Laminated filter device

Abstract

The laminated filter device of the present application includes a ground conductor layer, at least one through hole electrically connected to the ground conductor layer, a first resonator conductor layer and a second resonator conductor layer arranged to sandwich the at least one through hole, and a laminate. The first resonator conductor layer extends in a first direction away from the at least one through hole, i.e., the -X direction, and the second resonator conductor layer extends in a second direction away from the at least one through hole, i.e., the X direction.

Description

TECHNICAL FIELD

[0001] The present application relates to a laminated filter device having two resonators. BACKGROUND

[0002] Among electronic components used in communication devices, there is a bandpass filter having a plurality of resonators. Each of the plurality of resonators has, for example, a conductor portion that is long in one direction. In particular, for a bandpass filter used in a small communication device, miniaturization is required. As a bandpass filter suitable for miniaturization, a bandpass filter using a laminate including a plurality of dielectric layers and a plurality of conductor layers laminated is known.

[0003] In the specification of Chinese Patent Application Publication No. 108428974A, a bandpass filter having four 1 / 4 wavelength resonators is disclosed, and the bandpass filter uses a laminate including a plurality of dielectric layers and a plurality of conductor layers laminated. In the bandpass filter, two resonators are constituted by two resonator conductor portions having a shape long in the X direction, and the other two resonators are constituted by two resonator conductor portions each having a shape long in the Y direction.

[0004] In a bandpass filter using a laminate, due to manufacturing variation, there is a case where the positions of the conductor layers or the via holes deviate. In the bandpass filter disclosed in the specification of Chinese Patent Application Publication No. 108428974A, it is considered that the positions of the two resonator conductor portions having a shape long in the Y direction deviate in the Y direction. In this case, both of the two resonator conductor portions become long, or both become short. There is a portion in the characteristics of the resonator that varies depending on the length of the resonator conductor portion. Therefore, when the lengths of the two resonator conductor portions each vary, the characteristics of the two resonators also vary. As a result, there is a case where the characteristics greatly vary as a whole of the bandpass filter. SUMMARY

[0005] An object of the present application is to provide a laminated filter device capable of suppressing variation in characteristics caused by manufacturing variation.

[0006] The laminated filter device of the present application includes a ground conductor layer electrically connected to a ground line; at least one via hole electrically connected to the ground conductor layer; a first resonator conductor layer and a second resonator conductor layer disposed so as to sandwich the at least one via hole; and a laminate including a plurality of dielectric layers laminated, and serving to integrate the ground conductor layer, the at least one via hole, the first resonator conductor layer, and the second resonator conductor layer. The first resonator conductor layer extends in a first direction away from the at least one via hole. The second resonator conductor layer extends in a second direction away from the at least one via hole.

[0007] In the laminated filter device of the present application, each of the first resonator conductor layer and the second resonator conductor layer can constitute a resonator having one end short-circuited and the other end open. In this case, each of the first resonator conductor layer and the second resonator conductor layer can be electrically connected to at least one via hole.

[0008] Further, in the laminated filter device of the present application, the at least one via hole can include a plurality of via holes arranged in a direction orthogonal to the stacking direction of the plurality of dielectric layers and orthogonal to at least one of the first direction and the second direction.

[0009] Further, in the laminated filter device of the present application, the first direction and the second direction can be directions opposite to each other.

[0010] Further, the laminated filter device of the present application can further include a third resonator conductor layer coupled to the first resonator conductor layer and a fourth resonator conductor layer coupled to the second resonator conductor layer.

[0011] In the laminated filter device of the present application, the first resonator conductor layer extends in a first direction away from the at least one via hole, and the second resonator conductor layer extends in a second direction away from the at least one via hole. The at least one via hole is electrically connected to a ground conductor layer, and the ground conductor layer is electrically connected to a ground line. Thus, according to the present application, a laminated filter device capable of suppressing variation in characteristics caused by manufacturing variation can be achieved.

[0012] Other objects, features and advantages of the present application will become more fully apparent from the following description and appended claims, and appended drawings. BRIEF DESCRIPTION OF DRAWINGS

[0013] Figure 1 is a circuit diagram showing a circuit structure of a laminated filter device of a first embodiment of the present application.

[0014] Figure 2 is a perspective view showing an appearance of the laminated filter device of the first embodiment of the present application.

[0015] Figure 3 is an explanatory diagram showing a patterned surface of a first dielectric layer in a laminate of the laminated filter device of the first embodiment of the present application.

[0016] Figure 4 is an explanatory diagram showing patterned surfaces of second to seventh dielectric layers in the laminate of the laminated filter device of the first embodiment of the present application.

