Filter Device

Abstract

A filter device capable of reducing changes in filter characteristics due to stacking misalignment is provided. [Solution] The filter device (100) includes a laminate including multiple dielectric layers and an LC resonator including an inductor and a capacitor, transmitting a signal from an input terminal (T1) to an output terminal (T2). The LC resonator includes plate electrodes (PL20A) and (PL20B) disposed on different dielectric layers and connected to each other by vias. The plate electrodes (PL20A) and (PL20B) function as inductors. When viewed from above in the stacking direction of the laminate, the plate electrodes (PL20A) and (PL20B) at least partially overlap. The plate electrode (PL20A) includes an extension portion (201A) extending in the X-axis direction along the long side of the laminate and an extension portion (202A) extending in the Y-axis direction along the short side of the laminate. The plate electrode (20B) includes an extension portion (201B) extending in the X-axis direction and an extension portion (202B) extending in the Y-axis direction. The area of ​​the extension portion 201A is smaller than the area of ​​the extension portion 201B.

Description

[Technical Field]

[0001] The present disclosure relates to a filter device. [Background technology]

[0002] International Publication No. 2017 / 014058 (Patent Document 1) discloses a laminated LC filter (filter device) including multiple stages of resonators. In International Publication No. 2017 / 014058 (Patent Document 1), the electrodes constituting the inductor have a two-layer structure in which flat electrodes are stacked in parallel in the lamination direction. This configuration reduces the resistance of the current path and improves the Q value of the filter device. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] International Publication No. 2017 / 014058 Summary of the Invention [Problem to be solved by the invention]

[0004] In a filter device, when multiple dielectric layers are stacked and crimped, lamination misalignment can occur, whereby the positions of the dielectric layers shift in the in-plane direction on the crimped surface. If lamination misalignment occurs in the electrodes that make up the inductor, the inner diameter of the inductor coils that overlap in the lamination direction changes. This can cause the inductance value to deviate from the design value. The change in inductance value can affect filter characteristics such as the passband width and center frequency of the filter.

[0005] The present disclosure has been made to solve such problems, and its purpose is to provide a filter device that can reduce changes in filter characteristics due to stacking misalignment. [Means for solving the problem]

[0006] The filter device of the present disclosure includes a laminate including multiple dielectric layers, an input terminal and an output terminal disposed on the outer surface of the laminate, and an LC resonator including an inductor and a capacitor, transmitting a signal from the input terminal to the output terminal. The LC resonator includes a first plate electrode and a second plate electrode disposed on different dielectric layers and connected to each other by a via. The first plate electrode and the second plate electrode function as an inductor. When viewed from above in the stacking direction of the laminate, the first plate electrode and the second plate electrode at least partially overlap. When viewed from above in the stacking direction, the laminate has a rectangular shape with long and short sides. The first plate electrode includes a first extension portion extending in a first direction along the long side direction of the laminate and a second extension portion extending in a second direction along the short side direction of the laminate. The second plate electrode includes a third extension portion extending in the first direction and a fourth extension portion extending in the second direction. The area of ​​the first extension portion is smaller than the area of ​​the third extension portion. [Effects of the Invention]

[0007] In the filter device of the present disclosure, the area of ​​the first elongated member portion is smaller than the area of ​​the third elongated member portion. When the first plate electrode and the second plate electrode have approximately the same shape, the change in the area of ​​the overlapping portion of the two plate electrodes overlapping in the stacking direction is greater when stacking misalignment occurs in the short side direction than when stacking misalignment occurs in the long side direction. Therefore, by making the area of ​​the first elongated member portion in the long side direction smaller than the area of ​​the third elongated member portion, the change in the inner diameter of the coil formed by the electrodes functioning as an inductor can be suppressed, and the change in filter characteristics can be reduced even if stacking misalignment occurs and the position of the first plate electrode and the second plate electrode is shifted. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a block diagram of a communication device having a high-frequency front-end circuit to which a filter device according to a first embodiment is applied. [Figure 2] 1 is an equivalent circuit diagram of a filter device according to a first embodiment. [Figure 3]1 is an external perspective view of a filter device according to a first embodiment. [Figure 4] 1 is an exploded perspective view showing an example of a laminated structure of a filter device according to a first embodiment. [Figure 5] FIG. 2 is a diagram for explaining the shape of an electrode according to the first embodiment. [Figure 6] FIG. 10 is an exploded perspective view showing an example of a laminated structure of a filter device of a comparative example. [Figure 7] FIG. 4 is a diagram for explaining changes in characteristics of the first embodiment and the comparative example. [Figure 8] FIG. 10 is an exploded perspective view showing an example of a laminated structure of a filter device according to a second embodiment. [Figure 9] FIG. 10 is a diagram for explaining the electrode shape according to the second embodiment. [Figure 10] FIG. 10 is a diagram for explaining the electrode shape of Modification 1. [Figure 11] FIG. 10 is a diagram for explaining the electrode shape of Modification 2. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. In the drawings, the same or corresponding parts are designated by the same reference numerals, and description thereof will not be repeated.

[0010] [Embodiment 1] (Basic configuration of communication equipment) 1 is a block diagram of a communication device 10 having a high-frequency front-end circuit 20 to which a filter device 100 according to the first embodiment is applied. The communication device 10 is, for example, a mobile terminal such as a smartphone, or a mobile phone base station.

[0011] 1, a communication device 10 includes an antenna 12, a high-frequency front-end circuit 20, a mixer 30, a local oscillator 32, a D / A converter (DAC) 40, and an RF circuit 50. The high-frequency front-end circuit 20 also includes band-pass filters 22 and 28, an amplifier 24, and an attenuator 26. Although the description of FIG. 1 illustrates a case in which the high-frequency front-end circuit 20 includes a transmission circuit that transmits a high-frequency signal from the antenna 12, the high-frequency front-end circuit 20 may also include a reception circuit that receives a high-frequency signal via the antenna 12.

[0012] The communication device 10 upconverts a transmission signal transmitted from the RF circuit 50 to a high-frequency signal and radiates it from the antenna 12. The modulated digital signal output from the RF circuit 50, which is the transmission signal, is converted to an analog signal by the D / A converter 40. The mixer 30 upconverts the transmission signal, converted from digital to analog by the D / A converter 40, to a high-frequency signal by mixing it with an oscillation signal from the local oscillator 32. The bandpass filter 28 removes unwanted waves generated by the upconversion and extracts only the transmission signal in the desired frequency band. The attenuator 26 adjusts the intensity of the transmission signal. The amplifier 24 power-amplifies the transmission signal that has passed through the attenuator 26 to a predetermined level. The bandpass filter 22 removes unwanted waves generated during the amplification process and passes only signal components in the frequency band specified by the communication standard. The transmission signal that has passed through the bandpass filter 22 is radiated from the antenna 12.

[0013] A filter device according to the present disclosure can be employed as the bandpass filters 22, 28 in the communication device 10 described above.

[0014] (Configuration of filter device) Next, a detailed configuration of the filter device 100 according to the embodiment will be described with reference to Figures 2 to 4. In the following description, the circuit disposed inside the filter device 100 will also be referred to as a "filter circuit."

[0015] (1) Equivalent circuit 2 is an equivalent circuit diagram of the filter device 100 according to the first embodiment. Referring to Fig. 2, the filter device 100 includes an input terminal T1, an output terminal T2, a ground terminal GND, resonators RC1 to RC4, and capacitors C3, C4, and C7. Each of the resonators RC1 to RC4 is an LC resonator including an inductor and a capacitor.

[0016] The resonator RC1 includes inductors L1, L6, and L7 connected in series between the input terminal T1 and the ground terminal GND, and a capacitor C1 connected in parallel to the series-connected inductors L1 and L6.

[0017] The resonator RC2 includes inductors L2, L6, and L7 connected in series between the output terminal T2 and the ground terminal GND, and a capacitor C2 connected in parallel to the series-connected inductors L2 and L6.

[0018] A capacitor C7 is connected between the input terminal T1 and the output terminal T2, and the resonators RC1 and RC2 are electrically coupled by the capacitor C7.

