Layered filter device

Abstract

To realize a multilayer type filter device having a pass-through attenuation characteristic steeply changing at a frequency region close to the cutoff frequency.SOLUTION: A multilayer type filter device 1 includes: a first port 2; a second port 3; an LC resonator 11 electrically connected to the first port 2; an LC resonator 14 electrically connected to the second port 3; LC resonators 12, 13 arranged between the LC resonator 11 and the LC resonator 14 on its circuit configuration; and a multilayer body 50. The LC resonator 11 includes an inductor L11. The LC resonator 14 includes an inductor L14. The inductor L11 and the inductor L14 are configured so as to be magnetically coupled in the multilayer body 50.SELECTED DRAWING: Figure 10

Description

[Technical Field]

[0001] The present invention relates to a multilayer filter device including an LC resonator. [Background technology]

[0002] One type of electronic component used in communication devices is a bandpass filter that includes multiple resonators, each of which is, for example, an LC resonator configured using an inductor and a capacitor.

[0003] Bandpass filters used in small communication devices are particularly required to be miniaturized. Known bandpass filters suitable for miniaturization include those that use a laminate including multiple dielectric layers and multiple conductor layers stacked together.

[0004] Patent Document 1 discloses a bandpass filter having a laminate formed by stacking a plurality of insulating layers. This bandpass filter has a plurality of parallel resonant circuits each composed of an inductor and a capacitor. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2015-26883 Summary of the Invention [Problem to be solved by the invention]

[0006] One of the desirable characteristics of a bandpass filter is that the insertion loss changes sharply in a frequency range close to the cutoff frequency. Such a characteristic can be realized, for example, by creating an attenuation pole in the frequency range close to the cutoff frequency in the pass attenuation characteristics of the bandpass filter.

[0007] Generally, the attenuation pole can be adjusted by adjusting the resonant frequency of the resonator. However, LC resonators have the problem that it is difficult to realize a characteristic in which the attenuation changes sharply near the attenuation pole. Therefore, in the past, it was difficult to create an attenuation pole in the frequency range close to the cutoff frequency while maintaining the desired passband attenuation characteristics.

[0008] The present invention has been made in view of the above problems, and an object of the present invention is to provide a multilayer filter device including an LC resonator, which has bandpass attenuation characteristics that change sharply in a frequency range close to the cutoff frequency. [Means for solving the problem]

[0009] The multilayer filter device of the present invention includes a first port, a second port, a first LC resonator electrically connected to the first port, a second LC resonator electrically connected to the second port, a third LC resonator arranged between the first LC resonator and the second LC resonator in terms of circuit configuration, and a laminate. The laminate includes a plurality of laminated dielectric layers and is used to integrate the first port, the second port, the first LC resonator, the second LC resonator, and the third LC resonator. The first LC resonator includes a first inductor. The second LC resonator includes a second inductor. The first inductor and the second inductor are configured to be magnetically coupled within the laminate.

[0010] In the multilayer filter device of the present invention, the first inductor and the second inductor may be adjacent to each other within the multilayer body.

[0011] In the multilayer filter device of the present invention, the first inductor may include two first through-hole rows and a first conductor layer connecting the two first through-hole rows. The second inductor may include two second through-hole rows and a second conductor layer connecting the two second through-hole rows. Each of the two first through-hole rows and the two second through-hole rows may be formed by two or more through-holes connected in series. No conductor may be present between the two first through-hole rows and the two second through-hole rows. A first region sandwiched between the two first through-hole rows and a second region sandwiched between the two second through-hole rows may overlap each other when viewed from a direction perpendicular to the stacking direction of the multiple dielectric layers. The first conductor layer and the second conductor layer may not overlap each other when viewed from a direction parallel to the stacking direction of the multiple dielectric layers. The first conductor layer may include a portion extending in a direction away from the second conductor layer. The second conductor layer may include a portion extending in a direction away from the first conductor layer.

[0012] Furthermore, when the first inductor includes a first conductor layer and the second inductor includes a second conductor layer, the third LC resonator may include a third inductor. The third inductor may include a third conductor layer. The third conductor layer may overlap a region where the first conductor layer or the second conductor layer is disposed when viewed from a direction parallel to the stacking direction of the multiple dielectric layers. In this case, the laminate may have a first surface facing the mounted body and a second surface opposite to the first surface. The third conductor layer may be disposed between the first conductor layer or the second conductor layer and the first surface.

[0013] In the multilayer filter device of the present invention, each of the first LC resonator and the second LC resonator may constitute a low-pass filter, and the third LC resonator may constitute a high-pass filter. [Effects of the Invention]

[0014] In the multilayer filter device of the present invention, the first inductor and the second inductor are configured to be magnetically coupled within the laminate, thereby achieving the effect of realizing a multilayer filter device having bandpass attenuation characteristics that change sharply in a frequency range close to the cutoff frequency. [Brief explanation of the drawings]

