Filter device and high frequency front-end circuit

Abstract

The filter device has an input terminal (T1), an output terminal (T2), a ground electrode (G1) and a ground electrode (G2) opposite to each other, and a resonator (RT10) connected to one of the input terminal (T1) and the output terminal (T2). The resonator (RT10) has a ground electrode (G3), a resonating portion (RT11), a resonating portion (RT12), and a resonating portion (RT13). The ground electrode (G3) is disposed between the ground electrode (G1) and the ground electrode (G2) and connected to the ground electrode (G1) and the ground electrode (G2). The resonating portion (RT11) is disposed between the ground electrode (G1) and the ground electrode (G3) and connected to the ground electrode (G3) and one terminal. The resonating portion (RT12) is disposed between the ground electrode (G1) and the ground electrode (G3) and connected to the ground electrode (G3). The resonating portion (RT13) is disposed between the ground electrode (G2) and the ground electrode (G3) and connected to the ground electrode (G3).

Description

Technical Field

[0001] This disclosure relates to filter devices and high-frequency front-end circuits, and more particularly to techniques for improving the characteristics of filter devices with resonators. Background Technology

[0002] International Patent Publication No. 2009 / 060696 (Patent Document 1) discloses a chip-type filter component that has a ground electrode arranged around a resonator electrode and has input and output electrodes coupled to the resonator electrode. In the chip-type filter component disclosed in Patent Document 1, the electrode length of the electrode portion disposed inside the chip body is set to be half the wavelength of a frequency lower than the resonant frequency of the resonator electrode.

[0003] By constructing chip-type filter components as described above, unwanted spurious emissions caused by waveguide modes that occur near the passband can be reduced.

[0004] Prior art literature

[0005] Patent documents

[0006] Patent Document 1: International Publication No. 2009 / 060696 Summary of the Invention

[0007] The problem that the invention aims to solve

[0008] In recent years, with the increase in communication standards, the frequency bands used in wireless communication have increased, sometimes using frequency bands adjacent to each other with very narrow intervals. Therefore, it is generally sought that, in a filter device like the one disclosed in Patent Document 1, the passband of the signal can be appropriately adjusted, and the signal can pass through the desired passband with low loss and the signal can be efficiently attenuated in the non-passband outside the desired passband.

[0009] This disclosure is made to solve the above-mentioned problems, and its purpose is to enable the appropriate adjustment of the signal passband and the improvement of attenuation characteristics in the non-passband in a filter device equipped with a resonator.

[0010] Methods for solving problems

[0011] The filter device disclosed herein includes: an input terminal; an output terminal; a first ground electrode and a second ground electrode opposite to each other; and a first resonator connected to one of the input terminal and the output terminal. The first resonator includes a first intermediate ground electrode, a first resonant portion, a second resonant portion, and a third resonant portion. The first intermediate ground electrode is disposed between the first ground electrode and the second ground electrode and connected to both the first ground electrode and the second ground electrode. The first resonant portion is disposed between the first ground electrode and the first intermediate ground electrode and connected to both the first intermediate ground electrode and the aforementioned terminal. The second resonant portion is disposed between the first ground electrode and the first intermediate ground electrode and connected to the first intermediate ground electrode. The third resonant portion is disposed between the second ground electrode and the first intermediate ground electrode and connected to the first intermediate ground electrode.

[0012] The filter device disclosed herein includes: an input terminal; an output terminal; a first ground electrode and a second ground electrode opposite to each other; a first resonator connected to the input terminal; a second resonator connected to the output terminal; and at least one intermediate resonator coupled to at least one of the first and second resonators via inductive coupling. The first resonator includes a first intermediate ground electrode, a first resonant portion, a second resonant portion, and a third resonant portion. The first intermediate ground electrode is disposed between the first ground electrode and the second ground electrode and connected to both the first and second ground electrodes. The first resonant portion is disposed between the first ground electrode and the first intermediate ground electrode and connected to both the first intermediate ground electrode and the input terminal. The second resonant portion is disposed between the first ground electrode and the first intermediate ground electrode and connected to both the first intermediate ground electrode. The third resonant portion is disposed between the second ground electrode and the first intermediate ground electrode and connected to both the first intermediate ground electrode. The second resonator includes a second intermediate ground electrode, a fourth resonant portion, a fifth resonant portion, and a sixth resonant portion. The second intermediate ground electrode is disposed between the first ground electrode and the second ground electrode and connected to both the first and second ground electrodes. The fourth resonant portion is disposed between the first ground electrode and the second intermediate ground electrode and connected to both the second intermediate ground electrode and the output terminal. The fifth resonant part is disposed between the first ground electrode and the second intermediate ground electrode, and is connected to the second intermediate ground electrode. The sixth resonant part is disposed between the second ground electrode and the second intermediate ground electrode, and is connected to the second intermediate ground electrode.

[0013] The effects of the invention

[0014] According to the filter device disclosed herein, by adjusting the position of the third resonant section disposed between the second ground electrode and the first intermediate ground electrode, attenuation poles can be generated in the pass characteristics of the filter device through resonance in the first resonant section, the second resonant section, and the third resonant section. Therefore, the passband of the signal can be appropriately adjusted, and the attenuation characteristics in the non-passband can be improved. Attached Figure Description

[0015] Figure 1 This is a block diagram of a communication device having a high-frequency front-end circuit that applies the filter device of Embodiment 1.

[0016] Figure 2 This is a diagram showing the coupling relationships in the filter device of Embodiment 1.

[0017] Figure 3 This is the equivalent circuit diagram of the filter device in Implementation Method 1.

[0018] Figure 4 This is a perspective view of the filter device according to Embodiment 1.

[0019] Figure 5 This is a plan view showing an example of the stacked layers of the filter device in Embodiment 1.

[0020] Figure 6 This is an exploded perspective view showing an example of the stacked structure of the filter device in Embodiment 1.

[0021] Figure 7 This is a 3D view of a resonator connected to the input terminal.

[0022] Figure 8 It is a simplified diagram showing the positional relationship of each resonant part in a resonator connected to the input terminal.

[0023] Figure 9 It means Figure 8 The diagram shows the characteristics of the resonator.

[0024] Figure 10 This diagram illustrates an example of a resonator connected to the input terminal after reducing the number of resonant sections.

[0025] Figure 11 It means Figure 10 The diagram shows the characteristics of the resonator.

[0026] Figure 12 This diagram illustrates an example of a resonator connected to the input terminal after reducing the number of resonant sections.

[0027] Figure 13 It means Figure 12 The diagram shows the characteristics of the resonator.

[0028] Figure 14 This is a diagram showing the throughput characteristics of the filter device according to Embodiment 1.

[0029] Figure 15 This is a graph showing the pass characteristics of a proportional filter device.

[0030] Figure 16 It is a diagram that simply shows the positional relationship of the resonators in the modified resonator.

[0031] Figure 17 It means Figure 16 The diagram shows the characteristics of the resonator.

[0032] Figure 18 It is a diagram that simply shows the positional relationship of the resonators in the modified resonator.

[0033] Figure 19 It means Figure 18 The diagram shows the characteristics of the resonator.

[0034] Figure 20 It is used for comparison Figure 8 , Figure 16 and Figure 18 The diagram shows the throughput characteristics of each resonator.

[0035] Figure 21 It is a diagram that simply shows the positional relationship of the resonators in the modified resonator.

[0036] Figure 22 It means Figure 21 The diagram shows the characteristics of the resonator.

[0037] Figure 23 It is used for comparison Figure 16 and Figure 21 The diagram shows the throughput characteristics of each resonator.

[0038] Figure 24 This is a simplified diagram showing the positional relationship of each resonant part in the resonator of Embodiment 2.

[0039] Figure 25 It means Figure 24 The diagram shows the characteristics of the resonator. Detailed Implementation

[0040] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. Furthermore, identical or equivalent parts in the drawings will be labeled with the same reference numerals, and their descriptions will not be repeated.

[0041] [Implementation Method 1]

[0042] (Basic structure of communication device 10)

[0043] Figure 1 This is a block diagram of a communication device 10 having a high-frequency front-end circuit 20 that applies the filter device of embodiment 1. The communication device 10 is, for example, a mobile phone base station.

[0044] Reference Figure 1 The 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. Furthermore, the high-frequency front-end circuit 20 includes bandpass filters 22 and 28, an amplifier 24, and an attenuator 26. Additionally, in... Figure 1 In this description, the high-frequency front-end circuit 20 includes a transmitting circuit that transmits high-frequency signals from the antenna 12, but the high-frequency front-end circuit 20 may also include a receiving circuit that transmits high-frequency signals received through the antenna 12.