[0019] The resonator RC3 includes inductors L3, L5, L6, L7, and L8, and a capacitor C5. In the resonator RC3, one end of the capacitor C5 is connected to the ground terminal GND via the inductor L8. The other end of the capacitor C5 is connected to the ground terminal GND via the inductors L3, L5, L6, and L7 connected in series. In the resonator RC3, the inductors L3, L5, L6, and L7 are connected in parallel with the capacitor C5 and the inductor L8.

[0020] The resonator RC4 includes inductors L4, L5, L6, L7, and L8, and a capacitor C6. In the resonator RC4, one end of the capacitor C6 is connected to the ground terminal GND via the inductor L8. The other end of the capacitor C6 is connected to the ground terminal GND via the inductors L4, L5, L6, and L7 connected in series. The resonator RC4 shares the inductors L5, L6, L7, and L8 with the resonator RC3. In the resonator RC4, the inductors L4, L5, L6, and L7 are connected in parallel with the capacitor C6 and the inductor L8.

[0021] A capacitor C3 is connected between the input terminal T1 and a connection node N1 between the capacitor C5 and the inductor L3. The capacitor C3 electrically couples the resonators RC1 and RC3. A capacitor C4 is connected between the output terminal T2 and a connection node N2 between the capacitor C6 and the inductor L4. The capacitor C4 electrically couples the resonators RC2 and RC4. The inductors L6 and L7 are shared by the resonators RC1 to RC4.

[0022] The resonators are magnetically coupled to each other. The filter device 100 has a configuration in which four stages of resonators that are magnetically coupled to each other are arranged between an input terminal T1 and an output terminal T2. By adjusting the resonant frequency of each resonator, the filter device 100 functions as a bandpass filter that passes signals in a desired frequency band.

[0023] (2)Detailed structure Next, the structure of the filter device 100 will be described with reference to Figs. 3 to 5. Fig. 3 is an external perspective view of the filter device 100 according to the first embodiment. Fig. 4 is an exploded perspective view showing an example of the layered structure of the filter device 100 according to the first embodiment. Fig. 5 is a diagram for explaining the shape of electrodes according to the first embodiment.

[0024] 3 and 4, the filter device 100 includes a main body 110 having a rectangular or approximately rectangular parallelepiped shape as a whole, in which a plurality of dielectric layers LY1 to LY9 are stacked in a stacking direction. The dielectric layers LY1 to LY9 are formed of ceramics such as low-temperature co-fired ceramics (LTCC) or resin. Inside the main body 110, inductors and capacitors of an LC parallel resonator are formed by a plurality of electrodes provided on each dielectric layer and a plurality of vias provided between the dielectric layers. In this specification, the term "via" refers to a conductor provided in a dielectric layer to connect electrodes provided on different dielectric layers. The vias are formed by, for example, conductive paste, plating, and / or metal pins.

[0025] In the following description, the stacking direction of the dielectric layers LY1 to LY9 in the main body 110 is referred to as the "Z-axis direction," the direction perpendicular to the Z-axis direction and along the long side of the main body 110 is referred to as the "X-axis direction," and the direction along the short side of the main body 110 is referred to as the "Y-axis direction." In the following, the positive direction of the Z-axis in each drawing may be referred to as the upper side, and the negative direction as the lower side. The X-axis direction along the long side of the laminate corresponds to the "first direction" in the present disclosure, and the Y-axis direction along the short side of the laminate corresponds to the "second direction" in the present disclosure.

[0026] A directionality mark DM for identifying the orientation of the filter device 100 is arranged on an upper surface 111 (dielectric layer LY1) of the main body 110. External terminals (an input terminal T1, an output terminal T2, and a ground terminal GND) for connecting the filter device 100 to an external device are arranged on a lower surface 112 (dielectric layer LY9) of the main body 110, which is the outer surface of the laminate. The input terminal T1, the output terminal T2, and the ground terminal GND are each a flat-plate-shaped electrode, and are LGA (Land Grid Array) terminals regularly arranged on the lower surface 112 of the main body 110. As shown in FIG. 4, the elements within the laminate constituting the filter device 100 are arranged, as a whole, to be line-symmetrical with respect to an imaginary line CL.

[0027] As described with reference to Fig. 2, the filter device 100 is a four-stage filter device including resonators RC1 to RC4, which are LC parallel resonators. More specifically, the resonator RC1 includes vias V11, V12, V13, V14, V15, V16, V17, V18, V50, and VG1, capacitor electrodes PC1 and PC14, a ground electrode PG1, and plate electrodes PL10A, PL10B, PL11B, PL20A, and PL20B. The resonator RC2 includes vias V21, V22, V23, V24, V25, V26, V27, V28, V50, and VG1, capacitor electrodes PC2 and PC15, a ground electrode PG1, and plate electrodes PL30A, PL30B, PL31B, PL22A, and PL20B.

[0028] The resonator RC3 includes vias V30, V31, V32, V50, V51, V52, VG1, VG2, VG3, and VG4, a ground electrode PG2, a capacitor electrode PC12, and plate electrodes PL21A, PL24A, and PL20B. The resonator RC4 includes vias V40, V41, V42, V50, V51, V52, VG1, VG2, VG3, and VG4, a ground electrode PG2, a capacitor electrode PC13, and plate electrodes PL23A, PL24A, and PL20B.

[0029] The laminate constituting the filter device 100 has a rectangular shape with long and short sides when viewed in a plan view from the stacking direction. The shapes of the electrodes arranged on each dielectric layer will be specifically described. First, the shapes of the electrodes constituting the capacitor will be described. The capacitor electrodes PC1, PC2 and the ground electrode PG2 arranged on the dielectric layer LY8 are electrodes of a substantially rectangular shape extending in the X-axis direction.

[0030] Capacitor electrodes PC12 and PC13 arranged on the dielectric layer LY7 are generally L-shaped electrodes extending in the X-axis direction and the Y-axis direction. Capacitor electrode PC11 and ground electrode PG1 arranged on the dielectric layer LY7 are generally rectangular electrodes extending in the X-axis direction. Capacitor electrodes PC14 and PC15 arranged on the dielectric layer LY6 are generally rectangular electrodes extending in the X-axis direction.

[0031] Next, the shapes of the electrodes that make up the inductor will be described. The plate electrodes PL10B, PL11B, PL30B, and PL31B arranged on the dielectric layer LY5 are strip-shaped electrodes formed with a substantially C-shaped wiring pattern. The plate electrodes PL10A and PL30A arranged on the dielectric layer LY4 are strip-shaped electrodes wound around the Z axis, and have, for example, a substantially J-, U-, or C-shape.

[0032] Plate electrodes PL20A, PL21A, PL22A, PL23A, and PL24A, which are disposed on dielectric layer LY2 and correspond to the first plate electrode in the present disclosure, and plate electrode PL20B, which is disposed on dielectric layer LY3 and corresponds to the second plate electrode in the present disclosure, will be described in detail with reference to Fig. 5. Fig. 5(a) is a plan view of plate electrodes PL20A, PL21A, PL22A, PL23A, and PL24A on dielectric layer LY2, viewed from the Z-axis direction. Fig. 5(b) is a plan view of plate electrode PL20B on dielectric layer LY3, viewed from the Z-axis direction.

[0033] Figure 5(c) is a plan view of the dielectric layers LY2 and LY3 from the Z-axis direction. Figure 5(d) is a plan view of the dielectric layers LY2 and LY3 from the Y-axis direction. Regions S1, S2, and S3 surrounded by dashed lines in Figures 5(c) and 5(d) indicate electrode portions that overlap in the stacking direction. In this way, the flat electrodes in regions S1, S2, and S3 are arranged overlapping in the stacking direction and connected in parallel by vias, which allows the cross-sectional area of ​​the inductor's current path to be increased. Increasing the cross-sectional area of ​​the inductor's current path reduces the resistance component and current loss, thereby improving the Q value.