[0017] Figure 5 is an explanatory diagram showing a patterned surface of an eighth dielectric layer in the laminate of the laminated filter device of the first embodiment of the present application.

[0018] Figure 6 FIG. 9 is an explanatory view of a pattern formation surface of the 9th dielectric layer in the stack of the laminated filter device according to the first embodiment of the present application.

[0019] Figure 7 FIG. 10 is an explanatory view of a pattern formation surface of the 10th dielectric layer in the stack of the laminated filter device according to the first embodiment of the present application.

[0020] Figure 8 FIG. 11 is an explanatory view of pattern formation surfaces of the 11th to 16th dielectric layers in the stack of the laminated filter device according to the first embodiment of the present application.

[0021] Figure 9 FIG. 12 is an explanatory view of a terminal formation surface of the 16th dielectric layer in the stack of the laminated filter device according to the first embodiment of the present application.

[0022] Figure 10 FIG. 13 is a perspective view of the inside of the stack of the laminated filter device according to the first embodiment of the present application.

[0023] Figure 11 FIG. 14 is an explanatory view of the structure of the laminated filter device according to the second embodiment of the present application.

[0024] Figure 12 FIG. 15 is an explanatory view of the structure of a modification of the laminated filter device according to the second embodiment of the present application. DETAILED DESCRIPTION

[0025] [First Embodiment]

[0026] Hereinafter, an embodiment of the present application will be described in detail with reference to the drawings. First, the general situation of the structure of a laminated filter device (hereinafter, simply referred to as a filter device.) 1 according to the first embodiment of the present application will be described with reference to FIG. 1. Figure 1 The filter device 1 includes two ports 3, 4, a first resonant circuit 10, and a second resonant circuit 20. The ports 3, 4 are ports for input or output of a signal, respectively.

[0027] In the present embodiment, the first resonant circuit 10 constitutes a bandpass filter, and the second resonant circuit 20 constitutes a band elimination filter. In particular in the present embodiment, the first resonant circuit 10 is a main resonant circuit, and the second resonant circuit 20 is a slave resonant circuit. The filter device 1 as a whole functions as a bandpass filter.

[0028] The first resonant circuit 10 is provided between the two ports 3, 4 in a circuit structure. Further, the first resonant circuit 10 is coupled to both of the two ports 3, 4. In addition, in the present application, the expression "in a circuit structure" is not a configuration in a physical structure, but is used to refer to a configuration on a circuit diagram.

[0029] The second resonant circuit 20 is provided between the two ports 3, 4 in a circuit structure. Further, the second resonant circuit 20 is coupled to at least one of the two ports 3, 4. In the present embodiment, in particular, the second resonant circuit 20 is coupled to both of the two ports 3, 4. In addition, in the present embodiment, the second resonant circuit 20 is provided in parallel with the first resonant circuit 10 between the two ports 3, 4 in a circuit structure, and is not provided between the first resonant circuit 10 and the port 3 or the port 4.

[0030] The filter device 1 further includes two first capacitors C11, C12 that capacitively couple the first resonant circuit 10 to the two ports 3, 4. The first capacitor C11 capacitively couples the first resonant circuit 10 to the port 3. The first capacitor C12 capacitively couples the first resonant circuit 10 to the port 4.

[0031] The filter device 1 further includes at least one second capacitor that capacitively couples the second resonant circuit 20 to the two ports 3, 4. In the present embodiment, in particular, the filter device 1 includes two second capacitors C21, C22 as the at least one second capacitor. The second capacitor C21 capacitively couples the second resonant circuit 20 to the port 3. The second capacitor C22 capacitively couples the second resonant circuit 20 to the port 4.

[0032] The coupling of the second resonant circuit 20 to the two ports 3, 4 is weaker than the coupling of the first resonant circuit 10 to the two ports 3, 4. In the case where the coupling between the resonant circuit and the port is a capacitive coupling as in the present embodiment, the coupling becomes stronger as the capacitance of the capacitor that capacitively couples the resonant circuit to the port becomes larger. That is, the coupling between the resonant circuit and the port becomes weaker as the above-described capacitance becomes smaller.

[0033] In the present embodiment, the capacitance of each of the second capacitors C21, C22 is smaller than the capacitance of each of the first capacitors C11, C12. Due to this, the coupling between the second resonant circuit 20 and the port 3 and the coupling between the second resonant circuit 20 and the port 4 each become weaker than the coupling between the first resonant circuit 10 and the port 3 and the coupling between the first resonant circuit 10 and the port 4. In one example, the capacitance of each of the second capacitors C21, C22 is 0.03 pF, and the capacitance of each of the first capacitors C11, C12 is 0.14 pF.

