Laminated filter device

Abstract

A filter device is provided with: a laminate including a plurality of laminated dielectric layers; and a resonator configured using a conductor integrated with the laminate. Each of the plurality of dielectric layers is composed of a dielectric material and has a resonance frequency that varies depending on temperature. The dielectric material linearly changes the resonance frequency with respect to a change in temperature when the temperature is within a first temperature range, and does not linearly change the resonance frequency with respect to a change in temperature when the temperature is within a second temperature range.

Description

Technical Field

[0001] The present invention relates to a multilayer filter device including a multilayer body including a plurality of dielectric layers. Background Art

[0002] In recent years, the market requires miniaturization and space saving of small mobile communication equipment, and also requires miniaturization of bandpass filters used in such communication equipment. As a bandpass filter suitable for miniaturization, a bandpass filter using a laminated body including a plurality of laminated dielectric layers and a plurality of conductor layers is known. Hereinafter, a bandpass filter using a laminated body is referred to as a laminated bandpass filter.

[0003] The characteristics of a stacked bandpass filter can change according to temperature. One of the main reasons for the change in the characteristics of a stacked bandpass filter is the temperature characteristics of the dielectric layer. In the specification of the Chinese patent application publication No. 115051125A, a technology is disclosed that focuses on the temperature coefficient of the resonant frequency of the dielectric material constituting the dielectric layer to suppress the change in the pass attenuation characteristics of the stacked filter device caused by temperature.

[0004] In the specification of Chinese Patent Application Publication No. 115051125A, the focus is on the sign and absolute value of the temperature coefficient of the resonant frequency of the dielectric material. However, in Patent Document 1, as a means of suppressing the change in the pass attenuation characteristics of the stacked filter device caused by temperature, no attention is paid to the temperature characteristics of the dielectric material other than the sign and absolute value of the temperature coefficient of the resonant frequency of the dielectric material. Summary of the invention

[0005] An object of the present invention is to provide a multilayer filter device capable of suppressing changes in characteristics due to temperature.

[0006] The present invention provides a stacked filter device, which comprises a stacked body including a plurality of stacked dielectric layers and a resonator formed by using a conductor integrated with the stacked body. The plurality of dielectric layers are respectively formed of dielectric materials and have a resonant frequency that varies depending on temperature. When the temperature is within a first temperature range, the dielectric material causes the resonant frequency to vary linearly with respect to the change in temperature, and when the temperature is within a second temperature range, the dielectric material causes the resonant frequency to vary nonlinearly with respect to the change in temperature.

[0007] In the multilayer filter device of the present invention, the dielectric material changes the resonance frequency as described above. Therefore, according to the present invention, the effect of being able to suppress the change in characteristics due to temperature is achieved.

[0008] Other objects, features and advantages of the present invention will become more apparent from the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 This is a circuit diagram showing an example of a circuit configuration of a multilayer filter device according to the first embodiment of the present invention.

[0010] Figure 2 It is a perspective view showing the appearance of the multilayer filter device according to the first embodiment of the present invention.

[0011] Figure 3 It is an explanatory diagram showing a pattern formation surface of a first dielectric layer in a laminated body of the laminated filter device according to the first embodiment of the present invention.

[0012] Figure 4 It is an explanatory diagram showing a pattern forming surface of a second dielectric layer in a laminated body of the laminated filter device according to the first embodiment of the present invention.

[0013] Figure 5 It is an explanatory diagram showing a pattern forming surface of a third dielectric layer in the laminated body of the laminated filter device according to the first embodiment of the present invention.

[0014] Figure 6 It is an explanatory diagram showing a pattern formation surface of a fourth dielectric layer in the laminated body of the laminated filter device according to the first embodiment of the present invention.

[0015] Figure 7 It is an explanatory diagram showing the pattern formation surface of the fifth and sixth dielectric layers in the laminated body of the laminated filter device according to the first embodiment of the present invention.

[0016] Figure 8 It is an explanatory diagram showing a pattern forming surface of a seventh dielectric layer in the laminated body of the laminated filter device according to the first embodiment of the present invention.

[0017] Fig. 9 It is an explanatory diagram showing a pattern formation surface of the eighth dielectric layer in the laminated body of the laminated filter device according to the first embodiment of the present invention.

[0018] Fig.10 It is an explanatory diagram showing a pattern forming surface of a ninth dielectric layer in the laminated body of the laminated filter device according to the first embodiment of the present invention.

[0019] Fig.11 It is an explanatory diagram showing a pattern forming surface of a tenth dielectric layer in the laminated body of the laminated filter device according to the first embodiment of the present invention.

[0020] Fig.12It is an explanatory diagram showing the pattern formation surface of the eleventh to seventeenth dielectric layers in the laminated body of the multilayer filter device according to the first embodiment of the present invention.

[0021] Fig.13 It is an explanatory diagram showing a pattern-formed surface of the eighteenth dielectric layer in the laminated body of the laminated filter device according to the first embodiment of the present invention.

[0022] Fig.14 It is an explanatory diagram showing a pattern-formed surface of a nineteenth dielectric layer in the laminated body of the laminated filter device according to the first embodiment of the present invention.

[0023] Fig.15 It is a perspective view showing the interior of a laminated body of the laminated filter device according to the first embodiment of the present invention.

[0024] Fig.16 This is a characteristic diagram showing the temperature characteristic of the resonance frequency of the dielectric layer according to the first embodiment of the present invention.

[0025] Fig.17 It is a circuit diagram showing an example of a circuit configuration of a multilayer filter device according to a second embodiment of the present invention.

[0026] Fig.18 It is a perspective view showing the appearance of a multilayer filter device according to a second embodiment of the present invention.

[0027] Fig.19A , Fig.19B and Fig.19C It is an explanatory diagram showing the pattern formation surfaces of the first, second and third dielectric layers in the laminated body of the laminated filter device according to the second embodiment of the present invention.

[0028] Fig. 20A , Fig. 20B and Fig. 20C It is an explanatory diagram showing the pattern formation surfaces of the fourth, fifth, and sixth dielectric layers in the laminated body of the laminated filter device according to the second embodiment of the present invention.

[0029] Fig.21A It is an explanatory diagram showing a pattern forming surface of a seventh dielectric layer in a laminated body of a laminated filter device according to a second embodiment of the present invention.

[0030] Fig.21B It is an explanatory diagram showing the pattern formation surface of the eighth to fourteenth dielectric layers in the laminated body of the laminated filter device according to the second embodiment of the present invention.

[0031] Fig. 21CIt is an explanatory diagram showing a pattern-formed surface of a fifteenth dielectric layer in a laminated body of a laminated filter device according to a second embodiment of the present invention.

[0032] Fig.22A It is an explanatory diagram showing a pattern-formed surface of a sixteenth dielectric layer in a laminated body of a laminated filter device according to a second embodiment of the present invention.

[0033] Fig. 22B It is an explanatory diagram showing the pattern formation surface of the seventeenth to twenty-third dielectric layers in the laminated body of the multilayer filter device according to the second embodiment of the present invention.

[0034] Fig. 22C It is an explanatory diagram showing a pattern-formed surface of a twenty-fourth dielectric layer in a laminated body of a laminated filter device according to a second embodiment of the present invention.

[0035] Fig.23A , Fig. 23B and Fig.23C It is an explanatory diagram showing the pattern formation surfaces of the twenty-fifth, twenty-sixth and twenty-seventh dielectric layers in the laminated body of the multilayer filter device according to the second embodiment of the present invention.

[0036] Fig.24 It is a perspective view showing the interior of a laminated body of a laminated filter device according to a second embodiment of the present invention.

