Bandpass Filter

Abstract

To miniaturize a band-pass filter that includes a plurality of open-ended resonators.SOLUTION: A band-pass filter 1 includes a first input / output port 3, a second input / output port 4, a plurality of resonators 51 to 55, and a multilayer stack 2. The multilayer stack 2 includes a plurality of stacked dielectric layers 31 to 38. Each of the resonators 51 to 55 is an open-ended resonator formed of a conductor line in the multilayer stack 2. Each of the resonators 51, 52, 54, and 55 includes a resonator conductor portion including a first line part and a second line part located away from each other in a direction orthogonal to a stacking direction of the plurality of dielectric layers, and a third line part connecting the first line part and the second line part. The first to third line parts extend to surround a space between the first line part and the second line part.SELECTED DRAWING: Figure 13

Description

[Technical field]

[0001] The present invention relates to a bandpass filter including a plurality of resonators. [Background technology]

[0002] Currently, communication services using the fifth generation mobile communication system (hereinafter referred to as 5G) are beginning to be provided. 5G is expected to use frequency bands of 10 GHz or higher, in particular the quasi-millimeter wave band of 10 to 30 GHz and the millimeter wave band of 30 to 300 GHz.

[0003] One of the electronic components used in communication devices 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. Bandpass filters used in small communication devices in particular are required to be compact.

[0004] Patent Document 1 discloses a bandpass filter in which two U-shaped stripline resonators, one end of which is grounded and the other end of which is open, are formed, and the grounded sides of the U-shaped stripline resonators are arranged adjacent to each other. Patent Document 2 discloses a bandpass filter in which two U-shaped resonator electrodes, one end of which is open and the other end of which is short-circuited, are formed, and the open end sides of the resonator electrodes are arranged adjacent to each other. In the bandpass filters disclosed in Patent Documents 1 and 2, the conductors constituting the resonators are bent to reduce the size of the bandpass filter.

[0005] Patent Document 3 discloses a bandpass filter in which a linear resonator having a resonator conductor including a narrow portion and two wide portions located on both sides of the narrow portion is formed. The resonator having the above configuration is a type of stepped impedance resonator (hereinafter, also referred to as SIR). The resonator in Patent Document 3 is a 1 / 2 wavelength resonator with both ends open. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Publication No. 10-209708 [Patent Document 2] JP 2004-266696 A [Patent Document 3] JP 2020-57920 A Summary of the Invention [Problem to be solved by the invention]

[0007] A bandpass filter including multiple 1 / 2 wavelength resonators has a problem in that it is difficult to reduce the size because the 1 / 2 wavelength resonators are long. In Patent Document 3, the bandpass filter is reduced in size by shortening the resonator conductor using an SIR. However, this bandpass filter has room for improvement in terms of miniaturization.

[0008] The present invention has been made in view of the above problems, and has an object to provide a bandpass filter including a plurality of open-ended resonators, which can be miniaturized. band The object of the present invention is to provide a pass filter. [Means for solving the problem]

[0009] The bandpass filter of the present invention includes a first input / output port, a second input / output port, a plurality of resonators arranged between the first input / output port and the second input / output port in a circuit configuration such that two adjacent resonators are electromagnetically coupled in the circuit configuration, and a laminate for integrating the first input / output port, the second input / output port, and the plurality of resonators. The laminate includes a plurality of laminated dielectric layers.

[0010] Each of the multiple resonators is an open-ended resonator configured by a conductor line in the laminate. At least one of the multiple resonators has a resonator conductor portion including a first line portion and a second line portion that are arranged at positions spaced apart from each other in a direction perpendicular to the lamination direction of the multiple dielectric layers, and a third line portion that connects the first line portion and the second line portion. The first to third line portions extend so as to surround a space between the first line portion and the second line portion.

[0011] In the bandpass filter of the present invention, the multiple resonators may include a first resonator closest to the first input / output port in the circuit configuration, a second resonator closest to the second input / output port in the circuit configuration, and at least one intermediate resonator provided between the first resonator and the second resonator in the circuit configuration. In this case, the first and second resonators may each have the resonator conductor. Also, the third line portion of the resonator conductor of the first resonator and the third line portion of the resonator conductor of the second resonator may be adjacent to each other and extend along the same direction perpendicular to the stacking direction.

[0012] Furthermore, when the multiple resonators include at least one intermediate resonator, the at least one intermediate resonator may be multiple intermediate resonators. In this case, at least one of the multiple intermediate resonators may have the resonator conductor portion. Alternatively, the at least one intermediate resonator may be a third resonator, a fourth resonator, and a fifth resonator. The fourth resonator is provided between the third resonator and the fifth resonator in terms of the circuit configuration. In this case, each of the third and fifth resonators may have the resonator conductor portion.

[0013] The bandpass filter of the present invention may further include at least one capacitor. In this case, each of the first and second line portions may have an end portion located farthest from the third line portion in the longitudinal direction of the resonator conductor. The at least one capacitor may be connected to the resonator conductor at a position away from the end portion toward the third line portion in the longitudinal direction.

[0014] In the bandpass filter of the present invention, the first line portion may include a first constant width portion having a constant dimension in the short side direction, and the second line portion may include a second constant width portion having a constant dimension in the short side direction. In this case, the dimension in the short side direction of the third line portion may be smaller than the dimensions in the short side direction of each of the first and second constant width portions. Effect of the Invention

[0015] In the bandpass filter of the present invention, at least one of the resonators has a resonator conductor including a first line portion and a second line portion that are spaced apart from each other in a direction perpendicular to the lamination direction of the dielectric layers, and a third line portion that connects the first line portion and the second line portion. The first to third line portions extend so as to surround the space between the first line portion and the second line portion. This makes it possible to achieve an effect of miniaturization of the bandpass filter of the present invention. [Brief description of the drawings]

[0016] [Figure 1] 1 is a perspective view showing a structure of a bandpass filter according to a first embodiment of the present invention. [Diagram 2] 1 is a circuit diagram showing a circuit configuration of a bandpass filter according to a first embodiment of the present invention. [Diagram 3] 2 is an explanatory diagram showing a pattern-forming surface of a first dielectric layer in the laminate shown in FIG. 1. [Figure 4] 2 is an explanatory diagram showing a pattern-forming surface of a second dielectric layer in the laminate shown in FIG. 1. FIG. [Diagram 5] 2 is an explanatory diagram showing a pattern-forming surface of a third dielectric layer in the laminate shown in FIG. 1. FIG. [Figure 6] 2 is an explanatory diagram showing a pattern-forming surface of a fourth dielectric layer in the laminate shown in FIG. 1. FIG. [Figure 7]2 is an explanatory diagram showing the pattern formation surfaces of the fifth and sixth dielectric layers in the laminate shown in FIG. 1. FIG. [Figure 8] 2 is an explanatory diagram showing a pattern-forming surface of a seventh dielectric layer in the laminate shown in FIG. 1. FIG. [Figure 9] 2 is an explanatory diagram showing a pattern-forming surface of an eighth dielectric layer in the laminate shown in FIG. 1. FIG. [Figure 10] 2 is an explanatory diagram showing a pattern-forming surface of a ninth dielectric layer in the laminate shown in FIG. 1. FIG. [Figure 11] 2 is an explanatory diagram showing the pattern formation surfaces of the 10th to 17th dielectric layers in the laminate shown in FIG. 1. FIG. [Figure 12] 2 is an explanatory diagram showing a pattern-forming surface of an 18th dielectric layer in the laminate shown in FIG. 1. FIG. [Figure 13] 1 is a plan view showing a main portion of a bandpass filter according to a first embodiment of the present invention. [Figure 14] FIG. 11 is a characteristic diagram showing an example of frequency characteristics of insertion loss and return loss of a bandpass filter obtained by simulation. [Figure 15] 15 is a characteristic diagram showing an enlarged portion of the frequency characteristic of the insertion loss shown in FIG. 14. [Figure 16] 15 is a characteristic diagram showing an enlarged portion of the frequency characteristic of the return loss shown in FIG. 14. [Figure 17] FIG. 11 is a perspective view showing a structure of a bandpass filter according to a second embodiment of the present invention. [Figure 18] FIG. 11 is an explanatory diagram showing a pattern formation surface of an eighth dielectric layer in a second embodiment of the present invention. [Figure 19] FIG. 11 is a plan view showing a main portion of a bandpass filter in accordance with a second embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0017] [First embodiment] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. First, the configuration of a bandpass filter according to a first embodiment of the present invention will be described with reference to Fig. 1 and Fig. 2. Fig. 1 is a perspective view showing the structure of a bandpass filter according to this embodiment. Fig. 2 is a circuit diagram showing the circuit configuration of the bandpass filter according to this embodiment.