[0034] Further, the first resonant circuit 10 can be directly connected to the ports 3, 4, respectively. In the case where the resonant circuit is directly connected to the ports, in the high frequency region, it is substantially the same as the case where the capacitive coupling is performed through an infinite large capacitor. Therefore, in this case, the respective coupling between the first resonant circuit 10 and the port 3 and between the first resonant circuit 10 and the port 4 is stronger than when the capacitive coupling is performed through the first capacitors Cll, C12.

[0035] Next, one example of the structure of the first and second resonant circuits 10, 20 will be described with reference to Figure 1 First, the first resonant circuit 10 will be described. The first resonant circuit 10 includes a plurality of first resonators. In particular in the present embodiment, the first resonant circuit 10 includes, as the plurality of first resonators, two first resonators 11, 12 arranged in order from the port 3 side in the circuit structure. Each of the first resonators 11, 12 is a ¼ wavelength resonator of one end short-circuit and the other end open type. The first resonators 11, 12 are magnetically coupled to each other.

[0036] The first resonator 11 is coupled to the port 3. The first resonator 11 has a first end 11a closest to the port 3 and a second end 11b farthest from the port 3. The first capacitor Cll is provided between the first end 11a of the first resonator 11 and the port 3 in the circuit structure.

[0037] The first resonator 12 is coupled to the port 4. The first resonator 12 has a first end 12a closest to the port 4 and a second end 12b farthest from the port 4. The first capacitor C12 is provided between the first end 12a of the first resonator 12 and the port 4 in the circuit structure.

[0038] The second end 11b of the first resonator 11 and the second end 12b of the first resonator 12 are each connected to a ground line. In Figure 1 In the drawing, the reference symbol Lll denotes an inductive component of a line connecting the first resonators 11, 12 and the ground line.

[0039] Next, the second resonant circuit 20 will be described. The second resonant circuit 20 includes a plurality of second resonators. In particular in the present embodiment, the second resonant circuit 20 includes, as the plurality of second resonators, two second resonators 21, 22 arranged in order from the port 3 side in the circuit structure. Each of the second resonators 21, 22 is a ½ wavelength resonator of both ends open type. The second resonators 21, 22 are magnetically coupled to each other.

[0040] The second resonator 21 is coupled to the port 3. The second resonator 21 has a first end 21a closest to the port 3 and a second end 21b farthest from the port 3. The second capacitor C21 is provided between the first end 21a of the second resonator 21 and the port 3 in the circuit structure.

[0041] The second resonator 22 is coupled with the port 4. The second resonator 22 has a first end 22a closest to the port 4 and a second end 22b farthest from the port 4. The second capacitor C22 is provided on the circuit structure between the first end 22a of the second resonator 22 and the port 4.

[0042] Next, other structures of the filter device 1 will be described with reference to Figure 2 Figure 2 is a perspective view showing the appearance of the filter device 1.

[0043] The filter device 1 further includes a laminate 50. The laminate 50 includes a plurality of dielectric layers laminated, and a plurality of conductor layers and a plurality of vias formed in the plurality of dielectric layers. The ports 3, 4, the first resonant circuit 10, the second resonant circuit 20, the first capacitors C11, C12, and the second capacitors C21, C22 are integrated with the laminate 50.

[0044] The laminate 50 has a bottom surface 50A and an upper surface 50B at both ends in the laminating direction T of the plurality of dielectric layers, and four side surfaces 50C to 50F connecting the bottom surface 50A and the upper surface 50B. The side surfaces 50C, 50D face opposite sides to each other, and the side surfaces 50E, 50F also face opposite sides to each other. The side surfaces 50C to 50F are perpendicular with respect to the upper surface 50B and the bottom surface 50A.

[0045] Here, the X direction, the Y direction, and the Z direction are defined as shown in Figure 2 The X direction, the Y direction, and the Z direction are orthogonal to each other. In the present embodiment, one direction parallel to the laminating direction T is taken as the Z direction. Further, a direction opposite to the X direction is taken as the -X direction, a direction opposite to the Y direction is taken as the -Y direction, and a direction opposite to the Z direction is taken as the -Z direction.

[0046] As shown in Figure 2 The bottom surface 50A is located at the -Z direction end of the laminate 50. The upper surface 50B is located at the Z direction end of the laminate 50. The side surface 50C is located at the -X direction end of the laminate 50. The side surface 50D is located at the X direction end of the laminate 50. The side surface 50E is located at the -Y direction end of the laminate 50. The side surface 50F is located at the Y direction end of the laminate 50.