[0034] As shown in FIG. 5(a), the plate electrode PL20A includes extended portions PL201A and PL203A extending in the X-axis direction and corresponding to the first and second portions of the first extension portion in the present disclosure, respectively, and an extended portion PL202A extending in the Y-axis direction and corresponding to the second extension portion in the present disclosure. The negative end of the extended portion PL201A along the X-axis is connected to one end of PL202A. The negative end of PL203A along the X-axis is connected to the other end of PL202A. The plate electrode PL21A includes extended portions PL211A and PL213A extending in the X-axis direction and an extended portion PL212A extending in the Y-axis direction. The negative end of the extended portion PL211A along the X-axis is connected to one end of PL212A. The negative end of PL213A along the X-axis is connected to the other end of PL212A.

[0035] The plate electrode PL22A includes extended portions PL221A and PL223A extending in the X-axis direction, and an extended portion PL222A extending in the Y-axis direction. The end of extended portion PL221A in the positive X-axis direction is connected to one end of PL222A. The end of PL223A in the positive X-axis direction is connected to the other end of PL222A. The plate electrode PL23A includes extended portions PL231A and PL233A extending in the X-axis direction, and an extended portion PL232A extending in the Y-axis direction. The end of extended portion PL231A in the positive X-axis direction is connected to one end of PL232A. The end of PL233A in the positive X-axis direction is connected to the other end of PL232A.

[0036] 5(b), the plate electrode PL20B includes an extension portion PL213B extending in the Y-axis direction. An extension portion PL201B extends from one end of the extension portion PL213B in the negative direction of the X-axis, and an extension portion PL207B extends in the positive direction of the X-axis. An extension portion PL206B extends from the other end of the extension portion PL213B in the negative direction of the X-axis, and an extension portion PL212B extends in the positive direction of the X-axis.

[0037] The negative X-axis end of the extended member PL201B, which corresponds to the first portion of the third extension member in this disclosure, extends in the Y-axis direction and is connected to one end of the extended member PL202B, which corresponds to the fourth extension member in this disclosure. The other end of the extended member PL202B extends in the X-axis direction and is connected to the negative X-axis end of the extended member PL203B, which corresponds to the second portion of the third extension member in this disclosure. The positive X-axis end PL241B of the extended member PL203B is an open end. The positive X-axis end of the extended member PL207B is connected to one end of the extended member PL208B, which extends in the Y-axis direction. The other end of the extended member PL208B is connected to the positive X-axis end of the extended member PL209B, which extends in the X-axis direction. The end PL243B of the extension portion PL209B in the negative direction of the X axis is an open end.

[0038] The negative end of extended member PL206B along the X axis is connected to one end of extended member PL205B extending in the Y axis direction. The other end of extended member PL205B is connected to the negative end of extended member PL204B extending in the X axis direction. The positive end PL242B of extended member PL204B along the X axis is an open end. The positive end of extended member PL212B along the X axis is connected to one end of extended member PL211B extending in the Y axis direction. The other end of extended member PL211B is connected to the positive end of extended member PL210B extending in the X axis direction. The negative end PL244B of extended member PL210B along the X axis is an open end.

[0039] The flat electrode PL20B is composed of four annular band-shaped electrodes arranged with the Z-axis direction as the winding axis, and is composed of extended portions PL201B to PL203B, extended portions PL204B to PL206B, extended portions PL207B to PL209B, and extended portions PL210B to PL212B, and as a whole has an axisymmetric shape with extended portion PL213B as the axis of symmetry.

[0040] 5(a) to 5(d), in region S1, plate electrode PL20A is arranged to overlap with extension portions PL201B, PL202B, and PL203B of plate electrode PL20B in the stacking direction and are connected by vias. In region S1, plate electrode PL21A is arranged to overlap with extension portions PL204B, PL205B, and PL206B of plate electrode PL20B in the stacking direction and are connected by vias.

[0041] In region S2, plate electrode PL24A is arranged to overlap extension portion PL213B of plate electrode PL20B in the stacking direction and is connected to them by vias. In region S3, plate electrode PL22A is arranged to overlap extension portions PL207B, PL208B, and PL209B of plate electrode PL20B in the stacking direction and is connected to them by vias. In region S3, plate electrode PL23A is arranged to overlap extension portions PL210B, PL211B, and PL212B of plate electrode PL20B in the stacking direction and is connected to them by vias.

[0042] 5(c), in the plate electrode PL20B, the distance in the Y-axis direction between the extension portion 207B and the extension portion 209B is defined as r1, and the distance in the X-axis direction between the end portion PL243B and the extension portion 208B is defined as r2. In this case, the plate electrode PL20B is formed so that the distance r2 on the inside of the annular band-shaped electrode is greater than the distance r1 on the inside of the annular band-shaped electrode. This relationship is also true for the remaining three annular band-shaped electrode portions of the plate electrode PL20B.

[0043] Here, in the plate electrodes PL20A and PL20B that overlap in the stacking direction, the length of the extension portion PL201A in the X-axis direction is shorter than the length of the extension portion PL201B in the X-axis direction. Note that the length of each extension portion is the length of the portion of each plate electrode that extends in the X-axis direction, and does not include the length of the tapered electrode at the corners of each electrode. In terms of area, the area of ​​the extension portion PL201A is smaller than the area of ​​the extension portion PL201B. Note that the area of ​​an extension portion is the product of the length of each extension portion and the electrode width of each extension portion in the Y-axis direction. This relationship is also true for the relationship between extended material portion PL203A and extended material portion PL203B, the relationship between extended material portion PL211A and extended material portion PL204B, the relationship between extended material portion PL213A and extended material portion PL206B, the relationship between extended material portion PL221A and extended material portion PL207B, the relationship between extended material portion PL223A and extended material portion PL209B, the relationship between extended material portion PL231A and extended material portion PL210B, and the relationship between extended material portion PL233A and extended material portion PL212B.

[0044] Returning to Figure 4, the connection relationships of the elements of the laminate will be described. The input terminal T1 is connected to a capacitor electrode PC1 arranged on a dielectric layer LY8 by a via V10. The capacitor electrode PC1 is connected to a capacitor electrode PC14 arranged on a dielectric layer LY6 by a via V11. The capacitor electrode PC14 is connected to one end of a plate electrode PL10A arranged on a dielectric layer LY4 by a via V12.

[0045] The other end of plate electrode PL10A is connected to end PL241B of plate electrode PL20B and one end of plate electrode PL11B by via V16. Vias V13, V14, and V15 are connected in order from one end to the other along the line of plate electrode PL10A. Via V13 is connected to one end of PL10B, and via V14 is connected to the other end of PL10B. Via V15 is connected to the other end of plate electrode PL11B.

[0046] The via V17 is connected to one end of the plate electrode PL20A. The via V18 is connected to the other end of the plate electrode PL20A. The vias V17 and V18 are connected in order along the line of the plate electrode PL20B.

[0047] The plate electrodes PL10B and PL11B are arranged to overlap with the plate electrode PL10A when viewed from above in the stacking direction. The plate electrode PL20A is arranged to overlap with the plate electrode PL20B when viewed from above in the stacking direction. The plate electrode PL20B is connected to the ground electrode PG1 arranged on the dielectric layer LY7 by a via V50. The ground electrode PG1 is connected to the ground terminal GND arranged on the dielectric layer LY9 by a via VG1.

[0048] The vias V11, V12, V13, V14, V15, V16, V17, and V18 and the plate electrodes PL10A, PL10B, PL11B, PL20A, and PL20B form the inductor L1 in Figure 2. The via V50 forms the inductor L6 in Figure 2. The via VG1 forms the inductor L7 in Figure 2. Furthermore, the capacitor electrodes PC1 and PC14 and the ground electrode PG1 form the capacitor C1 in Figure 2.

[0049] The output terminal T2 is connected to a capacitor electrode PC2 disposed on a dielectric layer LY8 by a via V20. The capacitor electrode PC2 is connected to a capacitor electrode PC15 disposed on a dielectric layer LY6 by a via V21. The capacitor electrode PC15 is connected to one end of a plate electrode PL30A disposed on a dielectric layer LY4 by a via V22.

[0050] The other end of plate electrode PL30A is connected to end PL243B of plate electrode PL20B and one end of plate electrode PL31B by via V26. Vias V23, V24, and V25 are connected in order from one end to the other along the line of plate electrode PL30A. Via V23 is connected to one end of PL30B, and via V24 is connected to the other end of PL30B. Via V25 is connected to the other end of plate electrode PL31B.

