FILTER DEVICE AND HIGH-FREQUENCY FRONT-END CIRCUIT INCLUDING THE SAME

Abstract

To improve loss characteristics of filter devices each including a plurality of LC resonators.SOLUTION: A filter device 100 includes a body 110, a ground terminal GND, and a plurality of resonators RC1 to RC4. The resonators are disposed in the body, and coupled to each other by electromagnetic field coupling. The resonators include a resonator RC1 coupled to an input terminal T1, a resonator RC2 coupled to an output terminal T2, and a resonator RC3 and a resonator RC4. The resonator RC2 is disposed to be adjacent to the resonator RC1 in a first direction. The resonator RC3 is disposed to be adjacent to the resonator RC1 in a second direction perpendicular to the first direction. The resonator RC4 is disposed to be adjacent to the resonator RC3 in the first direction. The resonators RC3 and RC4 partially share a path connected to the ground terminal GND.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present disclosure relates to a filter device and a high-frequency front-end circuit including the same, and more particularly to a technique for improving the characteristics of the filter device. [Background technology]

[0002] Multistage filter devices in which multiple LC resonators are arranged are known. For example, Japanese Patent Application Laid-Open Publication No. 2019-79865 (Patent Document 1) discloses a bandpass filter in which four LC resonators are arranged in one direction in a rectangular parallelepiped body. Japanese Patent Application Laid-Open Publication No. 2019-79865 (Patent Document 1) also discloses a configuration in which the via wiring on the ground side of the two middle resonators is shared. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2019-79865 Summary of the Invention [Problem to be solved by the invention]

[0004] The above-described filter devices are widely used in communication devices such as smartphones, mobile phones, and mobile phone base stations. In such communication devices, there is a demand for improved filter characteristics by further reducing insertion loss.

[0005] The present disclosure has been made to solve such problems, and its purpose is to improve the loss characteristics of a filter device including a plurality of LC resonators. [Means for solving the problem]

[0006] A filter device according to the present disclosure includes a main body, a ground terminal, and a plurality of resonators. The resonators are disposed in the main body and are electromagnetically coupled to one another. The resonators include a first resonator connected to an input terminal, a second resonator connected to an output terminal, a third resonator, and a fourth resonator. The second resonator is disposed adjacent to the first resonator in a first direction. The third resonator is disposed adjacent to the first resonator in a second direction orthogonal to the first direction. The fourth resonator is disposed adjacent to the third resonator in the first direction. A portion of a path connected to the ground terminal is shared between the third resonator and the fourth resonator. [Effects of the Invention]

[0007] The filter device according to the present disclosure includes four resonators, with a resonator (first resonator) connected to an input terminal and a resonator (second resonator) connected to an output terminal arranged adjacent to each other in a first direction, and two resonators (third resonator and fourth resonator) arranged adjacent to these resonators in a second direction. The third resonator and the fourth resonator are arranged adjacent to each other in the first direction, and a portion of the path connected to the ground terminal is shared. By arranging the four resonators as described above, it is possible to ensure a distance between adjacent resonators, thereby improving the Q value of the filter device. Furthermore, a portion of the middle resonators (third resonator and fourth resonator) is shared, which strengthens the magnetic coupling between these resonators, thereby further improving the Q value of the filter device. Therefore, the loss characteristics of the filter device according to the present disclosure can be improved. [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] 3 is an exploded perspective view showing an example of a layered structure of the filter device of FIG. 2. FIG. [Figure 4] FIG. 4 is a plan view of the filter device of FIG. 3. [Figure 5] FIG. 10 is a plan view of a filter device according to a comparative example. [Figure 6] 3A and 3B are diagrams for explaining the arrangement of resonators in the filter devices of the first embodiment and the comparative example. [Figure 7] 5A and 5B are diagrams for explaining the current direction due to differences in modes in the filter devices of the first embodiment and the comparative example. [Figure 8] 5 is a diagram illustrating the pass characteristics of the filter devices according to the first embodiment and the comparative example. FIG. [Figure 9] FIG. 9 is a partially enlarged view of the graph of insertion loss in FIG. 8. [Figure 10] FIG. 10 is a plan view of a filter device according to a first modified example. [Figure 11] FIG. 11 is an equivalent circuit diagram of the filter device of FIG. [Figure 12] FIG. 10 is a plan view of a filter device according to a second modification. [Figure 13] FIG. 11 is a plan view of a filter device according to a third modification. [Figure 14] FIG. 10 is an exploded perspective view showing an example of a laminated structure of a filter device according to a fourth modification. [Figure 15] FIG. 13 is an exploded perspective view showing an example of a laminated structure of a filter device according to a fifth modified example. [Figure 16] FIG. 13 is an exploded perspective view showing an example of a laminated structure of a filter device according to a sixth modification. [Figure 17] FIG. 13 is an exploded perspective view showing an example of a laminated structure of a filter device according to a seventh modification. [Figure 18] FIG. 13 is an exploded perspective view showing an example of a laminated structure of a filter device according to an eighth modification. [Figure 19] FIG. 13 is an exploded perspective view showing an example of a laminated structure of a filter device according to a ninth modification. [Figure 20] FIG. 10 is an equivalent circuit diagram of a filter device according to a second embodiment. [Figure 21] FIG. 21 is an exploded perspective view showing an example of a layered structure of the filter device of FIG. 20. [Figure 22]FIG. 20 is an exploded perspective view showing an example of a laminated structure of a filter device according to a tenth modification. [Figure 23] FIG. 20 is an exploded perspective view showing an example of a laminated structure of a filter device according to an eleventh modification. [Figure 24] FIG. 11 is an exploded perspective view showing an example of a laminated structure of a filter device according to a third embodiment. [Figure 25] FIG. 10 is an exploded perspective view showing an example of a laminated structure of a filter device according to a fourth embodiment. [Figure 26] FIG. 26 is a plan view of the filter device of FIG. 25. [Figure 27] FIG. 23 is an exploded perspective view showing an example of a laminated structure of a filter device according to a twelfth modification. [Figure 28] FIG. 28 is a plan view of the filter device of FIG. 27. [Figure 29] FIG. 23 is a plan view of a filter device according to a thirteenth modification. 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 the filter device of Embodiment 1 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, the detailed configuration of the filter device 100 according to the first embodiment will be described with reference to FIGS.

[0015] Fig. 2 is an equivalent circuit diagram of the filter device 100. Referring to Fig. 2, the filter device 100 includes an input terminal T1, an output terminal T2, and resonators RC1 to RC4. Each of the resonators RC1 to RC4 is an LC parallel resonator including an inductor and a capacitor. The resonator RC1 is connected to the input terminal T1, and the resonator RC2 is connected to the output terminal T2. The resonators RC3 and RC4 are connected between the resonators RC1 and RC2.

[0016] The resonator RC1 includes an inductor L1 and a capacitor C1 connected in parallel. One connection node N1A between the inductor L1 and the capacitor C1 is connected to the input terminal T1. The other connection node N1B between the inductor L1 and the capacitor C1 is connected to the ground terminal GND.

[0017] The resonator RC2 includes an inductor L2 and a capacitor C2 connected in parallel. One connection node N2A between the inductor L2 and the capacitor C2 is connected to the output terminal T2. The other connection node N2A between the inductor L2 and the capacitor C2 is connected to the output terminal T2. N2B is connected to the ground terminal GND.

[0018] The resonator RC3 includes inductors L3 and L34 connected in series and a capacitor C3 connected in parallel to the inductors L3 and L34. A connection node N3A between the inductor L3 and the capacitor C3 is connected to a connection node N1A (i.e., the input terminal T1) of the resonator RC1 via a capacitor C13. A connection node N3B between the inductor L34 and the capacitor C3 is connected to the ground terminal GND.

[0019] The resonator RC4 includes inductors L4 and L34 connected in series and a capacitor C4 connected in parallel to the inductors L4 and L34. A connection node N4A between the inductor L4 and the capacitor C4 is connected to the connection node N2A of the resonator RC2 (i.e., the output terminal T2) via the capacitor C24. A connection node N4B between the inductor L34 and the capacitor C4 is connected to the ground terminal GND. That is, the resonators RC4 and RC3 share the inductor L34.

[0020] The capacitor C12 is connected between the connection nodes N1A and N2A, and the capacitor C34 is connected between the connection nodes N3A and N4A.

[0021] The resonators are coupled to each other by electromagnetic coupling. In this way, the filter device 100 has a configuration in which four stages of resonators that are electromagnetically coupled to each other are arranged between the input terminal T1 and the output terminal T2. A high-frequency signal input to the input terminal T1 is transmitted by the electromagnetic coupling of the resonators RC1 to RC4 and output from the output terminal T2. At this time, only signals in a frequency band determined by the resonant frequency of each resonator are transmitted to the output terminal T2. In other words, the filter device 100 functions as a band-pass filter that passes signals in a desired frequency band by adjusting the resonant frequency of each resonator.

[0022] Fig. 3 is an exploded perspective view showing an example of the layered structure of the filter device 100. Fig. 4 is a plan view of the dielectric layer LY2 in the filter device 100 of Fig. 3.

[0023] 3 and 4, the filter device 100 includes a rectangular or substantially rectangular parallelepiped main body 110 formed by stacking a plurality of dielectric layers LY1 to LY6 along a predetermined direction. The direction in which the plurality of dielectric layers LY1 to LY6 are stacked in the main body 110 is referred to as the stacking direction. Each dielectric layer of the main body 110 is formed of ceramic, such as low-temperature co-fired ceramics (LTCC), or resin. Inside the main body 110, inductors and capacitors for forming an LC resonator are configured by a plurality of electrodes provided on each dielectric layer and a plurality of vias formed between the dielectric layers. In this specification, the term "via" refers to a conductor extending in the stacking direction and provided to connect electrodes provided on different dielectric layers. The vias are formed, for example, by conductive paste, plating, and / or metal pins.

[0024] In the following description, the stacking direction of 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 main body 110 is referred to as the "X-axis direction" (first direction), and the direction along the short side of main body 110 is referred to as the "Y-axis direction" (second 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 may be referred to as the lower side.

[0025] A direction mark DM for specifying the orientation of the filter device 100 is arranged on an upper surface 111 (dielectric layer LY1) of the main body 110. An input terminal T1, an output terminal T2, and a ground terminal GND, which are external terminals for connecting the filter device 100 to an external device, are arranged on a lower surface 112 (dielectric layer LY6) of the main body 110. Each of the input terminal T1, the output terminal T2, and the ground terminal GND is a flat electrode, and is an LGA (Land Grid Array) terminal regularly arranged on the lower surface 112 of the main body 110.