[0047] The filter device 1 further includes terminals 511, 661 and ground conductor layers 512, 662. The terminals 511 and the ground conductor layers 512 are disposed on the bottom surface 50A. In the present embodiment, in particular, the ground conductor layer 512 covers almost the entire bottom surface 50A. A gap is formed between the terminals 511 and the ground conductor layers 512.

[0048] ​The terminal 661 and the ground conductor layer 662 are arranged on the upper surface 50B. In this embodiment, in particular, the ground conductor layer 662 covers almost the entire upper surface 50B. A gap is formed between the terminal 661 and the ground conductor layer 662.

[0049] The terminal 511 corresponds to port 3, and the terminal 661 corresponds to port 4. Each of the ground conductor layers 512, 662 is connected to a ground line.

[0050] Next, one example of the plurality of dielectric layers and the plurality of conductor layers that constitute the laminate 50 will be described with reference to Figures 3 to 9 In this example, the laminate 50 has 16 layers of dielectric layers stacked. Hereinafter, the 16 layers of dielectric layers will be referred to as the first to sixteenth dielectric layers from the bottom. Further, the first to sixteenth dielectric layers will be denoted by symbols 51 to 66. In Figures 3 to 9 In the drawing, a plurality of circles represent a plurality of through holes.

[0051] Figure 3 The drawing represents a pattern formation surface of the first dielectric layer 51. On the pattern formation surface of the dielectric layer 51, the terminal 511 and the ground conductor layer 512 are formed. Further, on the dielectric layer 51, a specific through hole 51T1 connected to the terminal 511 is formed. A plurality of through holes formed on the dielectric layer 51 other than the specific through hole 51T1 are connected to the ground conductor layer 512. The plurality of through holes connected to the ground conductor layer 512 include the specific through holes 51T2, 51T3.

[0052] Figure 4 The drawing represents a pattern formation surface of each of the second to seventh dielectric layers 52 to 57. On each of the dielectric layers 52 to 57, specific through holes 52T1, 52T2, 52T3 are formed. The specific through holes 51T1 to 51T3 formed on the dielectric layer 51 are respectively connected to the specific through holes 52T1 to 52T3 formed on the dielectric layer 52. Further, on the dielectric layers 52 to 57, the specific through holes of the same symbols adjacent to each other are connected to each other.

[0053] Figure 5 The drawing represents a pattern formation surface of the eighth dielectric layer 58. On the pattern formation surface of the dielectric layer 58, conductor layers 581, 582 are formed. Further, on the dielectric layer 58, specific through holes 58T1, 58T2, 58T3 are formed. The specific through holes 52T1 to 52T3 formed on the dielectric layer 57 are respectively connected to the specific through holes 58T1 to 58T3.

[0054] Figure 6A pattern formation surface of the dielectric layer 59 representing the 9th layer. The resonator conductor layers 591, 592, 593, 594, the conductor layers 595, 596, and the ground conductor layer 597 are formed on the pattern formation surface of the dielectric layer 59. Each of the conductor layers 591 to 596 has a first end and a second end located on opposite sides of each other.

[0055] Each of the conductor layers 591, 595 extends in the -X direction from the first end to the second end. Each of the conductor layers 592, 596 extends in the X direction from the first end to the second end. Each of the conductor layers 593, 594 extends in the -Y direction from the first end to the second end.

[0056] Further, the specific vias 59T1, 59T2, 59T3 are formed in the dielectric layer 59. The specific via 59T1 is connected to a portion near the first end of the conductor layer 596. The specific vias 58T1 formed in the dielectric layer 58 are connected to a portion near the first end of the conductor layer 595. The specific vias 58T2, 58T3 formed in the dielectric layer 58 and the specific vias 59T2, 59T3 are connected to the ground conductor layer 597.

[0057] A portion near the first end of the conductor layer 591 is adjacent to a portion near the second end of the conductor layer 595 with a prescribed interval therebetween. A portion near the first end of the conductor layer 592 is adjacent to a portion near the second end of the conductor layer 596 with a prescribed interval therebetween. The second ends of the conductor layers 591, 592 are connected to the ground conductor layer 597. In Figure 6 In the 9th layer, the boundaries of the conductor layers 591, 592 and the ground conductor layer 597 are indicated by dotted lines.

[0058] A portion near the first end of the conductor layer 593 is adjacent to a portion near the second end of the conductor layer 595 with a prescribed interval therebetween. A portion near the first end of the conductor layer 594 is adjacent to a portion near the second end of the conductor layer 596 with a prescribed interval therebetween.