[0045] The communication device 10 up-converts the transmit signal from the RF circuit 50 into a high-frequency signal and transmits it from the antenna 12. The modulated digital signal output from the RF circuit 50 is converted into an analog signal by the D / A converter 40. The mixer 30 mixes the transmitted signal (converted from digital to analog by the D / A converter 40) with the oscillation signal from the local oscillator 32 and up-converts it into a high-frequency signal. The bandpass filter 28 removes unwanted waves generated during up-conversion, extracting only the transmit signal within the desired frequency band. The attenuator 26 adjusts the strength of the transmit signal. The amplifier 24 amplifies the power of the transmit signal after passing through the attenuator 26 to a specified level. The bandpass filter 22 removes unwanted waves generated during amplification and allows only the signal components within the frequency band determined according to the communication standard to pass through. The transmit signal after passing through the bandpass filter 22 is transmitted via the antenna 12.

[0046] The bandpass filters 22 and 28 in the aforementioned communication device 10 may be the filter device 100 corresponding to this disclosure.

[0047] (Circuit configuration of filter device 100)

[0048] use Figure 2 and Figure 3 The circuit configuration of the filter device 100 according to Embodiment 1 is explained. Figure 2 This is a diagram showing the coupling relationships in the filter device 100 of Embodiment 1. Figure 3 This is an equivalent circuit diagram of the filter device 100 according to Embodiment 1.

[0049] Reference Figure 2 and Figure 3The filter device 100 includes an input terminal T1, an output terminal T2, and a plurality of resonators RT10 to RT70 disposed between the input terminal T1 and the output terminal T2. Specifically, the filter device 100 includes a resonator RT10 connected to the input terminal T1, a resonator RT20 connected to the output terminal T2, and a plurality of resonators RT30, RT40, RT50, RT60, and RT70 disposed between the resonator RT10 and the resonator RT20.

[0050] The resonator RT10 corresponds to the "first resonator" or "second resonator" of this disclosure. The resonator RT10 includes a resonant section RT11, a resonant section RT12, a resonant section RT13, and a capacitor C14 connected to the resonant sections RT11 and RT12.

[0051] The resonant section RT11 corresponds to the "first resonant section" or "fourth resonator" of this disclosure. For example... Figure 3 As shown, the resonant section RT11 includes an inductor L11 and a capacitor C11 connected in parallel between the input terminal T1 and the ground terminal GND. One end of each of the inductor L11 and the capacitor C11 is connected to the input terminal T1, and the other end of each of the inductor L11 and the capacitor C11 is connected to the ground terminal GND. The inductor L11 includes a conductor (passage V11 described later) having a length of 1 / 4 of the wavelength λ corresponding to the center frequency of the signal's passband. The resonant section RT11 is a so-called λ / 4 resonator.

[0052] The resonant section RT12 corresponds to the "second resonant section" or "fifth resonator" of this disclosure. The resonant section RT12 comprises an inductor L12 and a capacitor C12 connected in parallel between a capacitor C14 and a ground terminal GND. One end of the capacitor C14 is connected to the input terminal T1, and the other end of the capacitor C14 is connected to one end of each of the inductor L12 and the capacitor C12. One end of each of the inductor L12 and the capacitor C12 is connected to the input terminal T1 via the capacitor C14, and the other end of each of the inductor L12 and the capacitor C12 is connected to the ground terminal GND. The inductor L12 comprises a conductor (path V12 described later) having a length of 1 / 4 of the wavelength λ corresponding to the center frequency of the signal's passband. The resonant section RT12 is a so-called λ / 4 resonator.

[0053] The resonant section RT13 corresponds to the "third resonant section" or "sixth resonator" of this disclosure. The resonant section RT13 includes an inductor L13 and a capacitor C13. One end of the inductor L13 is connected to the ground terminal GND, and the other end of the inductor L13 is connected to one end of the capacitor C13. The other end of the capacitor C13 is also connected to the ground terminal GND. The inductor L13 includes a conductor (path V13 described later) having a length of 1 / 4 of the wavelength λ corresponding to the center frequency of the signal's passband. The resonant section RT13 is a so-called λ / 4 resonator.

[0054] The resonator RT20 corresponds to the "first resonator" or "second resonator" of this disclosure. The resonator RT20 includes a resonant section RT21, a resonant section RT22, a resonant section RT23, and a capacitor C24 connected to the resonant sections RT21 and RT22.

[0055] The resonant section RT21 corresponds to the "first resonant section" or "fourth resonant section" of this disclosure. The resonant section RT21 includes an inductor L21 and a capacitor C21 connected in parallel between the output terminal T2 and the ground terminal GND. One end of each of the inductor L21 and the capacitor C21 is connected to the output terminal T2, and the other end of each is connected to the ground terminal GND. The inductor L21 includes a conductor (path V21 described later) having a length of 1 / 4 of the wavelength λ corresponding to the center frequency of the signal's passband. The resonant section RT21 is a so-called λ / 4 resonator.

[0056] The resonant section RT22 corresponds to the "second resonant section" or "fifth resonant section" of this disclosure. The resonant section RT22 includes an inductor L22 and a capacitor C22 connected in parallel between a capacitor C24 and a ground terminal GND. One end of the capacitor C24 is connected to the output terminal T2, and the other end of the capacitor C24 is connected to one end of both the inductor L22 and the capacitor C22. One end of each of the inductor L22 and the capacitor C22 is connected to the output terminal T2 via the capacitor C24, and the other end of each of the inductor L22 and the capacitor C22 is connected to the ground terminal GND. The inductor L22 includes a conductor (path V22 described later) having a length of 1 / 4 of the wavelength λ corresponding to the center frequency of the signal's passband. The resonant section RT22 is a so-called λ / 4 resonator.

[0057] The resonant section RT23 corresponds to the "third resonant section" or "sixth resonant section" of this disclosure. The resonant section RT23 includes an inductor L23 and a capacitor C23. One end of the inductor L23 is connected to the ground terminal GND, and the other end of the inductor L23 is connected to one end of the capacitor C23. The other end of the capacitor C23 is also connected to the ground terminal GND. The inductor L23 includes a conductor (path V23 described later) having a length of 1 / 4 of the wavelength λ corresponding to the center frequency of the signal's passband. The resonant section RT23 is a so-called λ / 4 resonator.

[0058] Resonator RT30 corresponds to the "intermediate resonator" of this disclosure. Resonator RT30 includes a capacitor C31, an inductor L31, and a capacitor C32 connected in series. One end of capacitor C31 is connected to the ground terminal GND, and the other end of capacitor C31 is connected to one end of inductor L31. One end of capacitor C32 is connected to the ground terminal GND, and the other end of capacitor C32 is connected to the other end of inductor L31. Inductor L31 includes a conductor (path V31 described later) having a length of 1 / 2 wavelength λ corresponding to the center frequency of the signal's passband. Resonator RT30 is a so-called λ / 2 resonator.

[0059] Resonator RT40 corresponds to the "intermediate resonator" of this disclosure. Resonator RT40 includes a capacitor C41, an inductor L41, and a capacitor C42 connected in series. One end of capacitor C41 is connected to the ground terminal GND, and the other end of capacitor C41 is connected to one end of inductor L41. One end of capacitor C42 is connected to the ground terminal GND, and the other end of capacitor C42 is connected to the other end of inductor L41. Inductor L41 includes a conductor (path V41 described later) having a length of 1 / 2 wavelength λ corresponding to the center frequency of the signal's passband. Resonator RT40 is a so-called λ / 2 resonator.

[0060] Resonator RT50 corresponds to the "intermediate resonator" of this disclosure. Resonator RT50 includes a capacitor C51, an inductor L51, and a capacitor C52 connected in series. One end of capacitor C51 is connected to the ground terminal GND, and the other end of capacitor C51 is connected to one end of inductor L51. One end of capacitor C52 is connected to the ground terminal GND, and the other end of capacitor C52 is connected to the other end of inductor L51. Inductor L51 includes a conductor (path V51 described later) having a length of 1 / 2 wavelength λ corresponding to the center frequency of the signal's passband. Resonator RT50 is a so-called λ / 2 resonator.

[0061] Resonator RT60 corresponds to the "intermediate resonator" of this disclosure. Resonator RT60 includes a capacitor C61, an inductor L61, and a capacitor C62 connected in series. One end of capacitor C61 is connected to the ground terminal GND, and the other end of capacitor C61 is connected to one end of inductor L61. One end of capacitor C62 is connected to the ground terminal GND, and the other end of capacitor C62 is connected to the other end of inductor L61. Inductor L61 includes a conductor (path V61 described later) having a length of 1 / 2 wavelength λ corresponding to the center frequency of the signal's passband. Resonator RT60 is a so-called λ / 2 resonator.