[0018] As shown in Fig. 1 and Fig. 2, the bandpass filter 1 according to the present embodiment includes a first input / output port 3, a second input / output port 4, a plurality of resonators configured such that two adjacent resonators in a circuit configuration are electromagnetically coupled, and a laminate 2 for integrating the first input / output port 3, the second input / output port 4, and the plurality of resonators. The laminate 2 includes a plurality of laminated dielectric layers. Each of the plurality of resonators is a double-open resonator and a 1 / 2 wavelength resonator configured by a conductor line in the laminate 2. In this application, the expression "in the circuit configuration" is used to refer to the arrangement on a circuit diagram, not the arrangement in a physical configuration.

[0019] Here, the X direction, Y direction, and Z direction are defined as shown in FIG. 1. The X direction, Y direction, and Z direction are mutually perpendicular. In this embodiment, the stacking direction of multiple dielectric layers (the direction toward the top in FIG. 1) is defined as the Z direction. Also, the direction opposite to the X direction is defined as the -X direction, the direction opposite to the Y direction is defined as the -Y direction, and the direction opposite to the Z direction is defined as the -Z direction.

[0020] The laminate 2 has a rectangular parallelepiped shape. The laminate 2 has a bottom surface 2A and a top surface 2B located at both ends of the laminate 2 in the Z direction, and four side surfaces 2C, 2D, 2E, and 2F connecting the bottom surface 2A and the top surface 2B. The bottom surface 2A is located at the end of the laminate 2 in the -Z direction. The top surface 2B is located at the end of the laminate 2 in the Z direction. The side surface 2C is located at the end of the laminate 2 in the -X direction. The side surface 2D is located at the end of the laminate 2 in the X direction. The side surface 2E is located at the end of the laminate 2 in the -Y direction. The side surface 2F is located at the end of the laminate 2 in the Y direction.

[0021] The multiple resonators are provided between the first input / output port 3 and the second input / output port 4 in terms of the circuit configuration. As shown in FIG. 2, in this embodiment, the multiple resonators are five resonators 51, 52, 53, 54, and 55. The five resonators 51, 52, 53, 54, and 55 are arranged in this order from the first input / output port 3 side in terms of the circuit configuration. The resonator 51 is closest to the first input / output port 3 in terms of the circuit configuration, and the resonator 55 is closest to the second input / output port 4 in terms of the circuit configuration. The resonator 51 corresponds to the "first resonator" in the present invention. The resonator 55 corresponds to the "second resonator" in the present invention.

[0022] In terms of the circuit configuration, the resonators 52 to 54 are provided between the resonators 51 and 55. The resonators 52 to 54 correspond to the "intermediate resonators" of the present invention. The resonator 53 is provided between the resonators 52 and 54 in terms of the circuit configuration. The resonator 52 corresponds to the "third resonator" of the present invention. The resonator 53 corresponds to the "fourth resonator" of the present invention. The resonator 54 corresponds to the "fifth resonator" of the present invention.

[0023] The resonators 51 to 55 are configured such that the resonators 51 and 52 are adjacent and electromagnetically coupled in the circuit configuration, the resonators 52 and 53 are adjacent and electromagnetically coupled in the circuit configuration, the resonators 53 and 54 are adjacent and electromagnetically coupled in the circuit configuration, and the resonators 54 and 55 are adjacent and electromagnetically coupled in the circuit configuration. In this embodiment, the electromagnetic coupling between two resonators adjacent in the circuit configuration is capacitive coupling.

[0024] The bandpass filter 1 includes a capacitor C12 that realizes capacitive coupling between the resonators 51 and 52, a capacitor C23 that realizes capacitive coupling between the resonators 52 and 53, a capacitor C34 that realizes capacitive coupling between the resonators 53 and 54, and a capacitor C45 that realizes capacitive coupling between the resonators 54 and 55.

[0025] Here, in a bandpass filter having three or more resonators configured such that two adjacent resonators are coupled to each other in the circuit configuration, the electromagnetic coupling between two resonators that are not adjacent in the circuit configuration is called a cross coupling. The bandpass filter 1 according to this embodiment has two cross couplings, as described below.

[0026] In this embodiment, the resonator 51, which is the closest to the first input / output port 3 in terms of the circuit configuration among the five resonators 51 to 55, and the resonator 55, which is the closest to the second input / output port 4 in terms of the circuit configuration among the five resonators 51 to 55, are not adjacent to each other in terms of the circuit configuration, but are magnetically coupled to each other.

[0027] In this embodiment, the resonator 52, which is the second closest to the first input / output port 3 among the five resonators 51 to 55 in terms of the circuit configuration, and the resonator 54, which is the second closest to the second input / output port 4 among the five resonators 51 to 55 in terms of the circuit configuration, are not adjacent to each other in terms of the circuit configuration, but are capacitively coupled to each other. The bandpass filter 1 further includes a capacitor C24 that realizes capacitive coupling between the resonators 52 and 54.

[0028] The bandpass filter 1 further includes a capacitor C1 provided between the first input / output port 3 and the resonator 51, and a capacitor C2 provided between the second input / output port 4 and the resonator 55.

[0029] The bandpass filter 1 further includes a shield 6, a first partition portion 7, and a second partition portion 8. The shield 6 is made of a conductor and is integrated with the laminate 2. The shield 6 is also connected to ground. The shield 6 has a function of preventing electromagnetic waves from being emitted to the periphery of the bandpass filter 1. The shield 6 is disposed so as to surround the five resonators. Each of the first partition portion 7 and the second partition portion 8 is made of a conductor, is provided in the laminate 2, and is electrically connected to the shield 6.

[0030] The first partition portion 7 extends in the Z direction. The first partition portion 7 penetrates two or more dielectric layers constituting the laminate 2. The first partition portion 7 has a function of suppressing the TE mode. In this embodiment, the first partition portion 7 includes a plurality of first through-hole rows penetrating two or more dielectric layers constituting the laminate 2. In FIG. 1, each of the first through-hole rows is represented by a cylinder. Each of the plurality of first through-hole rows includes two or more through holes connected in series. Each of the plurality of first through-hole rows extends in the Z direction. The plurality of first through-hole rows are arranged to be aligned in the Y direction. In this embodiment, the number of the first through-hole rows is four.