[0059] Figure 7 A pattern formation surface of the dielectric layer 60 representing the 10th layer. The conductor layers 601, 602 are formed on the pattern formation surface of the dielectric layer 60. Further, the specific vias 60T1, 60T2, 60T3 are formed in the dielectric layer 60. The specific vias 59T1 to 59T3 formed in the dielectric layer 59 are connected to the specific vias 60T1 to 60T3, respectively.

[0060] Figure 8indicates a pattern formation surface of each of the dielectric layers 61 to 66 of the 11th to 16th layers. In each of the dielectric layers 61 to 66, a specific via 61T1, 61T2, 61T3 is formed. The specific vias 60T1 to 60T3 formed in the dielectric layer 60 are connected to the specific vias 61T1 to 61T3 formed in the dielectric layer 61, respectively. Further, in the dielectric layers 61 to 66, the vias of the same reference numerals adjacent to each other are connected to each other.

[0061] Figure 9 indicates a terminal formation surface of a surface opposite to the pattern formation surface of the dielectric layer 66 of the 16th layer. In the terminal formation surface of the dielectric layer 66, a terminal 661 and a ground conductor layer 662 are formed. The specific via 61T1 formed in the dielectric layer 66 is connected to the terminal 661. The plurality of vias (except for the specific via 61T1) formed in the dielectric layer 66 including the specific vias 61T2, 61T3 formed in the dielectric layer 66 are connected to the ground conductor layer 662.

[0062] Figure 2 The laminated body 50 shown is configured by laminating the dielectric layers 51 to 66 of the 1st to 16th layers in such a manner that the pattern formation surface of the dielectric layer 51 of the 1st layer becomes a bottom surface 50A of the laminated body 50 and the terminal formation surface of the dielectric layer 66 of the 16th layer becomes an upper surface 50B of the laminated body 50.

[0063] Figure 10 indicates the inside of the laminated body 50 configured by laminating the dielectric layers 51 to 66 of the 1st to 16th layers. As shown in Figure 10 indicated, in the inside of the laminated body 50, the Figures 3 to 9 plurality of conductor layers and the plurality of vias are laminated. The conductor layer 595 is connected to the terminal 511 via the specific vias 51T1, 52T1, 58T1. The conductor layer 596 is connected to the terminal 661 via the specific vias 59T1, 60T1, 61T1. The ground conductor layers 512, 597, 662 are connected to each other by the plurality of vias except for the specific vias 51T1, 52T1, 58T1, 59T1, 60T1, 61T1. In particular, the ground conductor layer 597 is connected to the ground conductor layer 512 via the specific vias 51T2, 51T3, 52T2, 52T3, 58T2, 58T3 and is connected to the ground conductor layer 662 via the specific vias 59T2, 59T3, 60T2, 60T3, 61T2, 61T3.

[0064] Hereinafter, the constituent elements of the filter device 1 shown in Figure 1 and the Figures 4 to 8The correspondence of the constituent elements inside the illustrated laminate 50 will be described. The first resonator 11 of the first resonant circuit 10 is constituted by the resonator conductor layer 591. The first resonator 12 of the first resonant circuit 10 is constituted by the resonator conductor layer 592. The second resonator 21 of the second resonant circuit 20 is constituted by the resonator conductor layer 593. The second resonator 22 of the second resonant circuit 20 is constituted by the resonator conductor layer 594.

[0065] The first capacitor C11 is constituted by the conductor layers 581, 591, 595 and the dielectric layer 58 between these conductor layers. The first capacitor C12 is constituted by the conductor layers 582, 592, 596 and the dielectric layer 58 between these conductor layers. The second capacitor C21 is constituted by the conductor layers 593, 595, 601 and the dielectric layer 59 between these conductor layers. The second capacitor C22 is constituted by the conductor layers 594, 596, 602 and the dielectric layer 59 between these conductor layers.

[0066] Next, the features of the configuration of the filter device 1 in the present embodiment will be described simply. In the filter device 1, the resonator conductor layers 591 to 594 are provided in a space surrounded by the ground conductor layers 512, 662 and the plurality of through holes.

[0067] Further, in the filter device 1, the areas of the conductor layers 601, 602 that constitute the second capacitors C21, C22 are each smaller than the areas of the conductor layers 581, 582 that constitute the first capacitors C11, C12.

[0068] The specific through holes 51T2, 51T3, 52T2, 52T3, 58T2, 58T3, 59T2, 59T3, 60T2, 60T3, 61T2, 61T3 are electrically connected to the ground conductor layers 512, 597, 662. The ground conductor layers 512, 597, 662 are electrically connected to a ground line. Hereinafter, the specific through holes 51T2, 51T3, 52T2, 52T3, 58T2, 58T3, 59T2, 59T3, 60T2, 60T3, 61T2, 61T3 will be referred to as a plurality of specific through holes connected to the ground line.