[0062] Resonator RT70 corresponds to the "intermediate resonator" of this disclosure. Resonator RT70 includes a capacitor C71, an inductor L71, and a capacitor C72 connected in series. One end of capacitor C71 is connected to the ground terminal GND, and the other end of capacitor C71 is connected to one end of inductor L71. One end of capacitor C72 is connected to the ground terminal GND, and the other end of capacitor C72 is connected to the other end of inductor L71. Inductor L71 includes a conductor (path V71 described later) having a length of 1 / 2 wavelength λ corresponding to the center frequency of the signal's passband. Resonator RT70 is a so-called λ / 2 resonator.

[0063] like Figure 2 As shown, the resonant sections RT11 and RT12 of resonator RT10 are coupled via inductive coupling M1. The resonant sections RT21 and RT22 of resonator RT20 are coupled via inductive coupling M2. The resonant section RT13 of resonator RT10 and resonator RT30 are coupled via inductive coupling M3. Resonator RT30 and resonator RT40 are coupled via inductive coupling M4. Resonator RT40 and resonator RT50 are coupled via inductive coupling M5. Resonator RT50 and resonator RT60 are coupled via inductive coupling M6. Resonator RT60 and resonator RT70 are coupled via inductive coupling M7. Resonator RT70 and the resonant section RT23 of resonator RT20 are coupled via inductive coupling M8. Furthermore, resonator RT40 and resonator RT60 are coupled via inductive coupling M9.

[0064] (Internal configuration of filter device 100)

[0065] use Figures 4-6 The internal structure of the filter device 100 according to Embodiment 1 will be explained. Figure 4 This is a perspective view of the filter device 100 according to Embodiment 1. Figure 5 This is a plan view showing an example of each stack of the filter device 100 in Embodiment 1. Figure 6 This is an exploded perspective view showing an example of the stacked structure of the filter device 100 according to Embodiment 1.

[0066] The filter device 100 includes a cuboid or substantially cuboid dielectric substrate 110 formed by stacking multiple dielectric layers in a predetermined direction. The direction in which the multiple dielectric layers are stacked in the dielectric substrate 110 is called the stacking direction. Each dielectric layer in the dielectric substrate 110 is formed, for example, of a dielectric ceramic such as low-temperature co-fired ceramic (LTCC), or a dielectric material such as crystal or resin. Inside the dielectric substrate 110, multiple electrodes and multiple pathways constitute resonators RT10 to RT70. Furthermore, in this specification, "path" refers to a conductor provided on the dielectric substrate for connecting multiple electrodes located at different positions in the stacking direction. Paths are formed, for example, by conductive paste, plating, and / or metal pins.

[0067] In the following description, the stacking direction of the dielectric substrate 110 is referred to as the "Z-axis direction", the direction perpendicular to the Z-axis direction and along the long side of the dielectric substrate 110 is referred to as the "X-axis direction", and the direction perpendicular to the Z-axis direction and along the short side of the dielectric substrate 110 is referred to as the "Y-axis direction". In addition, the positive direction of the Z-axis in each figure is sometimes referred to as the upper side and the negative direction as the lower side.

[0068] In addition, Figures 4-6 and the following Figure 7 In order to show the internal structure, the dielectric of the dielectric substrate 110 is omitted, and only the conductors such as electrodes (plate electrodes, ground electrodes), passages and terminals disposed inside are shown.

[0069] Reference Figures 4-6 The dielectric substrate 110 has a lower surface 111 and an upper surface 112 extending in the XY direction, and a side surface 113 connecting the outer edge of the lower surface 111 and the outer edge of the upper surface 112. A first layer S101 is sequentially disposed on the dielectric substrate 110 from the lower surface 111 toward the upper surface 112 along the positive Z-axis. Figure 5 (A)), second layer S102 ( Figure 5 (B)), third layer S103 ( Figure 5 (C)), fourth layer S104 ( Figure 5 (D)), fifth layer S105 ( Figure 5 (E)) and the sixth layer S106 ( Figure 5 (F)).

[0070] The first layer S101 is configured with a ground electrode G100 corresponding to the ground terminal GND, an input terminal T1, and an output terminal T2. Two cutouts K1 and K2 are formed in the ground electrode G100. The input terminal T1 is located at cutout K1, and the output terminal T2 is located at cutout K2. The input terminal T1, the output terminal T2, and the ground terminal GND function as external terminals for connecting the filter device 100 to external devices.

[0071] The second layer S102 includes a grounding electrode G1 corresponding to the grounding terminal GND. The grounding electrode G1 corresponds to the "first grounding electrode" of this disclosure. Two cut-out portions K11 and K12 are formed in the grounding electrode G1. A flat plate electrode P1 is provided at the cut-out portion K11, and a flat plate electrode P2 is provided at the cut-out portion K12.

[0072] Viewed from the normal direction (Z-axis direction) of the dielectric substrate 110, the cutout portions K11 and K12 of the second layer S102 overlap with the cutout portions K1 and K2 of the first layer S101, respectively. The planar electrode P1 disposed at the cutout portion K11 of the second layer S102, when viewed from the normal direction (Z-axis direction) of the dielectric substrate 110, is positioned to overlap with the input terminal T1 disposed at the cutout portion K1 of the first layer S101. The planar electrode P2 disposed at the cutout portion K12 of the second layer S102, when viewed from the normal direction (Z-axis direction) of the dielectric substrate 110, is positioned to overlap with the output terminal T2 disposed at the cutout portion K2 of the first layer S101.

[0073] The third layer S103 includes planar electrodes P11 and P12 disposed on the input terminal T1 side, and planar electrodes P21 and P22 disposed on the output terminal T2 side. Planar electrodes P11 and P12 are positioned to overlap with the input terminal T1 and planar electrode P1 when viewed from above in the normal direction (Z-axis direction) of the dielectric substrate 110. Planar electrodes P21 and P22 are positioned to overlap with the output terminal T2 and planar electrode P2 when viewed from above in the normal direction (Z-axis direction) of the dielectric substrate 110. None of the planar electrodes P11, P12, P21, and P22 are connected to the ground electrode G1; instead, they are disposed at intervals from the ground electrode G1.

[0074] Furthermore, the third layer S103 includes planar electrodes P311, P411, P511, P611, and P711. Each of the planar electrodes P311, P411, P511, P611, and P711 corresponds to the "first planar electrode" of this disclosure. None of the planar electrodes P311, P411, P511, P611, and P711 are connected to the ground electrode G1; instead, they are arranged at intervals from the ground electrode G1, opposite to it.

[0075] The fourth layer S104 includes a ground electrode G3 and a ground electrode G4 corresponding to the ground terminal GND. Ground electrodes G3 and G4 each correspond to either the "first intermediate ground electrode" or the "second intermediate ground electrode" of this disclosure. Ground electrode G3 is disposed on the input terminal T1 side, while ground electrode G4 is disposed on the output terminal T2 side. Ground electrode G3 is positioned to overlap with the input terminal T1, the plate electrode P1, and the plate electrodes P11 and P12 when viewed from above in the normal direction (Z-axis direction) of the dielectric substrate 110. Ground electrode G4 is positioned to overlap with the output terminal T2, the plate electrode P2, and the plate electrodes P21 and P22 when viewed from above in the normal direction (Z-axis direction) of the dielectric substrate 110.

[0076] The fifth layer S105 includes plate electrodes P13, P23, P312, P412, P512, P612, and P712. Each of the plate electrodes P312, P412, P512, P612, and P712 corresponds to the "second plate electrode" of this disclosure. None of the plate electrodes P13, P23, P312, P412, P612, and P712 are connected to the ground electrode G2 (described later), but are instead arranged at intervals from the ground electrode G2 in a manner opposite to the ground electrode G2.

[0077] The sixth layer S106 includes a ground electrode G2 corresponding to the ground terminal GND. The ground electrode G2 is configured opposite to the ground electrode G1. The ground electrode G2 corresponds to the "second ground electrode" of this disclosure.

[0078] Multiple grounding paths VG are provided in the dielectric substrate 110. Each grounding path VG is a columnar conductor extending in the Z-axis direction and connected to the grounding electrode of each of the first layer S101 to the sixth layer S106. For example, the grounding electrodes G1 and G2 of the second layer and the grounding electrode G3 of the fourth layer are connected by multiple grounding paths VG (7 in this example), including grounding paths VG11 and VG12. The grounding electrodes G1 and G2 of the second layer and the grounding electrode G4 of the fourth layer are connected by multiple grounding paths VG (5 in this example), including grounding paths VG21 and VG22.