[0037] Fig.25 It is a characteristic diagram showing the temperature coefficient of the resonance frequency of each dielectric layer in the first to third embodiments.

[0038] Fig.26 It is a characteristic diagram showing the temperature coefficient of the resonance frequency of each dielectric layer in the third to eighth examples.

[0039] Fig. 27 It is a characteristic diagram showing the insertion loss of the multilayer filter device according to the ninth embodiment.

[0040] Fig.28 It is a characteristic diagram showing the pass attenuation characteristics of the multilayer filter device according to the ninth embodiment. DETAILED DESCRIPTION

[0041] [First embodiment]

[0042] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. First, the structure of a stacked filter device (hereinafter referred to as a filter device) 1 according to a first embodiment of the present invention will be briefly described. The filter device 1 of this embodiment comprises a stacked body including a plurality of stacked dielectric layers, and a plurality of resonators formed using a conductor integrated with the stacked body. The plurality of dielectric layers are respectively formed of dielectric materials and have a resonant frequency that varies depending on temperature. The dielectric material will be described in detail later.

[0043] The plurality of resonators are configured so that the filter device 1 functions as a filter for filtering a signal. Each of the plurality of resonators may be an LC resonator including an inductor and a capacitor, or a distributed constant resonator at least part of which is configured by a distributed constant line.

[0044] In the present embodiment, each of the plurality of resonators is a distributed constant resonator. Hereinafter, an example of a circuit configuration of a filter device 1 including a plurality of distributed constant resonators will be described. Figure 1 1 is a circuit diagram showing an example of a circuit structure of a filter device 1. The filter device 1 includes a first terminal 2, a second terminal 3, and six resonators 11, 12, 13, 14, 15, and 16. The first and second terminals 2 and 3 are terminals for inputting or outputting signals, respectively. That is, when a signal is input to the first terminal 2, a signal is output from the second terminal 3. When a signal is input to the second terminal 3, a signal is output from the first terminal 2.

[0045] The six resonators 11, 12, 13, 14, 15, and 16 are arranged between the first terminal 2 and the second terminal 3 in terms of the circuit structure. In addition, the six resonators 11, 12, 13, 14, 15, and 16 are arranged in order from the first terminal 2 side in terms of the circuit structure. In addition, in the present application, the expression "in terms of the circuit structure" is used to refer to the arrangement on the circuit diagram, not the arrangement on the physical structure.

[0046] Resonators 11 to 16 are configured such that resonators 11 and 12 are adjacent in circuit structure and electromagnetically coupled, resonators 12 and 13 are adjacent in circuit structure and electromagnetically coupled, resonators 13 and 14 are adjacent in circuit structure and electromagnetically coupled, resonators 14 and 15 are adjacent in circuit structure and electromagnetically coupled, and resonators 15 and 16 are adjacent in circuit structure and electromagnetically coupled. In addition, in the present embodiment, the electromagnetic coupling between two resonators adjacent in circuit structure is capacitive.

[0047] In addition, the resonators 11 to 16 are configured so that two specific resonators that are not adjacent in the circuit structure are electromagnetically coupled. In the present embodiment, the group of resonators 12 and 15, the group of resonators 11 and 13, and the group of resonators 14 and 16 are configured so as to be electromagnetically coupled. In the present embodiment, in particular, the electromagnetic coupling between the resonators 12 and 15, the electromagnetic coupling between the resonators 11 and 13, and the electromagnetic coupling between the resonators 14 and 16 are all inductive.

[0048] In the present embodiment, in particular, each of the resonators 11 to 16 is a one-end short-circuit type quarter-wavelength resonator in which one end is short-circuited and the other end is open.

[0049] The filter device 1 further includes a capacitor C1 for achieving capacitive coupling between the resonators 11 and 12 , a capacitor C2 for achieving capacitive coupling between the resonators 12 and 13 , a capacitor C3 for achieving capacitive coupling between the resonators 13 and 14 , a capacitor C4 for achieving capacitive coupling between the resonators 14 and 15 , and a capacitor C5 for achieving capacitive coupling between the resonators 15 and 16 .

[0050] The filter device 1 further includes an inductor L1 provided between the first terminal 2 and the resonator 11 in terms of the circuit structure, and an inductor L2 provided between the second terminal 3 and the resonator 16 in terms of the circuit structure. One end of the inductor L1 is electrically connected to the first terminal 2. The other end of the inductor L1 is electrically connected to the resonator 11. One end of the inductor L2 is electrically connected to the second terminal 3. The other end of the inductor L2 is electrically connected to the resonator 16. In the present application, the expression "electrically connected" includes a case where the inductor is electrically connected via a metal conductor (including an inductor), but does not include a case where the inductor is connected via a capacitor.

[0051] exist Figure 1 In the illustrated example, the resonators 11 to 16 , the capacitors C1 to C5 , and the inductors L1 and L2 constitute the filter device 1 so as to function as a bandpass filter that selectively passes signals within a predetermined frequency band.

[0052] Next, refer to Figure 2 The other structures of the filter device 1 will be described. Figure 2 It is a perspective view showing the appearance of the filter device 1 .

[0053] The filter device 1 further includes a laminate 50 including a plurality of laminated dielectric layers and a plurality of conductors (a plurality of conductor layers and a plurality of through holes). The first terminal 2 , the second terminal 3 , the resonators 11 to 16 , the capacitors C1 to C5 , and the inductors L1 and L2 are integrated with the laminate 50 .

[0054] The stacked body 50 has a bottom surface 50A and an upper surface 50B located at both ends of the stacking direction T of the plurality of dielectric layers, and four side surfaces 50C to 50F connecting the bottom surface 50A and the upper surface 50B. The side surfaces 50C and 50D face opposite sides, and the side surfaces 50E and 50F also face opposite sides. The side surfaces 50C to 50F are perpendicular to the bottom surface 50A and the upper surface 50B.

[0055] Here, if Figure 2 As shown, the X direction, Y direction, and Z direction are defined. The X direction, Y direction, and Z direction are orthogonal to each other. In this embodiment, a direction parallel to the stacking direction T is set as the Z direction. In addition, the direction opposite to the X direction is set as the -X direction, the direction opposite to the Y direction is set as the -Y direction, and the direction opposite to the Z direction is set as the -Z direction. In addition, the expression "when observed from the stacking direction T" means observing the object from a position away from the Z direction or the -Z direction.

[0056] like Figure 2 As shown, the bottom surface 50A is located at one end of the stack 50 in the -Z direction. The upper surface 50B is located at one end of the stack 50 in the Z direction. The side surface 50C is located at one end of the stack 50 in the -X direction. The side surface 50D is located at one end of the stack 50 in the X direction. The side surface 50E is located at one end of the stack 50 in the -Y direction. The side surface 50F is located at one end of the stack 50 in the Y direction.

[0057] The filter device 1 further includes electrodes 111 and 112 provided on the bottom surface 50A of the stacked body 50. The electrode 111 is arranged near the side surface 50C. The electrode 112 is arranged near the side surface 50D. The electrode 111 corresponds to the first terminal 2, and the electrode 112 corresponds to the second terminal 3. Therefore, the first and second terminals 2 and 3 are provided on the bottom surface 50A of the stacked body 50.

[0058] The filter device 1 further includes a plurality of ground electrodes 113 provided on the bottom surface 50A of the laminate 50. In the present embodiment, the plurality of ground electrodes 113 include a plurality of electrodes disposed between the electrodes 111 and 112 and the side surface 50E, a plurality of electrodes disposed between the electrodes 111 and 112 and the side surface 50F, and a plurality of electrodes disposed between the electrode 111 and the electrode 112. The plurality of ground electrodes 113 are grounded.