[0015] [Figure 1] 1 is a circuit diagram showing a circuit configuration of a multilayer filter device according to an embodiment of the present invention. [Figure 2] 1 is a perspective view showing the appearance of a multilayer filter device according to an embodiment of the present invention. [Figure 3] 1 is an explanatory diagram showing pattern-formed surfaces of first to third dielectric layers in a laminate of a multilayer filter device according to an embodiment of the present invention. FIG. [Figure 4] 3 is an explanatory diagram showing pattern-formed surfaces of fourth to sixth dielectric layers in a laminate of a multilayer filter device according to an embodiment of the present invention. FIG. [Figure 5] 1 is an explanatory diagram showing pattern-forming surfaces of the seventh to fourteenth dielectric layers in a laminate of a multilayer filter device according to an embodiment of the present invention. FIG. [Figure 6] 3 is an explanatory diagram showing the pattern-forming surfaces of the 15th to 17th dielectric layers in the laminate of the multilayer filter device according to one embodiment of the present invention. FIG. [Figure 7] 3 is an explanatory diagram showing the pattern-forming surfaces of the 18th to 20th dielectric layers in the laminate of the multilayer filter device according to one embodiment of the present invention. FIG. [Figure 8] 3 is an explanatory diagram showing pattern-forming surfaces of the 21st to 24th dielectric layers in the laminate of the multilayer filter device according to one embodiment of the present invention. FIG. [Figure 9] 3 is an explanatory diagram showing the pattern-forming surfaces of the 25th to 27th dielectric layers in the laminate of the multilayer filter device according to one embodiment of the present invention. FIG. [Figure 10]1 is a perspective view showing the inside of a laminate of a multilayer filter device according to an embodiment of the present invention. [Figure 11] 1 is a perspective view showing the inside of a laminate of a multilayer filter device according to an embodiment of the present invention. [Figure 12] FIG. 10 is a characteristic diagram showing attenuation characteristics obtained by simulation. [Figure 13] FIG. 13 is an enlarged characteristic diagram showing a part of FIG. 12. [Figure 14] FIG. 13 is an enlarged characteristic diagram showing a part of FIG. 12. DETAILED DESCRIPTION OF THE INVENTION

[0016] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. First, with reference to FIG. 1, an outline of the configuration of a multilayer filter device (hereinafter simply referred to as a filter device) 1 according to an embodiment of the present invention will be described. FIG. 1 shows a bandpass filter as an example of the filter device 1. The filter device 1 includes a first port 2, a second port 3, and LC resonators 11, 12, 13, and 14. Each of the first and second ports 2 and 3 is a port for inputting or outputting a signal.

[0017] The LC resonator 11 is electrically connected to the first port 2. The LC resonator 14 is electrically connected to the second port 3. In terms of the circuit configuration, the LC resonators 12 and 13 are arranged between the LC resonator 11 and the LC resonator 14 in this order from the LC resonator 11 side. Note that in this application, the expression "in terms of the circuit configuration" is used to refer to the arrangement on a circuit diagram, not the arrangement in a physical configuration.

[0018] The LC resonator 11 corresponds to the "first LC resonator" in the present invention. The LC resonator 14 corresponds to the "second LC resonator" in the present invention. Each of the LC resonators 12 and 13 corresponds to the "third LC resonator" in the present invention. LC This corresponds to the "resonator".

[0019] The LC resonator 11 includes an inductor L11 and a capacitor C11. The LC resonator 12 includes an inductor L12 and a capacitor C12. The LC resonator 13 includes an inductor L13 and a capacitor C13. The LC resonator 14 includes an inductor L14 and a capacitor C14. In this embodiment in particular, the inductor and capacitor of each of the LC resonators 11 to 14 are connected in parallel. Furthermore, as will be described in detail later, the inductor L11 and the inductor L14 are configured to be magnetically coupled.

[0020] Hereinafter, an example of another circuit configuration of the filter device 1 will be described with reference to Fig. 1. The filter device 1 further includes inductors L1, L2, and L3, and capacitors C1, C2, C3, C4, C5, C6, C7, C8, C9, and C10. One end of the inductor L1 is connected to the first port 2. One end of the inductor L11 is connected to the other end of the inductor L1. The capacitor C11 is connected in parallel to the inductor L11. One end of the capacitor C1 is connected to one end of the inductor L11. One end of the capacitor C2 is connected to the other end of the inductor L11.

[0021] One end of capacitor C3 is connected to the other end of inductor L11. One end of capacitor C4 is connected to the other end of capacitor C3. One end of capacitor C5 is connected to the other end of capacitor C4. One end of inductor L12 is connected to the connection point between capacitors C3 and C4. One end of inductor L13 is connected to the connection point between capacitors C4 and C5. Capacitor C12 is connected in parallel to inductor L12. Capacitor C13 is connected in parallel to inductor L13.

[0022] One end of the inductor L14 is connected to the other end of the capacitor C5. One end of the inductor L2 is connected to the other end of the inductor L14. The other end of the inductor L2 is connected to the second port 3. The capacitor C14 is connected in parallel to the inductor L14. The capacitor C6 Part of is connected to one end of inductor L14. Capacitor C7 Part of is connected to the other end of inductor L14.

[0023] One end of each of capacitors C8 and C10 is connected to the connection point between inductor L11 and capacitor C3. The other end of capacitor C8 is connected to the connection point between capacitors C4 and C5. One end of capacitor C9 is connected to the connection point between capacitors C3 and C4. The other end of each of capacitors C9 and C10 is connected to the connection point between capacitor C5 and inductor L14.

[0024] One end of the inductor L3 is connected to the other ends of the inductors L12 and L13 and the capacitors C1, C2, C6, and C7, and the other end of the inductor L3 is connected to ground.