[0079] like Figure 4 and Figure 6 As shown, a passage V1 extending in the Z-axis direction is provided between the input terminal T1 and the plate electrode P1. The passage V1 connects the input terminal T1 and the plate electrode P1.

[0080] A passage V10 extending in the Z-axis direction is provided between plate electrode P1 and plate electrode P11. Passage V10 connects plate electrode P1 and plate electrode P11.

[0081] A passage V11 extending in the Z-axis direction is provided between the plate electrode P11 and the ground electrode G3. The passage V11 corresponds to the "first conductor" of this disclosure and connects the plate electrode P11 and the ground electrode G3.

[0082] A passage V12 extending in the Z-axis direction is provided between the plate electrode P12 and the ground electrode G3. The passage V12 corresponds to the "first conductor" of this disclosure and connects the plate electrode P12 and the ground electrode G3.

[0083] A passage V13 extending in the Z-axis direction is provided between the ground electrode G3 and the plate electrode P13. The passage V13 corresponds to the "first conductor" of this disclosure and connects the ground electrode G3 and the plate electrode P13.

[0084] Figure 2 and Figure 3 The resonant RT10 shown in the figure has a resonant section RT11 disposed between the ground electrode G1 and the ground electrode G3, and connected to the ground electrode G3 and the input terminal T1. Specifically, the resonant section RT11 is composed of a plate electrode P11, a ground electrode G3 opposite to the plate electrode P11, and a passage V11 connecting the plate electrode P11 and the ground electrode G3. Figure 3 The inductor L11 is formed by the path V11. Figure 3 The capacitor C11 consists of a flat plate electrode P11 and a ground electrode G1.

[0085] Figure 2 and Figure 3 The resonant section RT12 of the resonator RT10 shown is disposed between the ground electrode G1 and the ground electrode G3 and is connected to the ground electrode G3. Furthermore, the resonant section RT12 is not connected to the input terminal T1. Specifically, the resonant section RT12 consists of a planar electrode P12, a ground electrode G3 opposite to the planar electrode P12, and a passage V12 connecting the planar electrode P12 and the ground electrode G3. Figure 3 The inductor L12 is composed of the circuit V12. Figure 3 The capacitor C12 is composed of a flat plate electrode P12 and a ground electrode G1.

[0086] Figure 2 and Figure 3 The resonant RT10 shown in the figure has a resonant section RT13 disposed between the ground electrode G2 and the ground electrode G3, and connected to the ground electrode G3. Specifically, the resonant section RT13 consists of the ground electrode G3, a plate electrode P13 opposite to the ground electrode G3, and a passage V13 connecting the ground electrode G3 and the plate electrode P13. Figure 3 The inductor L13 is formed by the path V13. The plate electrode P13 is not connected to the ground electrode G2, therefore, a local capacitance is formed between the plate electrode P13 and the ground electrode G2. Figure 3 The capacitor C13 consists of a flat plate electrode P13 and a ground electrode G2.

[0087] A passage V2 extending in the Z-axis direction is provided between the output terminal T2 and the flat plate electrode P2. The passage V2 connects the output terminal T2 and the flat plate electrode P2.

[0088] A passage V20 extending in the Z-axis direction is provided between plate electrode P2 and plate electrode P21. Passage V20 connects plate electrode P2 and plate electrode P21.

[0089] A passage V21 extending in the Z-axis direction is provided between the plate electrode P21 and the ground electrode G4. The passage V21 corresponds to the "first conductor" of this disclosure and connects the plate electrode P21 and the ground electrode G4.

[0090] A passage V22 extending in the Z-axis direction is provided between the plate electrode P22 and the ground electrode G4. The passage V22 corresponds to the "first conductor" of this disclosure and connects the plate electrode P22 and the ground electrode G4.

[0091] A passage V23 extending in the Z-axis direction is provided between the ground electrode G4 and the plate electrode P23. The passage V23 corresponds to the "first conductor" of this disclosure and connects the ground electrode G4 and the plate electrode P23.

[0092] Figure 2 and Figure 3 The resonant section RT21 of the resonator RT20 shown is disposed between the ground electrode G1 and the ground electrode G4, and is connected to the ground electrode G4 and the output terminal T2. Specifically, the resonant section RT21 is composed of a plate electrode P21, a ground electrode G4 opposite to the plate electrode P21, and a passage V21 connecting the plate electrode P21 and the ground electrode G4. Figure 3 The inductor L21 is formed by the path V21. Figure 3 The capacitor C21 consists of a flat plate electrode P21 and a ground electrode G1.

[0093] Figure 2 and Figure 3The resonant section RT22 of the resonator RT20 shown is disposed between the ground electrode G1 and the ground electrode G4, and is connected to the ground electrode G4. Furthermore, the resonant section RT22 is not connected to the output terminal T2. Specifically, the resonant section RT22 consists of a planar electrode P22, a ground electrode G4 opposite to the planar electrode P22, and a passage V22 connecting the planar electrode P22 and the ground electrode G4. Figure 3 The inductor L22 is composed of the circuit V22. Figure 3 The capacitor C22 consists of a flat plate electrode P22 and a ground electrode G1.

[0094] Figure 2 and Figure 3 The resonant RT20 shown in the figure has a resonant section RT23 disposed between the ground electrode G2 and the ground electrode G4, and connected to the ground electrode G4. Specifically, the resonant section RT23 consists of the ground electrode G4, a plate electrode P23 opposite to the ground electrode G4, and a passage V23 connecting the ground electrode G4 and the plate electrode P23. Figure 3 The inductor L23 is formed by the path V23. The plate electrode P23 is not connected to the ground electrode G2, therefore, a local capacitance is formed between the plate electrode P23 and the ground electrode G2. Figure 3 The capacitor C23 consists of a flat plate electrode P23 and a ground electrode G2.

[0095] A passage V31 extending in the Z-axis direction is provided between the plate electrode P311 and the plate electrode P312. The passage V31 corresponds to the "second conductor" of this disclosure and connects the plate electrode P311 and the plate electrode P312.

[0096] A passage V41 extending in the Z-axis direction is provided between plate electrode P411 and plate electrode P412. Passage V41 corresponds to the "second conductor" of this disclosure and connects plate electrode P411 and plate electrode P412.

[0097] A passage V511, V512, and V513 extending in the Z-axis direction is provided between the plate electrode P511 and the plate electrode P512. The passage V511, V512, and V513 correspond to the "second conductor" of this disclosure and connect the plate electrode P511 and the plate electrode P512.

[0098] A passage V61 extending in the Z-axis direction is provided between the plate electrode P611 and the plate electrode P612. The passage V61 corresponds to the "second conductor" of this disclosure and connects the plate electrode P611 and the plate electrode P612.

[0099] A passage V71 extending in the Z-axis direction is provided between the plate electrode P711 and the plate electrode P712. The passage V71 corresponds to the "second conductor" of this disclosure and connects the plate electrode P711 and the plate electrode P712.

[0100] Figure 2 and Figure 3 The resonator RT30 shown is disposed between the ground electrode G1 and the ground electrode G2. Specifically, the resonator RT30 consists of a plate electrode P311, a plate electrode P312 opposite to the plate electrode P311, and a passage V31 connecting the plate electrode P311 and the plate electrode P312. Figure 3 The inductor L31 is formed by the path V31. The planar electrode P311 is not connected to the ground electrode G1, therefore, a local capacitance is formed between the planar electrode P311 and the ground electrode G1. Figure 3 The capacitor C31 is composed of a plate electrode P311 and a ground electrode G1. The plate electrode P312 is not connected to the ground electrode G2; therefore, a local capacitance is formed between the plate electrode P312 and the ground electrode G2. Figure 3 The capacitor C32 is composed of a flat plate electrode P312 and a ground electrode G2.

[0101] Figure 2 and Figure 3 The resonator RT40 shown is disposed between the ground electrode G1 and the ground electrode G2. Specifically, the resonator RT40 consists of a plate electrode P411, a plate electrode P412 opposite to the plate electrode P411, and a passage V41 connecting the plate electrode P411 and the plate electrode P412. Figure 3 The inductor L41 is formed by the path V41. The planar electrode P411 is not connected to the ground electrode G1, therefore, a local capacitance is formed between the planar electrode P411 and the ground electrode G1. Figure 3 The capacitor C41 consists of a plate electrode P411 and a ground electrode G1. The plate electrode P412 is not connected to the ground electrode G2; therefore, a local capacitance is formed between the plate electrode P412 and the ground electrode G2. Figure 3 The capacitor C42 consists of a flat plate electrode P412 and a ground electrode G2.