[0031] The second partitioning portion 8 extends in the Z direction. The second partitioning portion 8 penetrates two or more dielectric layers constituting the laminate 2. In this embodiment, the second partitioning portion 8 includes a plurality of second through-hole rows each penetrating two or more dielectric layers constituting the laminate 2. In FIG. 1, each of the second through-hole rows is represented by a cylinder. Second Each of the through hole rows includes two or more through holes connected in series. Each of the second through hole rows extends in the Z direction. The second through hole rows are arranged in the X direction. In this embodiment, the number of the second through hole rows is four.

[0032] Next, the configuration of the resonators 51 to 55 will be described in detail with reference to Figures 1 and 2. The resonators 51, 52, 53, 54, and 55 respectively have resonator conductors 510, 520, 530, 540, and 550. Each of the resonator conductors 510, 520, 530, 540, and 550 extends in a stacking direction of the multiple dielectric layers, that is, in a direction perpendicular to the Z direction.

[0033] As described above, each of the resonators 51 to 55 is an open-ended resonator. Therefore, both ends of each of the resonator conductors 510, 520, 530, 540, and 550 are open. Each of the resonator conductors 510, 520, 530, 540, and 550 has a length that is half or close to a wavelength corresponding to the center frequency of the passband of the bandpass filter 1.

[0034] Each of the resonator conductors 510, 520, 530, 540, 550 includes a first line portion and a second line portion arranged at positions spaced apart from each other in a direction perpendicular to the Z direction, and a third line portion connecting the first line portion and the second line portion.

[0035] Hereinafter, the first line portion, the second line portion, and the third line portion of the resonator conductor 510 are represented by the reference characters 51A, 51B, and 51C, respectively. The first line portion, the second line portion, and the third line portion of the resonator conductor 520 are represented by the reference characters 52A, 52B, and 52C, respectively. The first line portion, the second line portion, and the third line portion of the resonator conductor 530 are represented by the reference characters 53A, 53B, and 53C, respectively. The first line portion, the second line portion, and the third line portion of the resonator conductor 540 are represented by the reference characters 54A, 54B, and 54C, respectively. The first line portion, the second line portion, and the third line portion of the resonator conductor 550 are represented by the reference characters 55A, 55B, and 55C, respectively.

[0036] Next, an example of the configuration of the multiple dielectric layers constituting the laminate 2, and the multiple conductor layers and multiple through holes formed in the multiple dielectric layers will be described with reference to Figures 3 to 12. In this example, the laminate 2 has 18 laminated dielectric layers. Hereinafter, the 18 dielectric layers will be referred to as the 1st to 18th dielectric layers from the bottom up. The 1st to 18th dielectric layers will be represented by the reference numerals 31 to 48. In Figures 3 to 12, multiple circles represent multiple through holes.

[0037] 3 shows the pattern-formed surface of the first dielectric layer 31. On the pattern-formed surface of the dielectric layer 31, a conductor layer 311 constituting the first input / output port 3, a conductor layer 312 constituting the second input / output port 4, and conductor layers 313, 314, 315, and 316 constituting the shield 6 are formed.

[0038] Further, in the dielectric layer 31, a through hole 31T1 connected to the conductor layer 311, a through hole 31T2 connected to the conductor layer 312, and a plurality of through holes 6T1 constituting the shield 6 are formed. In FIG. 3, any one of the plurality of through holes 6T1 is represented by a circle with a reference symbol 6T1, and the other through holes 6T1 are represented by a plurality of circles without reference symbols. Note that in the following explanations, in the same figures as FIG. 3, the plurality of through holes constituting the shield 6 are represented in the same manner as FIG. 3. Each of the plurality of through holes 6T1 is connected to one of the conductor layers 313 to 316.

[0039] 4 shows the pattern-formed surface of the second dielectric layer 32. On the pattern-formed surface of the dielectric layer 32, a conductor layer 321 constituting the shield 6 is formed.

[0040] Furthermore, through holes 32T1 and 32T2 are formed in the dielectric layer 32. The through holes 32T1 and 32T2 are connected to the through holes 31T1 and 31T2 shown in FIG.

[0041] The dielectric layer 32 further includes a plurality of through holes 6T2 constituting the shield 6, four through holes 7T2 constituting the first partition portion 7, and four through holes 8T2 constituting the second partition portion 8. A portion of the plurality of through holes 6T2, the four through holes 7T2, the four through holes 8T2, and a portion of the plurality of through holes 6T1 shown in Fig. 3 are connected to the conductor layer 321. A portion of the plurality of through holes 6T2 that is not connected to the conductor layer 321 is connected to a portion of the plurality of through holes 6T1 that is not connected to the conductor layer 321.

[0042] 5 shows a pattern-formed surface of the third dielectric layer 33. Through holes 33T1 and 33T2 are formed in the dielectric layer 33. The through holes 33T1 and 33T2 are connected to the through holes 32T1 and 32T2 shown in FIG.

[0043] The dielectric layer 33 further includes a plurality of through holes 6T3 constituting the shield 6, four through holes 7T3 constituting the first partition portion 7, and four through holes 8T3 constituting the second partition portion 8. The plurality of through holes 6T3 are connected to the plurality of through holes 6T2 shown in Fig. 4. The four through holes 7T3 are connected to the four through holes 7T2 shown in Fig. 4. The four through holes 8T3 are connected to the four through holes 8T2 shown in Fig. 4.

[0044] Fig. 6 shows the pattern formation surface of the fourth dielectric layer 34. Two conductor layers 341 and 342 are formed on the pattern formation surface of the dielectric layer 34. The conductor layer 341 is connected to the through hole 33T1 shown in Fig. 5. The conductor layer 342 is connected to the through hole 33T2 shown in Fig. 5.

[0045] In addition, in the dielectric layer 34, a through hole 34T1 connected to the conductor layer 341 and a through hole 34T2 connected to the conductor layer 342 are formed.

[0046] The dielectric layer 34 further includes a plurality of through holes 6T4 constituting the shield 6, four through holes 7T4 constituting the first partition portion 7, and four through holes 8T4 constituting the second partition portion 8. The plurality of through holes 6T4 are connected to the plurality of through holes 6T3 shown in Fig. 5. The four through holes 7T4 are connected to the four through holes 7T3 shown in Fig. 5. The four through holes 8T4 are connected to the four through holes 8T3 shown in Fig. 5.

[0047] 7 shows the pattern-formed surfaces of the fifth and sixth dielectric layers 35, 36. Through holes 35T1, 35T2 are formed in the dielectric layers 35, 36, respectively. The through holes 35T1, 35T2 formed in the fifth dielectric layer 35 are connected to the through holes 34T1, 34T2 shown in FIG. 6, respectively.

[0048] Each of the dielectric layers 35 and 36 further includes a plurality of through holes 6T5 constituting the shield 6, four through holes 7T5 constituting the first partition portion 7, and four through holes 8T5 constituting the second partition portion 8. The plurality of through holes 6T5 formed in the fifth dielectric layer 35 are connected to the plurality of through holes 6T4 shown in FIG. 6. The four through holes 7T5 formed in the fifth dielectric layer 35 are connected to the four through holes 7T4 shown in FIG. 6. The four through holes 8T5 formed in the fifth dielectric layer 35 are connected to the four through holes 8T4 shown in FIG. 6.