[0025] The LC resonator 11 and capacitors C1 and C2 form a low-pass filter. The LC resonators 12 and 13 and capacitors C3 to C5 and C8 to C10 form a high-pass filter. The LC resonator 14 and capacitors C6 and C7 form a low-pass filter. The filter device 1 is a band-pass filter formed by combining two low-pass filters and one high-pass filter.

[0026] The manner in which an LC resonator is electrically connected to a port includes a manner in which the LC resonator is directly connected to the port via a conductor and a manner in which the LC resonator is connected to the port via an inductor. On the other hand, a manner in which the conductor of the path connecting the LC resonator and the port is interrupted, such as a manner in which the LC resonator is connected to the port via a capacitor, is not included in the manner in which the LC resonator is electrically connected to the port.

[0027] In this embodiment, one end of the inductor L11 and one end of the capacitor C11 of the LC resonator 11 are connected to the first port 2 via the inductor L1, thereby electrically connecting the LC resonator 11 to the first port 2. The other end of the inductor L14 and one end of the capacitor C14 of the LC resonator 14 are connected to the second port 3 via the inductor L2, thereby electrically connecting the LC resonator 14 to the second port 3.

[0028] Note that the inductors L1 and L2 are not essential components of the filter device 1 and may not be provided. In this case, one end of each of the inductor L11 and the capacitor C11 of the LC resonator 11 is directly connected to the first port 2, thereby electrically connecting the LC resonator 11 to the first port 2. In addition, in this case, the other end of each of the inductor L14 and the capacitor C14 of the LC resonator 14 is directly connected to the second port 3, thereby electrically connecting the LC resonator 14 to the second port 3.

[0029] Next, other configurations of the filter device 1 will be described with reference to Fig. 2. Fig. 2 is a perspective view showing the appearance of the filter device 1.

[0030] The filter device 1 further includes a laminate 50 including a plurality of laminated dielectric layers and a plurality of laminated conductor layers. The first port 2, the second port 3, the LC resonators 11 to 14, the inductors L1 to L3, and the capacitors C1 to C10 are integrated into the laminate 50.

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

[0032] Here, the X direction, Y direction, and Z direction are defined as shown in FIG. 2. The X direction, Y direction, and Z direction are perpendicular to each other. In this embodiment, a direction parallel to the stacking direction T is defined as the Z direction. Furthermore, 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.

[0033] As shown in FIG. 2, the bottom surface 50A is located at the end of the laminate 50 in the -Z direction. The top surface 50B is located at the end of the laminate 50 in the Z direction. The bottom surface 50A and the top surface 50B each have a rectangular shape that is long in the X direction. The side surface 50C is located at the end of the laminate 50 in the -X direction. The side surface 50D is located at the end of the laminate 50 in the X direction. The side surface 50E is located at the end of the laminate 50 in the -Y direction. The side surface 50F is located at the end of the laminate 50 in the Y direction.

[0034] The bottom surface 50A faces a substrate or other object to be mounted (not shown). The bottom surface 50A corresponds to the "first surface" in the present invention. The top surface 50B of the laminate 50 is located on the opposite side to the bottom surface 50A. The top surface 50B corresponds to the "second surface" in the present invention.

[0035] The filter device 1 further includes terminals 111, 112, 113, and 114 provided on the bottom surface 50A of the laminate 50. The terminal 111 extends in a direction parallel to the Y direction at a position closer to the side surface 50C than to the side surface 50D. The terminal 113 extends in a direction parallel to the Y direction at a position closer to the side surface 50D than to the side surface 50C. The terminals 112 and 114 are disposed between the terminals 111 and 113. The terminal 112 is disposed in a position closer to the side surface 50E than to the side surface 50F. The terminal 114 is disposed in a position closer to the side surface 50F than to the side surface 50E.

[0036] Terminal 111 corresponds to the first port 2, and terminal 113 corresponds to the second port 3. Therefore, the first and second ports 2 and 3 are provided on the bottom surface 50A of the laminate 50. Each of terminals 112 and 114 is connected to ground.

[0037] Next, an example of the plurality of dielectric layers and the plurality of conductor layers constituting the laminate 50 will be described with reference to Figures 3(a) to 9(c). In this example, the laminate 50 has 27 laminated dielectric layers. Hereinafter, these 27 dielectric layers will be referred to as the 1st to 27th dielectric layers, in order from the bottom up. The 1st to 27th dielectric layers will be denoted by reference numerals 51 to 77.

[0038] In Figures 3(a) to 9(c), multiple circles represent multiple through holes. Multiple through holes are formed in each of the dielectric layers 51 to 75. The multiple through holes are formed by filling holes for the through holes with conductive paste. Each of the multiple through holes is connected to a terminal, a conductive layer, or another through hole.

[0039] Fig. 3(a) shows the pattern-formed surface of the first dielectric layer 51. Terminals 111 to 114 are formed on the pattern-formed surface of the dielectric layer 51. Fig. 3(b) shows the pattern-formed surface of the second dielectric layer 52. Conductor layers 521, 522, and 523 are formed on the pattern-formed surface of the dielectric layer 52.

[0040] Fig. 3(c) shows the pattern formation surface of the third dielectric layer 53. Conductor layers 531, 532, 533, and 534 are formed on the pattern formation surface of the dielectric layer 53. In Fig. 3(c), two specific through holes connected to the conductor layers 531 and 532 are indicated by the reference numerals 53T1 and 53T3, respectively.