[0026] As described with reference to FIG. 2, the filter device 100 has four-stage LC parallel resonators RC1 to RC4. More specifically, the resonator RC1 includes vias V10 and V11, a capacitor electrode P1, and a plate electrode PC1. The resonator RC2 includes vias V20 and V21, a capacitor electrode P2, and a plate electrode PC2. The resonator RC3 includes vias V30 and V31, a capacitor electrode P3, and a plate electrode PC34. The resonator RC4 includes vias V40 and V31, a capacitor electrode P4, and a plate electrode PC34. The resonators RC3 and RC4 share the via V31 and the plate electrode PC34.

[0027] The capacitor electrode P1 of the resonator RC1 is provided on the dielectric layer LY4. When viewed from above in the normal direction (Z-axis direction) of the main body 110, a portion of the capacitor electrode P1 overlaps with a ground electrode PG provided on the dielectric layer LY5. The capacitor electrode P1 and the ground electrode PG form the capacitor C1 in FIG. 2. The capacitor electrode P1 is connected to a plate electrode PT1 provided on the dielectric layer LY5 by a via VT11. The plate electrode PT1 is connected to the input terminal T1 by a via VT10.

[0028] The plate electrode PC1 of the resonator RC1 has a substantially U-shape. As shown in FIG. 4, the plate electrode PC1 is arranged on the dielectric layer LY2 so that the opening of the U-shape faces the positive direction of the X-axis. One end of the plate electrode PC1 is connected to the capacitor electrode P1 through a via V10. The other end of the plate electrode PC1 is connected to the ground electrode PG on the dielectric layer LY5 through a via V11. The ground electrode PG is connected to the ground terminal GND by a plurality of vias VG. The plate electrode PC1 and the vias V10 and V11 form the inductor L1 in FIG. 2.

[0029] The capacitor electrode P2 of the resonator RC2 is provided on the dielectric layer LY4. When viewed from above in the normal direction of the main body 110, a portion of the capacitor electrode P2 overlaps with a ground electrode PG provided on the dielectric layer LY5. The capacitor electrode P2 and the ground electrode PG form the capacitor C2 in FIG. 2. The capacitor electrode P2 is connected to a plate electrode PT2 formed on the dielectric layer LY5 by a via VT21. The plate electrode PT2 is connected to the output terminal T2 by a via VT20.

[0030] The plate electrode PC2 of the resonator RC2 has a substantially U-shape, similar to the plate electrode PC1. As shown in FIG. 4, the plate electrode PC2 is arranged on the dielectric layer LY2 so that the opening of the U-shape faces the negative direction of the X-axis. In other words, the plate electrodes PC1 and PC2 are arranged adjacent to each other in the X-axis direction on the dielectric layer LY2 so that their openings face each other. One end of the plate electrode PC2 is connected to the capacitor electrode P2 through a via V20. The other end of the plate electrode PC2 is connected to the ground electrode PG on the dielectric layer LY5 through a via V21. The plate electrode PC2 and the vias V20 and V21 form the inductor L2 in FIG. 2.

[0031] The capacitor electrode P3 of the resonator RC3 is provided on the dielectric layer LY4. When viewed from above in the normal direction of the main body 110, a portion of the capacitor electrode P3 overlaps with a ground electrode PG provided on the dielectric layer LY5. The capacitor electrode P3 and the ground electrode PG form the capacitor C3 in FIG. 2. The capacitor electrode P2 is connected to a plate electrode PC34 provided on the dielectric layer LY2 by a via V30.

[0032] As shown in Fig. 4, the plate electrode PC34 has a substantially T-shape. The plate electrode PC34 includes a first portion PC341 configured as a strip electrode extending in the X-axis direction, and a second portion PC342 protruding in the negative direction of the Y-axis from the center of the first portion PC341 in the X-axis direction. The first portion PC341 of the plate electrode PC34 is spaced apart in the positive direction of the Y-axis from the plate electrodes PC1 and PC2. The second portion PC342 of the plate electrode PC34 protrudes from the first portion PC341 toward between the plate electrodes PC1 and PC2.

[0033] The via V30 is connected to the end (first end) of the first portion PC341 facing the negative X-axis. The via V31 is connected to the end of the second portion PC342 facing the negative Y-axis. The via V31 is connected to the ground electrode PG of the dielectric layer LY5. The via V30 and the portion from the connection position of the via V30 in the first portion PC341 to the second portion PC342 form the inductor L3 in FIG. 2. The second portion PC342 and the vias V31 and VG form the inductor L34 in FIG. 2.

[0034] A capacitor electrode P4 of the resonator RC4 is provided on the dielectric layer LY4. When viewed from above in the normal direction of the main body 110, a portion of the capacitor electrode P4 overlaps with a ground electrode PG provided on the dielectric layer LY5. The capacitor electrode P4 and the ground electrode PG form the capacitor C4 in FIG. 2. The capacitor electrode P4 is connected to the end (second end) of the first portion PC341 of the plate electrode PC34 in the positive direction of the X-axis by a via V40. The via V40 and the portion of the first portion PC341 from the connection position of the via V40 to the second portion PC342 form the inductor L4 in FIG. 2.

[0035] Capacitor electrodes P12, P13, P24, and P34 are provided on the dielectric layer LY3. When viewed in a plan view from the normal direction of the main body 110, the capacitor electrode P12 partially overlaps with the capacitor electrodes P1 and P2 of the dielectric layer LY4. The capacitor electrodes P1, P2, and P12 form the capacitor C12 in FIG. 2. When viewed in a plan view from the normal direction of the main body 110, the capacitor electrode P13 partially overlaps with the capacitor electrodes P1 and P3 of the dielectric layer LY4. The capacitor C13 in FIG. 2 is formed by the capacitor electrodes P1, P3, and P13.

[0036] When viewed from above in the normal direction of the main body 110, the capacitor electrode P24 partially overlaps with the capacitor electrodes P2 and P4 of the dielectric layer LY4. The capacitor electrodes P2, P4, and P24 form the capacitor C24 in FIG. 2. When viewed from above in the normal direction of the main body 110, the capacitor electrode P34 partially overlaps with the capacitor electrodes P3 and P4 of the dielectric layer LY4. The capacitor C34 in FIG. 2 is formed by the capacitor electrodes P3, P4, and P34.

[0037] The vias V11 to V31 on the ground side of each resonator are arranged side by side along the X-axis direction, and the common via V31 between the resonators RC3 and RC4 is arranged between the via V11 of the resonator RC1 and the via V21 of the resonator RC2. By adjusting the spacing between the vias, the strength of the magnetic coupling between the resonators can be adjusted.

[0038] In the plate electrode PC34, the inductances of the inductors L3 and L4 of the resonators RC3 can be adjusted by adjusting the length (i.e., LG1 in FIG. 4) and / or the width (W in FIG. 4) of the first portion PC341. Also, the inductance of the inductor L34 can be adjusted by adjusting the length LG2 of the second portion PC342 of the plate electrode PC34.

[0039] In the following description, vias such as vias V10, V20, V30, and V40 that are connected to the ground terminal GND through a capacitor in each resonator will be referred to as "first vias." Also, vias such as vias V11, V21, and V31 that are connected to the ground terminal GND without a capacitor in each resonator will be referred to as "second vias."

[0040] Multistage laminated LC filter devices such as those described above are widely used in communication devices such as smartphones, mobile phones, and mobile phone base stations. In such communication devices, there is a demand for filter devices with even lower insertion loss to improve communication quality and reduce power consumption.

[0041] In the filter device 100 of the first embodiment, the insertion loss is improved by devising an arrangement of the multiple resonators included in the filter device and adjusting the strength of the magnetic coupling between the resonators. Below, the characteristics of the filter device 100 of the first embodiment will be described in detail, while comparing it with the configurations of conventionally known filter devices.

[0042] 5 is a plan view of a dielectric layer on which the plate electrodes of the resonators are arranged in a filter device 100X of a comparative example. The filter device 100X has a configuration in which four resonators RC1X to RC4X are arranged in the X-axis direction.

[0043] 5, in the filter device 100X, a resonator RC1X is arranged on the short side of a main body 110X in the negative direction of the X axis, and a resonator RC2X is arranged on the short side of a main body 110X in the positive direction of the X axis. The resonators RC3X and RC4X are arranged between the resonators RC1X and RC2X.

[0044] The resonator RC1X includes a plate electrode PC1X and vias V10X and V11X. The plate electrode PC1X has a generally U-shape that is open in the positive direction of the Y-axis. In the plate electrode PC1X, the via V10X corresponding to the first via is connected to one end, and the via V11X corresponding to the second via is connected to the other end.

[0045] The resonator RC2X includes a plate electrode PC2X and vias V20X and V21X. Like the plate electrode PC1X, the plate electrode PC2X also has a generally U-shape that is open in the positive direction of the Y-axis. In the plate electrode PC2X, the via V20X corresponding to the first via is connected to one end, and the via V21X corresponding to the second via is connected to the other end.

[0046] The resonator RC3X includes a plate electrode PC34X and vias V30X and V31X. The resonator RC4X includes a plate electrode PC34X and vias V40X and V31X. That is, similar to the filter device 100 of the first embodiment, the plate electrodes of the resonators RC3X and RC4X are integrally configured, and share the ground-side via V31X.

[0047] The plate electrode PC34X has a substantially Y-shape and includes a first portion PC341X having a U-shape that opens in the negative direction of the Y axis, and a second portion PC342X that protrudes from the center of the first portion in the positive direction of the Y axis. V30X is connected to an end of the first portion PC341X on the resonator RC1X side, and V40X is connected to an end of the first portion PC341X on the resonator RC2X side. A shared via V31X is connected to the second portion PC342X.

[0048] 6 is a diagram illustrating the arrangement of resonators in the filter device 100 of the first embodiment and the filter device 100X of the comparative example. The left diagram (a) of FIG. 6 shows a schematic arrangement of the resonators in the filter device 100, and the right diagram (b) shows a schematic arrangement of the resonators in the filter device 100X of the comparative example.

[0049] 6, in the filter device 100 of the first embodiment, the input-side resonator RC1 and the output-side resonator RC2 are arranged adjacent to each other in the longitudinal direction (X-axis direction) of the main body 110, and the middle-stage resonators RC3 and RC4 are also arranged adjacent to each other in the X-axis direction. A set of the resonators RC1 and RC2 (first resonator group) and a set of the resonators RC3 and RC4 (second resonator group) are arranged adjacent to each other in the Y-axis direction. Meanwhile, in the filter device 100X of the comparative example, the resonators RC1X, RC3X, RC4X, and RC2X are arranged in this order along the positive X-axis direction of the main body 110X.

[0050] In the filter device 100X of the comparative example, four resonators are arranged one-dimensionally, making it difficult to ensure sufficient spacing between the conductor portions of adjacent resonators. In particular, each of the middle resonators RC3X and RC4X is sandwiched between two other resonators, so increasing the spacing between one resonator results in a narrower spacing between the other resonator. Therefore, the Q value cannot be increased with the resonator arrangement of the filter device 100X.