[0102] Figure 2 and Figure 3 The resonator RT50 shown is disposed between the ground electrode G1 and the ground electrode G2. Specifically, the resonator RT50 is composed of a plate electrode P511, a plate electrode P512 opposite to the plate electrode P511, and a passage V511 to V513 connecting the plate electrode P511 and the plate electrode P512. Figure 3The inductor L51 is composed of paths V511 to V513. The planar electrode P511 is not connected to the ground electrode G1, therefore, a local capacitance is formed between the planar electrode P511 and the ground electrode G1. Figure 3 The capacitor C51 consists of a plate electrode P511 and a ground electrode G1. The plate electrode P512 is not connected to the ground electrode G2; therefore, a local capacitance is formed between the plate electrode P512 and the ground electrode G2. Figure 3 The capacitor C52 consists of a flat plate electrode P512 and a ground electrode G2.

[0103] The resonator RT50 has a ring shape formed by connecting the parallel paths V511 to V513 between the plate electrodes P511 and P512. In this ring-shaped resonator RT50, the hollow diameter of the inductor formed by the resonator RT50 is increased, thus, the Q value can be improved while keeping the size of the dielectric substrate 110 the same. Alternatively, the size of the dielectric substrate 110 can be reduced while maintaining the Q value.

[0104] Figure 2 and Figure 3 The resonator RT60 shown is disposed between ground electrode G1 and ground electrode G2. Specifically, the resonator RT60 consists of a plate electrode P611, a plate electrode P612 opposite to plate electrode P611, and a passage V61 connecting plate electrode P611 and plate electrode P612. Figure 3 The inductor L61 is formed by the path V61. The planar electrode P611 is not connected to the ground electrode G1, therefore, a local capacitance is formed between the planar electrode P611 and the ground electrode G1. Figure 3 The capacitor C61 consists of a plate electrode P611 and a ground electrode G1. The plate electrode P612 is not connected to the ground electrode G2; therefore, a local capacitance is formed between the plate electrode P612 and the ground electrode G2. Figure 3 The capacitor C62 consists of a flat plate electrode P612 and a ground electrode G2.

[0105] Figure 2 and Figure 3 The resonator RT70 shown is disposed between ground electrode G1 and ground electrode G2. Specifically, the resonator RT70 consists of a plate electrode P711, a plate electrode P712 opposite to the plate electrode P711, and a passage V71 connecting the plate electrode P711 and the plate electrode P712. Figure 3 The inductor L71 is formed by the path V71. The planar electrode P711 is not connected to the ground electrode G1, therefore, a local capacitance is formed between the planar electrode P711 and the ground electrode G1. Figure 3The capacitor C71 consists of a plate electrode P711 and a ground electrode G1. The plate electrode P712 is not connected to the ground electrode G2; therefore, a local capacitance is formed between the plate electrode P712 and the ground electrode G2. Figure 3 The capacitor C72 consists of a flat plate electrode P712 and a ground electrode G2.

[0106] As described above, resonator RT10 is connected to input terminal T1, and resonator RT20 is connected to output terminal T2. Resonators RT10, RT30, RT40, and RT50 are arranged in this order along the positive X-axis. Resonators RT50, RT60, RT70, and RT20 are arranged in this order along the negative X-axis. Furthermore, resonators RT10 and RT20, RT30 and RT70, and RT40 and RT60 are adjacent in the Y-axis direction.

[0107] That is, the path from resonator RT10 through resonator RT30, resonator RT40, resonator RT50, resonator RT60 and resonator RT70 to resonator RT20 becomes a linearly symmetrical reversal with resonator RT50 as the reversal point.

[0108] Resonators RT10 to RT70 are each resonators based on the TE101 mode, with the Z-axis as the electric field direction and the magnetic field rotating in a plane along the XY plane to transmit signals.

[0109] Adjacent resonators are coupled through inductive or capacitive coupling. It is known that capacitive coupling generally occurs when the spacing of the electric field direction (i.e., the spacing in the Z-axis direction) in the coupling window between adjacent resonators becomes narrower, while inductive coupling occurs when the spacing in the direction orthogonal to the electric field direction in the coupling window becomes narrower.

[0110] In the filter device 100, a local capacitance is formed between the plate electrode P11 of the resonant section RT11 and the plate electrode P12 of the resonant section RT12. Figure 3 The capacitor C14 is composed of plate electrodes P11 and P12. A local capacitance is formed between plate electrode P21 of resonant section RT21 and plate electrode P22 of resonant section RT22. Figure 3 The capacitor C24 is composed of plate electrodes P21 and P22.

[0111] Inductive coupling M1 occurs between the path V11 of resonator RT11 and the path V12 of resonator RT12. Inductive coupling M2 occurs between the path V21 of resonator RT21 and the path V22 of resonator RT22. Inductive coupling M3 occurs between the path V13 of resonator RT13 and the path V31 of resonator RT30. Inductive coupling M4 occurs between the path V31 of resonator RT30 and the path V41 of resonator RT40. Inductive coupling M5 occurs between the path V41 of resonator RT40 and the path V51 of resonator RT50. Inductive coupling M6 occurs between the path V51 of resonator RT50 and the path V61 of resonator RT60. Inductive coupling M7 occurs between the path V61 of resonator RT60 and the path V71 of resonator RT70. Inductive coupling M8 occurs between the path V71 of resonator RT70 and the path V23 of resonator RT23. Inductive coupling M9 occurs between the path V41 of resonator RT40 and the path V61 of resonator RT60.

[0112] (Pass characteristics of the resonator)

[0113] use Figures 7-13 Explain the throughput characteristics of resonator RT10. Figure 7 This is a 3D view of the resonator RT10 connected to the input terminal T1. Figure 8 This is a simplified diagram showing the positional relationship of the resonant sections RT11 to RT13 in the resonator RT10 connected to the input terminal T1. Furthermore, in Figure 8 and the following Figure 10 , Figure 12 , Figure 16 , Figure 18 , Figure 21 , Figure 24 In simplified terms, the direction is orthogonal to the Z-axis and to the path connecting position A, which is symmetrical to the resonant part RT11 with reference to ground electrode G3, and position B, which is symmetrical to the resonant part RT12 with reference to ground electrode G3. Figure 7 The positional relationship of each resonator RT11 to RT13 when observing the resonator RT10 (direction of arrow Y, side direction of filter device 100).

[0114] Reference Figure 7 and Figure 8The resonant section RT11 includes a planar electrode P11, a ground electrode G3 opposite to the planar electrode P11, and a passage V11 connecting the planar electrode P11 and the ground electrode G3. One end of the passage V11 is connected to the ground electrode G3, and the other end of the passage V11 is connected to the input terminal T1 via the passage V10. The resonant section RT12 includes a planar electrode P12, a ground electrode G3 opposite to the planar electrode P12, and a passage V12 connecting the planar electrode P12 and the ground electrode G3. One end of the passage V12 is connected to the ground electrode G3, and the other end of the passage V12 is an open circuit. The resonant section RT13 includes a planar electrode P13, a ground electrode G3 opposite to the planar electrode P12, and a passage V13 connecting the planar electrode P12 and the ground electrode G3. One end of the passage V12 is connected to the ground electrode G3, and the other end of the passage V13 is an open circuit.

[0115] like Figure 8 As shown, in from Figure 7 When the resonator RT10 is viewed from the direction of arrow Y, the resonant part RT13 is positioned on the path connecting position A, which is symmetrical to resonant part RT11 with reference to ground electrode G3, and position B, which is symmetrical to resonant part RT12 with reference to ground electrode G3. In other words, when the resonator RT10 is viewed from the side in a direction orthogonal to the path connecting positions A and B (the direction of arrow Y), the resonant part RT13 is positioned between positions A and B.

[0116] Figure 9 It means Figure 8 The diagram shows the throughput characteristics of the resonator RT10. Figure 9 In the diagram, the horizontal axis represents frequency, and the vertical axis represents insertion loss (solid line LN11) and return loss (dashed line LN12). It is worth noting that... Figure 9 The diagram shows the signal transmission characteristics when the signal passes only through resonator RT10, without considering the transmission characteristics of other resonators RT20 to RT70.