[0049] In the dielectric layers 35 and 36, the through holes having the same reference numerals and adjacent to each other vertically are connected to each other.

[0050] Fig. 8 shows the pattern-formed surface of the seventh dielectric layer 37. A conductor layer 371 for forming the capacitor C1 shown in Fig. 2 and a conductor layer 372 for forming the capacitor C2 shown in Fig. 2 are formed on the pattern-formed surface of the dielectric layer 37. A through-hole 35T1 formed in the sixth dielectric layer 36 is connected to the conductor layer 371. A through-hole 35T2 formed in the sixth dielectric layer 36 is connected to the conductor layer 372.

[0051] Further, in the dielectric layer 37, a plurality of through holes 6T7 constituting the shield 6, four through holes 7T7 constituting the first partition portion 7, and four through holes 8T7 constituting the second partition portion 8 are formed. A plurality of through holes 6T5 formed in the sixth dielectric layer 36 are connected to the plurality of through holes 6T7. Four through holes 7T5 formed in the sixth dielectric layer 36 are connected to the four through holes 7T7. Four through holes 8T5 formed in the sixth dielectric layer 36 are connected to the four through holes 8T7.

[0052] 9 shows the pattern-formed surface of the eighth dielectric layer 38. Resonator conductors 510, 520, 530, 540, and 550, each of which is formed by a conductor line, are formed on the pattern-formed surface of the dielectric layer 38. The shapes and arrangement of the resonator conductors 510, 520, 530, 540, and 550 will be described in detail later.

[0053] Further, in the dielectric layer 38, a plurality of through holes 6T8 constituting the shield 6, four through holes 7T8 constituting the first partition portion 7, and four through holes 8T8 constituting the second partition portion 8 are formed. The plurality of through holes 6T8 are arranged around the resonator conductors 510, 520, 530, 540, and 550. The four through holes 7T8 are arranged between the resonator conductor 510 and the resonator conductor 550. The four through holes 8T8 are arranged in a space surrounded by the resonator conductors 520 and 540. The plurality of through holes 6T8 are connected to the plurality of through holes 6T7 shown in FIG. 8. The four through holes 7T8 are connected to the four through holes 7T7 shown in FIG. 8. The four through holes 8T8 are connected to the four through holes 8T7 shown in FIG. 8.

[0054] 10 shows a pattern-formed surface of the ninth dielectric layer 39. On the pattern-formed surface of the dielectric layer 39, conductor layers 391, 392, 393, 394, and 395 for constituting the capacitors C12, C23, C34, C45, and C24 shown in FIG.

[0055] Furthermore, the dielectric layer 39 is formed with a plurality of through holes 6T9 constituting the shield 6, four through holes 7T9 constituting the first partition portion 7, and four through holes 8T9 constituting the second partition portion 8. The plurality of through holes 6T9 are connected to the plurality of through holes 6T8 shown in FIG. 9. The four through holes 7T9 are connected to the four through holes 7T8 shown in FIG. 9. The four through holes 8T9 are connected to the four through holes 8T8 shown in FIG. 9.

[0056] FIG. 11 shows the pattern-formed surfaces of the 10th to 17th dielectric layers 40-47. In each of the dielectric layers 40-47, a plurality of through holes 6T10 constituting the shield 6, four through holes 7T10 constituting the first partitioning portion 7, and four through holes 8T10 constituting the second partitioning portion 8 are formed. The plurality of through holes 6T10 formed in the 10th dielectric layer 40 are connected to the plurality of through holes 6T9 shown in FIG. 10. The four through holes 7T10 formed in the 10th dielectric layer 40 are connected to the four through holes 7T9 shown in FIG. 10. The four through holes 8T10 formed in the 10th dielectric layer 40 are connected to the four through holes 8T9 shown in FIG. 10.

[0057] In the dielectric layers 40 to 47, vertically adjacent through holes having the same reference numerals are connected to each other.

[0058] 12 shows the pattern-formed surface of the 18th dielectric layer 48. A conductor layer 481 constituting the shield 6 is formed on the pattern-formed surface of the dielectric layer 48. The through holes 6T10, 7T10, and 8T10 formed in the 17th dielectric layer 47 are connected to the conductor layer 481.

[0059] The bandpass filter 1 according to the present embodiment is configured by laminating the first to eighteenth dielectric layers 31-48 such that the pattern-formed surface of the first dielectric layer 31 becomes the lower surface 2A of the laminate 2. The surface of the eighteenth dielectric layer 48 opposite to the pattern-formed surface becomes the upper surface 2B of the laminate 2.

[0060] Next, the shapes and arrangement of the resonator conductors 510, 520, 530, 540, and 550 will be described with reference to Fig. 13. Fig. 13 is a plan view showing a main part of the bandpass filter 1. The resonator conductors 510, 520, 530, 540, and 550 of the resonators 51 to 55 are arranged at the same position in the laminate 2 in the Z direction.

[0061] The resonator conductor 510 includes a first line portion 51A and a second line portion 51B that are spaced apart in the Y direction, and a third line portion 51C that connects the first line portion 51A and the second line portion 51B. In FIG. 13, the boundary between the first line portion 51A and the third line portion 51C and the boundary between the second line portion 51B and the third line portion 51C are indicated by dotted lines. The first to third line portions 51A to 51C extend so as to surround the space between the first line portion 51A and the second line portion 51B. Specifically, the entire resonator conductor 510, i.e., the first to third line portions 51A to 51C, have a U-shape surrounding the space when viewed from the Z direction. Most of each of the first and second line portions 51A and 51B extends along the X-direction. The third line portion 51C extends along the Y-direction.

[0062] The first line portion 51A has an end 51a located farthest from the third line portion 51C in the longitudinal direction of the resonator conductor 510. The second line portion 51B has an end 51b located farthest from the third line portion 51C in the longitudinal direction of the resonator conductor 510.

[0063] Here, the dimension in the short-side direction of each line portion is referred to as the width. The first line portion 51A includes a first constant-width portion having a constant width. The second line portion 51B includes a second constant-width portion having a constant width. The width of the third line portion 51C is smaller than the width of each of the first and second constant-width portions. In particular, in this embodiment, the first line portion 51A includes, as the first constant-width portion, a portion including the end portion 51a and a portion located between this portion and the third line portion 51C. The second constant-width portion includes the end portion 51b. The width of the third line portion 51C is constant regardless of the position in the longitudinal direction of the third line portion 51C. In addition, the width of the third line portion 51C is smaller than the maximum width of the first line portion 51A and the maximum width of the second line portion 51B, and is equal to the minimum width of the first line portion 51A and the minimum width of the second line portion 51B.

[0064] The resonator conductor 520 includes a first line portion 52A and a second line portion 52B that are disposed at positions separated from each other in the Y direction, and a third line portion 52C that connects the first line portion 52A and the second line portion 52B. In FIG. 13, the boundary between the first line portion 52A and the third line portion 52C and the boundary between the second line portion 52B and the third line portion 52C are indicated by dotted lines. The first to third line portions 52A to 52C extend so as to surround the space between the first line portion 52A and the second line portion 52B. Specifically, the entire resonator conductor 520, i.e., the first to third line portions 52A to 52C, have a U-shape surrounding the space when viewed from the Z direction. Most of each of the first and second line portions 52A and 52B extends along the X-direction. The third line portion 52C extends along the Y-direction.