[0051] In contrast, in the filter device 100 of the first embodiment, two resonators are arranged in the X-axis direction, and two more resonators are arranged in the Y-axis direction. That is, in the filter device 100, four resonators are arranged two-dimensionally. Therefore, for example, by arranging the conductor of each resonator close to the outer periphery of the body 110, the distance between adjacent resonators becomes wider. Therefore, even if the total area of ​​the dielectric layer is the same, the Q value can be increased, and the loss of the filter device can be reduced.

[0052] Furthermore, in the filter device 100 of the first embodiment, the plate electrode PC34 of the middle resonators RC3 and RC4 has a more linear shape than the plate electrode PC34X of the filter device 100X of the comparative example. Generally, when a bent portion exists in a signal transmission path (i.e., a current path), current tends to concentrate at the bent portion. This increases loss in the portion where the current concentrates. In the plate electrode PC34X of the comparative example, two bent portions occur in the paths from the via V30X and the via V40X to the via V31X, respectively. In contrast, in the plate electrode PC34 of the first embodiment, only one bent portion occurs in the paths from the via V30 and the via V40 to the via V31, respectively. Therefore, also in this respect, the filter device 100 can reduce loss compared to the filter device 100X of the comparative example.

[0053] Furthermore, the shape of the plate electrode PC34 of the first embodiment has the advantage that it is less likely to cause variations in characteristics than the plate electrode PC34X of the comparative example. Fig. 7 is a diagram for explaining the current directions of each mode in the filter devices of the first embodiment and the comparative example. In Fig. 7, the comparative example is shown in the upper part, and the first embodiment is shown in the lower part.

[0054] 7, when a high-frequency signal is transmitted through two transmission paths, there are generally two modes: a first mode (even mode) in which currents flow in the same direction through each transmission path, and a second mode (odd mode) in which currents flow in opposite directions through each transmission path. For example, in the case of the resonators RC3 and RC4 of the filter device 100 described above, in the first mode, a current flows from the via V30 to the via V31 in the resonator RC3, and a current flows from the via V40 to the via V31 in the resonator RC4. On the other hand, in the second mode, a current flows from the via V30 to the via V31 in the resonator RC3, and a current flows from the via V31 to the via V40 in the resonator RC4. In the second mode, the current flowing into the via V31 and the current flowing out of the via V31 cancel each other out, resulting in a current flowing from the via V30 to the via V40. The same applies to the filter device 100X of the comparative example.

[0055] Here, consider a case where variations in the shapes of the plate electrodes PC34 and PC34X occur during the manufacturing process. In the comparative example, variations in the dimension and position of the U-shaped first portion of the plate electrode PC34X in the Y-axis direction are likely to occur. Even in this case, in the first mode, the path length of the current path including the vias in the resonator RC3X (via V30X + arrows AR10 and AR12 + via V31X) and the path length of the current path including the vias in the resonator RC4X (via V40X + arrows AR11 and AR12 + via V31X) hardly change. However, in the second mode, the current path is indicated by arrows AR20, AR22, and AR21. Therefore, if the dimension of the first portion in the Y-axis direction varies, the path length from the via V30X to the via V40X will vary. This may affect the filter characteristics.

[0056] On the other hand, in the filter device 100 of embodiment 1, the path from via V30 to via V40 is straight, so even if the dimensions of the plate electrode PC34 vary, the path lengths of the current path in the first mode (arrows AR15, AR17: arrows AR16, AR17) and the current path in the second mode (arrow AR25) hardly change.

[0057] As described above, the filter characteristics of the filter device 100 according to the first embodiment are less affected by variations in the shape of the plate electrodes than those of the filter device 100X according to the comparative example.

[0058] Fig. 8 is a diagram illustrating the pass characteristics of filter device 100 according to the first embodiment and filter device 100X according to the comparative example. In Fig. 8, the horizontal axis represents frequency, and the vertical axis represents insertion loss (LN10, LN11) and return loss (LN15, LN16) of the filter device. Solid lines LN10 and LN15 represent the results for filter device 100 according to the first embodiment, and dashed lines LN11 and LN16 represent the results for filter device 100X according to the comparative example. Fig. 9 is a partially enlarged view of the graph of insertion loss in Fig. 8.

[0059] 8 and 9, the filter device 100 of the first embodiment and the filter device 100X of the comparative example have almost the same return loss within the pass band (3.8 to 5.2 GHz) and attenuation characteristics in the non-pass band. However, as shown in Fig. 9, the peak insertion loss within the pass band is 1.52 dB for the filter device 100X of the comparative example and 1.37 dB for the filter device 100 of the first embodiment, which is an improvement of about 10%.

[0060] As described above, in a filter device including four resonators, the resonators are arranged two-dimensionally to ensure spacing between the conductors, and part of the middle resonators are shared to strengthen magnetic coupling, thereby improving the Q value and, as a result, reducing losses in the filter device.

[0061] [Variations 1 to 3] In Modifications 1 to 3, modes in which the shape of the plate electrodes constituting the resonators RC3 and RC4 on the dielectric layer LY2 of the main body 110 is different will be described.

[0062] (Variation 1) Fig. 10 is a plan view of a filter device 100A of Modification 1. Referring to Fig. 10, the filter device 100A has a configuration in which the plate electrode PC34 of the dielectric layer LY2 in the filter device 100 shown in Fig. 3 is replaced with a plate electrode PC34A. The plate electrode PC34A is configured as a strip electrode corresponding to the first portion PC341 of the plate electrode PC34. In other words, the plate electrode PC34A has a shape in which the second portion PC342 of the plate electrode PC34 has been removed.

[0063] The common via V31 connected to the ground electrode PG is connected between the via V30 connected to the first end and the via V40 connected to the second end of the plate electrode PC34A. In the filter device 100A, the inductance value of the inductor L3 in the resonator RC3 and the inductance value of the inductor L4 in the resonator RC4 can be adjusted by adjusting the distance LG11 between the via V30 and the via V31 and the distance LG12 between the via V40 and the via V31.

[0064] Fig. 11 is an equivalent circuit diagram of the filter device 100A of Fig. 10. As described above, in the filter device 100A, the position of the via V31 is shifted to the positive direction of the Y axis compared to the filter device 100. Accordingly, the capacitor electrode P34 on the dielectric layer LY3 of Fig. 3 is deleted. Therefore, in the filter device 100A, as shown in the equivalent circuit of Fig. 11, the capacitor C34 between the connection node N3A of the resonator RC3 and the connection node N4A of the resonator RC4 is deleted from the equivalent circuit of Fig. 3.

[0065] In this filter device 100A, the resonators RC3 and RC4 are arranged parallel to the arrangement direction of the resonators RC1 and RC2, and a part of the path leading to the ground terminal of the resonators RC3 and RC4 is shared, thereby improving the Q value of the filter device and, as a result, improving the loss characteristics of the filter device.

[0066] In the filter device 100 of the first embodiment, the shared via V31 is disposed between the via V11 of the resonator RC1 and the via V21 of the resonator RC2. Therefore, the magnetic coupling between the resonator RC1 and the resonators RC3 and RC4, and the magnetic coupling between the resonator RC2 and the resonators RC3 and RC4 are relatively strong, while the magnetic coupling between the resonator RC1 and the resonator RC4 is somewhat weaker due to the influence of the via V31.

[0067] On the other hand, in the configuration of the filter device 100A of the first modification, the position of the shared via V31 is shifted in the positive direction of the Y axis compared to the filter device 100 of the first embodiment. Therefore, the magnetic coupling between the resonator RC1 and the resonators RC3 and RC4, and the magnetic coupling between the resonator RC2 and the resonators RC3 and RC4 are weaker compared to the filter device 100 of the first embodiment. However, the via V11 of the resonator RC1 and the via V12 of the resonator RC2 are weaker than the via V11 of the resonator RC1 and the via V13 of the resonator RC2. V21 Since there is no common via V31 between resonator RC1 and resonator RC2 The magnetic coupling between the filter device 100 and the filter 100 is stronger than that in the filter device 100.

[0068] That is, by changing the position of the shared via V31 in the Y-axis direction, the strength of the magnetic coupling between the resonators can be adjusted.

[0069] (Variation 2) Fig. 12 is a plan view of a filter device 100B of Modification 2. Referring to Fig. 12, in the filter device 100B, the plate electrode PC34 of the dielectric layer LY2 in the filter device 100 is replaced with a plate electrode PC34B. The plate electrode PC34B is substantially E-shaped and includes a first portion PC341B configured as a strip electrode extending in the X-axis direction, and three protruding portions (a second portion PC342B, a third portion PC343B, and a fourth portion PC344B) protruding from the first portion PC341B in the negative direction of the Y-axis.

[0070] More specifically, the second portion PC342B protrudes from the center of the first portion PC341B along the extension direction (X-axis direction) toward between the plate electrodes PC1 and PC2. The third portion PC343B protrudes from the end (first end) of the first portion PC341B in the negative direction of the X-axis toward the plate electrode PC1. The fourth portion PC344B protrudes from the end (second end) of the first portion PC341B in the positive direction of the X-axis toward the plate electrode PC2.

[0071] The via V30 in the resonator RC3 is connected to the third portion PC343B. The via V40 in the resonator RC4 is connected to the fourth portion PC344B. The common via V31 connected to the ground electrode PG is disposed in the second portion PC342B.

[0072] With this configuration, the distance between the via V30 and the via V31 in the resonators RC3 and RC4 and the distance between the via V40 and the via V31 (corresponding to the arrow LG20) can be made longer than in the filter device 100. As a result, the inductor L3 in the resonator RC3, the inductor L4 in the resonator RC4, and the shared inductor L34 can be made longer. Inductance can be adjusted.

[0073] Furthermore, the distance (corresponding to the arrow LG21) between the first portion PC341B of the plate electrode PC34B and the plate electrodes PC1 and PC2 is increased, which makes it possible to weaken the magnetic coupling between the resonators RC1 and RC3 and between the resonators RC2 and RC4 compared to the filter device 100 of the first embodiment.

[0074] In this filter device 100B, the resonators RC3 and RC4 are arranged parallel to the arrangement direction of the resonators RC1 and RC2, and a part of the path leading to the ground terminal of the resonators RC3 and RC4 is shared, thereby improving the Q value of the filter device and, as a result, improving the loss characteristics of the filter device.

[0075] (Variation 3) Fig. 13 is a plan view of a filter device 100C of Modification 3. Referring to Fig. 13, in the filter device 100C, the plate electrode PC34 of the dielectric layer LY2 in the filter device 100 is replaced with a plate electrode PC34C. The plate electrode PC34C is substantially Y-shaped and includes a first portion PC341C configured as a strip electrode extending in the X-axis direction, and three protruding portions (a second portion PC342C, a fifth portion PC345C, and a sixth portion PC346C) protruding in the Y-axis direction from the first portion PC341C.