[0117] Reference Figure 9 In the resonator RT10, an attenuation pole AP11 is generated on the lower frequency side compared to the passband, and an attenuation pole AP12 is generated on the higher frequency side compared to the passband. Specifically, the attenuation pole AP11 is generated around 25 GHz on the lower frequency side compared to the passband of the signal set around 29 GHz, and the attenuation pole AP12 is generated around 33 GHz on the higher frequency side compared to the passband.

[0118] Figure 10 This diagram illustrates an example of a resonator RT10 connected to input terminal T1 after reducing the number of resonant sections. Figure 10In the example shown, the resonator RT10 with the resonant section RT12 removed is denoted as resonator RT10A. For example... Figure 10 As shown, the resonator RT10A is composed of a resonant part RT11 and a resonant part RT13. The resonant part RT11 is disposed between the ground electrode G1 and the ground electrode G3 and is connected to the ground electrode G3 and the input terminal T1. The resonant part RT13 is disposed between the ground electrode G2 and the ground electrode G3 and is connected to the ground electrode G3.

[0119] Figure 11 It means Figure 10 The diagram shows the throughput characteristics of the RT10A resonator. Figure 11 In the diagram, the horizontal axis represents frequency, and the vertical axis represents insertion loss (solid line LN11A) and return loss (dashed line LN12A). It is worth noting that... Figure 11 The diagram shows the signal transmission characteristics when the signal passes only through resonator RT10A, without considering the transmission characteristics of other resonators RT20 to RT70.

[0120] Reference Figure 11 In the resonator RT10A, an attenuation pole AP11A is generated near approximately 24 GHz, which is lower than the passband. Based on this, it can be concluded that the low-frequency attenuation pole is generated due to the action of the resonant section RT11 located between ground electrodes G1 and G3, and the resonant section RT13 located between ground electrodes G2 and G3. Figure 9 AP11, Figure 11 AP11A).

[0121] Figure 12 This diagram illustrates an example of a resonator RT10 connected to input terminal T1 after reducing the number of resonant sections. Figure 12 In the example shown, the resonator RT10 with the resonant section RT13 removed is denoted as resonator RT10B. For example... Figure 12 As shown, the resonator RT10B is composed of a resonant part RT11 and a resonant part RT12. The resonant part RT11 is disposed between the ground electrode G1 and the ground electrode G3 and is connected to the ground electrode G3 and the input terminal T1. The resonant part RT12 is disposed between the ground electrode G1 and the ground electrode G3 and is connected to the ground electrode G3.

[0122] Figure 13 It means Figure 12 The diagram shows the throughput characteristics of the RT10B resonator. Figure 13 In the diagram, the horizontal axis represents frequency, and the vertical axis represents insertion loss (solid line LN11B) and return loss (dashed line LN12B). It is worth noting that... Figure 13The diagram shows the signal transmission characteristics when the signal passes only through resonator RT10B, without considering the transmission characteristics of other resonators RT20 to RT70.

[0123] Reference Figure 13 In the resonator RT10B, an attenuation pole AP12B is generated near approximately 33 GHz on the high-frequency side compared to the passband. Based on this, it can be concluded that the high-frequency attenuation pole is generated due to the action of the resonant section RT11 and RT12 located between ground electrodes G1 and G3. Figure 9 AP12, Figure 13 AP12B).

[0124] like Figures 10-13 As shown, in the resonator RT10, a low-frequency attenuation pole is generated due to the action of the resonant section RT11 and the resonant section RT13, and a high-frequency attenuation pole is generated due to the action of the resonant section RT11 and the resonant section RT12.

[0125] (Pass characteristics of the filter device)

[0126] use Figure 14 and Figure 15 The throughput characteristics of filter device 100 are explained while comparing them with those of a comparative filter device. Figure 14 This is a diagram showing the transmission characteristics of the filter device 100 according to Embodiment 1. Figure 15 This is a graph showing the pass characteristics of a proportional filter device.

[0127] Furthermore, the comparative filter device does not have the resonator RT10 containing three λ / 4 resonators as in the filter device 100 of Embodiment 1. Instead, it has a λ / 2 resonator between the input terminal T1 and the ground electrode G2. Specifically, in the comparative filter device, the resonator on the input terminal T1 side has: a path coupled to the input terminal T1 via capacitive coupling and having a length of 1 / 2 wavelength λ corresponding to the center frequency of the passband; and a plate electrode opposite to the ground electrode G2 and connected to the path. Additionally, the comparative filter device does not have the resonator RT20 containing three λ / 4 resonators as in the filter device 100 of Embodiment 1. Instead, it has a λ / 2 resonator between the output terminal T2 and the ground electrode G2. Specifically, in the comparative filter device, the resonator on the output terminal T2 side has: a path coupled to the output terminal T2 via capacitive coupling and having a length of 1 / 2 wavelength λ corresponding to the center frequency of the passband; and a plate electrode opposite to the ground electrode G2 and connected to the path.

[0128] exist Figure 14 and Figure 15 In the diagram, the horizontal axis represents frequency, and the vertical axis represents insertion loss (solid lines LN1, LN201) and return loss (dashed lines LN2, LN202). Furthermore, Figure 14 and Figure 15 The bandwidth shown is 24.25 GHz to 27.5 GHz.

[0129] Reference Figure 14 and Figure 15 In the comparative filter device, no attenuation poles are generated on either the low-frequency side or the high-frequency side compared to the passband. In contrast, in the filter device 100 of Embodiment 1, two attenuation poles AP1 and AP2 are generated on the low-frequency side compared to the passband, and three attenuation poles AP3, AP4, and AP5 are generated on the high-frequency side compared to the passband.

[0130] If used Figure 10 and Figure 11 As explained, the attenuation pole AP1 is mainly generated by the interaction of resonant sections RT11 and RT13 of resonator RT10. The attenuation pole AP2 is mainly generated by the interaction of resonant sections RT21 and RT23 of resonator RT20. If using... Figure 12 and Figure 13 As explained, the attenuation pole AP3 is mainly generated by the interaction of the resonant sections RT11 and RT12 of resonator RT10. The attenuation pole AP4 is mainly generated by the interaction of the resonant sections RT21 and RT22 of resonator RT20. Furthermore, it is believed that the attenuation pole AP5 is mainly generated by the inductive coupling M9 between resonators RT40 and RT60.

[0131] In this way, in the filter device 100 of Embodiment 1, attenuation poles are generated on the high-frequency side and low-frequency side of the passband by the resonators RT10 connected to the input terminal T1 and RT20 connected to the output terminal T2, respectively.

[0132] Furthermore, by adjusting the positions of the resonant section RT13 in resonator RT10 and the resonant section RT23 in resonator RT20, the frequencies of the attenuation pole AP1 generated by the resonance of resonator RT10 and the attenuation pole AP2 generated by the resonance of resonator RT20 can be made consistent. Thus, by the combined effect of the attenuation poles AP1 and AP2 generated by the resonance of resonator RT10 and resonator RT20, the signal attenuation at the low-frequency side attenuation poles can be increased.

[0133] As can be seen, in the filter device 100 of Embodiment 1, through these attenuation poles AP1 to AP5, a steeper and higher attenuation characteristic than that of a comparative filter device can be obtained in both the low-frequency and high-frequency sides compared to the passband. In particular, in the filter device 100, since two attenuation poles are generated in the low-frequency side compared to the passband, a steeper attenuation characteristic in the low-frequency side is obtained. Furthermore, since three attenuation poles are generated in the high-frequency side compared to the passband, a steeper attenuation characteristic in the high-frequency side is obtained.

[0134] Furthermore, in the filter device 100, each resonator RT10 to RT70 uses a path to form a transmission line, thus reducing insertion loss compared to resonators that use a strip line to form a transmission line.

[0135] As described above, in the filter device 100 of Embodiment 1, the passband of the signal can be appropriately adjusted and the attenuation characteristics in the non-passband can be improved.

[0136] [Variation Example]

[0137] use Figures 16-23 A variation of the resonator in Implementation Method 1 is described. Figure 16 This is a simplified diagram showing the positional relationship of the resonant sections RT11 to RT13 in the modified resonator RT101. Figure 16 In the example, from Figure 7 When observing the resonator RT101 in the direction of arrow Y, the resonant part RT13 is positioned at a position A that is symmetrical to the resonant part RT11 with reference to the ground electrode G3.

[0138] Figure 17 It means Figure 16 The diagram shows the throughput characteristics of the resonator RT101. Figure 17 In the diagram, the horizontal axis represents frequency, and the vertical axis represents insertion loss (solid line LN21) and return loss (dashed line LN22). It is worth noting that... Figure 17 The diagram shows the signal transmission characteristics when the signal passes only through resonator RT101, without considering the transmission characteristics of other resonators RT20 to RT70.