[0065] The first line portion 52A has an end 52a located farthest from the third line portion 52C in the longitudinal direction of the resonator conductor 520. The second line portion 52B has an end 52b located farthest from the third line portion 52C in the longitudinal direction of the resonator conductor 520.

[0066] The first line portion 52A includes a first constant width portion having a constant width. The second line portion 52B includes a second constant width portion having a constant width. The width of the third line portion 52C is smaller than the widths of the first and second constant width portions. In particular, in this embodiment, the first constant width portion includes the end portion 52a. The second constant width portion includes the end portion 52b. The width of the third line portion 52C is constant regardless of the longitudinal position of the third line portion 52C. In addition, the width of the third line portion 52C is smaller than the maximum width of the first line portion 52A and the maximum width of the second line portion 52B, and is equal to the minimum width of the first line portion 52A and the minimum width of the second line portion 52B.

[0067] The resonator conductor 530 includes a first line portion 53A and a second line portion 53B that are spaced apart in the X direction, and a third line portion 53C that connects the first line portion 53A and the second line portion 53B. In Fig. 13, the boundary between the first line portion 53A and the third line portion 53C and the boundary between the second line portion 53B and the third line portion 53C are indicated by dotted lines. The entire resonator conductor 530, i.e., the first to third line portions 53A to 53C, extend along the X direction.

[0068] The first line portion 53A has an end 53a located farthest from the third line portion 53C in the longitudinal direction of the resonator conductor 530. The second line portion 53B has an end 53b located farthest from the third line portion 53C in the longitudinal direction of the resonator conductor 530.

[0069] The first line portion 53A includes a first constant width portion having a constant width. The second line portion 53B includes a second constant width portion having a constant width. The width of the third line portion 53C is smaller than the widths of the first and second constant width portions. Particularly in this embodiment, the first constant width portion includes an end portion 53a. The second constant width portion includes an end portion 53b. The width of the third line portion 53C is constant regardless of the longitudinal position of the third line portion 53C. The width of the third line portion 53C is smaller than the maximum width of the first line portion 53A and the maximum width of the second line portion 53B, and is equal to the minimum width of the first line portion 53A and the minimum width of the second line portion 53B.

[0070] The resonator conductor 520 and the resonator conductor 540 have shapes symmetrical with respect to the YZ plane. If the resonator conductor 520, the first line portion 52A, the second line portion 52B, and the third line portion 52C in the description of the first to third line portions 52A to 52C of the resonator conductor 520 are replaced with the resonator conductor 540, the first line portion 54A, the second line portion 54B, and the third line portion 54C, respectively, the description will be of the first to third line portions 54A to 54C of the resonator conductor 540.

[0071] The first line portion 54A has an end 54a located farthest from the third line portion 54C in the longitudinal direction of the resonator conductor 540. The second line portion 54B has an end 54b located farthest from the third line portion 54C in the longitudinal direction of the resonator conductor 540.

[0072] The first line portion 54A includes a first constant width portion having a constant width. The second line portion 54B includes a second constant width portion having a constant width. The width of the third line portion 54C is smaller than the widths of the first and second constant width portions. In particular, in this embodiment, the first constant width portion includes an end portion 54a. The second constant width portion includes an end portion 54b. The width of the third line portion 54C is constant regardless of the longitudinal position of the third line portion 54C. The width of the third line portion 54C is smaller than the maximum width of the first line portion 54A and the maximum width of the second line portion 52B, and is equal to the minimum width of the first line portion 54A and the minimum width of the second line portion 54B.

[0073] The resonator conductor 510 and the resonator conductor 550 have shapes symmetrical with respect to the YZ plane. If the resonator conductor 510, the first line portion 51A, the second line portion 51B, and the third line portion 51C in the description of the first to third line portions 51A to 51C of the resonator conductor 510 are replaced with the resonator conductor 550, the first line portion 55A, the second line portion 55B, and the third line portion 55C, respectively, the description will be of the first to third line portions 55A to 55C of the resonator conductor 550.

[0074] The first line portion 55A has an end 55a located farthest from the third line portion 55C in the longitudinal direction of the resonator conductor 550. The second line portion 55B has an end 55b located farthest from the third line portion 55C in the longitudinal direction of the resonator conductor 550.

[0075] The first line portion 55A includes a first constant width portion having a constant width. The second line portion 55B includes a second constant width portion having a constant width. The width of the third line portion 55C is smaller than the widths of the first and second constant width portions. In particular, in this embodiment, the first constant width portion includes the end portion 55a. The second line portion 55B includes, as the second constant width portion, a portion including the end portion 55b and a portion located between this portion and the third line portion 55C. The width of the third line portion 55C is constant regardless of the longitudinal position of the third line portion 55C. In addition, the width of the third line portion 55C is smaller than the maximum width of the first line portion 55A and the maximum width of the second line portion 55B, and is equal to the minimum width of the first line portion 55A and the minimum width of the second line portion 55B.

[0076] The resonator conductor 550 is disposed ahead of the resonator conductor 510 in the X direction. The resonator conductors 520 and 540 are disposed ahead of the resonator conductors 510 and 550 in the Y direction, respectively. The resonator conductor 530 is disposed ahead of the resonator conductors 520 and 540 in the Y direction.

[0077] In the resonator conductor 510, the second line portion 51B is disposed ahead of the first line portion 51A in the Y direction. In the resonator conductor 520, the second line portion 52B is disposed ahead of the first line portion 52A in the Y direction. In the resonator conductor 530, the second line portion 53B is disposed ahead of the first line portion 53A in the X direction. In the resonator conductor 540, the second line portion 54B is disposed ahead of the first line portion 54A in the -Y direction. In the resonator conductor 550, the second line portion 55B is disposed ahead of the first line portion 55A in the -Y direction.

[0078] The second line portion 51B of the resonator conductor section 510 and the first line portion 52A of the resonator conductor section 520 are adjacent to each other and are coupled by a capacitor C12. The second line portion 52B of the resonator conductor section 520 and the first line portion 53A of the resonator conductor section 530 are adjacent to each other and are coupled by a capacitor C23. The second line portion 53B of the resonator conductor section 530 and the first line portion 54A of the resonator conductor section 540 are adjacent to each other and are coupled by a capacitor C34. The second line portion 54B of the resonator conductor section 540 and the first line portion 55A of the resonator conductor section 550 are adjacent to each other and are coupled by a capacitor C45.

[0079] The third line portion 51C of the resonator conductor 510 and the third line portion 55C of the resonator conductor 550 are adjacent to each other and extend along the Y direction, so that the resonators 51 and 55 are magnetically coupled to each other.

[0080] The first line portion 52A of the resonator conductor 520 and the second line portion 54B of the resonator conductor 540 are arranged such that their ends 52a and 54b are adjacent to each other in the X direction and are coupled by a capacitor C24. The second line portion 52B of the resonator conductor 520 and the first line portion 54A of the resonator conductor 540 are arranged such that their ends 52b and 54a are adjacent to each other in the X direction.