[0076] More specifically, the second portion PC342C protrudes from the center of the first portion PC341C along the extension direction (X-axis direction) toward between the plate electrodes PC1 and PC2. The fifth portion PC345C protrudes from the end (first end) of the first portion PC341C on the negative side of the X-axis in the opposite direction to the plate electrode PC1 (positive direction of the Y-axis). The sixth portion PC346C protrudes from the end (second end) of the first portion PC341C on the positive side of the X-axis in the opposite direction to the plate electrode PC2 (positive direction of the Y-axis).

[0077] The via V30 in the resonator RC3 is connected to the fifth portion PC345C. The via V40 in the resonator RC4 is connected to the sixth portion PC346C. The common via V31 connected to the ground electrode PG is disposed in the second portion PC342C.

[0078] With this configuration, the distance between the vias V30 and V31 in the resonators RC3 and RC4 and the distance between the vias V40 and V31 (corresponding to the arrow LG25) are longer than in the filter device 100. This allows adjustment of the inductors L3 in the resonator RC3, L4 in the resonator RC4, and the shared inductor L34.

[0079] Furthermore, the distance (corresponding to arrow LG26) between the first portion PC341C of the plate electrode PC34C and the plate electrodes PC1 and PC2 becomes narrower, which makes it possible to strengthen the magnetic coupling between the resonators RC1 and RC3 and between the resonators RC2 and RC4 compared to the filter device 100 of the first embodiment.

[0080] In this filter device 100C, the resonators RC3 and RC4 are arranged parallel to the arrangement direction of the resonators RC1 and RC2, and a part of the path leading to the ground terminal of the resonators RC3 and RC4 is shared, thereby improving the Q value of the filter device and, as a result, improving the loss characteristics of the filter device.

[0081] [Variations 4-6] In Modifications 4 to 6, aspects for adjusting the magnetic coupling between the resonators will be described.

[0082] (Variation 4) FIG. 14 is an exploded perspective view showing an example of a laminated structure of a filter device 100D according to Modification 4. In the filter device 100D, the plate electrodes of the resonators on the dielectric layer LY2 of the main body 110D are integrated into a plate electrode PCD. More specifically, the plate electrode PCD has a shape similar to that shown in FIG. 4 of Embodiment 1, in which the end of the plate electrode PC1 connected to the via V11 of the resonator RC1 and the end of the plate electrode PC2 connected to the via V21 of the resonator RC2 are connected to the second portion PC342 of the plate electrode PC34 constituting the resonators RC3 and RC4. That is, the via V11 of the resonator RC1, the via V21 of the resonator RC2, and the via V31 of the resonators RC3 and RC4 are integrated into a single via V31D. The via V31D connects the plate electrode PCD on the dielectric layer LY2 to the ground electrode PG on the dielectric layer LY5. The other configurations are similar to those of the filter device 100 shown in FIG. 3, and the description of the common elements will not be repeated.

[0083] In the filter device 100D, the four resonators RC1 to RC4 are connected by sharing the via V31D. This strengthens the magnetic coupling between the resonators compared to the filter device 100 of the first embodiment, further improving the Q value of the filter device. This can improve the loss characteristics of the filter device.

[0084] (Variation 5) Fig. 15 is an exploded perspective view showing an example of the layered structure of a filter device 100E of Modification 5. Schematically, the filter device 100E has an intermediate configuration between the filter device 100 of the first embodiment shown in Fig. 3 and the filter device 100D of Modification 4 shown in Fig. 14, in which vias leading to the ground terminal GND in each resonator are integrated in a layer below the plate electrode provided on the dielectric layer.

[0085] This will be described in more detail with reference to Fig. 15. In Fig. 15, elements similar to those in the filter device 100 of Fig. 3 are given the same reference numerals.

[0086] The filter device 100E includes a rectangular or approximately rectangular parallelepiped main body 110E formed by stacking a plurality of dielectric layers LY11 to LY17 along a predetermined direction. A direction mark DM for identifying the orientation of the filter device 100E is arranged on an upper surface 111 (dielectric layer LY11) of the main body 110E. An input terminal T1, an output terminal T2, and a ground terminal GND, which are external terminals for connecting the filter device 100E to an external device, are arranged on a lower surface 112 (dielectric layer LY17) of the main body 110E.

[0087] Similar to the filter device 100 of the first embodiment, the filter device 100E has four-stage LC parallel resonators RC1 to RC4. The resonator RC1 includes vias V10 and V11E, a capacitor electrode P1, and a plate electrode PC1. The resonator RC2 includes vias V20 and V21E, a capacitor electrode P2, and a plate electrode PC2. The resonator RC3 includes vias V30 and V31E, a capacitor electrode P3, and a plate electrode PC34. The resonator RC4 includes vias V40 and V31E, a capacitor electrode P4, and a plate electrode PC34. The resonators RC3 and RC4 share the via V31E and the plate electrode PC34.

[0088] As in the filter device 100, the dielectric layer LY12 is provided with a plate electrode PC1 included in the resonator RC1, a plate electrode PC2 included in the resonator RC2, and a plate electrode PC34 shared by the resonators RC3 and RC4.

[0089] A plate electrode PA1 configured as a strip electrode extending in the X-axis direction is disposed on the dielectric layer LY13. The via V11E of the resonator RC1 is connected to the plate electrode PC1 and the plate electrode PA1. The via V11E of the resonator RC2 V21E is connected to the plate electrode PC2 and the plate electrode PA1. Also, the via V31E shared by the resonators RC3 and RC4 is connected from the plate electrode PC34 through the plate electrode PA1 to the ground electrode PG provided on the dielectric layer LY16. In other words, the via V11E of the resonator RC1 and the via V21E of the resonator RC2 are shared with the via V31E of the resonators RC3 and RC4 by the plate electrode PA1.

[0090] The configurations of the dielectric layers LY14 to LY17 correspond to the configurations of the dielectric layers LY3 to LY6 of the filter device 100 in Fig. 3, except for the shared via V31E, so detailed description of the dielectric layers LY14 to LY17 will not be repeated.

[0091] As described above, in the filter device 100E of the fifth modification, a part of the path from the plate electrode of the dielectric layer LY12 to the ground electrode PG in the resonators RC1 and RC2 is shared by the via V31E of the resonators RC3 and RC4. This makes it possible to strengthen the magnetic coupling between the resonators more than in the filter device 100 of the first embodiment. Therefore, compared with the filter device 100 of the first embodiment, the Q value of the filter device is further improved, and the loss characteristics of the filter device are improved.

[0092] The magnetic coupling between the resonators in the filter device 100E is weaker than the magnetic coupling between the resonators in the filter device 100D of Modification 4. That is, by adjusting the position (dielectric layer) where the ground-side vias of the resonators are shared, the magnetic coupling between the resonators can be finely adjusted.

[0093] (Variation 6) Fig. 16 is an exploded perspective view showing an example of a layered structure of a filter device 100F of Modification 6. The filter device 100F has a configuration in which the second portion PC342 of the plate electrode PC34 in the filter device 100 of the first embodiment shown in Fig. 3 is arranged in a layer different from the first portion PC341.

[0094] This will be described in more detail with reference to Fig. 16. On the dielectric layer LY12 of the main body 110F, the plate electrode PC34F integrated with the resonators RC3 and RC4 is configured as a strip electrode extending in the X-axis direction, similar to the filter device 100A of Fig. 10. Also, on the dielectric layer LY13, a plate electrode PA2 configured as a strip electrode extending in the Y-axis direction is arranged.

[0095] The ground-side via V31F1 shared by the resonators RC3 and RC4 is connected to the center of the plate electrode PC34F and one end of the plate electrode PA2. The other end of the plate electrode PA2 is connected to the ground electrode PG on the dielectric layer LY16 through the via V31F2. That is, in the filter device 100F, the ground-side via shared by the resonators RC3 and RC4 is offset at a position (dielectric layer LY13) different from the position where the plate electrode PC34F is located (dielectric layer LY12).

[0096] The via V31F2 extending from the dielectric layer LY13 to the dielectric layer LY16 is the same as the via V31 in FIG. 3, and is connected to the via V11 of the resonator RC1 and the via V12 of the resonator RC2. V21 Here, the via V31F2 of the filter device 100F is shorter than the via V31 of the filter device 100 of the first embodiment, and the area where they face each other is smaller than in the filter device 100. Therefore, the magnetic coupling between the resonators RC1 and RC2 and the resonators RC3 and RC4 is weaker than in the filter device 100.

[0097] On the other hand, since the length of the via V31F2 is shorter than the lengths of the vias V11 and V21, there is a region where the vias V11 and V21 directly face each other, which results in stronger magnetic coupling between the resonators RC1 and RC2 than in the filter device 100.

[0098] In this way, in the filter device 100F of the sixth modification, the magnetic coupling between the resonators can be adjusted by offsetting the common ground-side vias of the middle resonators RC3 and RC4 at the midpoint in the extension direction.

[0099] [Variations 7-9] In Modifications 7 to 9, configurations will be described that achieve miniaturization and improved characteristics by increasing the input impedance of the resonator RC1 connected to the input terminal T1 and the output impedance of the resonator RC2 connected to the output terminal T2.

[0100] (Variation 7) Fig. 17 is an exploded perspective view showing an example of the layered structure of a filter device 100G of Modification 7. The filter device 100G has a configuration in which the plate electrode PC1 of the input-side resonator RC1 and the plate electrode PC2 of the output-side resonator RC2 in the filter device 100 of Embodiment 1 are configured as a compound-wound coil. In Fig. 17, the dielectric layers LY14 to LY17 correspond to the dielectric layers LY3 to LY6 of the filter device 100 of Fig. 3, respectively, and therefore detailed description of the dielectric layers LY14 to LY17 will not be repeated.

[0101] 17, a plate electrode PC1G2 constituting a part of resonator RC1, a plate electrode PC2G2 constituting a part of resonator RC2, and a plate electrode PC34 constituting a part of resonators RC3 and RC4 are arranged on a dielectric layer LY12 of a main body 110G. Further, a plate electrode PC1G1 and a plate electrode PC2G1 are provided on a dielectric layer LY13. Each of the plate electrodes PC1G1, PC1G2, PC2G1, and PC2G2 is configured in a loop shape with a winding axis in the stacking direction (Z-axis direction).

[0102] One end of the plate electrode PC1G2 is connected to the ground electrode PG provided on the dielectric layer LY16 through a via V11. The other end of the plate electrode PC1G2 is connected to one end of the plate electrode PC1G1 on the dielectric layer LY13 through a via V10G2. The other end of the plate electrode PC1G1 is connected to the capacitor electrode P1 on the dielectric layer LY15 through a via V10G1. The plate electrodes PC1G1 and PC1G2 and the via V10G2 form a compound-turn coil whose winding direction is in the Z-axis direction. This configuration can increase the inductance of the inductor L1 formed by the vias V10G1, V10G2, and V11 and the plate electrodes PC1G1 and PC1G2, thereby increasing the impedance of the resonator RC1 (i.e., the input impedance of the filter device 100F).