[0041] Fig. 4(a) shows the pattern-forming surface of the fourth dielectric layer 54. Conductor layers 541 and 542 are formed on the pattern-forming surface of the dielectric layer 54. Also, in Fig. 4(a), two specific through holes connected to specific through holes 53T1 and 53T3 formed in the dielectric layer 53 are indicated by reference numerals 54T1 and 54T3, respectively.

[0042] Fig. 4(b) shows the pattern-forming surface of the fifth dielectric layer 55. Conductor layers 551, 552, and 553 are formed on the pattern-forming surface of the dielectric layer 55. In Fig. 4(b), two specific through-holes connected to specific through-holes 54T1 and 54T3 formed in the dielectric layer 54 are indicated by the reference numerals 55T1 and 55T3, respectively.

[0043] Fig. 4(c) shows the pattern-formed surface of the sixth dielectric layer 56. Conductor layers 561 and 562 are formed on the pattern-formed surface of the dielectric layer 56. Also, in Fig. 4(c), two specific through holes connected to specific through holes 55T1 and 55T3 formed in the dielectric layer 55 are indicated by reference numerals 56T1 and 56T3, respectively. Also, two specific through holes connected to the conductor layers 561 and 562 are indicated by reference numerals 56T5 and 56T6, respectively.

[0044] Fig. 5(a) shows the pattern-forming surface of the seventh dielectric layer 57. Conductor layers 571 and 572 are formed on the pattern-forming surface of the dielectric layer 57. Also, in Fig. 5(a), four specific through-holes connected to specific through-holes 56T1, 56T3, 56T5, and 56T6 formed in the dielectric layer 56 are indicated by the reference numerals 57T1, 57T3, 57T5, and 57T6, respectively.

[0045] Fig. 5(b) shows the pattern-formed surface of the eighth dielectric layer 58. A conductor layer 581 is formed on the pattern-formed surface of the dielectric layer 58. Also, in Fig. 5(b), four specific through holes connected to specific through holes 57T1, 57T3, 57T5, and 57T6 formed in the dielectric layer 57 are indicated by the reference numerals 58T1, 58T3, 58T5, and 58T6, respectively.

[0046] 5(c) shows the pattern-forming surface of each of the ninth to fourteenth dielectric layers 59 to 64. Specific through holes 59T1, 59T3, 59T5, and 59T6 are formed in each of the dielectric layers 59 to 64. Specific through holes 58T1, 58T3, 58T5, and 58T6 formed in the dielectric layer 58 are connected to specific through holes 59T1, 59T3, 59T5, and 59T6 formed in the dielectric layer 59, respectively. Furthermore, in the dielectric layers 59 to 64, adjacent through holes with the same reference numerals are connected to each other.

[0047] 6(a) shows the pattern formation surface of the 15th dielectric layer 65. Inductor conductor layers 651 and 652 and conductor layers 653 and 654 are formed on the pattern formation surface of the dielectric layer 65. Each of the conductor layers 653 and 654 has a first end and a second end located opposite to each other. A specific through-hole 59T5 formed in the dielectric layer 64 is connected to a portion of the conductor layer 653 near the first end. A specific through-hole 59T6 formed in the dielectric layer 64 is connected to a portion of the conductor layer 654 near the first end.

[0048] 6(a), two specific through holes connected to the specific through holes 59T1 and 59T3 formed in the dielectric layer 64 are indicated by reference numerals 65T1 and 65T3, respectively. Also, the specific through hole connected to the portion near the second end of the conductor layer 653 is indicated by reference numeral 65T2, the specific through hole connected to the portion near the second end of the conductor layer 654 is indicated by reference numeral 65T4, the specific through hole connected to the portion near the first end of the conductor layer 653 is indicated by reference numeral 65T5, and the specific through hole connected to the portion near the first end of the conductor layer 654 is indicated by reference numeral 65T6.

[0049] FIG. 6(b) shows the pattern formation surface of the 16th dielectric layer 66. On the pattern formation surface of the dielectric layer 66, inductor conductor layers 661 and 662 and conductor layers 663 and 664 are formed. Each of the conductor layers 663 and 664 has a first end and a second end located opposite to each other. A specific through-hole 65T2 formed in the dielectric layer 65 is connected to a portion of the conductor layer 663 near the second end. A specific through-hole 65T4 formed in the dielectric layer 65 is connected to a portion of the conductor layer 664 near the second end. 2nd end A specific through-hole 65T5 formed in the dielectric layer 65 is connected to a portion of the conductor layer 663 near the first end. A specific through-hole 65T6 formed in the dielectric layer 65 is connected to a portion of the conductor layer 664 near the first end.

[0050] 6(b), two specific through holes connected to the specific through holes 65T1 and 65T3 formed in the dielectric layer 65 are indicated by reference numerals 66T1 and 66T3, respectively. Also, the specific through hole connected to the portion near the second end of the conductor layer 663 is indicated by reference numeral 66T2, and the specific through hole connected to the portion near the second end of the conductor layer 664 is indicated by reference numeral 66T4.

[0051] Fig. 6(c) shows the pattern formation surface of the 17th dielectric layer 67. Inductor conductor layers 671 and 672 are formed on the pattern formation surface of the dielectric layer 67. Also, in Fig. 6(c), four specific through holes connected to specific through holes 66T1, 66T2, 66T3, and 66T4 formed in the dielectric layer 66 are indicated by the reference numerals 67T1, 67T2, 67T3, and 67T4, respectively.