[0081] Next, the correspondence between the components of the bandpass filter 1 and the components inside the laminate 2 will be described with reference to FIGS. 2 to 13. The conductor layer 311 constituting the first input / output port 3 is connected to the conductor layer 371 shown in FIG. 8 via the through holes 31T1, 32T1, 33T1, the conductor layer 341, and the through hole 35T1. As shown in FIG. 13, the conductor layer 371 faces the first line portion 51A of the resonator conductor 510 via the dielectric layer 37. The capacitor C1 shown in FIG. 2 is composed of the conductor layer 371, the resonator conductor 510, and the dielectric layer 37 therebetween. The capacitor C1 is connected to the first line portion 51A of the resonator conductor 510 at a position away from the end 51a toward the third line portion 51C in the longitudinal direction of the resonator conductor 510.

[0082] The conductor layer 312 constituting the second input / output port 4 is connected to the conductor layer 372 shown in FIG. 8 via the through holes 31T2, 32T2, 33T2, the conductor layer 342, and the through hole 35T2. As shown in FIG. 13, the conductor layer 372 faces the second line portion 55B of the resonator conductor 550 via the dielectric layer 37. The capacitor C2 shown in FIG. 2 is composed of the conductor layer 372, the resonator conductor 550, and the dielectric layer 37 therebetween. The capacitor C2 is connected to the second line portion 55B of the resonator conductor 550 at a position away from the end 55b toward the third line portion 55C in the longitudinal direction of the resonator conductor 550.

[0083] As shown in FIG. 13, the conductor layer 391 faces the second line portion 51B of the resonator conductor 510 and the first line portion 52A of the resonator conductor 520 via the dielectric layer 38. The capacitor C12 shown in FIG. 2 is composed of the conductor layer 391, the resonator conductors 510 and 520, and the dielectric layer 38 therebetween. The capacitor C12 is connected to the second line portion 51B of the resonator conductor 510 at a position away from the end 51b toward the third line portion 51C in the longitudinal direction of the resonator conductor 510. The capacitor C12 is connected to the first line portion 52A of the resonator conductor 520 at a position away from the end 52a toward the third line portion 52C in the longitudinal direction of the resonator conductor 520.

[0084] As shown in FIG. 13, the conductor layer 392 is disposed near the second line portion 52B of the resonator conductor 520 and the first line portion 53A of the resonator conductor 530 via the dielectric layer 38. The capacitor C23 shown in FIG. 2 is composed of the conductor layer 392, the resonator conductors 520 and 530, and the dielectric layer 38 therebetween. The capacitor C23 is connected to the second line portion 52B of the resonator conductor 520 at a position away from the end 52b toward the third line portion 52C in the longitudinal direction of the resonator conductor 520. The capacitor C23 is connected to the first line portion 53A of the resonator conductor 530 at a position away from the end 53a toward the third line portion 53C in the longitudinal direction of the resonator conductor 530.

[0085] As shown in FIG. 13, the conductor layer 393 is disposed near the second line portion 53B of the resonator conductor 530 and the first line portion 54A of the resonator conductor 540 via the dielectric layer 38. The capacitor C34 shown in FIG. 2 is composed of the conductor layer 393, the resonator conductors 530 and 540, and the dielectric layer 38 therebetween. The capacitor C34 is connected to the second line portion 53B of the resonator conductor 530 at a position away from the end 53b toward the third line portion 53C in the longitudinal direction of the resonator conductor 530. The capacitor C34 is connected to the first line portion 54A of the resonator conductor 540 at a position away from the end 54a toward the third line portion 54C in the longitudinal direction of the resonator conductor 540.

[0086] As shown in FIG. 13, the conductor layer 394 faces the second line portion 54B of the resonator conductor 540 and the first line portion 55A of the resonator conductor 550 via the dielectric layer 38. The capacitor C45 shown in FIG. 2 is composed of the conductor layer 394, the resonator conductors 540 and 550, and the dielectric layer 38 therebetween. The capacitor C45 is connected to the second line portion 54B of the resonator conductor 540 at a position away from the end 54b toward the third line portion 54C in the longitudinal direction of the resonator conductor 540. The capacitor C45 is connected to the first line portion 55A of the resonator conductor 550 at a position away from the end 55a toward the third line portion 55C in the longitudinal direction of the resonator conductor 550.

[0087] 13, the conductor layer 395 faces the first line portion 52A of the resonator conductor 520 and the second line portion 54B of the resonator conductor 540 via the dielectric layer 38. The capacitor C24 shown in FIG. 2 is composed of the conductor layer 395, the resonator conductors 520 and 540, and the dielectric layer 38 therebetween.

[0088] Each of the four first through-hole rows of the first partition portion 7 is configured by connecting through-holes 7T2, 7T3, 7T4, 7T5, 7T7, 7T8, 7T9, and 7T10 in series in the Z direction. In the example shown in Figures 3 to 12, the first partition portion 7 extends to pass between the resonator conductor portion 510 and the resonator conductor portion 550, and is in contact with the conductor layer 321 and the conductor layer 481.

[0089] Each of the four second through-hole rows of the second partition portion 8 is configured by connecting through holes 8T2, 8T3, 8T4, 8T5, 8T7, 8T8, 8T9, and 8T10 in series in the Z direction. In the example shown in Fig. 3 to Fig. 12, the second partition portion 8 extends to pass through the space surrounded by the resonator conductor portion 520 and the resonator conductor portion 540, and is in contact with the conductor layer 321 and the conductor layer 481.

[0090] The shield 6 is formed by connecting the conductor layers 313 to 316, 321, and 481 to the through holes 6T1, 6T2, 6T3, 6T4, 6T5, 6T7, 6T8, 6T9, and 6T10.

[0091] The bandpass filter 1 according to the present embodiment is designed and constructed so that its passband is in the quasi-millimeter wave band of 10 to 30 GHz or the millimeter wave band of 30 to 300 GHz, for example.

[0092] Next, the operation and effect of the bandpass filter 1 according to the present embodiment will be described. The bandpass filter 1 according to the present embodiment includes resonators 51, 52, 53, 54, and 55 that are open at both ends. The resonators 51, 52, 53, 54, and 55 have resonator conductors 510, 520, 530, 540, and 550, respectively. The resonator conductors 510, 520, 540, and 550, except for the resonator conductor 530, are all specific resonator conductors that correspond to the "resonator conductor" in the present invention. The resonator conductors 510, 520, 540, and 550 each include a first line portion to a third line portion that extend so as to surround the space between the first line portion and the second line portion. As a result, according to the present embodiment, the bandpass filter 1 can be made smaller than when all the resonator conductors are linear.

[0093] In this embodiment, the resonator conductors 510, 520, 540, and 550 each have a U-shape when viewed from the Z direction. However, the shape of the resonator conductors 510, 520, 540, and 550 is not limited to a U-shape, and may be a C-shape, an arch shape, or other shape. For example, the first line portion and the second line portion may not be parallel. When comparing resonator conductors with the same length, in any of the above shapes, the area for arranging the resonator conductors can be made smaller than when the resonator conductors are linear or L-shaped.

[0094] In the present embodiment, the number of U-shaped resonator conductors is four. However, even if the number of U-shaped resonator conductors is one, the bandpass filter 1 can be made smaller than when all resonator conductors are linear.

[0095] In addition, in the present embodiment, in each of the resonator conductors 510, 520, 530, 540, and 550, the width of the third line portion is smaller than the width of the first constant width portion of the first line portion and the width of the second constant width portion of the second line portion. Each of the resonators 51 to 55 including such a third line portion is a type of stepped impedance resonator (hereinafter, also referred to as SIR). According to the present embodiment, by making the resonators 51 to 55 SIRs, the length of the resonator conductor can be shortened. This also enables the bandpass filter 1 to be miniaturized according to the present embodiment.

