubular resonator 42 will be explained. The second distributed constant line 42A is composed of... Figure 3C The second conductor line 532 shown is configured as follows. Additionally, as... Figure 11 As shown, a portion of the second conductor line 532 is connected to... Figure 3B The ground conductor layer 523 is shown opposite to the ground conductor layer 523. The capacitor C42 is composed of the ground conductor layer 523, the second conductor line 532, and the dielectric layer 52.

[0103] Next, refer to Figures 1 to 12 The structural features of the bandpass filter 1 in this embodiment will be described. Figure 12 It means Figure 10The diagram shows a cross-sectional view of a portion of the interior of the laminate 50. The laminate 50 includes multiple conductor layers comprising at least one first conductor layer constituting an inductor L12 of a first high-pass filter 12, at least one second conductor layer constituting an inductor L11 of a first low-pass filter 11, at least one third conductor layer constituting an inductor L22 of a second high-pass filter 22, at least one fourth conductor layer constituting an inductor L21 of a second low-pass filter 21, and a ground conductor layer 523 connected to ground. Figures 3A to 10 In the stack 50 shown, conductor layers 641, 651, 681, and 691 correspond to the first conductor layer, conductor layers 571, 581, 591, and 601 correspond to the second conductor layer, conductor layers 661, 671, 682, and 692 correspond to the third conductor layer, and conductor layers 592, 602, 611, and 621 correspond to the fourth conductor layer.

[0104] The first conductor layers 641, 651, 681, and 691, the second conductor layers 571, 581, 591, and 601, and the ground conductor layer 523 are arranged at different positions in the stacking direction T. The second conductor layers 571, 581, 591, and 601 are arranged between the first conductor layers 641, 651, 681, and 691 and the ground conductor layer 523 in the stacking direction T. In addition, the first conductor layers 641, 651, 681, and 691 and the second conductor layers 571, 581, 591, and 601 are arranged between the ground conductor layer 523 and the upper surface 50B of the laminate 50 in the stacking direction T.

[0105] The inductor L12 of the first high-pass filter 12 includes a first portion L12a composed of first conductor layers 641, 651, 681, and 691. The first portion L12a has a first end E12a that is structurally closest to the terminal 112 constituting the second input / output port 3, and a second end E12b that is structurally furthest from the terminal 112. For example... Figure 7B As shown, in the first conductor layer 641, the portion connecting the through hole 63T1 corresponds to the first end E12a. For example... Figure 8C As shown, in the first conductor layer 681, the portion connecting the through-hole 67T3 corresponds to the second end E12b. Viewed from a direction parallel to the stacking direction T (Z direction), the first portion L12a extends from the first end E12a toward the second end E12b along the first winding direction D1 (refer to...). Figure 8C )wound.

[0106] The inductor L11 of the first low-pass filter 11 includes a second portion L11a composed of second conductor layers 571, 581, 591, and 601. The second portion L11a has a third end E11a that is structurally closest to the terminal 112 constituting the second input / output port 3, and a fourth end E11b that is structurally furthest from the terminal 112. For example... Figure 5A As shown, in the second conductor layer 571, the portion connecting the through hole 56T5 corresponds to the third end E11a. Figure 5C As shown, in the second conductor layer 591, the portion connecting the through-hole 58T1 corresponds to the fourth end E11b. Viewed from a direction parallel to the stacking direction T (Z direction), the second portion L11a extends from the third end E11a toward the fourth end E11b along a second winding direction D2 opposite to the first winding direction D1 (see reference). Figure 5C )wound.

[0107] exist Figure 12 In the diagram, the center of the group of first conductor layers 641, 651, 681, and 691 in the stacking direction T is indicated by the symbol C1, and the center of the group of second conductor layers 571, 581, 591, and 601 in the stacking direction T is indicated by the symbol C2. The distance from center C2 to center C1 is greater than the distance from center C2 to ground conductor layer 523.