[0103] Furthermore, one end of the plate electrode PC2G2 is connected to the ground electrode PG provided on the dielectric layer LY16 through a via V21. The other end of the plate electrode PC2G2 is connected to one end of the plate electrode PC2G1 on the dielectric layer LY13 through a via V20G2. The other end of the plate electrode PC2G1 is connected to the capacitor electrode P2 on the dielectric layer LY15 through a via V20G1. The plate electrodes PC2G1, PC2G2 and the via V20G2 form a compound-turn coil whose winding direction is in the Z-axis direction. This configuration can increase the inductance of the inductor L2 formed by the vias V20G1, V20G2, V21 and the plate electrodes PC2G1, PC2G2, and therefore the impedance of the resonator RC2 (i.e., the output impedance of the filter device 100F) can be increased.

[0104] By increasing the input and output impedance, the degree of coupling with external devices connected to the filter increases, reducing the Q value for the external devices. This reduces reflection loss within the passband and enables a wider bandwidth.

[0105] (Variation 8) In Variation 7, a configuration was described in which the input / output impedance is increased by configuring a compound-wound coil with the winding axis in the stacking direction (Z-axis direction). In Variation 8, a configuration was described in which the input / output impedance is increased by configuring a compound-wound coil with the winding axis in a direction perpendicular to the stacking direction.

[0106] Fig. 18 is an exploded perspective view showing an example of the laminated structure of a filter device 100H of Modification 8. Plate electrodes PC11 and PC13 constituting a part of resonator RC1, plate electrodes PC21 and PC23 constituting a part of resonator RC2, and plate electrode PC34 constituting a part of resonators RC3 and RC4 are arranged on a dielectric layer LY12 of a main body 110H. Furthermore, plate electrodes PC12 and PC22 are provided on the dielectric layer LY13. Note that descriptions of elements of the filter device 100H of Fig. 18 that overlap with those of Fig. 17 will not be repeated.

[0107] The plate electrodes PC11, PC13, PC21, and PC23 are configured as strip electrodes extending in the X-axis direction. The plate electrodes PC11 and PC13 are arranged parallel to an area in the negative direction of the X-axis relative to the second portion PC342 of the plate electrode PC34. The plate electrodes PC21 and PC23 are arranged parallel to an area in the positive direction of the X-axis relative to the second portion PC342.

[0108] The end of the plate electrode PC11 in the negative direction along the X axis is connected to the capacitor electrode P1 on the dielectric layer LY15 through a via V10. The end of the plate electrode PC11 in the positive direction along the X axis is connected to one end of a plate electrode PC12 provided on the dielectric layer LY13 through a via VC11. The other end of the plate electrode PC12 is connected to the plate electrode PC13 The plate electrode is connected to the end of the negative X-axis direction. PC13 The end of each of the electrodes PC11 to PC13 in the positive direction along the X-axis is connected to the ground electrode PG on the dielectric layer LY16 through a via V11. The plate electrodes PC11 to PC13 and the vias VC11 and VC12 form a compound-wound coil with the winding direction along the Y-axis. This configuration increases the inductance of the inductor L1 formed by the vias V10, V11, VC11, and VC12 and the plate electrodes PC11 to PC13, thereby increasing the input impedance of the filter device 100H.

[0109] The positive end of the plate electrode PC21 in the X-axis direction is connected to the capacitor electrode P2 on the dielectric layer LY15 through a via V20. The negative end of the plate electrode PC21 in the X-axis direction is connected to one end of a plate electrode PC22 provided on the dielectric layer LY13 through a via VC21. The other end of the plate electrode PC22 is connected to the capacitor electrode P2 on the dielectric layer LY15 through a via VC22. PC23 The plate electrode is connected to the positive end of the X-axis. PC23The end of each of the electrodes PC20, PC21, VC21, and VC22 facing in the negative direction along the X-axis is connected to the ground electrode PG on the dielectric layer LY16 through a via V21. The plate electrodes PC21 to PC23 and the vias VC21 and VC22 form a compound-wound coil with the winding direction in the Y-axis direction. This configuration increases the inductance of the inductor L2 formed by the vias V20, V21, VC21, and VC22 and the plate electrodes PC21 to PC23, thereby increasing the output impedance of the filter device 100H.

[0110] In addition, in FIG. 18, an example has been described in which the compound-wound coils in the resonators RC1 and RC2 have their winding axes in the Y-axis direction, but the direction of the winding axes may be any direction as long as it is perpendicular to the Z-axis direction, and for example, the coils may have their winding axes in the X-axis direction.

[0111] The configuration of the filter device 100G of the eighth modification also increases the input and output impedance, thereby achieving a lower resonance frequency, a smaller filter device, and a wider passband and reduced reflection loss within the passband.

[0112] (Variation 9) Fig. 19 is an exploded perspective view showing an example of the laminated structure of a filter device 100I of Modification 9. The filter device 100I has a configuration that roughly combines the configuration of the filter device 100D of Modification 4 shown in Fig. 14 and the configuration of the filter device 100G of Modification 7 shown in Fig. 17. In other words, in the dielectric layer LY12 of the main body 110I, the plate electrodes that form part of each resonator are configured as one plate electrode PCI, similar to the filter device 100D, and further, the resonators RC1 and RC2 form a compound-wound coil with the lamination direction as the winding axis.

[0113] 19, the plate electrode PCI on the dielectric layer LY12 of the main body 110I is connected to the ground electrode PG on the dielectric layer LY16 by a common via V31I. In the plate electrode PCI, an end of a loop-shaped portion corresponding to the plate electrode PC1 in FIG. 3 is connected to one end of a loop-shaped plate electrode PC11 provided on the dielectric layer LY13 via a via V10I2. The other end of the plate electrode PC11 is connected to the capacitor electrode P1 on the dielectric layer LY15 via a via V10I1. The plate electrodes PCI, PC11, and the via V10I2 form a compound-wound coil with the winding axis in the stacking direction.

[0114] 3 is connected to one end of a loop-shaped plate electrode PC21 provided on the dielectric layer LY13 through a via V20I2. The other end of the plate electrode PC21 is connected to the capacitor electrode P2 on the dielectric layer LY15 through a via V20I1. The plate electrodes PCI, PC21, and the via V20I2 form a compound-wound coil with the winding axis in the stacking direction.

[0115] The description of elements of filter device 100I that overlap with those of filter device 100G in FIG. 17 will not be repeated.

[0116] As in the filter device 100I, by sharing the ground-side vias of each resonator, the magnetic coupling between the resonators is strengthened, thereby improving the loss characteristics of the filter device. Also, by configuring the input-side resonator and the output-side resonator with compound-wound coils to increase the input / output impedance, it is possible to lower the resonant frequency, reduce the size of the filter device, and reduce reflection loss within the passband and widen the band.

[0117] [Embodiment 2] In the first embodiment, a configuration in which the filter device includes four resonators has been described, whereas in the second embodiment, a configuration in which the filter device includes six resonators will be described.

[0118] FIG. 20 is an equivalent circuit diagram of a filter device 100J according to the second embodiment. Referring to FIG. 20, the filter device 100J includes an input terminal T1, an output terminal T2, and resonators RC1 to RC6. Each of the resonators RC1 to RC6 is an LC parallel resonator including an inductor and a capacitor. The resonator RC1 is connected to the input terminal T1, and the resonator RC2 is connected to the output terminal T2. The resonators RC3 to RC6 are connected between the resonator RC1 and the resonator RC2. The filter device 100J is generally configured such that resonators RC5 and RC6 are further connected between the resonator RC3 and the resonator RC4 in the filter device 100 described in FIG. 2.

[0119] The resonator RC1 includes an inductor L1 and a capacitor C1 connected in parallel. One connection node N1A between the inductor L1 and the capacitor C1 is connected to the input terminal T1. The other connection node N1B between the inductor L1 and the capacitor C1 is connected to the ground terminal GND.

[0120] The resonator RC2 includes an inductor L2 and a capacitor C2 connected in parallel. One connection node N2A between the inductor L2 and the capacitor C2 is connected to the output terminal T2. The other connection node N1B between the inductor L2 and the capacitor C2 is connected to the ground terminal GND.

[0121] The resonator RC3 includes inductors L3 and L36 connected in series and a capacitor C3 connected in parallel to the inductors L3 and L36. A connection node N3A between the inductor L3 and the capacitor C3 is connected to a connection node N1A (i.e., the input terminal T1) of the resonator RC1 via a capacitor C13. A connection node N3B between the inductor L36 and the capacitor C3 is connected to the ground terminal GND.

[0122] The resonator RC4 includes inductors L4 and L36 connected in series and a capacitor C4 connected in parallel to the inductors L4 and L36. A connection node N4A between the inductor L4 and the capacitor C4 is connected to a connection node N2A (i.e., the output terminal T2) of the resonator RC2 via a capacitor C24. A connection node N4B between the inductor L36 and the capacitor C4 is connected to the ground terminal GND.

[0123] The resonator RC5 includes inductors L5 and L36 connected in series and a capacitor C5 connected in parallel to the inductors L5 and L36. A connection node N5A between the inductor L5 and the capacitor C5 is connected to a connection node N3A of the resonator RC3 via a capacitor C35. A connection node N5B between the inductor L36 and the capacitor C5 is connected to the ground terminal GND.

[0124] The resonator RC6 includes inductors L6 and L36 connected in series and a capacitor C6 connected in parallel to the inductors L6 and L36. A connection node N6A between the inductor L6 and the capacitor C6 is connected to a connection node N4A of the resonator RC4 via a capacitor C46. A connection node N6B between the inductor L36 and the capacitor C6 is connected to the ground terminal GND. As described above, the resonators RC3 to RC6 share the inductor L36.

[0125] Capacitor C12 is connected between connection nodes N1A and N2A (i.e., between input terminal T1 and output terminal T2). Capacitor C34 is connected between connection nodes N3A and N4A. Capacitor C56 is connected between connection nodes N5A and N6A.

[0126] The resonators are coupled to each other by electromagnetic coupling. In this way, the filter device 100J has a configuration in which four stages of resonators that are electromagnetically coupled to each other are arranged between the input terminal T1 and the output terminal T2. A high-frequency signal input to the input terminal T1 is transmitted by the electromagnetic coupling of the resonators RC1 to RC6 and output from the output terminal T2. At this time, only signals in a frequency band determined by the resonant frequency of each resonator are transmitted to the output terminal T2. In other words, the filter device 100J functions as a band-pass filter that passes signals in a desired frequency band by adjusting the resonant frequency of each resonator.