[0059] Next, refer to Figure 3 to Figure 14 An example of a plurality of dielectric layers and a plurality of conductors constituting the laminate 50 is described. In this example, the laminate 50 has nineteen laminated dielectric layers. Hereinafter, the nineteen dielectric layers are referred to as the first to nineteenth dielectric layers in order from the bottom. In addition, the first to nineteenth dielectric layers are represented by reference numerals 51 to 69.

[0060] exist Figure 3 to Figure 12 In the figure, a plurality of circles represent a plurality of through holes. A plurality of through holes are formed on each of the dielectric layers 51 to 67. The plurality of through holes are formed by filling the holes for the through holes with a conductor paste. The plurality of through holes are connected to electrodes, conductor layers, or other through holes. In the following description, the connection relationship between each of the plurality of through holes and electrodes, conductor layers, or other through holes is described in the state where the first to nineteenth layers of dielectric layers 51 to 69 are stacked. In addition, in Figure 3 to Figure 12 In the figure, symbols are respectively given to specific through holes among the multiple through holes.

[0061] Figure 3 The pattern forming surface of the first dielectric layer 51 is shown. On the pattern forming surface of the dielectric layer 51, electrodes 111 and 112 and a plurality of ground electrodes 113 are formed.

[0062] exist Figure 3 In the figure, the through holes marked with reference numerals 51T1 and 51T2 are connected to the electrodes 111 and 112, respectively. In the following description, the through hole marked with reference numeral 51T1 is simply referred to as through hole 51T1. In addition, through holes marked with reference numerals other than through hole 51T1 are also described in the same manner as through hole 51T1.

[0063] Figure 4 51T1 and 51T2 are respectively connected to the pattern forming surface of the dielectric layer 52 of the second layer. A conductor layer 521 is formed on the pattern forming surface of the dielectric layer 52. Figure 4 The through holes 52T1, 52T2 are shown connected.

[0064] Figure 5 52T1 and 52T2 are respectively connected to the pattern forming surface of the third dielectric layer 53. Figure 5 The through holes 53T1, 53T2 are shown connected.

[0065] Figure 6 : shows the patterned surface of the fourth dielectric layer 54. Conductive layers 541 and 542 for inductors are formed on the patterned surface of the dielectric layer 54. The through hole 53T1 and Figure 6 The through holes 54T1a and 54T1b are connected to the conductor layer 541. The through holes 53T2 and Figure 6 The vias 54T2 a , 54T2 b shown are connected to the conductor layer 542 .

[0066] Figure 7The pattern forming surfaces of the fifth and sixth dielectric layers 55 and 56 are shown. The through holes 54T1a, 54T1b, 54T2a, and 54T2b are respectively connected to the through holes 55T1a, 55T1b, 55T2a, and 55T2b formed in the dielectric layer 55. In the dielectric layers 55 and 56, the through holes with the same reference numerals adjacent to each other are connected to each other.

[0067] Figure 8 : shows the patterned surface of the seventh dielectric layer 57. Conductive layers 571 and 572 for inductors are formed on the patterned surface of the dielectric layer 57. Through holes 55T1a, 55T1b and 55T1b formed in the dielectric layer 56 Figure 8 The through hole 57T1 shown is connected to the conductor layer 571. The through holes 55T2a, 55T2b and 55T2c formed in the dielectric layer 56 are connected to the conductor layer 571. Figure 8 The via 57T2 shown is connected to the conductor layer 572.

[0068] Fig. 9 2 shows the pattern forming surface of the eighth dielectric layer 58. Conductive layers 581 and 582 are formed on the pattern forming surface of the dielectric layer 58. In addition, through holes 57T1 and 57T2 are respectively connected to Fig. 9 The vias 58T1, 58T2 are shown connected.

[0069] Fig.10 The pattern formation surface of the ninth dielectric layer 59 is shown. Conductive layers 591, 592, 593, 594, 595, 596 and a conductive layer 597 for resonators are formed on the pattern formation surface of the dielectric layer 59. The conductive layers 591 and 596 each include a portion extending in one direction. The conductive layers 592 to 595 each have a shape that is long in one direction.

[0070] The through holes 58T1 and 58T2 are connected to the conductive layers 591 and 596 , respectively. Fig.10 The vias 59T3 and 59T4 shown are connected to the conductor layers 592 and 595 respectively.

[0071] Fig.11 1 shows the pattern forming surface of the tenth dielectric layer 60. Conductive layers 601, 602, and 603 are formed on the pattern forming surface of the dielectric layer 60. In addition, through holes 59T3 and 59T4 are respectively connected to Fig.11 The through holes 60T3, 60T4 are shown connected.

[0072] Fig.12The pattern formation surfaces of the eleventh to seventeenth dielectric layers 61 to 67 are shown. The vias 60T3 and 60T4 are connected to the vias 61T3 and 61T4 formed in the dielectric layer 61. In the dielectric layers 61 to 67, the vias with the same reference numerals adjacent to each other are connected to each other.

[0073] Fig.13 The pattern formation surface of the eighteenth dielectric layer 68 is shown. A conductor layer 681 is formed on the pattern formation surface of the dielectric layer 68. The through holes 61T3 and 61T4 formed in the dielectric layer 67 are connected to the conductor layer 681.

[0074] Fig.14 The pattern forming surface of the nineteenth dielectric layer 69 is shown. On the pattern forming surface of the dielectric layer 69, a mark 691 is formed.

[0075] Figure 2 The stacked body 50 shown is constructed by stacking first to nineteenth dielectric layers 51 to 69 so that the pattern forming surface of the first dielectric layer 51 becomes the bottom surface 50A of the stacked body 50, and the surface of the nineteenth dielectric layer 69 on the opposite side to the pattern forming surface becomes the upper surface 50B of the stacked body 50.

[0076] Fig.15 2 shows the interior of a laminate 50 formed by laminating the first to nineteenth dielectric layers 51 to 69. Fig.15 As shown, the laminated body 50 is laminated with Figure 3 to Figure 13 In addition, in Fig.15 Mark 691 is omitted.

[0077] The following, Figure 1 The components of the filter device 1 shown in FIG. Figure 2 to Figure 14 The corresponding relationship of the components inside the laminated body 50 shown will be described. The resonator 11 is composed of the conductor layer 591 for the resonator. The resonator 13 is composed of the conductor layer 593 for the resonator. The resonator 14 is composed of the conductor layer 594 for the resonator. The resonator 16 is composed of the conductor layer 596 for the resonator.

[0078] The resonator 12 is composed of a conductor layer 592 for the resonator and through holes 59T3, 60T3, and 61T3. Fig.15 In FIG. 1 , the symbol T3 represents a structure formed by connecting through holes 59T3, 60T3, and 61T3 in series. Hereinafter, a structure formed by connecting two or more through holes in series is also referred to as a through hole. It can also be said that the resonator 12 is composed of the conductor layer 592 and the through hole T3. One end of the through hole T3 is connected to the conductor layer 592. The other end of the through hole T3 is connected to the conductor layer 681.

[0079] The resonator 15 is composed of a conductor layer 595 for the resonator and a through hole T4. The through hole T4 is formed by connecting through holes 59T4, 60T4, and 61T4 in series. One end of the through hole T4 is connected to the conductor layer 595. The other end of the through hole T4 is connected to the conductor layer 681.

[0080] Capacitor C1 is composed of conductor layers 591, 592, 601 and dielectric layers 59 between these conductor layers. Capacitor C2 is composed of conductor layers 581, 592, 593 and dielectric layers 58 between these conductor layers. Capacitor C3 is composed of conductor layers 593, 594, 602 and dielectric layers 59 between these conductor layers. Capacitor C4 is composed of conductor layers 582, 594, 595 and dielectric layers 58 between these conductor layers. Capacitor C5 is composed of conductor layers 595, 596, 603 and dielectric layers 59 between these conductor layers.