[0051] The via V27 is connected to one end of the plate electrode PL22 A. The via V28 is connected to the other end of the plate electrode PL22 A. The vias V27 and V28 are connected in order along the line of the plate electrode PL20B.

[0052] The plate electrodes PL30B and PL31B are arranged to overlap the plate electrode PL30A when viewed from above in the stacking direction. The plate electrode PL22A is arranged to overlap the plate electrode PL20B when viewed from above in the stacking direction. The plate electrode PL20B is connected to the ground electrode PG1 arranged on the dielectric layer LY7 by a via V50. The ground electrode PG1 is connected to the ground terminal GND arranged on the dielectric layer LY9 by a via VG1.

[0053] The vias V21, V22, V23, V24, V25, V26, V27, and V28 and the plate electrodes PL30A, PL30B, PL31B, PL22A, and PL20B form inductor L2 in FIG. 2. The via V50 forms inductor L6 in FIG. 2. The via VG1 forms inductor L7 in FIG. 2. Furthermore, the capacitor electrodes PC2 and PC15 and the ground electrode PG1 form capacitor C2 in FIG. 2.

[0054] A ground electrode PG2 is arranged on the dielectric layer LY8 adjacent to the capacitor electrodes PC1 and PC2 in the positive direction of the Y axis. The ground electrode PG2 is connected to the ground terminal GND on the dielectric layer LY9 by vias VG2, VG3, and VG4. When viewed in a plan view from the stacking direction, the ground electrode PG2 partially overlaps with the capacitor electrode PC12 arranged on the adjacent dielectric layer LY7. The ground electrode PG2 and the capacitor electrode PC12 form the capacitor C5 in FIG. 2.

[0055] The capacitor electrode PC12 is connected to an end PL242B of the plate electrode PL20B arranged on the dielectric layer LY3 by a via V30. The plate electrode PL20B is connected to one end of the plate electrode PL21A arranged on the dielectric layer LY2 by a via V31. The plate electrode PL20B is connected to the other end of the plate electrode PL21A arranged on the dielectric layer LY2 by a via V32. The plate electrode PL21A is arranged to overlap with the plate electrode PL20B when viewed from above in the stacking direction.

[0056] One end of the extension portion 213B of the plate electrode PL20B is connected to one end of the plate electrode PL24A arranged on the dielectric layer LY2 by a via V51. The other end of the extension portion 213B of the plate electrode PL20B is connected to the other end of the plate electrode PL24A arranged on the dielectric layer LY2 by a via V52. In addition, one end of the extension portion 213B of the plate electrode PL20B is connected to the ground electrode PG1 arranged on the dielectric layer LY7 by a via V50. The ground electrode PG1 is connected to the ground terminal GND arranged on the dielectric layer LY9 by a via VG1.

[0057] The vias V30, V31, and V32 and the plate electrodes PL21A and PL20B form the inductor L3 in FIG. 2. The vias VG2, VG3, and VG4 form the inductor L8 in FIG. 2. The vias V52 and V51 and the plate electrodes PL24A and PL20B form the inductor L5 in FIG. 2. The via V50 forms the inductor L6 in FIG. 2. The via VG1 forms the inductor L7 in FIG. 2. The ground electrode PG2 and the capacitor electrode PC12 form the capacitor C5 in FIG. 2.

[0058] When viewed in plan from the stacking direction, the ground electrode PG2 partially overlaps with a capacitor electrode PC13 disposed on the adjacent dielectric layer LY7. The ground electrode PG2 and the capacitor electrode PC13 form a capacitor C6 in FIG.

[0059] The capacitor electrode PC13 is connected to an end PL244B of the plate electrode PL20B arranged on the dielectric layer LY3 by a via V40. The plate electrode PL20B is connected to one end of the plate electrode PL23A arranged on the dielectric layer LY2 by a via V41. The plate electrode PL20B is connected to the other end of the plate electrode PL23A arranged on the dielectric layer LY2 by a via V42. The plate electrode PL23A is arranged to overlap with the plate electrode PL20B when viewed from above in the stacking direction.

[0060] The vias V40, V41, and V42 and the plate electrodes PL23A and PL20B form the inductor L4 in FIG. 2. The vias VG2, VG3, and VG4 form the inductor L8 in FIG. 2. The vias V52 and V51 and the plate electrodes PL24A and PL20B form the inductor L5 in FIG. 2. The via V50 forms the inductor L6 in FIG. 2. The via VG1 forms the inductor L7 in FIG. 2. The ground electrode PG2 and the capacitor electrode PC13 form the capacitor C6 in FIG. 2.

[0061] In addition, when viewed in a plane from the stacking direction, the capacitor electrode PC12 also partially overlaps with the capacitor electrode PC14 arranged on the dielectric layer LY6. The capacitor electrodes PC12 and PC14 form the capacitor C3 in FIG. 2. When viewed in a plane from the stacking direction, the capacitor electrode PC13 also partially overlaps with the capacitor electrode PC15 arranged on the dielectric layer LY6. The capacitor electrodes PC13 and PC15 form the capacitor C4 in FIG. 2. The capacitor C3 electric field couples the resonators RC1 and RC3, and the capacitor C4 electric field couples the resonators RC2 and RC4.

[0062] A capacitor electrode PC11 is disposed on the dielectric layer LY7 and adjacent to the ground electrode PG1 in the positive direction of the Y axis. When viewed from above in the stacking direction, the capacitor electrode PC11 partially overlaps with capacitor electrodes PC14 and PC15 disposed on the dielectric layer LY6. The capacitor electrodes PC11, PC14, and PC15 form the capacitor C7 in FIG. 2. The capacitor C7 electrically couples the resonators RC1 and RC2.

[0063] In the filter device 100 described above, when multiple dielectric layers are stacked and pressure-bonded, lamination misalignment, in which each dielectric layer is misaligned in the X-axis and / or Y-axis directions, may occur. If lamination misalignment occurs in the electrodes that constitute the inductor, the inner diameter of the coil formed by the inductors stacked in the lamination direction changes. This may cause the inductance value to vary from the designed value. The change in inductance value may affect filter characteristics such as the passband width and center frequency of the filter.

[0064] In the filter device 100 according to the embodiment, the length of the extended member PL201A in the X-axis direction is shorter than the length of the extended member PL201B in the X-axis direction of the plate electrodes PL20A and PL20B that overlap in the stacking direction. In other words, the area of ​​the extended member PL201A is smaller than the area of ​​the extended member PL201B.

[0065] In a filter device in which two plate electrodes overlapping in the stacking direction have approximately the same shape, the change in inductor characteristics is greater when lamination misalignment occurs in the Y-axis direction (short side direction) than when lamination misalignment occurs in the X-axis direction (long side direction). This is because, when two plate electrodes overlapping in the stacking direction have approximately the same shape, the change in the coil inner diameter of the overlapping portion of the two plate electrodes overlapping in the stacking direction is greater when lamination misalignment occurs in the short side direction than when lamination misalignment occurs in the long side direction. Therefore, the electrode shape should be one that can reduce the impact of misalignment of the extension portion extending in the X-axis direction (long side direction) in the Y-axis direction (short side direction).

[0066] In the filter device 100 of the first embodiment, in consideration of changes in filter characteristics due to lamination misalignment, the shape of the extended material portion extending in the X-axis direction, which is the long side direction, of the plate electrodes constituting the inductor is given a distinctive feature. As described above, in the filter device 100, of two plate electrodes overlapping in the lamination direction, the length in the long side direction (X-axis direction) of the extended material portion of one plate electrode arranged in the X-axis direction, which is the long side direction, is shorter than the length in the long side direction (X-axis direction) of the extended material portion of the other plate electrode. In other words, in terms of area, the area of ​​the extended material portion of one plate electrode arranged in the X-axis direction, which is the long side direction, is smaller than the area of ​​the extended material portion of the other plate electrode.

[0067] In the filter device 100, even if lamination misalignment occurs and the positions of two overlapping flat electrodes in the lamination direction are shifted, the lengths (or areas) of the elongated portions in the long side direction, which have a large effect on changes in characteristics, are made different. This makes it possible for the filter device 100 to suppress changes in the inner diameter of the coil formed by the electrodes functioning as an inductor, thereby reducing changes in filter characteristics.