[0096] In this embodiment, the resonator conductor 510 of the resonator 51 closest to the first input / output port 3 in the circuit configuration and the resonator conductor 550 of the resonator 55 closest to the second input / output port 4 in the circuit configuration are arranged along the X direction, while the resonator conductors 520, 530, and 540 of the intermediate resonators provided between the resonators 51 and 55 in the circuit configuration, i.e., the resonator conductors 520, 530, and 540 of the resonators 52 to 54, are arranged ahead of the resonator conductors 510 and 550 in the Y direction. The X direction is a first direction perpendicular to the lamination direction of the multiple dielectric layers of the laminate 2, and the Y direction is a second direction perpendicular to the lamination direction of the multiple dielectric layers of the laminate 2. According to this embodiment, by arranging the resonator conductors 510, 520, 530, 540, and 550 in the first and second directions, the bandpass filter 1 can be made smaller than the case where all the resonator conductors are arranged in a row.

[0097] In addition, in this embodiment, the third line portion 51C of the resonator conductor 510 of the resonator 51 and the third line portion 55C of the resonator conductor 550 of the resonator 55 are adjacent to each other and extend in parallel along the Y direction. According to this embodiment, by arranging the resonator conductors 520, 530, and 540 ahead of the resonator conductors 510 and 550 in the Y direction as described above, it is possible to easily realize the cross-coupling between the resonators 51 and 55.

[0098] In this embodiment, the capacitors C1, C2, C12, C23, C34, and C45 are connected to the corresponding resonator conductors at positions away from both ends of the corresponding resonator conductors. The connection positions of these capacitors are preferably at or near the minimum voltage point in the higher mode. This makes it possible to suppress the higher mode. The higher mode may be a second mode.

[0099] Next, an example of the characteristics of the bandpass filter 1 according to the present embodiment obtained by simulation will be shown. In the simulation, a model of the bandpass filter 1 according to the present embodiment was used to obtain the frequency characteristics of the insertion loss and the frequency characteristics of the return loss of the bandpass filter 1. In the simulation, the bandpass filter 1 was designed so that the center frequency of the passband of the bandpass filter 1 was about 26 GHz.

[0100] Fig. 14 is a characteristic diagram showing an example of frequency characteristics of insertion loss and return loss. Fig. 15 is a characteristic diagram showing an enlarged part of the frequency characteristics of insertion loss shown in Fig. 14. Fig. 16 is a characteristic diagram showing an enlarged part of the frequency characteristics of return loss shown in Fig. 14. The horizontal axis in Figs. 14 to 16 indicates frequency. The vertical axis in Fig. 14 indicates attenuation, the vertical axis in Fig. 15 indicates insertion loss, and the vertical axis in Fig. 16 indicates return loss. In Fig. 14, the curve marked with reference numeral 81 indicates the frequency characteristics of insertion loss, and the curve marked with reference numeral 82 indicates the frequency characteristics of return loss.

[0101] [Second embodiment] Next, a second embodiment of the present invention will be described with reference to Fig. 17 to Fig. 19. Fig. 17 is a perspective view showing the structure of a bandpass filter according to this embodiment. Fig. 18 is an explanatory diagram showing a pattern formation surface of an eighth dielectric layer in this embodiment. Fig. 19 is a plan view showing a main part of the bandpass filter according to this embodiment.

[0102] The bandpass filter 1 according to this embodiment differs from the first embodiment in the following respects. In this embodiment, the resonators 51, 52, 53, 54, and 55 of the bandpass filter 1 have resonator conductors 1510, 1520, 1530, 1540, and 1550, respectively, instead of the resonator conductors 510, 520, 530, 540, and 550 in the first embodiment. Each of the resonator conductors 1510, 1520, 1530, 1540, and 1550 extends in a stacking direction of the multiple dielectric layers, i.e., in a direction perpendicular to the Z direction.

[0103] Both ends of each of the resonator conductors 1510, 1520, 1530, 1540, and 1550 are open. Each of the resonator conductors 1510, 1520, 1530, 1540, and 1550 has a length that is half or close to a wavelength corresponding to the center frequency of the passband of the bandpass filter 1.

[0104] Each of the resonator conductors 1510, 1520, 1530, 1540, and 1550 includes a first line portion and a second line portion arranged at positions spaced apart from each other in a direction perpendicular to the Z direction, and a third line portion connecting the first line portion and the second line portion.

[0105] Hereinafter, the first line portion, the second line portion, and the third line portion of the resonator conductor 1510 are represented by the reference symbols 151A, 151B, and 151C, respectively. The first line portion, the second line portion, and the third line portion of the resonator conductor 1520 are represented by the reference symbols 152A, 152B, and 152C, respectively. The first line portion, the second line portion, and the third line portion of the resonator conductor 1530 are represented by the reference symbols 153A, 153B, and 153C, respectively. The first line portion, the second line portion, and the third line portion of the resonator conductor 1540 are represented by the reference symbols 154A, 154B, and 154C, respectively. Moreover, the first line portion, the second line portion, and the third line portion of the resonator conductor 1550 are denoted by reference characters 155A, 155B, and 155C, respectively.

[0106] Furthermore, in the present embodiment, the laminate 2 of the bandpass filter 1 has an eighth dielectric layer 138 instead of the eighth dielectric layer 38 in the first embodiment. As shown in Fig. 18, resonator conductors 1510, 1520, 1530, 1540, and 1550 each formed of a conductor line are formed on the pattern forming surface of the dielectric layer 138.

[0107] Further, the dielectric layer 138 is formed with a plurality of through holes 6T18 constituting the shield 6, four through holes 7T18 constituting the first partition portion 7, and four through holes 8T18 constituting the second partition portion 8. The plurality of through holes 6T18 are arranged around the resonator conductors 1510, 1520, 1530, 1540, and 1550. The four through holes 7T18 are arranged between the resonator conductors 1510 and 1550. The four through holes 8T18 are arranged in a space surrounded by the resonator conductors 1520 and 1540.

[0108] The relationship between the resonator conductors 1510, 1520, 1530, 1540, 1550 and the through holes 6T18, 7T18, 8T18 and other components inside the laminate 2 is the same as the relationship between the resonator conductors 510, 520, 530, 540, 550 and the through holes 6T8, 7T8, 8T8 and other components inside the laminate 2 in the first embodiment.

[0109] The layout of all the line portions included in the resonator conductors 1510, 1520, 1530, 1540, and 1550 is basically the same as the layout of all the line portions included in the resonator conductors 510, 520, 530, 540, and 550 in the first embodiment.

[0110] In this embodiment, the entire resonator conductor 1510, i.e., the first to third line portions 151A to 151C, have a C-shape surrounding the space between the first line portion 151A and the second line portion 151B when viewed from the Z direction. The first line portion 151A has an end portion 151a located at a position farthest from the third line portion 151C in the longitudinal direction of the resonator conductor 1510. The second line portion 151B has an end portion 151b located at a position farthest from the third line portion 151C in the longitudinal direction of the resonator conductor 1510.

[0111] Moreover, the entire resonator conductor 1520, i.e., the first to third line portions 152A to 152C, have a C-shape surrounding the space between the first line portion 152A and the second line portion 152B when viewed from the Z direction. The first line portion 152A has an end portion 152a located at a position farthest from the third line portion 152C in the longitudinal direction of the resonator conductor 1520. The second line portion 152B has an end portion 152b located at a position farthest from the third line portion 152C in the longitudinal direction of the resonator conductor 1520.