[0127] Fig. 21 is an exploded perspective view showing an example of the layered structure of filter device 100J of Fig. 20. In Fig. 21, the same reference numerals are used for elements that are the same as those in filter device 100 of the first embodiment shown in Fig. 3. Description of elements that overlap with those in Fig. 3 will not be repeated.

[0128] 21, the filter device 100J includes a rectangular or substantially rectangular parallelepiped main body 110J formed by stacking a plurality of dielectric layers LY21 to LY26 along a predetermined direction. Each dielectric layer of the main body 110J is made of ceramic such as LTCC or resin.

[0129] A direction mark DM for identifying the orientation of the filter device 100J is arranged on an upper surface 111 (dielectric layer LY21) of the main body 110J. An input terminal T1, an output terminal T2, and a plurality of ground terminals GND, which are external terminals for connecting the filter device 100J to external devices, are arranged on a lower surface 112 (dielectric layer LY26) of the main body 110J. Each of the plurality of ground terminals GND is connected to a ground electrode PG provided on the dielectric layer LY25 by a corresponding via VG.

[0130] 20, the filter device 100J has six-stage LC parallel resonators RC1 to RC6. More specifically, the resonator RC1 includes vias V10 and V11, a capacitor electrode P1, and a plate electrode PC1. The resonator RC2 includes vias V20 and V21, a capacitor electrode P2, and a plate electrode PC2. The resonators RC3 to RC6 include vias V30, V40, V50, and V60, a shared plate electrode PCJ, and a via V31J.

[0131] The common plate electrode PCJ is provided on the dielectric layer LY22 and includes a first portion PCJ1 and a third portion PCJ3 configured as strip electrodes extending in the X-axis direction, and a second portion PCJ2 connecting the first portion PCJ1 and the third portion PCJ3. The second portion PCJ2 extends in the Y-axis direction from the center of the first portion PCJ1 and the third portion PCJ3.

[0132] The first portion PCJ1 of the plate electrode PCJ is disposed adjacent to, in the positive direction of the Y-axis, the plate electrodes PC1 and PC2 that form part of the resonators RC1 and RC2, respectively. The third portion PCJ3 of the plate electrode PCJ is disposed adjacent to, in the positive direction of the Y-axis, the first portion PCJ1. That is, the first portion PCJ1 is disposed between the third portion PCJ3 and the plate electrodes PC1 and PC2.

[0133] The second part PCJ2 is connected to the dielectric layer via via V31J. LY25 The via V31J functions as a common ground-side via for the resonators RC3 to RC6.

[0134] A via V30 is connected to the end of the first portion PCJ1 facing the negative X-axis direction. The first portion PCJ1 and the vias V30 and V31J form a resonator RC3. A via V40 is connected to the end of the first portion PCJ1 facing the positive X-axis direction. The first portion PCJ1 and the vias V40 and V31J form a resonator RC4.

[0135] A via V50 is connected to the end of the third portion PCJ3 in the negative direction of the X axis. The via V50 is connected to a capacitor electrode P5 provided on the dielectric layer LY24. When viewed from above in the normal direction of the main body 110J, a portion of the capacitor electrode P5 overlaps with the ground electrode PG. The capacitor electrode P5 and the ground electrode PG form the capacitor C5 in FIG. 20. When viewed from above in the normal direction of the main body 110J, a portion of the capacitor electrode P5 also overlaps with the plate electrode P35 provided on the dielectric layer LY23. The plate electrode P35 is connected to a via V30. The capacitor electrode P5 and the plate electrode P35 form the capacitor C35 in FIG. 20.

[0136] A via V60 is connected to the end of the third portion PCJ3 in the positive direction of the X-axis. The via V60 is connected to a capacitor electrode P6 provided on the dielectric layer LY24. When viewed from above in the normal direction of the main body 110J, a portion of the capacitor electrode P6 overlaps with the ground electrode PG. The capacitor electrode P6 and the ground electrode PG form the capacitor C6 in FIG. 20. When viewed from above in the normal direction of the main body 110J, a portion of the capacitor electrode P6 also overlaps with a plate electrode P46 provided on the dielectric layer LY23. The plate electrode P46 is connected to the via V40. The capacitor electrode P6 and the plate electrode P46 form the capacitor C46 in FIG. 20.

[0137] In addition, when viewed from above in the normal direction of the main body 110J, a portion of the capacitor electrode P5 and a portion of the capacitor electrode P6 overlap with the plate electrode P56 provided on the dielectric layer LY23. The capacitor electrodes P5, P6 and the plate electrode P56 form the capacitor C56 in FIG.

[0138] It is known that increasing the number of resonator stages improves attenuation characteristics outside the passband and makes it easier to design a wideband. However, if the number of resonator stages is increased while keeping the product size the same, the Q value decreases due to the narrower spacing between the resonators inside the main body, which can result in increased loss and degraded passband characteristics.

[0139] As in the filter device 100J of the second embodiment, by arranging a resonator group, in which two resonators are arranged in a direction along the long side of the main body (X-axis direction), next to each other in a direction along the short side of the main body (Y-axis direction), it is possible to maximize the spacing between each resonator group within the main body. Furthermore, by sharing the ground-side vias in some of the resonators, the magnetic coupling between the resonators is strengthened. This configuration improves the Q value compared to a filter device in which multiple resonators are arranged next to each other in one direction. Therefore, the loss characteristics of the filter device are improved.

[0140] [Variations 10 and 11] In Modifications 10 and 11, a filter device including six stages of resonators will be described, in which the magnetic coupling between the resonators is adjusted by changing the configuration of the plate electrodes that form part of the resonators RC3 to RC6.

[0141] (Variation 10) Fig. 22 is an exploded perspective view showing an example of a layered structure of a filter device 100K of Modification 10. The filter device 100K is roughly configured such that the plate electrode PCJ in the filter device 100J of Embodiment 2 shown in Fig. 21 is separated into a plate electrode for resonators RC3 and RC4 and a plate electrode for resonators RC5 and RC6, and the plate electrodes for resonators RC5 and RC6 are arranged in different positions (dielectric layers).

[0142] This will be described in more detail with reference to Fig. 22. The filter device 100K includes a rectangular or approximately rectangular parallelepiped main body 110K formed by stacking a plurality of dielectric layers LY31 to LY37 along a predetermined direction. Note that the dielectric layers LY31, LY34 to LY37 in Fig. 22 correspond to the dielectric layers LY21, LY23 to LY26 in Fig. 21, respectively. In Fig. 22, descriptions of elements that overlap with those in Fig. 21 will not be repeated.

[0143] The dielectric layer LY32 of the main body 110K is provided with a plate electrode PC1 that forms part of the resonator RC1, a plate electrode PC2 that forms part of the resonator RC2, and a plate electrode PC34K that is shared by the resonators RC3 and RC4. The dielectric layer LY33 is provided with a plate electrode PC56K that is shared by the resonators RC5 and RC6.

[0144] The plate electrode PC34K includes a first portion extending in the X-axis direction and a second portion protruding from the first portion in the positive direction of the Y-axis. One end of the first portion of the plate electrode PC34K is connected to the via V30 of the resonator RC3, and the other end is connected to the via V40 of the resonator RC4.

[0145] The plate electrode PC56K includes a first portion extending in the X-axis direction and a second portion protruding from the first portion in the negative direction of the Y-axis. One end of the first portion of the plate electrode PC56K is connected to a via V50 of the resonator RC5. The other end of the first portion of the plate electrode PC56K is connected to a via V60 of the resonator RC6, but in FIG. 22, the via V60 is hidden behind other elements.

[0146] When the main body 110K is viewed in a plane from the normal direction, a portion of the second portion of the plate electrode PC34K overlaps a portion of the second portion of the plate electrode PC56K, and the plate electrodes PC34K and PC56K are connected to the ground electrode PG of the dielectric layer LY36 by a via V31K that passes through this overlapping portion.

[0147] In the filter device 100K, the plate electrode PC34K constituting a part of the resonators RC3 and RC4 and the plate electrode PC56K constituting a part of the resonators RC5 and RC6 are provided on different dielectric layers, so the length of the shared portion of the via V31K is shorter than that of the filter device 100J of the second embodiment. Furthermore, the lengths of the vias V50 and V60 in the resonators RC5 and RC6 are shorter than the lengths of the vias V30 and V40 in the resonators RC3 and RC4, so the opposing regions of the vias are shorter. Therefore, in the filter device 100K, the magnetic coupling between the resonators RC3 and RC4 and the resonators RC5 and RC6 is weaker than in the filter device 100J.

[0148] As in the filter device 100K of variant 10, the magnetic coupling between the resonators can be adjusted by arranging the plate electrodes used in the resonators RC3 and RC4 and the plate electrodes used in the resonators RC5 and RC6 on different dielectric layers.

[0149] (Variation 11) Fig. 23 is an exploded perspective view showing an example of the layered structure of a filter device 100L of Modification 11. Filter device 100L is generally configured such that second portion PCJ2 of the plate electrode PCJ in filter device 100J of Embodiment 2 shown in Fig. 21 is provided on a different dielectric layer. Note that in Fig. 23, descriptions of elements that overlap with those in Figs. 21 and 22 will not be repeated.

[0150] 23, in addition to the plate electrode PC1 constituting a part of the resonator RC1 and the plate electrode PC2 constituting a part of the resonator RC2, the dielectric layer LY32 of the main body 110L is also provided with a plate electrode PC34L constituting a part of the resonators RC3 and RC4 and a plate electrode PC56L constituting a part of the resonators RC5 and RC6. The plate electrode PC34L corresponds to the first portion PCJ1 of the plate electrode PCJ in the filter device 100J, and the plate electrode PC56L corresponds to the third portion PCJ3 of the plate electrode PCJ in the filter device 100J.

[0151] A via V31L is connected to the center of the plate electrode PC34L. A via V51L is connected to the center of the plate electrode PC56L. Each of the vias V31L and V51L is connected to a plate electrode PA3 provided on the dielectric layer LY33. The plate electrode PA3 is configured as a strip electrode extending in the Y-axis direction on the dielectric layer LY33. A via V35L is connected to the center of the plate electrode PA3. The plate electrode PA3 is connected to the ground electrode PG on the dielectric layer LY36 through the via V35L.

[0152] This configuration allows adjustment of the common area of ​​the ground-side vias between the resonators RC3 and RC4 and the resonators RC5 and RC6. In the filter device 100L, the common area of ​​the ground-side vias between the resonators RC3 and RC4 and the resonators RC5 and RC6 is smaller than in the filter device 100J of Fig. 21. Therefore, the magnetic coupling between the resonators RC3 and RC4 and the resonators RC5 and RC6 in the filter device 100L is weaker than the magnetic coupling between the resonators RC3 and RC4 and the resonators RC5 and RC6 in the filter device 100J.