[0081] The inductor L1 is composed of conductor layers 541 and 571 and vias 54T1a, 54T1b, 55T1a, and 55T1b. The conductor layer 541 is connected to the electrode 111 corresponding to the first terminal 2 via vias 51T1, 52T1, and 53T1. The conductor layer 571 is connected to the resonator conductor layer 591 constituting the resonator 11 via vias 57T1 and 58T1.

[0082] The inductor L2 is composed of the conductor layers 542 and 572 and the vias 54T2a, 54T2b, 55T2a, and 55T2b. The conductor layer 542 is connected to the electrode 112 corresponding to the second terminal 3 via the vias 51T2, 52T2, and 53T2. The conductor layer 572 is connected to the resonator conductor layer 596 constituting the resonator 16 via the vias 57T2 and 58T2.

[0083] Next, a method for manufacturing the filter device 1 of the present embodiment is briefly described. In the present embodiment, in particular, the dielectric layers 51 to 69 are ceramic sintered bodies containing dielectric ceramics as dielectric materials. The laminate 50 is made, for example, by a low-temperature co-firing method. In this case, first, a plurality of green sheets that will later become the dielectric layers 51 to 69 are made respectively. Each green sheet is formed by a mixture containing raw material powder, additives, an organic binder, and an organic solvent, and the raw material powder contains dielectric ceramics and glass. Next, a plurality of pre-fired conductor layers that will later become a plurality of conductor layers and a plurality of pre-fired through holes that will later become a plurality of through holes are formed on each green sheet. Next, a plurality of green sheets are stacked to make a green sheet laminate. Next, the green sheet laminate is cut to make a pre-fired laminate. Next, the dielectric ceramics and conductors in the pre-fired laminate are fired by a low-temperature co-firing process to complete the laminate 50.

[0084] As described above, dielectric layers 51 to 69 are respectively formed of dielectric materials. The dielectric layer (ceramic sintered body) composed of dielectric materials has a characteristic that changes depending on temperature. Here, the resonant frequency of the dielectric layer is focused on. As an indicator representing the temperature dependence of the resonant frequency of the dielectric layer, there is a temperature coefficient of resonant frequency TCF. The temperature coefficient of resonant frequency TCF (unit: ppm / H) is defined by JIS standard R1627 (test method for dielectric properties of fine ceramics for microwave use) and is expressed by the following formula (1). In addition, f ref Indicates the reference temperature t ref The resonant frequency, f T Indicates the resonant frequency at a specified temperature t.

[0085] TCF=[(f T -f ref ) / {f ref (tt ref )}]×10 6 ……(1)

[0086] The inventors of the present application have found that by focusing on the resonant frequency f when the temperature t is changed T The change of the characteristics of the filter device 1 caused by temperature can be suppressed. Here, a range of temperature t including at least one continuous range is referred to as a first temperature range, and a range of temperature t including a continuous range different from the first temperature range is referred to as a second temperature range. The dielectric material in this embodiment makes the resonant frequency f T The way in which changes is different in the first temperature range and the second temperature range.

[0087] Fig.16 is the resonant frequency f of the dielectric layer of this embodiment. T The temperature characteristics of the characteristic diagram. Fig.16 In the figure, the horizontal axis represents temperature t and the vertical axis represents resonance frequency f T When the temperature t is within the first temperature range, the dielectric material of this embodiment makes the resonance frequency f T The dielectric material of this embodiment changes linearly with respect to the change of temperature t. When the temperature t is within the second temperature range, the resonant frequency f T The change in temperature t does not change linearly. In addition, "linear change" means that the resonant frequency f T In the characteristic diagram of the relationship between temperature t, the resonance frequency f T According to the resonant frequency f, it can be approximated by a linear function T The degree of relationship with temperature t changes linearly or approximately linearly. TWhen the resonant frequency f changes linearly, T The amount may increase while repeating a monotonically or slightly increasing and decreasing state with respect to a change in temperature t, or may decrease while repeating a monotonically or slightly increasing and decreasing state with respect to a change in temperature t.

[0088] In addition, “nonlinearly changing” means that in the above characteristic diagram, the resonance frequency f T In the present embodiment, the resonance frequency f may be changed in a curved manner, or may not be changed in a straight line or substantially straight line. T According to the quadratic function, the resonant frequency f T The case where the degree of the relationship with the temperature t changes linearly is referred to as “changing nonlinearly”.

[0089] exist Fig.16 In the example shown, the second temperature range is a temperature range including 20° C. The second temperature range may also be, for example, 0° C. to 40° C. In the second temperature range, the resonance frequency f T The resonant frequency f in the second temperature range approximated by a quadratic function T In the case of , the slope of the quadratic function may become 0 at a temperature of 20°C or in the vicinity of 20°C.

[0090] Here, the resonant frequency f in the second temperature range is approximated by a quadratic function T The temperature t at which the slope of the quadratic function becomes 0 is called the specific temperature. Fig.16 In the example shown, the resonant frequency f when the temperature t decreases from a specific temperature T The change of the resonant frequency f when the temperature t increases from a specific temperature T Specifically, when the temperature t decreases from a certain temperature and when the temperature t increases from a certain temperature, the resonant frequency f T In addition, when the temperature t is lower than a specific temperature, the temperature coefficient TCF of the resonance frequency is a positive value, and when the temperature t is higher than a specific temperature, the temperature coefficient TCF of the resonance frequency is a negative value.

[0091] In addition, Fig.16 In the example shown, the first temperature range includes a first sub-range lower than the second temperature range and a second sub-range higher than the second temperature range. The first sub-range may be, for example, -40°C to 0°C. The second sub-range may be, for example, 40°C to 125°C. That is, the second sub-range may also be wider than the first sub-range. In either the first sub-range or the second sub-range, the resonant frequency f T All change approximately linearly.

[0092] In addition, within the first sub-range, the resonant frequency f T It increases monotonically with the increase of temperature t. That is, in the first sub-range, the temperature coefficient TCF of the resonance frequency is positive. In the second sub-range, the resonance frequency f T It decreases monotonically with the increase of temperature t. That is, in the second sub-range, the temperature coefficient TCF of the resonance frequency is a negative value. In addition, the upper limit temperature of the second sub-range is not limited to the above example, and can be 85°C, 105°C, or 150°C.

[0093] The resonance frequency f in the second temperature range T The difference between the maximum value and the minimum value of can be less than the resonance frequency f in the first temperature range. T The difference between the maximum and minimum values ​​of . Fig.16 In the example shown, when the second temperature range is 0°C to 40°C, the first sub-range of the first temperature range is -40°C to 0°C, and the second sub-range of the first temperature range is 40°C to 125°C, the resonant frequency f is satisfied. T The above requirements for the maximum and minimum values ​​of .

[0094] The resonant frequency f of the ceramic sintered body forming the dielectric layer is known to be T The temperature characteristics can be adjusted by changing the mixing ratio of the dielectric material. As long as the dielectric material satisfies the resonance frequency f T By meeting the above requirements, various ceramic materials, various glass ceramic materials for low temperature co-fired ceramics (LTCC), and mixtures thereof can be used. Fig.16 The resonant frequency f of a ceramic sintered body formed by mixing dielectric materials such as aluminum oxide, silicon oxide, and titanate compounds is shown in FIG. T Temperature characteristics.