[0068] The filter device 100 is configured to reduce the area of ​​the portion that is significantly affected by changes in characteristics, thereby suppressing changes in the inner diameter of the coil formed by the electrodes that function as inductors, and reducing changes in filter characteristics even if stacking misalignment occurs and the plate electrodes PL20A and PL20B are misaligned. This effect is also achieved when the plate electrodes PL21A and PL20B are misaligned, when the plate electrodes PL22A and PL20B are misaligned, or when the plate electrodes PL23A and PL20B are misaligned.

[0069] Next, the characteristics of the plate electrodes will be described in comparison with a comparative example with reference to Fig. 6 and Fig. 7. Fig. 6 is an exploded perspective view showing an example of the laminated structure of filter device 200 of the comparative example. Fig. 7 is a diagram for explaining the change in characteristics between the first embodiment and the comparative example.

[0070] The filter device 200 of the comparative example in Fig. 6 differs from the filter device 100 of the first embodiment in Fig. 4 in the shapes of the plate electrodes and vias in the dielectric layers LY2 to LY5. Specifically, electrodes of the same shape are arranged in two layers in the dielectric layers LY2 and LY3, and in the dielectric layers LY4 and LY5. The filter device 200 in Fig. 6 will be described mainly in terms of the differences from the filter device 100 in Fig. 4.

[0071] The plate electrode PL20B disposed on the dielectric layer LY3 has the same shape as the plate electrode PL20B of the filter device 100 of Embodiment 1. The plate electrode PL20B has four annular band-shaped electrodes wound around the Z-axis direction, and has an overall shape that is line-symmetrical with respect to the extension portion PL213B as the axis of symmetry. A plate electrode 25A having substantially the same shape as the plate electrode PL20B is disposed on the dielectric layer LY2.

[0072] The plate electrode PL10A disposed on the dielectric layer LY4 has the same shape as the plate electrode PL10A of the filter device 100 of Embodiment 1. The plate electrode PL10A is a band-shaped electrode wound around the Z axis and has, for example, a substantially J-, U-, or C-shape. A plate electrode PL12B having substantially the same shape as the plate electrode PL10A is disposed on the dielectric layer LY5.

[0073] One end of plate electrode PL10A arranged on dielectric layer LY4 is connected by via V12 to one end of plate electrode PL12B arranged on dielectric layer LY5, and the other end of plate electrode PL10A is connected by via V16 to the other end of plate electrode PL12B arranged on dielectric layer LY5.

[0074] The other end of the plate electrode PL10A is connected by a via V16 to one end of a plate electrode PL20B arranged on the dielectric layer LY3. The plate electrode PL20B is connected by a via V16 to one end of a plate electrode PL25A arranged on the dielectric layer LY2.

[0075] One end of the plate electrode PL30A arranged on the dielectric layer LY4 is connected by a via V22 to one end of the plate electrode PL32B arranged on the dielectric layer LY5, and the other end of the plate electrode PL30A is connected by a via V26 to the other end of the plate electrode PL32B arranged on the dielectric layer LY5.

[0076] The other end of the plate electrode PL30A is connected by a via V26 to one end of a plate electrode PL20B disposed on the dielectric layer LY3. The plate electrode PL20B is connected by a via V26 to one end of a plate electrode PL25A disposed on the dielectric layer LY2.

[0077] The plate electrode PL25A arranged on the dielectric layer LY2 is connected to the end portion PL241B of the plate electrode PL20B arranged on the dielectric layer LY3 by a via V16. The plate electrode PL25A is connected to the end portion PL243B of the plate electrode PL20B arranged on the dielectric layer LY3 by a via V26. The plate electrode PL25A is connected to the end portion PL242B of the plate electrode PL20B arranged on the dielectric layer LY3 by a via V30. The plate electrode PL25A is connected to the end portion PL244B of the plate electrode PL20B arranged on the dielectric layer LY3 by a via V40. The plate electrode PL25A is connected to one end of the extension portion PL213B of the plate electrode PL20B arranged on the dielectric layer LY3 by a via V50.

[0078] Thus, in the filter device 200, unlike the filter device 100, the plate electrodes PL25A and PL20B that overlap in the stacking direction have substantially the same electrode shape. Furthermore, in the filter device 200, the plate electrodes PL10A and PL12B that overlap in the stacking direction have substantially the same electrode shape, and the plate electrodes PL30A and PL32B that overlap in the stacking direction have substantially the same electrode shape. The shapes of the two plate electrodes may be completely identical. Changes in characteristics between the first embodiment and the comparative example will be described with reference to FIG. 7.

[0079] Fig. 7 shows simulations of filter characteristics for the filter device 100 of the first embodiment and the filter device 200 of the comparative example, where lamination misalignment occurs in the X-axis direction (longer side direction) and where lamination misalignment occurs in the Y-axis direction (short side direction). In the graph of Fig. 7, the horizontal axis represents frequency and the vertical axis represents insertion loss. In Fig. 7, solid lines LN10, LN20, LN30, and LN40 represent cases where no lamination misalignment occurs, and dashed lines LN11, LN21, LN31, and LN41 represent cases where lamination misalignment occurs. Note that the amount of lamination misalignment in the X-axis direction and the Y-axis direction is the same.

[0080] 7, when lamination misalignment occurs in the X-axis direction, the change in insertion loss is negligible for both filter device 100 of the first embodiment and filter device 200 of the comparative example. On the other hand, when lamination misalignment occurs in the Y-axis direction, the change in insertion loss for filter device 100 of the first embodiment is negligible, whereas the change in insertion loss for filter device 200 of the comparative example is greater than that for filter device 100. As shown in FIG. 7, dashed line LN41 is generally shifted in the direction of increasing frequency from solid line LN40.

[0081] Here, there is a trade-off between improving the Q value and reducing the change in filter characteristics due to lamination misalignment. In other words, to improve the Q value, it is sufficient to increase the area of ​​the plate electrodes (parallel portions) overlapping in the lamination direction and reduce the resistance value. However, increasing the area of ​​the plate electrodes increases the change in the inner diameter of the coil formed by the electrodes functioning as inductors overlapping in the lamination direction when lamination misalignment occurs, resulting in a large change in the filter characteristics. In the filter device 100, the electrode shape is designed to take into consideration improving the Q value and reducing the change in filter characteristics.

[0082] In the filter device 100, the area of ​​the extended material portion of one of the two plate electrodes arranged in the Y-axis direction (short side direction) is approximately the same as the area of ​​the extended material portion of the other plate electrode. This is because, as shown in Figure 7, even if stacking misalignment occurs in the X-axis direction (long side direction) in the extended material portion extending in the short side direction, it has little effect on changes in characteristics. Note that the areas of the extended material portions in the short side direction may be the same.

[0083] In the filter device 100, the position where the extension portion in the long side direction and the extension portion in the short side direction are connected is called a corner. As shown in Fig. 5, in the filter device 100, the areas of adjacent corners of the plate electrode are approximately the same. This is because the corners are positions where current concentrates, so it is not preferable to change the shape (width) of the plate electrode. However, the areas of the corners may be the same.

[0084] Here, the relationship between the multiple plate electrodes in the stacking direction will be described again with reference to Fig. 4. As shown in Fig. 4, on the dielectric layers LY2 to LY5 aligned in the stacking direction of the laminate, the plate electrodes are arranged in the order PL20A, PL20B, PL10A, and PL10B. Furthermore, on the dielectric layers LY2 to LY5, the plate electrodes are arranged in the order PL22A, PL20B, PL30A, and PL30B so as to be line-symmetrical with respect to the imaginary line CL.

[0085] The plate electrodes PL20A, PL20B, PL10A, and PL10B partially overlap when viewed in plan from the stacking direction of the laminate. Furthermore, the plate electrodes PL22A, PL20B, PL30A, and PL30B partially overlap when viewed in plan from the stacking direction of the laminate. In these plate electrodes, the area of ​​the extended portion in the X-axis direction of the plate electrode PL20B on the dielectric layer LY3 is larger than the area of ​​the extended portion in the X-axis direction of the plate electrode PL20A on the dielectric layer LY2, and the area of ​​the extended portion in the X-axis direction of the plate electrode PL10A on the dielectric layer LY4 is larger than the area of ​​the extended portion in the X-axis direction of the plate electrode PL10B on the dielectric layer LY5.