[0052] Fig. 7(a) shows the pattern formation surface of the 18th dielectric layer 68. Inductor conductor layers 681 and 682 are formed on the pattern formation surface of the dielectric layer 68. Also, in Fig. 7(a), four specific through holes connected to specific through holes 67T1, 67T2, 67T3, and 67T4 formed in the dielectric layer 67 are indicated by the reference numerals 68T1, 68T2, 68T3, and 68T4, respectively.

[0053] Fig. 7(b) shows the pattern formation surface of the 19th dielectric layer 69. Inductor conductor layers 691 and 692 are formed on the pattern formation surface of the dielectric layer 69. Also, in Fig. 7(b), four specific through holes connected to specific through holes 68T1, 68T2, 68T3, and 68T4 formed in the dielectric layer 68 are indicated by the reference numerals 69T1, 69T2, 69T3, and 69T4, respectively.

[0054] Fig. 7(c) shows the pattern formation surface of the 20th dielectric layer 70. Inductor conductor layers 701 and 702 are formed on the pattern formation surface of the dielectric layer 70. Also, in Fig. 7(c), four specific through holes connected to specific through holes 69T1, 69T2, 69T3, and 69T4 formed in the dielectric layer 69 are indicated by the reference numerals 70T1, 70T2, 70T3, and 70T4, respectively.

[0055] Fig. 8(a) shows the pattern formation surface of the 21st dielectric layer 71. Inductor conductor layers 711 and 712 are formed on the pattern formation surface of the dielectric layer 71. Also, in Fig. 8(a), four specific through holes connected to specific through holes 70T1, 70T2, 70T3, and 70T4 formed in the dielectric layer 70 are indicated by the reference numerals 71T1, 71T2, 71T3, and 71T4, respectively.

[0056] Fig. 8(b) shows the pattern formation surface of the 22nd dielectric layer 72. Inductor conductor layers 721 and 722 are formed on the pattern formation surface of the dielectric layer 72. In Fig. 8(b), four specific through holes connected to specific through holes 71T1, 71T2, 71T3, and 71T4 formed in the dielectric layer 71 are indicated by the reference numerals 72T1, 72T2, 72T3, and 72T4, respectively.

[0057] 8(c) shows the pattern-formed surfaces of the 23rd and 24th dielectric layers 73, 74. Specific through-holes 73T1, 73T2, 73T3, and 73T4 are formed in each of the dielectric layers 73, 74. Specific through-holes 72T1 to 72T4 formed in the dielectric layer 72 are connected to specific through-holes 73T1 to 73T4 formed in the dielectric layer 73, respectively. Furthermore, in the dielectric layers 73, 74, adjacent through-holes with the same reference numerals are connected to each other.

[0058] 9(a) shows the pattern-formed surface of the 25th dielectric layer 75. Inductor conductor layers 751 and 752 are formed on the pattern-formed surface of the dielectric layer 75. Each of the conductor layers 751 and 752 has a first end and a second end located opposite to each other. A specific through-hole formed in the dielectric layer 74 73 T1 is connected to a portion of the conductor layer 751 near the first end. 73 T2 is connected to a portion of the conductor layer 751 near the second end. 73 T3 is connected to a portion of the conductor layer 752 near the first end. 73 T4 is connected to a portion of the conductor layer 752 near the second end.

[0059] Also, in Figure 9(a), a specific through hole connected to a portion near the first end of the conductor layer 751 is indicated by the symbol 75T1, a specific through hole connected to a portion near the second end of the conductor layer 751 is indicated by the symbol 75T2, a specific through hole connected to a portion near the first end of the conductor layer 752 is indicated by the symbol 75T3, and a specific through hole connected to a portion near the second end of the conductor layer 752 is indicated by the symbol 75T4.

[0060] FIG. 9(b) shows the pattern-formed surface of the 26th dielectric layer 76. Inductor conductor layers 761 and 762 are formed on the pattern-formed surface of the dielectric layer 76. The conductor layers 761 and 762 each have a first end and a second end located opposite each other. A specific through-hole 75T1 formed in the dielectric layer 75 is connected to a portion of the conductor layer 761 near the first end. A specific through-hole 75T2 formed in the dielectric layer 75 is connected to a portion of the conductor layer 761 near the second end. A specific through-hole 75T3 formed in the dielectric layer 75 is connected to a portion of the conductor layer 762 near the first end. A specific through-hole 75T4 formed in the dielectric layer 75 is connected to a portion of the conductor layer 762 near the second end.

[0061] 9(c) shows the pattern-formed surface of the 27th dielectric layer 77. On the pattern-formed surface of the dielectric layer 77, marks 771 made of a conductor layer are formed.

[0062] The laminate 50 shown in Figure 2 is constructed by stacking the first to 27th dielectric layers 51 to 77 so that the pattern-forming surface of the first dielectric layer 51 becomes the bottom surface 50A of the laminate 50, and the surface opposite the pattern-forming surface of the 27th dielectric layer 77 becomes the top surface 50B of the laminate 50.

[0063] Each of the multiple through holes shown in Figures 3(a) to 8(a), excluding the multiple specific through holes with reference numerals, is connected to a conductor layer that overlaps it in the stacking direction T or to another through hole that overlaps it in the stacking direction T when the 1st to 27th dielectric layers 51 to 77 are stacked. Furthermore, of the multiple through holes shown in Figures 3(a) to 8(a), excluding the multiple specific through holes, a through hole that is located within a terminal or a conductor layer is connected to that terminal or that conductor layer.