[0095] Next, the effects of the filter device 1 of the present embodiment will be described. As described above, when the temperature t is within the first temperature range, the dielectric material of the present embodiment makes the resonance frequency f T The dielectric material of this embodiment changes linearly with respect to the change of temperature t. When the temperature t is within the second temperature range, the resonant frequency f T It changes with temperature t but not linearly. Fig.16 As shown in the figure, when the width of the temperature range is set to be the same and compared, at the resonance frequency f T In the case of nonlinear changes, the resonant frequency f T Compared with the case of linear change, the resonance frequency f T Thus, according to the present embodiment, in the entire specification temperature range of the filter device 1, the resonant frequency fT Compared with the case where the resonant frequency f changes linearly with respect to the change in temperature t, the resonant frequency f that accompanies the change in temperature t can be reduced. T As a result, according to the present embodiment, it is possible to suppress the change in the characteristics of the filter device 1 caused by temperature. In addition, an example of the characteristics of the filter device 1 will be described later.

[0096] In addition, in this embodiment, when the resonance frequency f in the second temperature range is approximated by a quadratic function, T In the case of , the slope of the quadratic function becomes 0 at a specific temperature. That is, in this embodiment, there is a resonance frequency f T The temperature range and resonance frequency f increase monotonically with increasing temperature t T The temperature range in which the resonant frequency TCF decreases monotonically with the increase of the temperature t. In other words, in this embodiment, there is a temperature range in which the temperature coefficient TCF of the resonant frequency becomes a positive value and a temperature range in which the temperature coefficient TCF of the resonant frequency becomes a negative value. Thus, according to this embodiment, in the entire specification temperature range of the filter device 1, the resonant frequency f T Compared with the case where the resonant frequency f increases monotonically or decreases monotonically with the increase of temperature t, the resonant frequency f that accompanies the change of temperature t can be reduced. T , and can reduce the temperature coefficient TCF of the resonance frequency in the entire specification temperature range of the filter device 1.

[0097] However, in the filter device 1, during the outbound inspection, the attenuation of the filter device 1 is inspected at the lower limit temperature of the first sub-range and the upper limit temperature of the second sub-range. In the present embodiment, in the first sub-range of the first temperature range, the resonance frequency f T As the temperature t increases, the resonance frequency f increases monotonically. In the second sub-range of the first temperature range, the resonance frequency f T As the temperature t increases, it decreases monotonically. When the second sub-range is wider than the first sub-range, the resonant frequency f in the second sub-range can be T The change is greater than the resonant frequency f in the first sub-range T The resonant frequency f in the second sub-range T The minimum value is less than the resonant frequency f in the first sub-range T In the case of the minimum value of , the characteristic inspection at the lower limit temperature of the first sub-range can be omitted.

[0098] [Second embodiment]

[0099] Next, a filter device 101 according to a second embodiment of the present invention is described. The filter device 101 of this embodiment includes a laminate including a plurality of laminated dielectric layers and a plurality of resonators formed using a conductor integrated with the laminate. The plurality of dielectric layers may be formed of the same material as the dielectric layers 51 to 69 of the first embodiment.

[0100] In the present embodiment, each of the plurality of resonators is an LC resonator including an inductor and a capacitor. Hereinafter, an example of a circuit configuration of the filter device 101 including a plurality of LC resonators will be described. Fig.17 1 is a circuit diagram showing an example of a circuit configuration of the filter device 101 of the present embodiment. The filter device 101 includes a first terminal 102, a second terminal 103, and four resonators 21, 22, 23, and 24. The first and second terminals 102 and 103 are terminals for inputting or outputting signals, respectively.

[0101] The four resonators 21, 22, 23, and 24 are provided between the first terminal 102 and the second terminal 103 in terms of circuit configuration. In addition, the four resonators 21, 22, 23, and 24 are arranged in order from the first terminal 102 side in terms of circuit configuration.

[0102] The resonator 21 includes an inductor L11 and a capacitor C11. The resonator 22 includes an inductor L12 and a capacitor C12. The resonator 23 includes an inductor L13 and a capacitor C13. The resonator 24 includes an inductor L14 and a capacitor C14.

[0103] In the present embodiment, in particular, in each of the resonators 21 to 24, the inductor and the capacitor are connected in series. One end of the capacitor C11 is connected to one end of the inductor L11. One end of the capacitor C12 is connected to one end of the inductor L12. One end of the capacitor C13 is connected to one end of the inductor L13. One end of the capacitor C14 is connected to one end of the inductor L14. The other ends of the inductors L11 to L14 and the capacitors C11 to C14 are grounded.

[0104] One end of each of the inductor L11 and the capacitor C11 is connected to the first terminal 102 . One end of each of the inductor L14 and the capacitor C14 is connected to the second terminal 103 .

[0105] The filter device 101 further includes capacitors C15, C16, C17, and C18. One end of the capacitor C15 is connected to each end of the inductor L11 and the capacitor C11. The other end of the capacitor C15 and one end of the capacitor C16 are connected to each end of the inductor L12 and the capacitor C12. The other end of the capacitor C16 and one end of the capacitor C17 are connected to each end of the inductor L13 and the capacitor C13. The other end of the capacitor C17 is connected to each end of the inductor L14 and the capacitor C14. One end of the capacitor C18 is connected to one end of the capacitor C15. The other end of the capacitor C18 is connected to the other end of the capacitor C17.

[0106] In the present embodiment, the resonators 21 to 24 , the capacitors C11 to C18 , and the inductors L11 to L14 configure the filter device 101 so as to function as a bandpass filter that selectively passes signals within a predetermined frequency band.

[0107] Next, refer to Fig.18 The other structures of the filter device 101 will be described. Fig.18 It is a perspective view showing the appearance of the filter device 101 .

[0108] The filter device 101 further includes a laminate 150 including a plurality of laminated dielectric layers and a plurality of conductors (a plurality of conductor layers and a plurality of through holes). The first terminal 102 , the second terminal 103 , the resonators 21 to 24 (the inductors L11 to L14 and the capacitors C11 to C14 ), and the capacitors C15 to C18 are integrated with the laminate 150 .

[0109] The stacked body 150 has a bottom surface 150A and an upper surface 150B located at both ends of the stacking direction T of the plurality of dielectric layers, and four side surfaces 150C to 150F connecting the bottom surface 150A and the upper surface 150B. The side surfaces 150C and 150D face opposite sides, and the side surfaces 150E and 150F also face opposite sides. The side surfaces 150C to 150F are perpendicular to the bottom surface 150A and the upper surface 150B.

[0110] Compared with the first embodiment Figure 2 Same, in Fig.18 The X direction, Y direction, and Z direction are shown in FIG. Fig.18 As shown, the bottom surface 150A is located at one end of the stack 150 in the -Z direction. The upper surface 150B is located at one end of the stack 150 in the Z direction. The side surface 150C is located at one end of the stack 150 in the -X direction. The side surface 150D is located at one end of the stack 150 in the X direction. The side surface 150E is located at one end of the stack 150 in the -Y direction. The side surface 150F is located at one end of the stack 150 in the Y direction.

[0111] The filter device 101 further includes electrodes 211 and 212 provided on the bottom surface 150A of the stacked body 150. The electrode 211 extends in a direction parallel to the Y direction at a position closer to the side surface 150C than the side surface 150D. The electrode 212 extends in a direction parallel to the Y direction at a position closer to the side surface 150D than the side surface 150C. The electrode 211 corresponds to the first terminal 102, and the electrode 212 corresponds to the second terminal 103. Therefore, the first and second terminals 102 and 103 are provided on the bottom surface 150A of the stacked body 150.