[0086] That is, in a pair of plate electrodes PL20A, PL20B and a pair of plate electrodes PL10A, PL10B arranged in the stacking direction, the areas of the extended portions in the X-axis direction of the plate electrode PL20B on the dielectric layer LY3 and the plate electrode PL10A on the dielectric layer LY4, which are located opposite each other, are larger than the areas of the extended portions in the X-axis direction of the plate electrode PL20A on the dielectric layer LY2 and the plate electrode PL11B on the dielectric layer LY5, which are not located opposite each other. As a result, when the areas of the pair of plate electrodes are large, the resistance value of the current path can be reduced more than when the areas of the pair of plate electrodes located opposite each other are small.

[0087] In the filter device 100 of the first embodiment, the length in the long side direction (X-axis direction) of the extended material portion of one of the flat plate electrodes arranged in the X-axis direction, which is the long side direction, is made shorter than the length in the long side direction (X-axis direction) of the extended material portion of the other flat plate electrode. In other words, in terms of area, the area of ​​the extended material portion of one of the flat plate electrodes arranged in the X-axis direction, which is the long side direction, is made smaller than the area of ​​the extended material portion of the other flat plate electrode. By making the area of ​​the extended material portion of one flat plate electrode smaller than the area of ​​the extended material portion of the other flat plate electrode, changes in the inner diameter of the coil formed by the electrodes functioning as inductors can be suppressed, and changes in the filter characteristics can be reduced even if stacking misalignment occurs and the positions of the flat plate electrodes arranged in the stacking direction are shifted.

[0088] [Embodiment 2] Next, variations in electrode shape of filter device 300 according to the second embodiment will be described with reference to Figs. 8 and 9. The electrode shape of filter device 300 according to the second embodiment is different from that of filter device 100 according to the first embodiment, and is therefore capable of reducing changes in filter characteristics. Fig. 8 is an exploded perspective view showing an example of the layered structure of filter device 300 according to the second embodiment. Fig. 9 is a diagram for explaining the electrode shape according to the second embodiment.

[0089] Filter device 300 according to the second embodiment of Fig. 8 differs from filter device 100 according to the first embodiment of Fig. 4 in the shapes and arrangement of the plate electrodes and vias in dielectric layers LY2 to LY5. The following description of filter device 300 in Fig. 8 will focus on the differences from filter device 100 in Fig. 4. Note that the shapes and arrangement of the vias are the same as those of filter device 200 of the comparative example in Fig. 6, and therefore will not be repeated.

[0090] The plate electrode PL20B arranged on the dielectric layer LY3 has the same shape as the plate electrode PL20B of the filter device 100 of Embodiment 1. The plate electrode PL20B has four annular band-shaped electrodes arranged with the winding axis in the Z-axis direction, and has an overall shape that is line-symmetrical with the extension portion PL213B as the axis of symmetry. The plate electrode PL26A arranged on the dielectric layer LY2 has a shape that is generally similar to that of the plate electrode PL20B, but differs in that the portion of the electrode extending in the X-axis direction, which is the long side direction, is thinner than the portion of the plate electrode PL20B arranged on the dielectric layer LY3 that extends in the X-axis direction.

[0091] The plate electrode PL13B arranged on the dielectric layer LY5 is a band-shaped electrode wound around the Z-axis and has, for example, a substantially J-, U-, or C-shape. The shape of the plate electrode PL13B is different in that the portion of the electrode extending in the X-axis direction, which is the long side direction, is thinner than the portion of the plate electrode PL10A arranged on the dielectric layer LY4 extending in the X-axis direction.

[0092] The plate electrode PL33B arranged on the dielectric layer LY5 is a band-shaped electrode wound around the Z-axis and has, for example, a substantially J-, U-, or C-shape. The shape of the plate electrode PL33B is different in that the portion of the electrode extending in the X-axis direction, which is the long side direction, is thinner than the portion of the plate electrode PL30A arranged on the dielectric layer LY4 extending in the X-axis direction.

[0093] As described above, the filter device 300, like the filter device 100, has two flat plate electrodes that are overlapped in the stacking direction, but the shapes of the flat plate electrodes of the filter device 300 are different. The flat plate electrodes of the filter device 300 differ in that the width of the extended portion is narrower, rather than the length of the extended portion being shorter as in the flat plate electrodes of the filter device 100. The filter device 300 has the same electrode shapes as the filter device 200 of the comparative example, except for the dielectric layers LY2 and LY5.

[0094] (electrode shape) The laminate constituting the filter device 300 has a rectangular shape with long and short sides when viewed in a plan view from the stacking direction. Of the electrodes arranged on each dielectric layer, the electrodes constituting the inductor will be described. Fig. 9 describes the electrode shapes of the plate electrode PL26A arranged on the dielectric layer LY2 and the plate electrode PL20B arranged on the dielectric layer LY3, among the plate electrodes shown in Fig. 8.

[0095] Fig. 9(a) is a plan view of the plate electrode PL26A from the Z-axis direction, Fig. 9(b) is a plan view of the plate electrode PL20B from the Z-axis direction, and Fig. 9(c) is a plan view of the dielectric layers LY2 and LY3 from the Z-axis direction.

[0096] 9(a), the plate electrode PL26A includes an extension portion PL273A extending in the Y-axis direction. An extension portion PL261A extends from one end of the extension portion PL273A in the negative direction of the X-axis, and an extension portion PL267A extends in the positive direction of the X-axis. An extension portion PL266A extends from the other end of the extension portion PL273A in the negative direction of the X-axis, and an extension portion PL272A extends in the positive direction of the X-axis.

[0097] The negative end of the extended portion PL261A along the X axis is connected to one end of the extended portion PL262A extending in the Y axis direction. The other end of the extended portion PL262A is connected to the negative end of the extended portion PL263A extending in the X axis direction. The positive end PL251A of the extended portion PL263A along the X axis is an open end. The positive end of the extended portion PL267A along the X axis is connected to one end of the extended portion PL268A extending in the Y axis direction. The other end of the extended portion PL268A is connected to the positive end of the X axis of the extended portion PL269A extending in the X axis direction. The negative end PL253A of the extended portion PL269A along the X axis is an open end.

[0098] The end of extended member PL264A facing the negative X-axis is connected to one end of extended member PL265A extending in the Y-axis direction. The other end of extended member PL265A is connected to the end of extended member PL264A facing the negative X-axis direction. The end PL252A facing the positive X-axis direction of extended member PL264A is an open end. The end of extended member PL272A facing the positive X-axis is connected to one end of extended member PL271A extending in the Y-axis direction. The other end of extended member PL271A is connected to the end of extended member PL270A facing the positive X-axis direction. The end PL254A facing the negative X-axis direction of extended member PL270A is an open end.

[0099] The plate electrode PL26A has four annular belt-shaped electrodes arranged with the Z-axis direction as the winding axis, and has an overall shape that is axisymmetric with respect to the extension portion PL273A. Note that the shape of the plate electrode PL20B in Fig. 9(b) is the same as the shape of the plate electrode PL20B in Fig. 5(b) described above, and therefore description thereof will not be repeated.

[0100] In the plate electrodes PL26A and PL20B that overlap in the stacking direction, the length of the extended portion PL261A in the Y-axis direction is shorter than the length of the extended portion PL201B in the Y-axis direction. In terms of area, the area of ​​the extended portion PL261A is smaller than the area of ​​the extended portion PL201B. This relationship also applies to the relationship between the extended portion PL263A and the extended portion PL203B, the relationship between the extended portion PL264A and the extended portion PL204B, the relationship between the extended portion PL266A and the extended portion PL206B, the relationship between the extended portion PL267A and the extended portion PL207B, the relationship between the extended portion PL269A and the extended portion PL209B, the relationship between the extended portion PL270A and the extended portion PL210B, and the relationship between the extended portion PL272A and the extended portion PL212B.