[0069] The plurality of specific via holes connected to the ground line include two via holes arranged in a direction orthogonal to the stacking direction T. Specifically, the two via holes are a group of the specific via holes 71T2, 71T3; a group of the specific via holes 72T2, 72T3; a group of the specific via holes 78T2, 78T3; a group of the specific via holes 79T2, 79T3; a group of the specific via holes 80T2, 80T3; and a group of the specific via holes 81T2, 81T3. The two specific via holes included in these groups are arranged in a direction orthogonal to at least one of a direction in which the resonator conductor layer 591 extends and a direction in which the resonator conductor layer 592 extends. In the present embodiment, the two specific via holes included in these groups are arranged in a direction parallel to the Y direction.

[0070] The resonator conductor layer 591 extends in a first direction away from the plurality of specific via holes connected to the ground line. The resonator conductor layer 591 extends in a second direction away from the plurality of specific via holes connected to the ground line. In the present embodiment, specifically, each of the resonator conductor layers 591, 592 is electrically connected to the plurality of specific via holes connected to the ground line.

[0071] The first and second directions are directions orthogonal to the stacking direction T. In the present embodiment, specifically, the first direction is the X direction, and the second direction is the -X direction. Thus, the first direction and the second direction are directions opposite to each other.

[0072] Each of the resonator conductor layers 593, 594 includes a narrow-width portion and two wide-width portions located on both sides of the narrow-width portion. Each of the second resonators 21, 22 composed of the resonator conductor layers 593, 594 is a stepped-impedance resonator.

[0073] Next, the operation and effects of the filter device 1 in the present embodiment will be described. In the present embodiment, as described above, each of the resonator conductor layers 591, 592 extends in a direction away from the plurality of specific via holes connected to the ground line. Thus, in the present embodiment, in a case where the resonator conductor layers 591, 592 or the plurality of specific via holes connected thereto deviate from the direction parallel to the X direction due to manufacturing variations, one of the resonator conductor layers 591, 592 becomes longer, and the other becomes shorter. Thus, according to the present embodiment, it is possible to cancel out variations in characteristics of the resonators caused by variations in the lengths of the resonator conductor layers. As a result, according to the present embodiment, it is possible to suppress variations in characteristics of the first resonant circuit 10, i.e., the band-pass filter, caused by manufacturing variations.

[0074] Further, in the present embodiment, as described above, the plurality of specific through-holes connected to the ground include 2 through-holes arranged in a direction orthogonal to at least one of a direction orthogonal to the stacking direction T and a direction in which the resonator conductor layer 591 extends and a direction in which the resonator conductor layer 592 extends. In the present embodiment, in particular, the above 2 through-holes are arranged in a direction orthogonal to both the direction in which the resonator conductor layer 591 extends and the direction in which the resonator conductor layer 592 extends. Therefore, in a case where the resonator conductor layers 591, 592 or the connected plurality of specific through-holes deviate from a direction parallel to the Y direction, the respective lengths of the resonator conductor layers 591, 592 hardly change. Thus, according to the present embodiment, it is also possible to suppress a change in the characteristics of the first resonant circuit 10, that is, the band-pass filter, caused by manufacturing variation.

[0075] Hereinafter, the above effects of the present embodiment will be described with reference to the results of simulation. In the simulation, the model of the example and the model of the comparative example were used. Both the model of the example and the model of the comparative example were models of a band-pass filter having a ground conductor layer and two resonator conductor layers extending from the ground conductor layer.

[0076] In the model of the example, as with the filter device 1 in the present embodiment, the two resonator conductor layers were arranged so as to extend in opposite directions while sandwiching the ground conductor layer. In the model of the comparative example, the two resonator conductor layers extended in the same direction from the ground conductor layer. In the simulation, the long-side direction (a direction parallel to the extending direction) of the resonator conductor layers was made the same direction as in the model of the example and the model of the comparative example. In the simulation, the length of each of the two resonator conductor layers in the model of the example was made 700 μm, and the length of each of the two resonator conductor layers in the model of the comparative example was made 855 μm.