[0112] The filter device 101 further includes electrodes 213, 214, 215, and 216 provided on the bottom surface 150A of the stacked body 150. The electrodes 213, 214, 215, and 216 are arranged between the electrode 211 and the electrode 212. The electrodes 213 and 214 are arranged in sequence in the X direction at positions closer to the side surface 150E than the side surface 150F. The electrodes 215 and 216 are arranged in sequence in the X direction at positions closer to the side surface 150F than the side surface 150E. The electrodes 213, 214, 215, and 216 are grounded.

[0113] Next, refer to Figures 19A to 23C An example of a plurality of dielectric layers and a plurality of conductors constituting the stacked body 150 is described. In this example, the stacked body 150 has 27 stacked dielectric layers. Hereinafter, the 27 dielectric layers are referred to as the first to the twenty-seventh dielectric layers in order from the bottom. In addition, the first to the twenty-seventh dielectric layers are represented by reference numerals 151 to 177.

[0114] exist Figures 19A to 22C In the figure, a plurality of circles represent a plurality of through holes. A plurality of through holes are formed in each of the dielectric layers 151 to 174. In the following description, the connection relationship between each of the plurality of through holes and the electrode, the conductor layer or other through holes is described with respect to the connection relationship in the state where the first to twenty-seventh dielectric layers 151 to 177 are stacked. Figures 19A to 22C In the figure, symbols are respectively given to specific through holes among the multiple through holes.

[0115] Fig.19A The pattern forming surface of the first dielectric layer 151 is shown. Electrodes 211 to 216 are formed on the pattern forming surface of the dielectric layer 151.

[0116] Fig.19B The pattern forming surface of the second dielectric layer 152 is shown. On the pattern forming surface of the dielectric layer 152, a conductor layer 1521 is formed. Fig.19B The vias 152T1 b , 152T2 b , 152T3 b , and 152T4 b shown are connected to the conductor layer 1521 .

[0117] Fig.19C The pattern forming surface of the third dielectric layer 153 is shown. Conductive layers 1531, 1532, 1533, and 1534 are formed on the pattern forming surface of the dielectric layer 153. Fig.19C The through holes 153T1a and 153T4a are connected to the conductor layers 1531 and 1534, respectively. The through holes 152T1b, 152T2b, 152T3b, and 152T4b are connected to the conductor layers 1531 and 1534, respectively. Fig.19C The through holes 153T1b, 153T2b, 153T3b, 153T4b are shown connected.

[0118] Fig. 20A 1 shows the pattern forming surface of the fourth dielectric layer 154. Conductive layers 1541, 1542, and 1543 are formed on the pattern forming surface of the dielectric layer 154. Through holes 153T1a, 153T2b, 153T3b, and 153T4a are respectively connected to Fig. 20A The through holes 154T1a, 154T2b, 154T3b, and 154T4a are shown connected. The through hole 153T1b and Fig. 20A The through hole 154T1b is shown to be connected to the conductor layer 1541. The through hole 153T4b and Fig. 20A The via 154T4 b shown is connected to the conductor layer 1542 .

[0119] Fig. 20B 1 shows the patterned surface of the fifth dielectric layer 155. Conductive layers 1551 and 1552 are formed on the patterned surface of the dielectric layer 155. Through holes 154T1a, 154T1b, 154T2b, 154T3b, 154T4a, and 154T4b are respectively connected to Fig. 20B The through holes 155T1a, 155T1b, 155T2b, 155T3b, 155T4a, 155T4b are shown connected. Fig. 20B The vias 155T2a and 155T3a shown are connected to the conductor layers 1551 and 1552 respectively.

[0120] Fig. 20C 1 shows the patterned surface of the sixth dielectric layer 156. Conductive layers 1561 and 1562 are formed on the patterned surface of the dielectric layer 156. Through holes 155T1a, 155T1b, 155T2a, 155T2b, 155T3a, 155T3b, 155T4a, and 155T4b are respectively connected to Fig. 20C The through holes 156T1a, 156T1b, 156T2a, 156T2b, 156T3a, 156T3b, 156T4a, 156T4b are shown connected.

[0121] Fig.21A1 shows the pattern forming surface of the seventh dielectric layer 157. A conductor layer 1571 is formed on the pattern forming surface of the dielectric layer 157. The through holes 156T1a, 156T1b, 156T2a, 156T2b, 156T3a, 156T3b, 156T4a, and 156T4b are respectively connected to Fig.21A The through holes 157T1a, 157T1b, 157T2a, 157T2b, 157T3a, 157T3b, 157T4a, 157T4b are shown connected.

[0122] Fig.21B The pattern forming surfaces of the eighth to fourteenth dielectric layers 158 to 164 are shown. The through holes 157T1a, 157T1b, 157T2a, 157T2b, 157T3a, 157T3b, 157T4a, and 157T4b are respectively connected to the through holes 158T1a, 158T1b, 158T2a, 158T2b, 158T3a, 158T3b, 158T4a, and 158T4b formed in the dielectric layer 158. In addition, in the dielectric layers 158 to 164, the through holes with the same reference numerals adjacent to each other are connected to each other.

[0123] Fig. 21C 165 shows the patterned surface of the fifteenth dielectric layer 165. Conductive layers 1651 and 1652 for inductors are formed on the patterned surface of the dielectric layer 165. The conductive layer 1651 has a first end and a second end located at both ends of the long side direction of the conductive layer 1651. The conductive layer 1652 has a first end and a second end located at both ends of the long side direction of the conductive layer 1652. The through holes 158T1a and 158T2a formed in the dielectric layer 164 are Fig. 21C The through hole 165T1a shown is connected to the vicinity of the first end of the conductor layer 1651. The through hole 158T1b formed in the dielectric layer 164 and Fig. 21C The through hole 165T1b shown is connected to the vicinity of the second end of the conductor layer 1651. The through hole 158T4a formed in the dielectric layer 164 and Fig. 21C The through hole 165T4a shown is connected to the vicinity of the first end of the conductor layer 1652. The through hole 158T4b formed in the dielectric layer 164 and Fig. 21C The illustrated via 165T4 b is connected to a portion of the conductor layer 1652 near the second end.

[0124] The through holes 158T2a, 158T2b, 158T3a, and 158T3b formed in the dielectric layer 164 are respectively Fig. 21C The through holes 165T2a, 165T2b, 165T3a, 165T3b are shown connected.

[0125] Fig.22AThe pattern forming surface of the sixteenth layer dielectric layer 166 is shown. Conductive layers 1661 and 1662 for inductors are formed on the pattern forming surface of the dielectric layer 166. The conductive layer 1661 has a first end and a second end located at both ends of the long side direction of the conductive layer 1661. The conductive layer 1662 has a first end and a second end located at both ends of the long side direction of the conductive layer 1662. The through hole 165T1a is connected to a portion near the first end of the conductive layer 1661. The through hole 165T1b is connected to a portion near the second end of the conductive layer 1661. The through hole 165T4a is connected to a portion near the first end of the conductive layer 1662. The through hole 165T4b is connected to a portion near the second end of the conductive layer 1662.

[0126] Through holes 165T2a, 165T2b, 165T3a, 165T3b are respectively Fig.22A The through holes 166T2a, 166T2b, 166T3a, 166T3b are shown connected.

[0127] Fig. 22B The pattern forming surfaces of the seventeenth to twenty-third dielectric layers 167 to 173 are shown. The through holes 166T2a, 166T2b, 166T3a, and 166T3b are respectively connected to the through holes 167T2a, 167T2b, 167T3a, and 167T3b formed in the dielectric layer 167. In addition, in the dielectric layers 167 to 173, the through holes with the same reference numerals adjacent to each other are connected to each other.