[0101] Here, the plate electrode PL26A has a shape that is axisymmetric with respect to the extended material portion PL273A. In this structure, the distance r4 in the Y-axis direction between the extended material portions PL269A and PL269A is longer than the distance r3 in the Y-axis direction between the extended material portions PL209B and PL209B. This relationship also applies to the relationship between the distance between the extended material portion PL261A and PL262A and the distance between the extended material portion PL201B and PL203B, the relationship between the distance between the extended material portion PL264A and PL266A and the distance between the extended material portion PL204B and PL206B, and the relationship between the distance between the extended material portion PL270A and PL272A and the distance between the extended material portion PL210B and PL212B.

[0102] In the filter device 300 of the second embodiment, in consideration of changes in filter characteristics due to lamination misalignment, the shape of the extended material portion extending in the X-axis direction, which is the long side direction, of the plate electrodes constituting the inductor is given a distinctive feature. As described above, in the filter device 300, of two plate electrodes overlapping in the lamination direction, the length in the short side direction (Y-axis direction) of the extended material portion of one plate electrode arranged in the X-axis direction, which is the long side direction, is shorter than the length in the short side direction (Y-axis direction) of the extended material portion of the other plate electrode. In other words, in terms of area, the area of ​​the extended material portion of one plate electrode arranged in the X-axis direction, which is the long side direction, is smaller than the area of ​​the extended material portion of the other plate electrode.

[0103] In other words, in terms of distance, the distance between one of the extension portions arranged at opposite positions in the Y-axis direction is longer than the distance between the other of the extension portions arranged at opposite positions in the Y-axis direction.

[0104] Generally, the inductance value of a plate electrode forming an inductor depends primarily on the inner diameter of the coil formed by the plate electrode. In the filter device 300, only the shape of the inner diameter side of two plate electrodes overlapping in the stacking direction is changed, while the shape of the outer diameter side is unchanged. Specifically, the plate electrode PL26A of the dielectric layer LY2 has its inner diameter-side extension portions PL267A and PL269A each cut off by (r4-r3) / 2 compared to the plate electrode PL20B of the dielectric layer LY3. This prevents the inner diameter from changing within the cut-off area, even if stacking misalignment occurs and the positions of the two overlapping plate electrodes in the stacking direction are shifted in the Y-axis direction. This reduces changes in the inductance value. This reduces changes in the filter characteristics.

[0105] [Variation 1] Next, the electrode shape of Modification 1 will be described. In Modification 1, the shape of the extended portion of the plate electrode is different. The electrode of Modification 1 is an extracted portion of the extended portion of the plate electrode that constitutes the inductor. FIG. 10 is a diagram for explaining the electrode shape of Modification 1. The electrode of Modification 1 includes a plate electrode PL100A and a plate electrode PL100B arranged in the stacking direction.

[0106] The plate electrode PL100A is an electrode arranged in the area surrounded by the dashed line in Figure 10. When viewed from above in the stacking direction of the laminate, the plate electrodes PL100A and PL100B are arranged to overlap and are connected by vias in the stacking direction to form parallel lines. The plate electrode PL100B has a meandering shape in which U-shaped bent portions PL102B and straight portions PL101B are arranged alternately. The plate electrode PL100A is composed only of U-shaped bent portions PL102A that correspond to the bent portions PL102B in the plate electrode PL100B.

[0107] 10 of Modification 1, even in meander-shaped electrodes, when plate electrodes PL100A and PL100B overlap in a plan view in the stacking direction of the laminate, the area of ​​the straight line portion of plate electrode PL100A is made smaller than the area of ​​plate electrode PL100B. This makes it possible to suppress changes in the inner diameter of the coil formed by the electrodes functioning as inductors, even if stacking misalignment occurs and the positions of the two plate electrodes overlapping in the stacking direction become misaligned, thereby reducing changes in the filter characteristics.

[0108] [Variation 2] Next, the electrode shape of Modified Example 2 will be described. The electrode of Modified Example 2 has a different shape of the extension portion in the Y-axis direction. The electrode of Modified Example 2 is an extracted portion including a corner portion where the extension portion in the long side direction and the extension portion in the short side direction are connected. FIG. 11 is a diagram for explaining the electrode shape of Modified Example 2. The electrode in FIG. 11 corresponds to the portion of the plate electrodes PL20A, PL20B in Embodiment 1. The electrode of Modified Example 2 includes a pair of plate electrodes PL120A and PL120B arranged in the stacking direction.

[0109] As shown in Fig. 11(a), the first-layer plate electrode PL120A has a stepped shape due to the inner portion being partially removed. As shown in Fig. 11(b), the second-layer plate electrode PL120B has a uniform U-shape with a uniform electrode width. When the plate electrodes PL120A and PL120B are stacked in the stacking direction, the electrode arrangement is as shown in Fig. 11(c).

[0110] Plate electrode PL120A includes extension portions PL121A and PL123A extending in the X-axis direction and an extension portion PL122A extending in the Y-axis direction. Plate electrode PL120B includes extension portions PL121B and PL123B extending in the X-axis direction and an extension portion PL122B extending in the Y-axis direction.

[0111] Here, in two flat plate electrodes overlapping in the stacking direction, the area of ​​the extended portion PL121A extending in the X-axis direction is smaller than the area of ​​the extended portion PL121B. This relationship also applies to the relationship between the extended portion PL123A and the extended portion PL123B extending in the X-axis direction. Furthermore, in two flat plate electrodes overlapping in the stacking direction, the area of ​​the extended portion PL122A extending in the Y-axis direction is smaller than the area of ​​the extended portion PL122B.

[0112] The shape of the electrodes will be described in detail. Regions S4 surrounded by dashed lines in FIG. 11(c) indicate corners of the electrodes overlapping in the stacking direction. Regions S5 surrounded by dashed lines in FIG. 11(c) indicate centers in the Y-axis direction of the electrodes overlapping in the stacking direction. As shown in FIG. 11(c), the areas of the corners of region S4 are approximately the same in the two plate electrodes 120A and 120B overlapping in the stacking direction. On the other hand, the areas of the centers in the Y-axis direction in region S5 of the two plate electrodes overlapping in the stacking direction are different between plate electrode PL120A and plate electrode PL120B. Specifically, the width r5 in the X-axis direction of the extended portion PL122A is narrower than the width r6 in the X-axis direction of the extended portion PL122B. As a result, the area of ​​the center in the Y-axis direction shown in region S5 of plate electrode PL120A is smaller than that of plate electrode PL120B.

[0113] 11, in the electrode of Modification 2, the areas of the corners of region S4 on the first and second layers are approximately the same, and the area of ​​the center in the Y-axis direction of region S5 on the first layer is smaller than that on the second layer. In this way, in the electrode of Modification 2, the areas of the corners where the direction of current flow changes are approximately the same on the first and second layers, but the areas of the centers are different. This prevents the shape (width) of the corners where current concentrates, and also prevents changes in the inner diameter of the coil formed by the electrodes functioning as inductors from changing even if lamination misalignment occurs in the X-axis direction and the positions of two flat electrodes overlapping in the lamination direction are shifted, thereby reducing changes in filter characteristics.

[0114] In the LC resonator including an inductor and a capacitor for transmitting a signal from an input terminal to an output terminal, a configuration in which four resonators are arranged has been shown in the first embodiment. However, the number of stages of the LC resonator (the number of resonators) may be any number.

[0115] [Aspect] (Item 1) The filter device includes a laminate including multiple dielectric layers, an input terminal and an output terminal disposed on the outer surface of the laminate, and an LC resonator including an inductor and a capacitor, transmitting a signal from the input terminal to the output terminal. The LC resonator includes a first plate electrode and a second plate electrode disposed on different dielectric layers and connected to each other by a via. The first plate electrode and the second plate electrode function as an inductor. When viewed from above in the stacking direction of the laminate, the first plate electrode and the second plate electrode at least partially overlap. When viewed from above in the stacking direction, the laminate has a rectangular shape with long and short sides. The first plate electrode includes a first extension portion extending in a first direction along the long side direction of the laminate and a second extension portion extending in a second direction along the short side direction of the laminate. The second plate electrode includes a third extension portion extending in the first direction and a fourth extension portion extending in the second direction. The area of ​​the first extension portion is smaller than the area of ​​the third extension portion.