[0108] The group of third conductor layers 661, 671, 682, and 692, the group of fourth conductor layers 592, 602, 611, and 621, and the ground conductor layer 523 are arranged at different positions in the stacking direction T. The fourth conductor layers 592, 602, 611, and 621 are arranged in the stacking direction T between the third conductor layers 661, 671, 682, and 692 and the ground conductor layer 523. In addition, the third conductor layers 661, 671, 682, and 692 and the fourth conductor layers 592, 602, 611, and 621 are arranged in the stacking direction T between the ground conductor layer 523 and the upper surface 50B of the laminate 50.

[0109] The inductor L22 of the second high-pass filter 22 includes a third portion L22a composed of third conductor layers 661, 671, 682, and 692. The third portion L22a has a fifth end E22a that is structurally closest to the terminal 112 constituting the second input / output port 3, and a sixth end E22b that is structurally furthest from the terminal 112. For example... Figure 8A As shown, in the third conductor layer 661, the portion connecting the through hole 65T2 corresponds to the fifth end E22a. Figure 8CAs shown, in the third conductor layer 682, the portion connecting the through-hole 67T4 corresponds to the sixth end E22b. Viewed from a direction parallel to the stacking direction T (Z direction), the third portion L22a extends from the fifth end E22a toward the sixth end E22b along the third winding direction D3 (refer to...). Figure 8C )wound.

[0110] The inductor L21 of the second low-pass filter 21 includes a fourth portion L21a composed of fourth conductor layers 592, 602, 611, and 621. The fourth portion L21a has a seventh end E21a, which is structurally closest to the terminal 112 constituting the second input / output port 3, and an eighth end E21b, which is structurally furthest from the terminal 112. For example... Figure 6B As shown, in the fourth conductor layer 611, the portion connecting the through hole 60T2 corresponds to the seventh end E21a. Figure 5C As shown, in the fourth conductor layer 592, the portion connecting the through-hole 58T5 corresponds to the eighth end E21b. Viewed from a direction parallel to the stacking direction T (Z direction), the fourth portion L21a extends from the seventh end E21a toward the eighth end E21b along a fourth winding direction D4 opposite to the third winding direction D3 (see reference). Figure 6B )wound.

[0111] The first conductor layers 641 and 651 of the inductor L12 constituting the first high-pass filter 12 and the third conductor layers 661 and 671 of the inductor L22 constituting the second high-pass filter 22 are arranged at different positions in the stacking direction T. The second conductor layers 571 and 581 of the inductor L11 constituting the first low-pass filter 11 and the fourth conductor layers 611 and 621 of the inductor L21 constituting the second low-pass filter 21 are arranged at different positions in the stacking direction T.

[0112] Next, the function and effect of the bandpass filter 1 in this embodiment will be explained. The bandpass filter 1 in this embodiment includes first and second high-pass filters 12 and 22, first and second low-pass filters 11 and 21, and first and second stubular resonators 41 and 42. The first and second low-pass filters 11 and 21 and the first and second stubular resonators 41 and 42 each form attenuation electrodes on the high-frequency side of the passband of the bandpass filter 1. According to this embodiment, by providing the first and second stubular resonators 41 and 42, the attenuation on the high-frequency side of the passband can be increased.

[0113] The function and effect of the first and second stubular resonators 41 and 42 will now be explained with reference to simulation results. In the simulation, a model of the bandpass filter 1 of this embodiment (hereinafter referred to as the embodiment model) and a model of a comparative example bandpass filter without the first and second stubular resonators 41 and 42 (hereinafter referred to as the comparative example model) were used. Except for the absence of the first and second stubular resonators 41 and 42, the structure of the comparative example bandpass filter is the same as that of the bandpass filter 1 of this embodiment.

[0114] Figure 13 This is a characteristic diagram showing the attenuation characteristics of the model in the embodiment and the model in the comparative example. Figure 14 This is a characteristic plot representing an example of insertion loss near the passband. Figure 15 This is a characteristic diagram representing the reflection loss of the first input / output port 2. Figure 16 This is a characteristic diagram representing the reflection loss of the second input / output port 3. Figures 13 to 16 In the diagram, the curve labeled 91 represents the characteristics of the model in the embodiment, and the curve labeled 92 represents the characteristics of the model in the comparative example. Figures 13 to 16 In the diagram, the horizontal axis represents frequency. Figure 13 In the diagram, the vertical axis represents the attenuation. Figure 14 In the diagram, the vertical axis represents insertion loss. Figure 15 and Figure 16 In the diagram, the vertical axis represents reflection loss.