[0077] In the simulation, the amount of deviation of the low-frequency cutoff frequency, which is the lower limit of the passband, and the amount of deviation of the high-frequency cutoff frequency, which is the upper limit of the passband, were calculated when the two resonator conductor layers were deviated by 15 μm in the length direction of the resonator conductor layers. In the model of the example, when the two resonator conductor layers were deviated by 15 μm in the long-side direction of the resonator conductor layers, one of the two resonator conductor layers was made shorter by 15 μm and the other was made longer by 15 μm. In the model of the comparative example, when the two resonator conductor layers were deviated by 15 μm in the length direction of the resonator conductor layers, both of the two resonator conductor layers were made shorter by 15 μm or longer by 15 μm. In the simulation, the two resonator conductor layers were deviated in such a manner that both of the two resonator conductor layers were made longer.

[0078] In the case where the two resonators are offset from the conductor layer as described above, in the comparative example model, the amount of deviation of the low frequency cutoff frequency is 0.80%, and the amount of deviation of the high frequency cutoff frequency is 1.25%. Further, in the example model, the amount of deviation of the low frequency cutoff frequency is 0.11%, and the amount of deviation of the high frequency cutoff frequency is 0.11%. As a result of the simulation, it is found that according to the present embodiment, the variation of the low frequency cutoff frequency and the high frequency cutoff frequency caused by the manufacturing deviation can be suppressed.

[0079] Next, other effects of the filter device 1 of the present embodiment will be described. As described above, in the present embodiment, the coupling of the second resonant circuit 20 to the two ports 3, 4 is weaker than the coupling of the first resonant circuit 10 to the two ports 3, 4. Thus, according to the present embodiment, the effects caused by the second resonant circuit 20 can be suppressed and the second resonant circuit 20 can be incorporated into the filter device 1.

[0080] In the present embodiment, in particular, the first resonant circuit 10 constitutes a bandpass filter, and the second resonant circuit 20 constitutes a band elimination filter. The effects caused by the second resonant circuit 20 specifically mean that in the frequency characteristic of the insertion loss of the filter device 1 (the frequency characteristic of the insertion loss of the bandpass filter), the insertion loss of the frequency range near the center frequency of the stop band of the band elimination filter constituted by the second resonant circuit 20 is increased. Thus, according to the present embodiment, the insertion loss of the above-described frequency range can be reduced to a desired size and the second resonant circuit 20 can be incorporated into the filter device 1. Thus, according to the present embodiment, by making the center frequency of the stop band of the band elimination filter constituted by the second resonant circuit 20 close to the frequency of the pass band of the bandpass filter constituted by the first resonant circuit 10, the insertion loss of the pass band of the filter device 1 can be suppressed from being increased, and a characteristic in which the insertion loss sharply changes in the frequency range close to the pass band of the filter device 1 can be obtained.

[0081] In addition, the characteristic in which the insertion loss sharply changes in the frequency range close to the pass band can also be obtained by increasing the number of resonators constituting the bandpass filter. However, if the Q values of the resonators are made the same and are compared, it is found that as the number of resonators increases, the insertion loss of the pass band is increased.

[0082] In contrast to this, in the present embodiment, the number of resonators included in the first resonant circuit 10 is only two. According to the present embodiment, the characteristic in which the insertion loss sharply changes in the frequency range close to the pass band can be obtained without increasing the number of resonators constituting the bandpass filter. Thus, according to the present embodiment, the increase of the insertion loss of the pass band can be suppressed. Further, according to the present embodiment, the miniaturization of the filter device 1 can be achieved.

[0083] The center frequency of the stop band of the band elimination filter composed of the second resonant circuit 20 can exist in either the low frequency side of the pass band of the band pass filter composed of the first resonant circuit 10 or the high frequency side of the pass band.

[0084] [Second Embodiment]

[0085] Next, a second embodiment of the present application will be described with reference to Figure 11 Figure 11 is a diagram schematically showing the structure of the filter device 101 of the present embodiment.

[0086] The filter device 101 of the present embodiment is a band pass filter provided with four resonators 31, 32, 33, 34. The resonators 31 to 34 are each a ¼ wavelength resonator with one end short-circuited and the other end open, and are composed of a resonator conductor layer extending in one direction. In the following description, the resonator refers to at least one of the resonator and the resonator conductor layer.

[0087] The filter device 101 further includes ground conductor sections 41, 42, 43 each electrically connected to a ground line. The ground conductor sections 41 to 43 each include a ground conductor layer electrically connected to the ground line and at least one via hole electrically connected to the ground conductor layer. Each of the ground conductor sections 41 to 43 extends as a whole in a direction parallel to the Y direction.

[0088] One end of the resonator 31 is connected to the ground conductor section 41. The resonator 31 extends from the ground conductor section 41 in the X direction.