[0064] 10 and 11 show the inside of the laminate 50, which is formed by stacking the 1st to 27th dielectric layers 51 to 77. FIG. 10 shows the inside of the laminate 50 as seen from the side surfaces 50D and 50E. FIG. 11 shows the inside of the laminate 50 as seen from the side surfaces 50C and 50F. As shown in FIGS. 10 and 11, the inside of the laminate 50 has multiple conductor layers and multiple through holes as shown in FIGS. 3(a) to 9(c) stacked. Note that the mark 771 is omitted in FIGS. 10 and 11.

[0065] The following describes the correspondence between the circuit components of the filter device 1 shown in Fig. 1 and the internal components of the laminate 50 shown in Figs. 3(a) to 9(b). The inductor L11 of the LC resonator 11 is formed by inductor conductor layers 751 and 761 and specific through-holes 53T1, 54T1, 55T1, 56T1, 57T1, 58T1, 59T1, 65T1, 66T1, 66T2, 67T1, 67T2, 68T1, 68T2, 69T1, 69T2, 70T1, 70T2, 71T1, 71T2, 72T1, 72T2, 73T1, 73T2, 75T1, and 75T2. The capacitor C11 of the LC resonator 11 is formed by conductor layers 531 and 541 and a dielectric layer 53 between these conductor layers.

[0066] The inductor L12 of the LC resonator 12 is composed of inductor conductor layers 651, 661, 671, 681, 691, 701, 711, and 721 and a plurality of through holes connected to these conductor layers. The capacitor C12 of the LC resonator 12 is composed of conductor layers 521 and 551 and dielectric layers 52 to 54 between these conductor layers.

[0067] The inductor L13 of the LC resonator 13 is formed by inductor conductor layers 652, 662, 672, 682, 692, 702, 712, and 722 and a plurality of through holes connected to these conductor layers. The capacitor C13 of the LC resonator 13 is formed by conductor layers 521 and 552 and dielectric layers 52 to 54 between these conductor layers.

[0068] The inductor L14 of the LC resonator 14 is formed by the inductor conductor layers 752 and 762 and the specific through holes 53T3, 54T3, 55T3, 56T3, 57T3, 58T3, 59T3, 65T3, 66T3, 66T4, 67T3, 67T4, 68T3, 68T4, 69T3, 69T4, 70T3, 70T4, 71T3, 71T4, 72T3, 72T4, 73T3, 73T4, 75T3, and 75T4. The capacitor C14 of the LC resonator 14 is formed by the conductor layers 532 and 542 and the dielectric layer 53 between these conductor layers.

[0069] Capacitor C1 is composed of conductor layers 521 and 531 and a dielectric layer 52 between these conductor layers. Capacitor C2 is composed of conductor layers 533 and 541 and a dielectric layer 53 between these conductor layers.

[0070] Capacitor C3 is composed of conductor layers 541, 551, 561, and 571 and dielectric layers 54 to 56 between these conductor layers. Capacitor C4 is composed of conductor layers 571, 572, and 581 and dielectric layer 57 between these conductor layers. Capacitor C5 is composed of conductor layers 542, 552, 562, and 572 and dielectric layers 54 to 56 between these conductor layers.

[0071] Capacitor C6 is formed by conductor layers 534 and 542 and a dielectric layer 53 therebetween. Capacitor C7 is formed by conductor layers 521 and 532 and a dielectric layer 52 therebetween.

[0072] Capacitor C8 is composed of conductor layers 541 and 552 and a dielectric layer 54 between these conductor layers. Capacitor C9 is composed of conductor layers 542 and 551 and a dielectric layer 54 between these conductor layers. Capacitor C10 is composed of conductor layers 541, 542, and 553 and a dielectric layer 54 between these conductor layers.

[0073] Inductor L1 is composed of a conductor (including conductor layer 522) connecting terminal 111 and conductor layer 531. Inductor L2 is composed of a conductor (including conductor layer 523) connecting terminal 113 and conductor layer 532. Inductor L3 is composed of conductor layer 521, a plurality of through holes connecting terminals 112 and 114 and conductor layer 521, conductors (including conductor layer 535) connecting inductor conductor layer 711 and conductor layer 521, and conductors (including conductor layer 536) connecting inductor conductor layer 712 and conductor layer 521.

[0074] Next, structural features of the filter device 1 according to this embodiment will be described with reference to Figs. 2 to 11. Here, a structure formed by connecting two or more through holes in series is called a through-hole row. The laminate 50 includes through-hole rows T1, T2, T3, and T4. The through-hole row T1 is made up of specific through-holes 53T1, 54T1, 55T1, 56T1, 57T1, 58T1, 59T1, 65T1, 66T1, 67T1, 68T1, 69T1, 70T1, 71T1, 72T1, 73T1, and 75T1. The through-hole row T2 ... Specific through-holes It is composed of 66T2, 67T2, 68T2, 69T2, 70T2, 71T2, 72T2, 73T2, and 75T2. Through-hole row T3 is Specific through-holes It is composed of 53T3, 54T3, 55T3, 56T3, 57T3, 58T3, 59T3, 65T3, 66T3, 67T3, 68T3, 69T3, 70T3, 71T3, 72T3, 73T3, and 75T3. Through-hole row T4 is Specific through-holes It consists of 66T4, 67T4, 68T4, 69T4, 70T4, 71T4, 72T4, 73T4, and 75T4.