[0116] (Item 2) In the filter device described in item 1, the length of the first elongated member portion in the first direction is shorter than the length of the third elongated member portion in the first direction.

[0117] (Item 3) In the filter device described in item 1, the length of the first elongated member portion in the second direction is shorter than the length of the third elongated member portion in the second direction.

[0118] (Item 4) In the filter device described in item 3, the first elongated member portion includes a first portion and a second portion arranged opposite each other in the second direction. The third elongated member portion includes a third portion and a fourth portion arranged opposite each other in the second direction. One end of the second elongated member portion is connected to the first portion, and the other end of the second elongated member portion is connected to the second portion. One end of the fourth elongated member portion is connected to the third portion, and the other end of the fourth elongated member portion is connected to the fourth portion. The distance between the first portion and the third portion in the second direction is longer than the distance between the second portion and the fourth portion in the second direction.

[0119] (Item 5) In the filter device according to any one of items 1 to 4, the area of ​​the second elongated member portion is the same as or approximately the same as the area of ​​the fourth elongated member portion.

[0120] (Item 6) In the filter device according to any one of items 1 to 4, the area of ​​the second elongated member portion is smaller than the area of ​​the fourth elongated member portion.

[0121] (Item 7) In the filter device described in any one of Items 1 to 6, the first elongated member portion and the second elongated member portion are connected at a first corner portion, and the third elongated member portion and the fourth elongated member portion are connected at a second corner portion. The area of ​​the first corner portion is the same as or approximately the same as the area of ​​the second corner portion.

[0122] (Item 8) In the filter device according to any one of Items 1 to 7, the LC resonator further includes a third plate electrode and a fourth plate electrode disposed on different dielectric layers and connected to each other by a via. The third plate electrode and the fourth plate electrode function as inductors. The first plate electrode, the second plate electrode, the third plate electrode, and the fourth plate electrode are disposed in this order in the stacking direction of the laminate. When viewed from above in the stacking direction of the laminate, the first plate electrode, the second plate electrode, the third plate electrode, and the fourth plate electrode at least partially overlap. The third plate electrode includes a fifth extension portion extending in the first direction and a sixth extension portion extending in the second direction. The fourth plate electrode includes a seventh extension portion extending in the first direction and an eighth extension portion extending in the second direction. The area of ​​the fifth extension portion is larger than the area of ​​the seventh extension portion.

[0123] (Item 9) In the filter device according to any one of Items 1 to 8, the filter device includes a rectangular laminate including a plurality of dielectric layers, an input terminal and an output terminal disposed on the outer surface of the laminate, and an LC resonator including an inductor and a capacitor, transmitting a signal from the input terminal to the output terminal. The LC resonator includes a first plate electrode and a second plate electrode disposed on different dielectric layers and connected to each other by a via. The first plate electrode and the second plate electrode function as an inductor. When viewed from above in the stacking direction of the laminate, the first plate electrode and the second plate electrode at least partially overlap. The first plate electrode has a meander shape in which U-shaped bends and straight portions are alternately arranged. The second plate electrode is formed only from portions corresponding to the bends.

[0124] The embodiments disclosed herein should be considered to be illustrative in all respects and not restrictive. The scope of the present invention is defined by the claims, not by the description of the above embodiments, and is intended to include all modifications within the meaning and scope of the claims. [Explanation of symbols]

[0125] 10 communication device, 12 antenna, 20 high frequency front-end circuit, 22, 28 bandpass filter, 24 amplifier, 26 attenuator, 30 mixer, 32 local oscillator, 40 D / A converter, 50 RF circuit, 100, 200, 300 filter device, 110 main body, 111 upper surface, 112 lower surface, C1 to C7 capacitor, DM direction mark, GND ground terminal, L1 to L8 inductor, LY1 to LY9 dielectric layer, N1 to N2 connection node, PC1, PC2, PC11, PC12, PC13, PC14, PC15 capacitor electrode, PG1, PG2 Ground electrode, PL10A, PL10B, PL11B, PL12B, PL13B, PL20A, PL20B, PL21A, PL22A, PL23A, PL24A, PL25A, PL26A, PL30A, PL30B, PL31B, PL32B, PL100A, PL100B, PL120A, PL120B plate electrodes, RC1 to RC4 resonators, T1 input terminal, T2 output terminal.

Claims

1. a stack including a plurality of dielectric layers; input terminals and output terminals disposed on the outer surface of the laminate; an LC resonator including an inductor and a capacitor, transmitting a signal from the input terminal to the output terminal; the LC resonator includes a first plate electrode and a second plate electrode disposed on different dielectric layers and connected to each other by a via; the first plate electrode and the second plate electrode function as the inductor; When viewed from above in a stacking direction of the laminate, the first plate electrode and the second plate electrode at least partially overlap each other, The laminate has a rectangular shape having long sides and short sides when viewed in a plan view from the stacking direction, the first plate electrode includes a first elongated portion extending in a first direction along the long side direction of the laminated body, and a second elongated portion extending in a second direction along the short side direction of the laminated body, the second plate electrode includes a third elongated portion extending in the first direction and a fourth elongated portion extending in the second direction, A filter device, wherein the area of ​​the first extension portion is smaller than the area of ​​the third extension portion.

2. The filter device according to claim 1 , wherein the length of the first extension portion in the first direction is shorter than the length of the third extension portion in the first direction.

3. The filter device according to claim 1 , wherein the length of the first elongated member portion in the second direction is shorter than the length of the third elongated member portion in the second direction.

4. the first elongated portion includes a first portion and a second portion arranged opposite to each other in the second direction, the third elongated portion includes a third portion and a fourth portion arranged opposite to each other in the second direction, One end of the second elongated member portion is connected to the first portion, and the other end of the second elongated member portion is connected to the second portion, One end of the fourth elongated portion is connected to the third portion, and the other end of the fourth elongated portion is connected to the fourth portion, The filter device according to claim 3 , wherein a distance between the first portion and the third portion in the second direction is longer than a distance between the second portion and the fourth portion in the second direction.

5. The filter device according to claim 1 , wherein the area of ​​the second elongated member portion is the same as or approximately the same as the area of ​​the fourth elongated member portion.

6. The filter device according to claim 1 , wherein an area of ​​the second extension portion is smaller than an area of ​​the fourth extension portion.

7. The first elongated portion and the second elongated portion are connected at a first corner portion, and the third elongated portion and the fourth elongated portion are connected at a second corner portion, The filter device according to claim 1 , wherein an area of ​​the first corner portion is the same as or approximately the same as an area of ​​the second corner portion.

8. the LC resonator further includes a third plate electrode and a fourth plate electrode disposed on different dielectric layers and connected to each other by a via; the third plate electrode and the fourth plate electrode function as the inductor, the first plate electrode, the second plate electrode, the third plate electrode, and the fourth plate electrode are arranged in this order in the stacking direction of the stacked body; when viewed from above in a stacking direction of the laminate, the first plate electrode, the second plate electrode, the third plate electrode, and the fourth plate electrode at least partially overlap each other, the third plate electrode includes a fifth elongated portion extending in the first direction and a sixth elongated portion extending in the second direction, the fourth plate electrode includes a seventh elongated portion extending in the first direction and an eighth elongated portion extending in the second direction, The filter device according to claim 1 , wherein an area of ​​the fifth extension portion is larger than an area of ​​the seventh extension portion.

9. a rectangular laminate including a plurality of dielectric layers; input terminals and output terminals disposed on the outer surface of the laminate; an LC resonator including an inductor and a capacitor, transmitting a signal from the input terminal to the output terminal; the LC resonator includes a first plate electrode and a second plate electrode disposed on different dielectric layers and connected to each other by a via; the first plate electrode and the second plate electrode function as the inductor; When viewed from above in a stacking direction of the laminate, the first plate electrode and the second plate electrode at least partially overlap each other, the first plate electrode has a meander shape in which U-shaped bent portions and straight portions are alternately arranged, The second plate electrode is configured only with a portion corresponding to the bent portion.

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