[0089] The resonators 32, 33 are arranged so as to sandwich the ground conductor section 42. One end of each of the resonators 32, 33 is connected to the ground conductor section 42. The resonator 32 extends from the ground conductor section 42 in the -X direction. The resonator 33 extends from the ground conductor section 42 in the X direction.

[0090] One end of the resonator 34 is connected to the ground conductor section 43. The resonator 34 extends from the ground conductor section 43 in the -X direction.

[0091] The resonator 31 is electromagnetically coupled to the resonator 32, the resonator 32 is electromagnetically coupled to the resonator 31, and the resonator 33 is electromagnetically coupled to the resonator 34.

[0092] In the present embodiment, the other end of the resonator 34 is opposite to the other end of the resonator 31.

[0093] ​In this embodiment, if resonators 32 and 33 or ground conductor 42 deviate in a direction parallel to the X direction due to manufacturing deviations, one of resonators 32 and 33 becomes longer and the other becomes shorter. Similarly, if resonators 31 and 34 or ground conductor 41 and 43 deviate in a direction parallel to the X direction due to manufacturing deviations, one of resonators 31 and 34 becomes longer and the other becomes shorter. Therefore, according to this embodiment, changes in the characteristics of resonators 31 to 34 can be offset. As a result, according to this embodiment, changes in the characteristics of the filter device 101 caused by manufacturing deviations can be suppressed.

[0094] Furthermore, in this embodiment, each of the ground conductor portions 41 to 43 extends as a whole in a direction parallel to the Y direction. Therefore, even if the resonators 31 to 34 or the ground conductor portions 41 to 43 deviate from the direction parallel to the Y direction, the length of each of the resonators 31 to 34 remains almost unchanged. Thus, according to this embodiment, changes in the characteristics of the filter device 101 caused by manufacturing deviations can be suppressed.

[0095] [Variation Example]

[0096] Next, refer to Figure 12 This section describes a variation of the filter device 101 in this embodiment. Figure 12 This is an explanatory diagram schematically showing the structure of a modified example of the filter device 101 according to this embodiment. In the modified example, the ground conductor portion 42 is disposed between the resonator 31 and the resonator 34.

[0097] The other structures, functions, and effects of this embodiment are the same as those of the first embodiment.

[0098] Furthermore, the present invention is not limited to the embodiments described above, and various modifications are possible. For example, the number and structure of the first and second resonators are not limited to those shown in the embodiments, as long as they satisfy the scope defined in the claims. The number of the first and second resonators may also be three or more.

[0099] Furthermore, the first resonant circuit 10 is not limited to a bandpass filter, but can also be a resonant circuit that constitutes other filters such as low-pass filters and high-pass filters.

[0100] Furthermore, the first direction is not limited to the X direction; it can also be a direction inclined from the X direction towards the Y direction or towards the -Y direction. Similarly, the second direction is not limited to the -X direction; it can also be a direction inclined from the -X direction towards the Y direction or towards the -Y direction. Additionally, the angle formed by the first and second directions can be greater than 90° and less than 180°.

[0101] As described above, various modes and modifications of the present application can be implemented. Therefore, the present application can be implemented in a manner equivalent to the scope of the application, or in a manner other than the preferred modes described above.

Claims

1. A cascaded filter device, characterized in that: have: A grounding conductor layer that is electrically connected to the ground wire; At least one through-hole is electrically connected to the grounding conductor layer; The first resonator conductor layer and the second resonator conductor layer are configured to clamp the at least one through-hole; and A laminate comprising multiple stacked dielectric layers for integrating the grounding conductor layer, the at least one via, the first resonator conductor layer, and the second resonator conductor layer. The first resonator uses a conductor layer that extends along a first direction away from the at least one via. The second resonator uses a conductor layer that extends in a second direction away from the at least one via.

2. The cascaded filter device as described in claim 1, characterized in that: The first resonator conductor layer and the second resonator conductor layer each constitute a resonator with one end short-circuited and the other end open.

3. The cascaded filter device as described in claim 2, characterized in that: The first resonator conductor layer and the second resonator conductor layer are respectively electrically connected to the at least one via.

4. The cascaded filter device as described in claim 1, characterized in that: The at least one via comprises a plurality of vias arranged in a direction orthogonal to the stacking direction of the plurality of dielectric layers and orthogonal to at least one of the first direction and the second direction.

5. The cascaded filter device as described in claim 1, characterized in that: The first direction and the second direction are opposite to each other.

6. The cascaded filter device as described in claim 1, characterized in that: It also has: A third resonator conductor layer coupled to the first resonator conductor layer; and A fourth resonator conductor layer coupled to the second resonator conductor layer.

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