[0075] The inductor L11 of the LC resonator 11 includes through-hole rows T1 and T2 and inductor conductive layers 751 and 761. The inductor L14 of the LC resonator 14 includes through-hole rows T3 and T4 and inductor conductive layers 752 and 762. Each of the inductor conductive layers 751 and 761 connects the through-hole rows T1 and T2. Each of the inductor conductive layers 752 and 762 connects the through-hole rows T3 and T4.

[0076] Each of the through-hole rows T1 and T2 corresponds to a "first through-hole row" in the present invention. Each of the through-hole rows T3 and T4 corresponds to a "second through-hole row" in the present invention. Each of the inductor conductive layers 751 and 761 corresponds to a "first conductive layer" in the present invention. Each of the inductor conductive layers 752 and 762 corresponds to a "second conductive layer" in the present invention.

[0077] The inductor L11 and the inductor L14 are configured to be magnetically coupled within the laminate 50. In this embodiment, in particular, the inductor L11 and the inductor L14 are adjacent to each other within the laminate 50 so as to be magnetically coupled. Specifically, the through-hole rows T1 and T2 of the inductor L11 and the through-hole rows T3 and T4 of the inductor L14 are arranged near the center of the laminate 50 in a direction parallel to the Y direction (the longitudinal direction of the bottom surface 50A and the top surface 50B) and are adjacent to each other within the laminate 50. No conductors exist between the through-hole rows T1 and T3 and between the through-hole rows T2 and T4. Furthermore, the inductor conductor layers 751 and 761 of the inductor L11 and the inductor conductor layers 752 and 762 of the inductor L14 are adjacent to each other within the laminate 50. There are no conductors between the inductor conductive layer 751 and the inductor conductive layer 752 and between the inductor conductive layer 761 and the inductor conductive layer 762 .

[0078] Here, the area between the through-hole rows T1 and T2 is referred to as the first area, and the area between the through-hole rows T3 and T4 is referred to as the second area. X When viewed from the direction, i.e., with respect to the laminate 50 X When the first and second regions are viewed from a position at the end of the direction, they overlap. X They may match when viewed from the same direction.

[0079] The inductor conductive layer 751 and the inductor conductive layer 752 do not overlap each other when viewed from the Z direction, i.e., when the inductor conductive layers 751, 752 are viewed from a position further in the Z direction with respect to the laminate 50. Similarly, the inductor conductive layer 761 and the inductor conductive layer 762 do not overlap each other when viewed from the Z direction, i.e., when the inductor conductive layers 761, 762 are viewed from a position further in the Z direction with respect to the laminate 50.

[0080] Each of the inductor conductive layers 751 and 752 has a U-shaped planar shape. That is, the inductor conductive layer 751 has two portions extending in a direction away from the inductor conductive layer 752 (-X direction) and a portion connecting these two portions. Y The inductor conductor layer 752 includes two portions extending in a direction away from the inductor conductor layer 751 (X direction), and a portion connecting these two portions and extending in a direction parallel to the Y direction.

[0081] Similarly, each of the inductor conductive layers 761 and 762 has a U-shaped planar shape. That is, the inductor conductive layer 761 has two portions extending in a direction away from the inductor conductive layer 762 (-X direction) and a portion connecting these two portions. YThe inductor conductor layer 762 includes two portions extending in a direction away from the inductor conductor layer 761 (X direction), and a portion connecting these two portions and extending in a direction parallel to the Y direction.

[0082] When viewed from the Z direction, the inductor conductor layers 651, 661, 671, 681, 691, 701, 711, and 721 constituting the inductor L12 of the LC resonator 12 overlap with the region where the inductor conductor layers 751 and 761 are arranged. The inductor conductor layers 651, 661, 671, 681, 691, 701, 711, and 721 may overlap with the inductor conductor layers 751 and 761 themselves, or may overlap with the region surrounded by the inductor conductor layers 751 and 761.

[0083] When viewed from the Z direction, the inductor conductor layers 652, 662, 672, 682, 692, 702, 712, and 722 that form the inductor L13 of the LC resonator 13 overlap with the region in which the inductor conductor layers 752 and 762 are arranged. 652,662,672,682,692,702,712,722 may overlap the inductor conductive layers 752 and 762 themselves, or may overlap the area surrounded by the inductor conductive layers 752 and 762.

[0084] Next, the operation and effect of the filter device 1 according to this embodiment will be described. In this embodiment, the inductors L11 and L14 are configured to be magnetically coupled within the laminate 50. As a result, this embodiment can achieve a pass attenuation characteristic that changes sharply in a frequency range close to the cutoff frequency. This effect will be described below with reference to the results of a simulation.

[0085] The simulation used the structural model of the filter device 1 shown in Figures 2 to 11 and the circuit model of the filter device 1 shown in Figure 1. Both the structural model and the circuit model are configured as band-pass filter models. Note that in the circuit model, inductor L11 and inductor L14 are not magnetically coupled.

[0086] In the simulation, the structure model and the circuit model were designed so that the passbands of the structure model and the circuit model were approximately the same, and so that the insertion loss and return loss in the passbands of the structure model and the circuit model were approximately the same.