[0139] Reference Figure 17 In the resonator RT101, an attenuation pole AP21 is generated on the lower frequency side compared to the passband, and an attenuation pole AP22 is generated on the higher frequency side compared to the passband. Specifically, the attenuation pole AP21 is generated around 24 GHz on the lower frequency side compared to the passband of the signal set around 29 GHz, and the attenuation pole AP22 is generated around 32 GHz on the higher frequency side compared to the passband.

[0140] Figure 18 This is a simplified diagram showing the positional relationship of the resonant sections RT11 to RT13 in the modified resonator RT102. Figure 18 In the example, from Figure 7 When observing the resonator RT102 in the direction of arrow Y, the resonant part RT13 is positioned at position B, which is symmetrical to the resonant part RT12 with reference to the ground electrode G3.

[0141] Figure 19 It means Figure 18 The diagram shows the throughput characteristics of the resonator RT102. Figure 19 In the diagram, the horizontal axis represents frequency, and the vertical axis represents insertion loss (solid line LN31) and return loss (dashed line LN32). It is worth noting that... Figure 19 The diagram shows the signal transmission characteristics when the signal passes only through resonator RT102, without considering the transmission characteristics of other resonators RT20 to RT70.

[0142] Reference Figure 19 In the resonator RT102, an attenuation pole AP31 is generated on the lower frequency side compared to the passband, and an attenuation pole AP32 is generated on the higher frequency side compared to the passband. Specifically, the attenuation pole AP31 is generated around 27 GHz on the lower frequency side compared to the passband of the signal set around 29 GHz, and the attenuation pole AP32 is generated around 33 GHz on the higher frequency side compared to the passband.

[0143] Figure 20 It is used for comparison Figure 8 , Figure 16 and Figure 18 The diagram shows the throughput characteristics of each resonator RT. (Refer to...) Figure 20 It can be seen that the closer the resonator RT13 is to position A (the side of the resonator RT11), the more the attenuation pole on the low-frequency side moves towards the low-frequency side; the closer the resonator RT13 is to position B (the side of the resonator RT12), the more the attenuation pole on the low-frequency side moves towards the high-frequency side.

[0144] Figure 21 This is a simplified diagram showing the positional relationship of the resonators in the modified resonator RT103. Figure 21 In the example, from Figure 7 When observing resonator RT103 in the direction of arrow Y, the resonant section RT13 is positioned differently from the path connecting position A, which is symmetrical to resonant section RT11 with reference to ground electrode G3, and position B, which is symmetrical to resonant section RT12 with reference to ground electrode G3. In other words, from... Figure 7 When observing the resonator RT103 in the direction of arrow Y, the resonant part RT13 is located outside the region between the resonant parts RT11 and RT12.

[0145] Figure 22 It means Figure 21 The graph shows the pass-through characteristics of the resonator RT103. In the graph, the horizontal axis represents frequency, and the vertical axis represents insertion loss (solid line LN41) and return loss (dashed line LN42). It is worth noting that... Figure 22 The diagram shows the signal transmission characteristics when the signal passes only through resonator RT103, without considering the transmission characteristics of other resonators RT20 to RT70.

[0146] Reference Figure 22 In the resonator RT103, an attenuation pole AP41 is generated on the lower frequency side compared to the passband, and an attenuation pole AP42 is generated on the higher frequency side compared to the passband. Specifically, an attenuation pole AP41 is generated around 24 GHz on the lower frequency side compared to the passband of the signal set around 29 GHz, and an attenuation pole AP42 is generated around 32 GHz on the higher frequency side compared to the passband.

[0147] Figure 23 It is used for comparison Figure 16 and Figure 21 The diagram shows the throughput characteristics of each resonator. (Refer to...) Figure 23 It can be seen that if the resonator RT13 is moved from position A (the side of the resonator RT11) to a direction away from position B, the attenuation pole on the low-frequency side will move to the high-frequency side.

[0148] consider Figure 20 and Figure 23 Based on the characteristics, it can be seen that if the resonator RT13 is moved from position B to position A, the attenuation pole on the low-frequency side will move towards the low-frequency side. Furthermore, if the resonator RT13 is moved from position A away from position B, the attenuation pole on the low-frequency side will return to the high-frequency side.

[0149] In this way, if the position of the resonant section RT13 in the resonator RT10 changes, the frequency at which the attenuation poles are generated on the low-frequency side will also change. Therefore, by changing the position of the resonant section RT13 in the resonator RT10, the passband can be appropriately adjusted in such a way that the passband of the signal in the filter device 100 becomes the desired passband.

[0150] In addition, Figures 7 to 23 The diagram shows the configuration and throughput characteristics of the resonator connected to the input terminal T1, but it can be said that the configuration and throughput characteristics of the resonator RT20 connected to the output terminal T2 are similar. Figures 7 to 23The resonators shown have the same configuration and throughput characteristics. That is, by making the positions of the paths V2, V21 to V23 and the plate electrodes P21 to P23 of the resonator RT20 correspond to the positions of the paths V1, V11 to V13 and the plate electrodes P11 to P13 of the resonator connected to the input terminal T1, the same throughput characteristics of the resonators RT10 and RT101 to 103 connected to the input terminal T1 can also be obtained in the resonator RT20.

[0151] Similar to resonator RT10, if the position of resonant section RT23 changes in resonator RT20, the frequency at which attenuation poles are generated on the low-frequency side will also change. Therefore, by changing the position of resonant section RT23 in resonator RT20, the passband can be appropriately adjusted so that the passband of the signal in filter device 100 becomes the desired passband.

[0152] Furthermore, by adjusting the positions of the resonant section RT13 in resonator RT10 and the resonant section RT23 in resonator RT20, the frequencies of the low-frequency attenuation poles generated by the resonance of resonator RT10 and resonator RT20 can be made consistent. Thus, by the combined effect of the low-frequency attenuation poles generated by the resonance of resonator RT10 and resonator RT20, the signal attenuation at the low-frequency attenuation poles can be increased.

[0153] [Implementation Method 2]

[0154] In embodiment 1, resonator RT10 has a resonant section RT13 between ground electrode G1 and ground electrode G3, and resonator RT20 has a resonant section RT23 between ground electrode G1 and ground electrode G3. However, resonator RT10 and resonator RT20 may each have multiple resonant sections between ground electrode G1 and ground electrode G3.

[0155] Figure 24 This is a simplified diagram showing the positional relationship of each resonant part in the resonator RT110 of Embodiment 2. (Refer to...) Figure 24 In Embodiment 2, the resonator RT110 includes a resonant section RT14 in addition to the resonant section RT13, located between the ground electrode G2 and the ground electrode G3. Specifically, in the resonator RT110, the resonant section RT13 is provided at position A, symmetrical to the resonant section RT11 with reference to the ground electrode G3, and the resonant section RT14 is provided at position B, symmetrical to the resonant section RT12 with reference to the ground electrode G3. Both the resonant section RT13 and the resonant section RT14 are connected to the ground electrode G3.

[0156] Figure 25 It means Figure 24 The diagram shows the throughput characteristics of the RT110 resonator. Figure 25 In the diagram, the horizontal axis represents frequency, and the vertical axis represents insertion loss (solid line LN51) and return loss (dashed line LN52). It is worth noting that... Figure 25 The diagram shows the signal transmission characteristics when the signal passes only through resonator RT110, without considering the transmission characteristics of other resonators RT20 to RT70.

[0157] Reference Figure 25 In the resonator RT110, an attenuation pole AP51 is generated on the low-frequency side compared to the passband, and two attenuation poles AP52 and AP53 are generated on the high-frequency side compared to the passband.

[0158] If used Figures 8 to 23 As explained, when only one resonator RT13 is placed between ground electrodes G1 and G3, one attenuation pole is generated on the high-frequency side compared to the passband. When two resonators RT13 and RT14 are placed between ground electrodes G1 and G3, two attenuation poles AP52 and AP53 are generated on the high-frequency side compared to the passband. If using... Figure 10 and Figure 11 As explained, the attenuation pole AP51 is mainly generated by the interaction of the resonators RT11 and RT13. (If using...) Figure 12 and Figure 13 As explained, the attenuation pole AP52 is mainly generated by the interaction of resonators RT11 and RT12. It is assumed that the additional attenuation pole AP53 is mainly generated by the interaction of resonators RT13 and RT14.