[0112] The entire resonator conductor 1530, i.e., the first to third line portions 153A to 153C, extend along the X direction. The first line portion 153A has an end portion 153a that is located farthest from the third line portion 153C in the longitudinal direction of the resonator conductor 1530. The second line portion 153B has an end portion 153b that is located farthest from the third line portion 153C in the longitudinal direction of the resonator conductor 1530.

[0113] Moreover, the entire resonator conductor 1540, i.e., the first to third line portions 154A to 154C, have a C-shape surrounding the space between the first line portion 154A and the second line portion 154B when viewed from the Z direction. The first line portion 154A has an end portion 154a located at a position farthest from the third line portion 154C in the longitudinal direction of the resonator conductor 1540. The second line portion 154B has an end portion 154b located at a position farthest from the third line portion 154C in the longitudinal direction of the resonator conductor 1540.

[0114] Moreover, the entire resonator conductor 1550, i.e., the first to third line portions 155A to 155C, have a C-shape surrounding the space between the first line portion 155A and the second line portion 155B when viewed from the Z direction. The first line portion 155A has an end portion 155a located at a position farthest from the third line portion 155C in the longitudinal direction of the resonator conductor 1550. The second line portion 155B has an end portion 155b located at a position farthest from the third line portion 155C in the longitudinal direction of the resonator conductor 1550.

[0115] In each of the resonator conductors 1510, 1520, 1530, 1540, and 1550, the first line portion has a first constant width portion having a constant width, the second line portion has a second constant width portion having a constant width, and the width of the third line portion is smaller than the width of each of the first and second constant width portions.

[0116] Other configurations, operations, and effects of the present embodiment are similar to those of the first embodiment.

[0117] The present invention is not limited to the above-described embodiments, and various modifications are possible. For example, the number and configuration of the resonators are not limited to those shown in the embodiments, and may be any number that satisfies the scope of the claims. The number of resonators may be three, four, six or more. [Explanation of symbols]

[0118] 1...bandpass filter, 2...laminate, 3...first input / output port, 4...second input / output port, 6...shield, 7...first partition portion, 8...second partition portion, 51, 52, 53, 54, 55...resonator, 510, 520, 530, 540, 550...resonator conductor portion, 51A, 52A, 53A, 54A, 55A...first line portion, 51B, 52B, 53B, 54B, 55B...second line portion, 51C, 52C, 53C, 54C, 55C... The third track section , C1, C2, C12, C23, C24, C34, C45...capacitors.

Claims

1. a first input / output port; a second input / output port; a plurality of resonators provided between the first input / output port and the second input / output port in a circuit configuration, the resonators being configured such that two adjacent resonators are electromagnetically coupled to each other in the circuit configuration; a laminate for integrating the first input / output port, the second input / output port, and the plurality of resonators; at least one capacitor; The laminate includes a plurality of dielectric layers stacked together, each of the plurality of resonators is an open-ended resonator configured by a conductor line within the laminate, at least one of the plurality of resonators has a resonator conductor including a first line portion and a second line portion that are disposed at positions spaced apart from each other in a direction perpendicular to a stacking direction of the plurality of dielectric layers, and a third line portion that connects the first line portion and the second line portion; the first to third line portions extend so as to surround a space between the first line portion and the second line portion, each of the first and second line portions has an end portion located farthest from the third line portion in a longitudinal direction of the resonator conductor; the at least one capacitor is a capacitor that realizes capacitive coupling between the two resonators adjacent to each other in a circuit configuration; the two resonators adjacent to each other in a circuit configuration each have the resonator conductor portion; the capacitor is connected to the resonator conductor of one of the two resonators and the resonator conductor of the other of the two resonators; The bandpass filter, wherein the capacitor is connected to the resonator conductor at a position away from the end toward the third line portion in the longitudinal direction.

2. a first input / output port; a second input / output port; a plurality of resonators provided between the first input / output port and the second input / output port in a circuit configuration, the resonators being configured such that two adjacent resonators are electromagnetically coupled to each other in the circuit configuration; a laminate for integrating the first input / output port, the second input / output port, and the plurality of resonators; at least one capacitor; The laminate includes a plurality of dielectric layers stacked together, each of the plurality of resonators is an open-ended resonator configured by a conductor line within the laminate, at least one of the plurality of resonators has a resonator conductor including a first line portion and a second line portion that are disposed at positions spaced apart from each other in a direction perpendicular to a stacking direction of the plurality of dielectric layers, and a third line portion that connects the first line portion and the second line portion; the first to third line portions extend so as to surround a space between the first line portion and the second line portion, each of the first and second line portions has an end portion located farthest from the third line portion in a longitudinal direction of the resonator conductor; the plurality of resonators includes a resonator that is closest to either the first input / output port or the second input / output port in terms of a circuit configuration; the at least one capacitor is a capacitor provided between the input / output port and the resonator, The resonator has the resonator conductor portion, a first end of the resonator conductor connected to the first input / output port and the second ...

3. 3. The bandpass filter according to claim 1, wherein the plurality of resonators include a first resonator that is closest to the first input / output port in terms of the circuit configuration, a second resonator that is closest to the second input / output port in terms of the circuit configuration, and at least one intermediate resonator that is provided between the first resonator and the second resonator in terms of the circuit configuration.

4. 4. The bandpass filter according to claim 3, wherein said first and second resonators each have said resonator conductor portion.

5. 5. The bandpass filter according to claim 3, wherein the third line portion of the resonator conductor of the first resonator and the third line portion of the resonator conductor of the second resonator are adjacent to each other and extend along the same direction perpendicular to the stacking direction.

6. the at least one intermediate resonator is a plurality of intermediate resonators; 6. The bandpass filter according to claim 3, wherein at least one of the plurality of intermediate resonators has the resonator conductor portion.

7. a first input / output port; a second input / output port; a plurality of resonators provided between the first input / output port and the second input / output port in a circuit configuration, the resonators being configured such that two adjacent resonators are electromagnetically coupled to each other in the circuit configuration; a laminate for integrating the first input / output port, the second input / output port, and the plurality of resonators; The laminate includes a plurality of dielectric layers stacked together, each of the plurality of resonators is an open-ended resonator configured by a conductor line within the laminate, at least one of the plurality of resonators has a resonator conductor including a first line portion and a second line portion that are disposed at positions spaced apart from each other in a direction perpendicular to a stacking direction of the plurality of dielectric layers, and a third line portion that connects the first line portion and the second line portion; the first to third line portions extend so as to surround a space between the first line portion and the second line portion, the plurality of resonators include a first resonator closest to the first input / output port in terms of circuit configuration, a second resonator closest to the second input / output port in terms of circuit configuration, and at least one intermediate resonator provided between the first resonator and the second resonator in terms of circuit configuration; the at least one intermediate resonator is a third resonator, a fourth resonator and a fifth resonator; the fourth resonator is provided between the third resonator and the fifth resonator in terms of a circuit configuration, A bandpass filter, wherein the third and fifth resonators each have the resonator conductor portion.

8. the first line portion includes a first constant width portion having a constant dimension in a short side direction, the second line portion includes a second constant width portion having a constant dimension in a short side direction, 8. The bandpass filter according to claim 1, wherein a dimension in a short side direction of the third line portion is smaller than dimensions in the short side direction of each of the first and second constant width portions.

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