[0115] according to Figure 13 The simulation results show that, according to this embodiment, by setting the first and second stubular resonators 41 and 42, the pass attenuation near 20 GHz can be increased.

[0116] Next, other effects of the bandpass filter 1 in this embodiment will be explained. As described above, in this embodiment, the second conductor layers 571, 581, 591, and 601 of the inductor L11 constituting the first low-pass filter 11 are disposed in the stacking direction T between the first conductor layers 641, 651, 681, and 691 of the inductor L12 constituting the first high-pass filter 12 and the ground conductor layer 523. Therefore, according to this embodiment, compared with the case where the first conductor layers of the inductor L12 constituting the first high-pass filter 12 and the second conductor layers of the inductor L11 constituting the first low-pass filter 11 are disposed in the same position in the stacking direction T, the area of ​​the bottom surface 50A and the top surface 50B of the laminate 50 can be reduced.

[0117] Furthermore, when the second conductor layer of the inductor L11 constituting the first low-pass filter 11 is disposed between the ground conductor layer connected to the ground and the bottom surface 50A of the laminate with multiple terminals 111-116, if the dimensions of the laminate 50 in the stacking direction T are reduced, the electromagnetic field interacts between the second conductor layer and the ground conductor layer, and between the second conductor layer and the multiple terminals 111-116, respectively, and the Q value of the first low-pass filter 11 decreases. To prevent this from happening, it is necessary to increase the spacing between the second conductor layer and the ground conductor layer and the spacing between the second conductor layer and the multiple terminals 111-116 to a certain extent. In contrast, in this embodiment, the second conductor layers 571, 581, 591, and 601 are disposed in the stacking direction T between the ground conductor layer 523 and the upper surface 50B of the laminate 50. Therefore, according to this embodiment, it is possible to prevent the decrease in the Q value of the first low-pass filter 11, and reduce the size of the laminate 50 in the lamination direction T by the amount of the interval between the second conductor layer and the plurality of terminals 111 to 116 in the above case.

[0118] Furthermore, in this embodiment, the distance from the center C2 of the group of second conductor layers 571, 581, 591, 601 in the stacking direction T to the center C1 of the group of first conductor layers 641, 651, 681, 691 in the stacking direction T is greater than the distance from center C2 to ground conductor layer 523. Therefore, according to this embodiment, compared to the case where the distance from center C2 to center C1 is less than the distance from center C2 to ground conductor layer 523, the interaction between electromagnetic fields between the second conductor layers 571, 581, 591, 601 and the first conductor layers 641, 651, 681, 691 can be suppressed.

[0119] Similarly, in this embodiment, the fourth conductor layers 592, 602, 611, and 621 of the inductor L21 constituting the second low-pass filter 21 are disposed in the stacking direction T between the third conductor layers 661, 671, 682, and 692 of the inductor L22 constituting the second high-pass filter 22 and the ground conductor layer 523. Furthermore, the fourth conductor layers 592, 602, 611, and 621 are disposed in the stacking direction T between the ground conductor layer 523 and the upper surface 50B of the laminate 50. Therefore, according to this embodiment, the area of ​​the bottom surface 50A and the upper surface 50B of the laminate 50 can be reduced, and the decrease in the Q value of the second low-pass filter 21 can be prevented, and the dimensions of the laminate 50 in the stacking direction T can be reduced.

[0120] Based on the above description, according to this embodiment, the interaction between conductor layers can be suppressed, achieving miniaturization and desired characteristics.

[0121] Furthermore, in this embodiment, as described above, inductors L11, L12, L21, and L22 each comprise a group of two conductor layers with identical or substantially identical planar shapes, connected in parallel via vias. For example, inductor L11 comprises a group of conductor layers 571 and 581 connected in parallel and a group of conductor layers 591 and 601 connected in parallel. Therefore, according to this embodiment, the DC resistance of each inductor L11, L12, L21, and L22 can be reduced, and the Q value of each inductor L11, L12, L21, and L22 can be increased.