[0128] Fig. 22C 174 shows the patterned surface of the 24th dielectric layer 174. Conductive layers 1741 and 1742 for inductors are formed on the patterned surface of the dielectric layer 174. The conductive layer 1741 has a first end and a second end located at both ends of the long side direction of the conductive layer 1741. The conductive layer 1742 has a first end and a second end located at both ends of the long side direction of the conductive layer 1742. The through holes 167T2a and 167T2b formed in the dielectric layer 173 are Fig. 22C The through hole 174T2a shown is connected to the vicinity of the first end of the conductor layer 1741. The through hole 167T2b formed on the dielectric layer 173 and Fig. 22C The through hole 174T2b shown is connected to the vicinity of the second end of the conductor layer 1741. The through hole 167T3a and the through hole 167T3b formed on the dielectric layer 173 are connected to the conductive layer 1741. Fig. 22C The through hole 174T3a shown is connected to the vicinity of the first end of the conductor layer 1742. The through hole 167T3b formed on the dielectric layer 173 and Fig. 22C The illustrated through-hole 174T3 b is connected to a portion near the second end of the conductor layer 1742 .

[0129] Fig.23AThe pattern forming surface of the twenty-fifth dielectric layer 175 is shown. Conductive layers 1751 and 1752 for inductors are formed on the pattern forming surface of the dielectric layer 175. The conductive layer 1751 has a first end and a second end located at both ends of the long side direction of the conductive layer 1751. The conductive layer 1752 has a first end and a second end located at both ends of the long side direction of the conductive layer 1752. The through hole 174T2a is connected to a portion near the first end of the conductive layer 1751. The through hole 174T2b is connected to a portion near the second end of the conductive layer 1751. The through hole 174T3a is connected to a portion near the first end of the conductive layer 1752. The through hole 174T3b is connected to a portion near the second end of the conductive layer 1752.

[0130] Fig. 23B The pattern forming surface of the twenty-sixth dielectric layer 176 is shown. On the pattern forming surface of the dielectric layer 176, no conductive layer or through-hole is formed.

[0131] Fig.23C The pattern forming surface of the twenty-seventh dielectric layer 177 is shown. On the pattern forming surface of the dielectric layer 177, a mark 1771 is formed.

[0132] Fig.18 The stack 150 shown is constructed by stacking first to twenty-seventh dielectric layers 151 to 177 so that the pattern forming surface of the first dielectric layer 151 becomes the bottom surface 150A of the stack 150, and the surface of the twenty-seventh dielectric layer 177 on the opposite side of the pattern forming surface becomes the upper surface 150B of the stack 150.

[0133] Fig.24 1 shows the interior of a stacked body 150 formed by stacking the first to twenty-seventh dielectric layers 151 to 177. Fig.24 As shown, inside the stacked body 150, there are stacked Figures 19A to 23A In addition, in Fig.24 Mark 1771 is omitted.

[0134] The following, Fig.17 The components of the filter device 101 shown in FIG. Figures 19A to 23C1 and 16. The corresponding relationship of the components inside the laminate 150 shown in FIG. 1 is described. The inductor L11 is composed of the conductor layers 1651 and 1661 for the inductor, the through holes T1a and T1b, and the through holes 165T1a and 165T1b. The through hole T1a is formed by connecting the through holes 153T1a, 154T1a, 155T1a, 156T1a, 157T1a, and 158T1a in series. The through hole T1b is formed by connecting the through holes 152T1b, 153T1b, 154T1b, 155T1b, 156T1b, 157T1b, and 158T1b in series. The through holes 165T1a and 165T1b connect the conductor layers 1651 and 1661.

[0135] The inductor L12 is composed of the conductor layers 1741 and 1751 for the inductor, the through holes T2a and T2b, and the through holes 174T2a and 174T2b. The through hole T2a is formed by connecting the through holes 155T2a, 156T2a, 157T2a, 158T2a, 165T2a, 166T2a, and 167T2a in series. The through hole T2b is formed by connecting the through holes 152T2b, 153T2b, 154T2b, 155T2b, 156T2b, 157T2b, 158T2b, 165T2b, 166T2b, and 167T2b in series. The through holes 174T2a and 174T2b connect the conductor layers 1741 and 1751.

[0136] The inductor L13 is composed of the conductor layers 1742 and 1752 for the inductor, the through holes T3a and T3b, and the through holes 174T3a and 174T3b. The through hole T3a is formed by connecting the through holes 155T3a, 156T3a, 157T3a, 158T3a, 165T3a, 166T3a, and 167T3a in series. The through hole T3b is formed by connecting the through holes 152T3b, 153T3b, 154T3b, 155T3b, 156T3b, 157T3b, 158T3b, 165T3b, 166T3b, and 167T3b in series. The through holes 174T3a and 174T3b connect the conductor layers 1742 and 1752.

[0137] The inductor L14 is composed of the conductor layers 1652 and 1662 for the inductor, the through holes T4a and T4b, and the through holes 165T4a and 165T4b. The through hole T4a is formed by connecting the through holes 153T4a, 154T4a, 155T4a, 156T4a, 157T4a, and 158T4a in series. The through hole T4b is formed by connecting the through holes 152T4b, 153T4b, 154T4b, 155T4b, 156T4b, 157T4b, and 158T4b in series. The through holes 165T4a and 165T4b connect the conductor layers 1652 and 1662.

[0138] In addition, the first to fourth inductors L11, L12, L13, and L14 are also rectangular or substantially rectangular windings. In rectangular or substantially rectangular windings, when the winding is considered as a rectangle, each side of the rectangle can be counted as 1 / 4 turn. In the present embodiment, the first to fourth inductors L11, L12, L13, and L14 each have a 3 / 4 turn.

[0139] Capacitor C11 is composed of conductor layers 1521, 1531, 1541 and dielectric layers 152, 153 between these conductor layers. Capacitor C12 is composed of conductor layers 1521, 1532 and dielectric layer 152 between these conductor layers. Capacitor C13 is composed of conductor layers 1521, 1533 and dielectric layer 152 between these conductor layers. Capacitor C14 is composed of conductor layers 1521, 1534, 1542 and dielectric layers 152, 153 between these conductor layers.

[0140] Capacitor C15 is composed of conductor layers 1551, 1561 and dielectric layer 155 between these conductor layers. Capacitor C16 is composed of conductor layers 1532, 1533, 1543, 1551, 1552 and dielectric layers 153, 154 between these conductor layers. Capacitor C17 is composed of conductor layers 1552, 1562 and dielectric layer 155 between these conductor layers. Capacitor C18 is composed of conductor layers 1561, 1562, 1571 and dielectric layer 156 between these conductor layers.

[0141] The other structures, functions and effects of this embodiment are the same as those of the first embodiment.

[0142] [Example]

[0143] Next, embodiments of the present invention are described. First, the temperature coefficient TCF of the resonant frequency of the dielectric layer of the first to eighth embodiments is described. The dielectric layers of the first to eighth embodiments are all dielectric layers formed using raw material powders containing titanate compounds as dielectric materials. The dielectric layers of the first to third embodiments are dielectric layers formed using the same raw material powders. The dielectric layers of the fourth to eighth embodiments are dielectric layers formed using raw material powders of the same mixing ratio but different batches. In addition, the dielectric layers of the fourth to eighth embodiments use raw material powders of different batches from the raw material powders used for the dielectric layers of the first to third embodiments.

[0144] Below, we use the symbol TCF L The temperature coefficient TCF of the resonant frequency at -40 to 20°C is represented by the symbol TCF H The temperature coefficient TCF of the resonant frequency at 20 to 80°C is represented by the symbol TCF L-H Indicates the temperature coefficient TCF of the resonance frequency at -40 to 80°C.