[0153] As in the filter device 100L of variant example 11, the magnetic coupling between the resonators RC3, RC4 and the resonators RC5, RC6 can be adjusted by connecting the plate electrodes used in the resonators RC3, RC4 and the plate electrodes used in the resonators RC5, RC6 with different dielectric layers.

[0154] [Embodiment 3] In the third embodiment, a configuration will be described in which the insertion loss of the filter device is reduced by multi-layering each of the plate electrodes that constitute a part of the inductor in each resonator.

[0155] Fig. 24 is an exploded perspective view showing an example of a layered structure of filter device 100M according to embodiment 3. Referring to Fig. 24, filter device 100M is generally configured such that the configuration of dielectric layer LY2 in filter device 100 according to embodiment 1 described in Fig. 3 is provided on a plurality of dielectric layers. Note that, in filter device 100M in Fig. 24, description of elements that overlap with filter device 100 in Fig. 3 will not be repeated.

[0156] The filter device 100M includes a rectangular or substantially rectangular parallelepiped main body 110M formed by stacking a plurality of dielectric layers LY41 to LY47 along a predetermined direction. The dielectric layer LY41 and the dielectric layers LY43 to LY47 in the main body 110M correspond to the dielectric layers LY1 to LY6 in FIG. 3, respectively.

[0157] The dielectric layer LY43 is provided with plate electrodes PC1M, PC2M, and PC34M, which have the same shapes as the plate electrodes PC1, PC2, and PC34 on the dielectric layer LY42, respectively.

[0158] The plate electrode PC1M is connected in parallel to the plate electrode PC1 with respect to the vias V10 and V11. The plate electrode PC2M is connected in parallel to the plate electrode PC2 with respect to the vias V20 and V21. The plate electrode PC34M is connected in parallel to the plate electrode PC34 with respect to the vias V30, V31, and V40.

[0159] By multi-layering the plate electrodes of each resonator in this way, the current flowing through each plate electrode is reduced, thereby reducing the power loss in the inductor of each resonator, thereby reducing the insertion loss in the passband of the filter device and improving the pass characteristics.

[0160] [Embodiment 4] In the fourth embodiment, a configuration will be described that achieves miniaturization while suppressing degradation in the performance of the resonator.

[0161] Fig. 25 is an exploded perspective view showing an example of the layered structure of filter device 100N according to embodiment 4. Fig. 26 is a plan view of a portion of filter device 100N from dielectric layer to dielectric layer as viewed in the layered direction. The equivalent circuit of filter device 100N is the same as that of filter device 100 shown in Fig. 2.

[0162] 25 and 26, a filter device 100N includes resonators RC1 to RC4 provided in a main body 110N having a plurality of dielectric layers LY51 to LY60.

[0163] The resonator RC1 includes vias V10, V10N, and V11, a capacitor electrode P1, and plate electrodes PC10N, PC10N1, PC11N, and PC11N1. The resonator RC2 includes vias V20, V20N, and V21, a capacitor electrode P2, and plate electrodes PC20N, PC20N1, PC21N, and PC21N1.

[0164] The resonator RC3 includes vias V30 and V31, a capacitor electrode P3, and plate electrodes PC34N and PC34N1. The resonator RC4 includes vias V40 and V41. V31 , capacitor electrode P4, and plate electrodes PC34N, PC34N1. Note that the resonators RC3 and RC4 share the via V31 and the plate electrodes PC34N, PC34N1.

[0165] Main unit 110N The upper surface 111 (dielectric layer LY51) of the filter device 100N A directional mark DM is provided to identify the direction of the body. 110N On the lower surface 112 (dielectric layer LY60), an input terminal T1, an output terminal T2, and a ground terminal GND are arranged, which are external terminals for connecting the filter device 100N to an external device.

[0166] The input terminal T1 is connected by a via VT10 to a plate electrode PT1 provided on the dielectric layer LY59. The plate electrode PT1 is connected by a via VT11 to a capacitor electrode P1 of the resonator RC1 provided on the dielectric layer LY57.

[0167] When viewed from above in the normal direction of the main body 110, a portion of the capacitor electrode P1 overlaps with a capacitor electrode PT11 provided on the dielectric layer LY58. The capacitor electrode PT11 is connected to the ground electrode PG on the dielectric layer LY59 through a via VG1. The ground electrode PG is also connected to the ground terminal GND through a via VG. Therefore, the capacitor electrode P1 and the capacitor electrode P11 form the capacitor C1 in FIG. 2.

[0168] The capacitor electrode P1 is connected to one end of a plate electrode PC11N on the dielectric layer LY54 and one end of a plate electrode PC11N1 on the dielectric layer LY55 via a via V10. The plate electrodes PC11N and PC11N1 are both configured in the same approximately C-shape. The other ends of the plate electrodes PC11N and PC11N1 are connected to one end of a plate electrode PC10N on the dielectric layer LY52 and one end of a plate electrode PC10N1 on the dielectric layer LY53 via a via V10N. The plate electrodes PC10N and PC10N1 are both configured in the same approximately C-shape. The other ends of the plate electrodes PC10N and PC10N1 are connected to the ground electrode PG on the dielectric layer LY59 via a via V11. The plate electrodes PC10N, PC10N1, PC11N, and PC11N1 and the vias V10, V10N, and V11 form the inductor L1 in FIG.

[0169] The output terminal T2 is connected by a via VT20 to a plate electrode PT2 provided on the dielectric layer LY59. The plate electrode PT2 is connected by a via VT21 to a capacitor electrode P2 of the resonator RC2 provided on the dielectric layer LY57.

[0170] A portion of the capacitor electrode P2 overlaps with a capacitor electrode PT12 provided on the dielectric layer LY58 when viewed in a plan view from the normal direction of the main body 110. The capacitor electrode PT12 is connected to the ground electrode PG of the dielectric layer LY59 through a via VG2. PT12 The capacitor C2 in FIG. 2 is formed by these.

[0171] The capacitor electrode P2 is connected to one end of the plate electrode PC21N on the dielectric layer LY54 and one end of the plate electrode PC21N1 on the dielectric layer LY55 via a via V20. The plate electrodes PC21N and PC21N1 are both configured in the same approximately C-shape. The other ends of the plate electrodes PC21N and PC21N1 are connected to the plate electrode PC21N on the dielectric layer LY52 via a via V20N. PC20N , and is connected to one end of plate electrode PC20N1 on dielectric layer LY53. Plate electrodes PC20N and PC20N1 are both configured in the same approximately C-shape. The other ends of plate electrodes PC20N and PC20N1 are connected to ground electrode PG on dielectric layer LY59 through via V21. Plate electrodes PC20N, PC20N1, PC21N, and PC21N1 and vias V20, V20N, and V21 form inductor L2 in FIG. 2.

[0172] The capacitor electrode P1 of the resonator RC1 and the capacitor electrode P2 of the resonator RC2 partially overlap with the capacitor electrode P12 provided on the dielectric layer LY56 when viewed in a plan view from the normal direction of the main body 110. The capacitor electrodes P1, P2, and P12 form the capacitor C12 in FIG.

[0173] The via V10 of the resonator RC1 is also connected to a capacitor electrode P13 extending in the Y-axis direction on the dielectric layer LY56. When viewed from above in the normal direction of the main body 110, a part of the capacitor electrode P13 is connected to the resonator RC1 provided on the dielectric layer LY57. RC3 2. Capacitor electrode P3 is connected to plate electrode PC34N on dielectric layer LY52 and plate electrode PC34N1 on dielectric layer LY53 through via V30.

[0174] The via V20 of the resonator RC2 is also connected to a capacitor electrode P24 extending in the Y-axis direction on the dielectric layer LY56. When viewed from above in the normal direction of the main body 110, a part of the capacitor electrode P24 is connected to the resonator RC2 provided on the dielectric layer LY57. RC4 2. Capacitor electrode P4 is connected to plate electrode PC34N on dielectric layer LY52 and plate electrode PC34N1 on dielectric layer LY53 through via V40.

[0175] The plate electrodes PC34N and PC34N1 each have the same substantially E-shape. As shown in Fig. 26, the plate electrode PC34N includes a first portion PC341N configured as a strip electrode extending in the X-axis direction and three protruding portions (a second portion PC342N, a third portion PC343N, and a fourth portion PC344N) extending from the first portion PC341N in the positive direction of the Y-axis. The second portion PC342N extends from a central portion of the first portion PC341N along the extension direction (X-axis direction) toward between the plate electrodes PC10N and PC20N. The third portion PC343N extends from an end (first end) of the first portion PC341N in the negative direction of the X-axis toward the positive direction of the Y-axis. The fourth portion PC344N extends from the end (second end) of the first portion PC341N in the positive direction of the X axis toward the positive direction of the Y axis. The plate electrode PC34N1 has the same shape as the plate electrode PC34N.

[0176] The via V30 of the resonator RC3 is connected to the end of the third portion of the plate electrodes PC34N and PC34N1, and the via V40 of the resonator RC4 is connected to the end of the third portion of the plate electrodes PC34N and PC34N1.

[0177] At the end of the second portion of the plate electrodes PC34N and PC34N1, a via hole is formed which is shared by the resonators RC3 and RC4. V31 The via V31 is connected to the ground electrode PG of the dielectric layer LY59.

[0178] The capacitor electrode P3 of the resonator RC3 and the capacitor electrode P4 of the resonator RC4 partially overlap with the capacitor electrode P34 provided on the dielectric layer LY56 when viewed in a plan view from the normal direction of the main body 110. The capacitor electrodes P3, P4, and P34 form the capacitor C34 in FIG.

[0179] As described above, the equivalent circuit of the filter device 100N of the fourth embodiment is basically the same as that of the filter device 100 of the first embodiment, and two resonators are arranged in the X-axis direction and two more resonators are arranged in the Y-axis direction. This increases the distance between adjacent resonators, so that even if the total area of ​​the dielectric layers is the same, the Q value increases and the loss of the filter device is reduced.

[0180] 26, in the filter device 100N of the fourth embodiment, the resonator RC1 connected to the input terminal T1 is disposed in a region surrounded by the first portion PC341N, the second portion PC342N, and the third portion PC343N of the plate electrode PC34N that constitutes the resonator RC3. The resonator RC2 connected to the output terminal T2 is disposed in a region surrounded by the first portion PC341N, the second portion PC342N, and the fourth portion PC344N of the plate electrode PC34N that constitutes the resonator RC4.

[0181] By arranging the resonators in this manner, the distance between the vias connected to the plate electrodes of the second-stage resonator RC3 and the third-stage resonator RC4 is increased, thereby increasing the inductance of the resonators. To lower the resonant frequency or reduce the size of a filter device, it is common to increase the capacitance or inductance of the resonators. However, increasing the capacitance actually reduces the Q value. Therefore, by increasing the line length of the plate electrodes and increasing the inductance, as in the filter device 100N, it is possible to reduce the resonant frequency and / or reduce the size of the device while suppressing the reduction in the Q value.