[0159] In this way, since the resonator has multiple resonant sections between the ground electrode G2 and the ground electrode G3, the number of attenuation poles on the high-frequency side increases. As a result, the attenuation characteristics in the non-passband can be improved in the filter device 100.

[0160] In addition, Figure 24 and Figure 25 The diagram shows the configuration and throughput characteristics of the resonator RT110 connected to the input terminal T1, but it can be said that the configuration and throughput characteristics of the resonator RT20 connected to the output terminal T2 are similar. Figure 24 and Figure 25 The resonator RT110 shown has the same configuration and transmission characteristics. That is, the resonator RT20 can also have a resonant section between the ground electrode G2 and the ground electrode G3, in addition to the resonant section RT23. In this case, the same transmission characteristics as the resonator RT110 can also be obtained in the resonator RT20.

[0161] [Other variations]

[0162] The filter device disclosed herein is not limited to the embodiments described above, and can be further modified and applied in various ways. The following describes modifications of the filter device applicable to this disclosure.

[0163] The filter device 100 of the embodiment has five resonators RT30 to RT70 as intermediate resonators, but the filter device 100 only needs to have at least one intermediate resonator.

[0164] In the filter device 100 of the embodiment, both the resonator RT10 connected to the input terminal T1 and the resonator RT20 connected to the output terminal T2 are composed of multiple λ / 4 resonators. However, either the resonator RT10 connected to the input terminal T1 or the resonator RT20 connected to the output terminal T2 can also be a resonator that has a λ / 2 resonator between the input terminal T1 or the output terminal T2 and the ground electrode G2.

[0165] It should be considered that all aspects of the embodiments disclosed herein are merely illustrative and not limiting. The scope of this disclosure is not shown by the description of the above embodiments, but by the claims, which are intended to include all modifications in the same sense and scope as the claims.

[0166] Explanation of the label

[0167] 10 Communication device; 12 Antenna; 20 High-frequency front-end circuit; 22, 28 Bandpass filters; 24 Amplifier; 26 Attenuator; 30 Mixer; 32 Local oscillator; 40 Converter; 50 Circuit; 100 Filter device; 110 Dielectric substrate; 111 Lower surface; 112 Upper surface; 113 Side surface; C11, C12, C14, C21, C22, C24, C31, C32, C41, C42, C51, C52, C61, C 62, C71, C72 capacitors; G1, G2, G3, G4, G100 grounding electrodes; GND grounding terminal; K1, K2, K11, K12 cutouts; L11, L12, L13, L21, L22, L23, L31, L41, L51, L61, L71 inductors; P1, P2, P11, P12, P13, P21, P22, P23, P311, P312, P411, P412, P 511, P512, P611, P612, P711, P712 planar electrodes; RT10, RT10A, RT10B, RT13, RT14, RT20, RT30, RT40, RT50, RT60, RT70, RT101, RT102, RT103, RT110 resonators; RT11, RT12, RT13, RT14, RT21, RT22, RT23 resonator sections; S101 First layer; S102 Second layer; S103 Third layer; S105 Fifth layer; S106 Sixth layer; T1 Input terminal; T2 Output terminal; V1, V2, V10, V11, V12, V13, V20, V21, V22, V23, V31, V41, V51, V61, V71, V511, V512, V513 paths; VG, VG11, VG12, VG21, VG22 Grounding paths.

Claims

1. A filter device comprising: Input terminals; Output terminals; The first and second grounding electrodes, which are opposite to each other; and A first resonator connected to one of the input and output terminals. The first resonator includes: A first intermediate grounding electrode is disposed between the first grounding electrode and the second grounding electrode and is connected to the first grounding electrode and the second grounding electrode; The first resonant part is a λ / 4 resonator, which is disposed between the first ground electrode and the first intermediate ground electrode, and is connected to the first intermediate ground electrode and the terminal. The second resonant part is a λ / 4 resonator, which is disposed between the first ground electrode and the first intermediate ground electrode and connected to the first intermediate ground electrode. as well as The third resonant section is a λ / 4 resonator, which is located between the second ground electrode and the first intermediate ground electrode and is connected to the first intermediate ground electrode.

2. The filter device according to claim 1, wherein, The third resonant part is disposed on the following path, which connects a position symmetrical to the first resonant part with reference to the first intermediate ground electrode and a position symmetrical to the second resonant part with reference to the first intermediate ground electrode.

3. The filter device according to claim 1, wherein, The third resonant part is positioned symmetrically to the first resonant part, with the first intermediate ground electrode as a reference.

4. The filter device according to claim 1, wherein, The third resonant part is positioned symmetrically to the second resonant part, with the first intermediate ground electrode as a reference.

5. The filter device according to claim 1, wherein, The third resonant part is located at a position different from the position on the following path, which connects a position symmetrical to the first resonant part with reference to the first intermediate ground electrode and a position symmetrical to the second resonant part with reference to the first intermediate ground electrode.

6. The filter device according to any one of claims 1 to 5, wherein, The first resonant part and the second resonant part are coupled through inductive coupling or capacitive coupling.

7. The filter device according to any one of claims 1 to 5, wherein, The first resonant section, the second resonant section, and the third resonant section each include a first conductor having a length of 1 / 4 of the wavelength corresponding to the center frequency of the passband.

8. The filter device according to claim 7, wherein, The first resonant section, the second resonant section, and the third resonant section each include: a first conductor connected to the first intermediate ground electrode, and a plate electrode connected to the first conductor and opposite to the first ground electrode or the second ground electrode.

9. The filter device according to claim 7, wherein, It also includes at least one intermediate resonator comprising a second conductor having a length corresponding to half the wavelength of the center frequency. The first resonator is coupled to the at least one intermediate resonator via inductive coupling.

10. The filter device according to claim 9, wherein, The at least one intermediate resonator includes the second conductor, a first plate electrode connected to the second conductor and opposite to the first ground electrode, and a second plate electrode connected to the second conductor and opposite to the second ground electrode.

11. The filter device according to any one of claims 1 to 5, wherein, The first resonator includes multiple resonant sections, including the third resonant section, which is located between the second ground electrode and the first intermediate ground electrode. Each of the plurality of resonant parts is connected to the first intermediate ground electrode.

12. The filter device according to any one of claims 1 to 5, wherein, It also includes a second resonator, which is connected to a different terminal from the input terminal and the output terminal. The second resonator has: The second intermediate grounding electrode is disposed between the first grounding electrode and the second grounding electrode and is connected to the first grounding electrode and the second grounding electrode. The fourth resonant section is a λ / 4 resonator, which is disposed between the first ground electrode and the second intermediate ground electrode, and is connected to the second intermediate ground electrode and the other terminal; The fifth resonant section is a λ / 4 resonator, which is disposed between the first ground electrode and the second intermediate ground electrode and connected to the second intermediate ground electrode; as well as The sixth resonant section is a λ / 4 resonator, which is located between the second ground electrode and the second intermediate ground electrode and is connected to the second intermediate ground electrode.

13. A filter device comprising: Input terminals; Output terminals; The first and second grounding electrodes are opposite to each other; The first resonator connected to the input terminal; The second resonator is connected to the output terminal; as well as At least one intermediate resonator is coupled to at least one of the first resonator and the second resonator via inductive coupling. The first resonator includes: A first intermediate grounding electrode is disposed between the first grounding electrode and the second grounding electrode and is connected to the first grounding electrode and the second grounding electrode; The first resonant section is a λ / 4 resonator, which is disposed between the first ground electrode and the first intermediate ground electrode, and is connected to the first intermediate ground electrode and the input terminal. The second resonant part is a λ / 4 resonator, which is disposed between the first ground electrode and the first intermediate ground electrode and connected to the first intermediate ground electrode. as well as The third resonant section is a λ / 4 resonator, which is disposed between the second ground electrode and the first intermediate ground electrode and connected to the first intermediate ground electrode. The second resonator has: The second intermediate grounding electrode is disposed between the first grounding electrode and the second grounding electrode and is connected to the first grounding electrode and the second grounding electrode. The fourth resonant section is a λ / 4 resonator, which is disposed between the first ground electrode and the second intermediate ground electrode, and is connected to the second intermediate ground electrode and the output terminal; The fifth resonant section is a λ / 4 resonator, which is disposed between the first ground electrode and the second intermediate ground electrode and connected to the second intermediate ground electrode; as well as The sixth resonant section is a λ / 4 resonator, which is located between the second ground electrode and the second intermediate ground electrode and is connected to the second intermediate ground electrode.

14. A high-frequency front-end circuit comprising the filter device according to any one of claims 1 to 13.

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