[0145] Fig.25 is a TCF of each of the first to third embodiments. L 、TCF H 、TCF L-H Characteristic diagram of . Fig.26 The TCF of each of the third to eighth embodiments is shown in FIG. L 、TCF H 、TCF L-H Characteristic diagram of Fig.25 and Fig.26 In the figure, the vertical axis represents the value of the temperature coefficient TCF of the resonance frequency. Fig.25 and Fig.26 As shown, in any of the first to eighth embodiments, TCF L Both are positive, TCF H are all negative. In addition, Fig.25 and Fig.26 As shown, in any of the first to eighth embodiments, TCF L-H The absolute values ​​of become sufficiently small.

[0146] Next, the insertion loss and pass attenuation characteristics of the filter device of the ninth embodiment are described. The filter device of the ninth embodiment is a filter device corresponding to the filter device 101 of the second embodiment, and is a filter device designed so that the passband includes a frequency region of 26.5 GHz or more and 29.5 GHz or less. The dielectric layers 151 to 177 are formed using raw material powders containing titanate compounds as dielectric materials.

[0147] Fig. 27: is a characteristic diagram showing the insertion loss of the filter device of the ninth embodiment. Fig. 27 In the figure, the horizontal axis represents frequency and the vertical axis represents insertion loss. Fig. 27 In the figure, reference numeral 91 indicates the insertion loss at -40°C, reference numeral 92 indicates the insertion loss at 25°C, and reference numeral 93 indicates the insertion loss at 125°C. Here, the values ​​of the insertion loss are explained. The insertion loss at 26.5 GHz is 2.39 dB at -40°C, 2.59 dB at 25°C, and 2.89 dB at 125°C. In addition, the insertion loss at 29.5 GHz is 2.56 dB at -40°C, 2.85 dB at 25°C, and 3.39 dB at 125°C.

[0148] Fig.28 : is a characteristic diagram showing the pass attenuation characteristics of the filter device of the ninth embodiment. Fig.28 In the figure, the horizontal axis represents frequency and the vertical axis represents attenuation. Fig.28 In the figure, symbol 94 represents the pass-through attenuation characteristics at -40°C, symbol 95 represents the pass-through attenuation characteristics at 25°C, and symbol 96 represents the pass-through attenuation characteristics at 125°C. Here, the attenuation in the frequency region where the attenuation changes sharply near the passband of the filter device of the ninth embodiment is described. As for the attenuation at 25.5 GHz, it is 10.84 dB at -40°C, 11.67 dB at 25°C, and 11.00 dB at 125°C. As for the attenuation at 30.5 GHz, it is 29.22 dB at -40°C, 28.71 dB at 25°C, and 31.03 dB at 125°C. According to Fig.28 The results shown show that, particularly in a frequency region lower than the passband and in a frequency region where the attenuation changes rapidly, the attenuation hardly changes.

[0149] In addition, the present invention is not limited to the above-mentioned embodiment, and various modifications are possible. For example, the filter device of the present invention is not limited to a bandpass filter, and may be a filter device other than a bandpass filter including a plurality of resonators.

[0150] As described above, the stacked filter device of the present invention comprises a stacked body including a plurality of stacked dielectric layers, and a resonator formed by using a conductor integrated with the stacked body. The plurality of dielectric layers are respectively formed of dielectric materials and have a resonant frequency that varies depending on temperature. When the temperature is within a first temperature range, the dielectric material causes the resonant frequency to vary linearly with respect to the change in temperature, and when the temperature is within a second temperature range, the dielectric material causes the resonant frequency to vary nonlinearly with respect to the change in temperature.

[0151] In the multilayer filter device of the present invention, each of the plurality of dielectric layers may be a ceramic sintered body containing a dielectric material.

[0152] In addition, in the laminated filter device of the present invention, the change of the resonant frequency when the temperature decreases from a specific temperature relative to the change of the temperature can be the same as the change of the resonant frequency when the temperature increases from a specific temperature relative to the change of the temperature. Even in any case of the case where the temperature decreases from a specific temperature and the case where the temperature increases from a specific temperature, the resonant frequency can be smaller than the resonant frequency at the specific temperature. The specific temperature can also be within the second temperature range.

[0153] Furthermore, in the multilayer filter device of the present invention, within the first temperature range, the resonance frequency may increase monotonically or decrease monotonically with respect to a change in temperature.

[0154] In the multilayer filter device of the present invention, the second temperature range may include 20° C. The first temperature range may include a first sub-range lower than the second temperature range and a second sub-range higher than the second temperature range. The first sub-range may be narrower than the second sub-range.

[0155] In the multilayer filter device of the present invention, the difference between the maximum value and the minimum value of the resonance frequency in the second temperature range may be smaller than the difference between the maximum value and the minimum value of the resonance frequency in the first temperature range.

[0156] In the multilayer filter device of the present invention, the resonator may be an LC resonator including an inductor and a capacitor. The conductor may include an inductor conductor layer constituting the inductor and a capacitor conductor layer constituting the capacitor.

[0157] In the multilayer filter device of the present invention, the resonator may be a distributed constant resonator, and the conductor may include a conductor layer for a resonator constituting the distributed constant resonator.

[0158] It is clear from the above description that the present invention can be implemented in various forms or modifications. Therefore, within the scope of the equivalents of the claims, the present invention can be implemented even in forms other than the best form described above.

Claims

1. A stacked filter device, characterized in that: have: A laminate comprising a plurality of laminated dielectric layers; and A resonator is formed using a conductor integrated with the laminate, The plurality of dielectric layers are respectively made of dielectric materials and have a resonance frequency that varies depending on temperature. When the temperature is within a first temperature range, the dielectric material causes the resonant frequency to change linearly with respect to a change in the temperature; and when the temperature is within a second temperature range, the dielectric material causes the resonant frequency to change non-linearly with respect to a change in the temperature.

2. The multilayer filter device according to claim 1, wherein: Each of the plurality of dielectric layers is a ceramic sintered body containing the dielectric material.

3. The multilayer filter device according to claim 1, wherein: The manner in which the resonance frequency changes with respect to the change in temperature when the temperature decreases from a specific temperature is the same as the manner in which the resonance frequency changes with respect to the change in temperature when the temperature increases from the specific temperature.

4. The multilayer filter device according to claim 3, wherein: In any case where the temperature decreases from the specific temperature or increases from the specific temperature, the resonance frequency is smaller than the resonance frequency at the specific temperature.

5. The multilayer filter device according to claim 4, wherein: The specific temperature is within the second temperature range.

6. The multilayer filter device according to claim 1, wherein: In the first temperature range, the resonant frequency increases monotonically or decreases monotonically with respect to a change in the temperature.

7. The multilayer filter device according to claim 1, wherein: The second temperature range is a temperature range including 20°C.

8. The multilayer filter device according to claim 7, wherein: The first temperature range includes a first sub-range lower than the second temperature range and a second sub-range higher than the second temperature range, The first sub-range is narrower than the second sub-range.

9. The multilayer filter device according to claim 1, wherein: A difference between a maximum value and a minimum value of the resonance frequency in the second temperature range is smaller than a difference between a maximum value and a minimum value of the resonance frequency in the first temperature range.

10. The multilayer filter device according to claim 1, wherein: The resonator is an LC resonator including an inductor and a capacitor, The conductor includes a conductor layer for an inductor constituting the inductor and a conductor layer for a capacitor constituting the capacitor.

11. The multilayer filter device according to claim 1, wherein: The resonator is a distributed constant resonator, The conductor includes a conductor layer for a resonator constituting the distributed constant resonator.

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