[0182] In addition, in a four-stage filter, an attenuation pole occurs due to cross-coupling between resonator RC1 connected to input terminal T1 and resonator RC4 connected to output terminal T2. Therefore, if the vias connected to the input / output terminals are coupled to the shield of other equipment or the housing located outside the filter device, it may affect the filter characteristics.

[0183] In the filter device 100N of the fourth embodiment, the resonators RC1 and RC4 are provided inside the resonators RC2 and RC3 when the main body 110 is viewed in a plan view from the stacking direction, and therefore the vias connected to the input / output terminals are arranged closer to the center of the main body 110 than the resonators RC2 and RC3. Therefore, coupling between the vias connected to the input / output terminals and the external shield is suppressed compared to when the vias connected to the input / output terminals are arranged closer to the periphery of the main body 110, and the influence of the external shield on the filter characteristics is suppressed.

[0184] (Variation 12) Fig. 27 is an exploded perspective view showing an example of a layered structure of a filter device 100P according to Modification 12. Fig. 28 is a plan view of a portion of the filter device 100P extending from a dielectric layer to a dielectric layer as viewed in the layering direction.

[0185] In the filter device 100P, the vias connecting the respective plate electrodes of the dielectric layer LY52 and the ground electrode PG in the filter device 100N of the fourth embodiment are shared in the middle. In Figures 27 and 28, the description of the parts that overlap with Figures 25 and 26 will not be repeated.

[0186] 27 and 28, the filter device 100P includes a rectangular or substantially rectangular parallelepiped main body 110P formed by stacking a plurality of dielectric layers LY71 to LY80 along a predetermined direction.

[0187] In the main body 110P, one ends of the plate electrodes PC10N and PC10N1 that constitute the resonator RC1 are connected to a via V11. The via V11 extends from the dielectric layer LY72 to the dielectric layer LY75, is connected to the plate electrode PC50 on the dielectric layer LY74, and is connected to the plate electrode PC51 on the dielectric layer LY75. The plate electrodes PC50 and PC51 are linear electrodes that extend in the X-axis direction on the dielectric layers LY74 and LY75, respectively.

[0188] The plate electrodes PC50 and PC51 are plate electrodes that form the resonator RC2. PC20N, PC20N1 and a via V21 connected to one end of the plate electrodes PC34N and PC34N1 constituting the resonators RC3 and RC4, and a via V31 connected to one end of the plate electrodes PC34N and PC34N1 constituting the resonators RC3 and RC4 are also connected. Like the via V11, the via V21 extends from the dielectric layer LY72 to the dielectric layer LY75. On the other hand, the via V31 extends from the dielectric layer LY72 to the dielectric layer LY79 and is connected to the ground electrode PG. In other words, the vias V11 and V21 are common to the via V31 by the plate electrodes PC50 and PC51.

[0189] In this way, by sharing the vias from the plate electrodes constituting the resonators to the ground electrode PG, the magnetic coupling between the resonators RC1 and RC2, the magnetic coupling between the resonators RC1 and RC3, and the magnetic coupling between the resonators RC2 and RC4 are stronger than in the filter device 100N of Embodiment 4. When the magnetic coupling between the resonators is stronger, the impedance increases, and therefore the passband width is expanded and / or the steepness of attenuation in the vicinity of the passband width increases.

[0190] (Variation 13) 29 is a plan view of a filter device 100Q of Modification 13 as viewed from the stacking direction. In the filter device 100Q, one end of a plate electrode PC1Q constituting resonator RC1 and one end of a plate electrode PC2Q constituting resonator RC2 are both connected to via holes V31 in resonators RC3 and RC4. That is, the plate electrodes PC1Q, PC2Q, and PC34Q are connected to the ground electrode PG by the common via hole V31. In this way, by connecting all resonators RC1 to RC4 to the ground electrode PG by the common via hole V31, the magnetic coupling between the resonators is further strengthened compared to Modification 12. This further widens the passband width and improves the steepness of attenuation.

[0191] Furthermore, in filter device 100Q of modification 13, vias V10 and V20 connected to input / output terminals are arranged closer to the center of body 110 than in filter devices 100N and 100P. Therefore, in filter device 100Q, degradation of filter characteristics due to the external shield can be further suppressed.

[0192] In the above-described embodiment and each modification, the "resonators RC1" to "resonators RC6" correspond to the "first resonator" to "sixth resonators" in the present disclosure, respectively.

[0193] The embodiments disclosed herein should be considered to be illustrative in all respects and not restrictive. The scope of the present disclosure 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]

[0194] 10 communication device, 12 antenna, 20 high frequency front end circuit, 22, 28 band pass filter, 24 amplifier, 26 attenuator, 30 mixer, 32 local oscillator, 40 D / A converter, 50 RF circuit, 100, 100A to 100N, 100P, 100Q, 100X filter device, 110, 110D to 110N, 110P, 110Q, 110X main body, 111 top surface, 112 bottom surface, C1 to C6, C12, C13, C24, C34, C35, C46, ​​C56 capacitor, DM direction mark, GND ground terminal, L1 to L6, L34 to L36 Inductors: LY1 to LY6, LY11 to LY17, LY21 to LY26, LY31 to KY37, LY41 to LY47, LY51 to LY60, LY71 to LY80 Dielectric layers: N1A to N6A, N1B to N6B Connection nodes: P1 to P6, P12, P13, P24, P34 Capacitor electrodes, P34, P35, P46, P56, PA1 to PA3, PC1, PC1G1, PC1G2, PC1M, PC1X, PC2, PC2G1, PC2G2, PC2M, PC2X, PC10N, PC10N1, PC11 to PC13, PC11N, PC11N1, PC20N, PC20N1, PC21 to PC23, PC21N, PC21N1, PC34, PC34A to PC34C, PC34F, PC34K to PC34M, PC34X, PC50, PC51, PC56K, PC56L, PCD, PCI, PCJ, PT1, PT2, PT11 to PT14, plate electrodes, PG, ground electrodes, RC1 to RC6, RC1X to RC4X, resonators, T1 input terminals, T2 Output terminals, V10 to V12, V10G1, V10G2, V10I1, V10I2, V10N, V10X, V11E, V11X, V12E, V20, V20G1, V20G2, V20I1, V20I2, V20N, V20X, V21, V21E, V21X, V30, V30X, V31E, V31, V31D, V31E, V31F1, V31F2, V31I to V31K, V31X, V35L, V40, V40X, V50, V51L, V60, VC11, VC12, VC21, VC22, VG, VG1, VG2, VT10, VT11, VT20, VT21 vias.

Claims

1. A body having a plurality of dielectric layers laminated thereon; An input terminal, An output terminal; A ground terminal; a plurality of resonators disposed on the main body and electromagnetically coupled to each other; The plurality of resonators include: a first resonator connected to the input terminal; a second resonator connected to the output terminal and disposed adjacent to the first resonator in a first direction; a third resonator arranged adjacent to the first resonator in a second direction perpendicular to the first direction; a fourth resonator arranged adjacent to the third resonator in the first direction, a part of a path connected to the ground terminal in the third resonator and the fourth resonator is shared; Each of the plurality of resonators comprises: A plate electrode; a first via having one end connected to the plate electrode and the other end connected to the ground terminal via a capacitor; a second via having one end connected to the plate electrode and the other end connected to the ground terminal; a second via of the third resonator and a second via of the fourth resonator are shared; the plate electrode of the third resonator and the plate electrode of the fourth resonator each include a first portion integrally formed as a strip electrode extending in the first direction, a first via of the third resonator connected to a first end of the first portion; a first via of the fourth resonator connected to a second end of the first portion; a second via shared by the third resonator and the fourth resonator is connected between the first end and the second end of the first portion; a plate electrode of the third resonator and a plate electrode of the fourth resonator are disposed on the same dielectric layer as the plate electrode of the first resonator and the plate electrode of the second resonator;

2. the plate electrode of the third resonator and the plate electrode of the fourth resonator further include a second portion protruding in the second direction from a central portion of the first portion along the first direction toward the first resonator, a first via of the third resonator connected to a first end of the first portion; a first via of the fourth resonator connected to a second end of the first portion; The filter device according to claim 1 , wherein a second via shared by the third resonator and the fourth resonator is connected to the second portion.

3. The plate electrodes of the third resonator and the plate electrodes of the fourth resonator are a second portion protruding in the second direction from a central portion of the first portion along the first direction toward the first resonator; a third portion protruding from a first end of the first portion in the same direction as the second portion; a fourth portion protruding from the second end of the first portion in the same direction as the second portion, a first via of the third resonator connected to the third portion; a first via of the fourth resonator connected to the fourth portion; The filter device according to claim 1 , wherein a second via shared by the third resonator and the fourth resonator is connected to the second portion.

4. the first resonator is disposed in a region surrounded by the first portion, the second portion, and the third portion; The filter device according to claim 3 , wherein the second resonator is disposed in a region surrounded by the first portion, the second portion, and the fourth portion.

5. The plate electrodes of the third resonator and the plate electrodes of the fourth resonator are a second portion protruding in the second direction from a central portion of the first portion along the first direction toward the first resonator; a fifth portion protruding from a first end of the first portion in a direction opposite to the second portion; a sixth portion protruding from the second end of the first portion in a direction opposite to the second portion, a first via of the third resonator connected to the fifth portion; a first via of the fourth resonator connected to the sixth portion; The filter device according to claim 1 , wherein a second via shared by the third resonator and the fourth resonator is connected to the second portion.

6. The filter device according to any one of claims 1 to 5, wherein the second via of the first resonator and the second via of the second resonator are shared with the second via of the third resonator and the second via of the fourth resonator.

7. 7. The filter device according to claim 6, wherein the second via of the first resonator and the second via of the second resonator are shared with the second via of the third resonator and the second via of the fourth resonator at a position different from a position where the plate electrode of the main body is disposed.

8. 8. The filter device according to claim 1, wherein the plate electrodes of the first resonator and the second resonator are coils wound in a direction normal to the main body.

9. 8. The filter device according to claim 1, wherein the plate electrodes of the first resonator and the second resonator are coils wound in a direction perpendicular to a normal direction of the main body.

10. The plurality of resonators include: a fifth resonator arranged adjacent to the third resonator in the second direction; a sixth resonator arranged adjacent to the fifth resonator in the first direction, 10. The filter device according to claim 1, wherein a part of a path connected to the ground terminal is shared among the third to sixth resonators.

11. 11. The filter device according to claim 1, wherein the filter device is a band-pass filter that passes signals in a specific frequency band.

12. A high-frequency front-end circuit comprising the filter device according to any one of claims 1 to 11.

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