[0087] 12 to 14 are characteristic diagrams showing the pass attenuation characteristics obtained by simulation. In FIGS. 12 to 14, the horizontal axis represents frequency and the vertical axis represents attenuation. FIG. 13 shows an enlarged view of the frequency region near the pass band. FIG. 14 shows an enlarged view of the frequency region near the cutoff frequency on the high-frequency side of the pass band. In FIGS. 12 to 14, the curve labeled 91 represents the pass attenuation characteristics of the structure model. The curve labeled 92 represents the pass attenuation characteristics of the circuit model.

[0088] 14, it can be seen that the attenuation in the structure model (reference numeral 91) changes more sharply in the frequency region close to the cutoff frequency on the high-frequency side than in the circuit model (reference numeral 92). The structure model differs from the circuit model in that the inductors L11 and L14 are configured to be magnetically coupled within the laminate 50. As can be seen from the simulation results, according to this embodiment, by configuring the inductors L11 and L14 to be magnetically coupled within the laminate 50, it is possible to achieve pass attenuation characteristics that change sharply in the frequency region close to the cutoff frequency.

[0089] In some cases, increasing the number of LC resonators can also achieve a bandpass attenuation characteristic that changes sharply in a frequency range close to the cutoff frequency. However, as the number of LC resonators increases, it becomes more difficult to reduce the size of the filter device. In contrast, according to this embodiment, the bandpass attenuation characteristic can be achieved without increasing the number of LC resonators, thereby enabling the filter device 1 to be reduced in size.

[0090] Next, other effects of the present embodiment will be described. In addition, in the present embodiment, the through-hole rows T1 and T2 of the inductor L11 and the through-hole rows T3 and T4 of the inductor L14 are arranged near the center of the laminate 50 in a direction parallel to the Y direction, and the inductor conductor layers 751 and 752 (761 and 762) have shapes that extend in directions away from each other. Therefore, in the present embodiment, components of the filter device 1 can be arranged on the bottom surface 50A side of the inductor conductor layers 751 and 752 (761 and 762). In the present embodiment, the inductor L12 is arranged on the bottom surface 50A side of the inductor conductor layer 751 (761), and the inductor L13 is arranged on the bottom surface 50A side of the inductor conductor layer 752 (762). As described above, according to the present embodiment, the space in the laminate 50 can be efficiently utilized to reduce the size of the filter device 1.

[0091] The present invention is not limited to the above-described embodiment and various modifications are possible. For example, the filter device of the present invention may include only one of the LC resonators 12 and 13. Alternatively, one or more LC resonators may be provided between the LC resonators 11 and 12 or between the LC resonators 13 and 14. [Explanation of symbols]

[0092] 1...filter device, 2...first port, 3...second port, 11-14...resonators, 50...laminated body, 50A...bottom surface, 50B...top surface, 50C-50F...side surfaces, C1-C14...capacitors, L1-L3, L11-L14...inductors.

Claims

1. a first port; a second port; and a first LC resonator electrically connected to the first port; a second LC resonator electrically connected to the second port; a third LC resonator disposed between the first LC resonator and the second LC resonator in terms of circuit configuration; a laminate including a plurality of laminated dielectric layers for integrating the first port, the second port, the first LC resonator, the second LC resonator, and the third LC resonator; each of the first LC resonator and the second LC resonator is not connected to ground; the first LC resonator includes a first inductor; the second LC resonator includes a second inductor; the first inductor includes two first through-hole rows and a first conductor layer connecting the two first through-hole rows; each of the two first through-hole rows includes a portion formed by two or more through-holes directly connected in series without the first conductor layer therebetween; the second inductor includes two second through-hole rows and a second conductor layer connecting the two second through-hole rows; each of the two second through-hole rows includes a portion formed by two or more through-holes directly connected in series without the second conductor layer therebetween; The multilayer filter device according to claim 1, wherein the first inductor and the second inductor are configured to be magnetically coupled within the multilayer body.

2. 2. The multilayer filter device according to claim 1, wherein the first inductor and the second inductor are adjacent to each other within the laminate.

3. 3. The multilayer filter device according to claim 1, wherein no conductors are present between the two first through-hole rows and the two second through-hole rows.

4. 4. The multilayer filter device according to claim 1, wherein a first region sandwiched between the two first through-hole rows and a second region sandwiched between the two second through-hole rows overlap each other when viewed from a direction perpendicular to the stacking direction of the plurality of dielectric layers.

5. 5. The multilayer filter device according to claim 1, wherein the first conductor layer and the second conductor layer do not overlap each other when viewed from a direction parallel to the stacking direction of the plurality of dielectric layers.

6. the first conductor layer includes a portion extending in a direction away from the second conductor layer; 6. The multilayer filter device according to claim 1, wherein the second conductor layer includes a portion extending in a direction away from the first conductor layer.

7. the third LC resonator includes a third inductor; the third inductor includes a third conductor layer; 7. The multilayer filter device according to claim 1, wherein the third conductor layer overlaps with a region in which the first conductor layer or the second conductor layer is disposed when viewed from a direction parallel to the stacking direction of the plurality of dielectric layers.

8. the laminate has a first surface facing the object to be mounted and a second surface opposite to the first surface, 8. The multilayer filter device according to claim 7, wherein the third conductor layer is disposed between the first conductor layer or the second conductor layer and the first surface.

9. each of the first LC resonator and the second LC resonator constitutes a low-pass filter; 9. The multilayer filter device according to claim 1, wherein the third LC resonator constitutes a high-pass filter.

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