[0122] Furthermore, the present invention is not limited to the embodiments described above, and various modifications can be made. For example, within the scope of the claims, the structures of the high-pass filter and low-pass filter of the present invention are not limited to the examples shown in the embodiments, and can be arbitrarily modified.

[0123] As can be seen from the above description, various modes or variations of the present invention can be implemented. Therefore, the present invention can also be implemented in ways other than the preferred mode described above within the equivalent scope of the claims.

Claims

1. A bandpass filter, characterized in that, A bandpass filter is a filter that selectively allows signals of frequencies within a specified passband to pass through. have: First input / output port; Second input / output port; The first high-pass filter, the first low-pass filter, and the first stub resonator are arranged in the circuit structure between the first input / output port and the second input / output port; A stack comprising multiple dielectric layers and multiple conductor layers, used to integrate the first input / output port, the second input / output port, the first high-pass filter, the first low-pass filter, and the first stub resonator; as well as Multiple terminals are disposed on the bottom surface of the laminate. The first high-pass filter and the first low-pass filter each include at least one first inductor and at least one first capacitor. The first stubular resonator includes a first distribution constant circuit. The first low-pass filter is positioned between the first input / output port and the first high-pass filter in the circuit structure. The first distribution constant line has a first end connected to a first path that connects the first input / output port and the first low-pass filter, and a second end that is structurally closest to ground. The at least one first inductor of the first low-pass filter is directly connected to the first terminal of the first distributed constant line. The plurality of conductor layers include a first conductor line constituting the first distribution constant line and a ground conductor layer connected to the ground line. The plurality of terminals includes a first terminal corresponding to the first input / output port. The first conductor line is connected to the first terminal. The ground conductor layer is disposed between the first conductor line and the plurality of terminals in the stacking direction of the plurality of dielectric layers.

2. The bandpass filter according to claim 1, characterized in that, The first stub resonator further includes a second capacitor, which is disposed in the circuit structure between the first distribution constant line and the ground line.

3. The bandpass filter according to claim 1, characterized in that, The first low-pass filter and the first stub resonator each form an attenuation electrode on the high-frequency side of the passband.

4. The bandpass filter according to claim 1, characterized in that, The first distribution constant line is a 1 / 4 wavelength line.

5. The bandpass filter according to claim 1, characterized in that, A portion of the first conductor line is opposite to the ground conductor layer.

6. The bandpass filter according to claim 1, characterized in that, It also includes a second high-pass filter, a second low-pass filter, and a second stub resonator, which are positioned between the first high-pass filter and the second input / output port in the circuit structure. The stack integrates the first input / output port, the second input / output port, the first high-pass filter, the first low-pass filter, the first stub resonator, the second high-pass filter, the second low-pass filter, and the second stub resonator into one unit. The second high-pass filter and the second low-pass filter each include at least one second inductor and at least one third capacitor. The second stubular resonator includes a second distribution constant circuit. The second low-pass filter is positioned between the second input / output port and the second high-pass filter in the circuit structure. The second distribution constant line has a third terminal connected to the second path that connects the second input / output port and the second low-pass filter, and a fourth terminal that is structurally closest to the ground line.

7. The bandpass filter according to claim 6, characterized in that, The second stub-type resonator also includes a fourth capacitor, which is disposed in the circuit structure between the second distribution constant line and the ground line.

8. The bandpass filter according to claim 6, characterized in that, The second low-pass filter and the second stub resonator respectively form attenuation poles on the high-frequency side of the passband.

9. The bandpass filter according to claim 6, characterized in that, The second distribution constant line is a 1 / 4 wavelength line.

10. The bandpass filter according to claim 6, characterized in that, The plurality of conductor layers further include a second conductor line constituting the second distribution constant line. A portion of the first conductor line and a portion of the second conductor line are respectively opposite to the ground wire.

11. The bandpass filter according to claim 6, characterized in that, It also includes at least one resonator, which is disposed in the circuit structure between the first high-pass filter and the second high-pass filter.

12. The bandpass filter according to claim 11, characterized in that, The at least one resonator includes a third inductor, which is disposed in the circuit structure between the third path connecting the first high-pass filter and the second high-pass filter and the ground line.

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