JP2018107602A - Resonator and filter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a resonator and the like which can easily change electrical characteristics.SOLUTION: A resonator 11 includes: a resonating body 21 which resonates at a predetermined wavelength; a coupling member 31 capacitively coupled with the resonating body 21; and a coupling loop 41 that is capacitively coupled with the resonating body 21 and the coupling member 31 in which the capacitance with respect to the resonating body 21 or the capacitance with respect to the coupling member 31 can be changed.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a resonator and a filter.

  The bandpass filter (BPF) provided in the tower mount amplifier (TMA) of the radio base station has a transmission signal, an AISG (Antenna Interface Standard Group) signal for setting a remote tilt unit (RET), etc. May be transmitted to the antenna in a superimposed manner, or direct current (DC) may be bypassed.

  In Patent Document 1, a plurality of insertion ports into which a coupling element can be inserted are provided in a coupling element socket that holds the coupling element so that a position where the coupling element that couples the resonators is set is variable. The filter is provided with a screw that adjusts the coupling amount between the resonators by changing the position of the coupling element by being pushed toward the side.

  Patent Document 2 describes a duplexer that includes a plurality of resonators and in which resonators of the resonators are electrically coupled.

Chinese Patent Application No. 1058646020 Chinese Utility Model No. 2859833 Specification

Incidentally, in a band pass filter (BPF: Band Pass Filter) designed so as not to pass a direct current component, an electric field coupling type band pass filter constituted by a resonator and a coupling member disposed in the vicinity of the resonator. Is used. In such a type of filter, the amount of coupling is set by the distance between the resonator and the coupling member, but many of these distances are fixed due to mechanical characteristics.
On the other hand, the distance between the resonator and the coupling member is greatly related to the withstand voltage characteristics. In particular, when the amount of coupling is to be increased, it is necessary to narrow the distance between the resonator and the coupling member. In such a case, the withstand voltage characteristics deteriorate, so the distance between the resonator and the coupling member is changed. It was difficult. Therefore, it is difficult to change (adjust) the electrical characteristics of the filter.
Further, when the interval between the resonator and the coupling member is fixed, the electrical characteristics depend on the processing accuracy of the member, and it is difficult to obtain a high yield.
An object of the present invention is to provide a resonator and the like whose electrical characteristics can be easily changed.

For this purpose, a resonator to which the present invention is applied includes a resonator that resonates at a predetermined wavelength, a capacitive coupling member that is capacitively coupled to the resonator, and capacitively coupled to the resonator and the capacitive coupling member. And a capacity changing member capable of changing a capacity for the resonator or a capacity for the capacitive coupling member.
In such a resonator, the capacitance changing member may be characterized in that one end and the other end are connected to a reference potential and the distance to the resonator or the capacitive coupling member can be changed.
The capacity changing member may be characterized in that the length from one end to the other end is set to ½ of the wavelength.

From another point of view, the resonator to which the present invention is applied includes a first resonator and a second resonator each resonating at a predetermined wavelength, and a capacitive coupling between the first resonator and the first resonator. The first capacitive coupling member, the second capacitive coupling member capacitively coupled to the second resonator, the first resonator, the second resonator, the first capacitive coupling member, and the second capacitive coupling. A capacitance changing member that is capacitively coupled to the member and capable of changing a capacitance with respect to at least one of the first resonator, the second resonator, the first capacitive coupling member, and the second capacitive coupling member; The first capacitive coupling member and the second capacitive coupling member are arranged between the first resonator and the second resonator and are electrically connected to each other. .
In such a resonator, the capacitance changing member is capacitively coupled to the first resonator and the first capacitive coupling member, and the capacitance with respect to the first resonator or the capacitance with respect to the first capacitive coupling member can be changed. A first capacitance changing member and a second capacitance changing member that is capacitively coupled to the second resonator and the second capacitive coupling member, and capable of changing a capacitance with respect to the second resonator or a capacitance with respect to the second capacitive coupling member. It can be characterized by being.

  Furthermore, from another viewpoint, the filter to which the present invention is applied resonates at a predetermined wavelength, and includes a plurality of resonators arranged in a row and one end portion of the plurality of resonators. An input terminal connected to a resonator and receiving a signal and an output terminal connected to a resonator at the other end of the plurality of resonators and outputting a signal. And a capacitive coupling member that capacitively couples the body and the resonator, and the resonator at the other end includes another resonator and another capacitive coupling member that capacitively couples to the other resonator, A capacitive change member that can be capacitively coupled to the body and the capacitive coupling member and change a capacitance relative to the resonator or the capacitive coupling member, and is capacitively coupled to another resonator and the other capacitive coupling member, and another resonant body or another capacitance. At least one of the other capacity changing members whose capacity with respect to the coupling member can be changed. Wherein the Re or having one.

  ADVANTAGE OF THE INVENTION According to this invention, the filter etc. which can change an electrical property easily can be provided.

It is a figure which shows an example of the structure of the filter to which 1st Embodiment is applied. It is a figure explaining a resonator in detail. (A) is a top view, (b) is a side view. It is an equivalent circuit of a resonator. (A) is a resonator, and (b) is a filter. It is a figure which shows the group delay time in a resonator. It is a figure which shows group delay time at the time of changing the distance of a coupling loop, a resonator, and a coupling member in the resonator to which 1st Embodiment is applied. It is a figure which shows an example of the structure of the filter to which 2nd Embodiment is applied. It is the figure which extracted two resonators from the filter to which 2nd Embodiment is applied. It is the figure which showed the group delay time in two resonators. It is a figure which shows the modification of two resonators.

Embodiments of the present invention will be described below in detail with reference to the accompanying drawings.
Here, an electric field coupling type band pass filter (BPF) will be described as an example of the filter. However, the filter is not limited to a bandpass filter (BPF) as long as it is an electric field coupling type. The electric field coupling type is sometimes referred to as a capacitive coupling type.

[First Embodiment]
(Filter 1)
FIG. 1 is a diagram illustrating an example of a configuration of a filter 1 to which the first embodiment is applied.
The filter 1 to which the first embodiment is applied includes four resonators 11, 12, 13, and 14. These resonators 11, 12, 13, and 14 are connected in a row so that the casings 71, 72, 73, and 74 included in the resonators 11, 12, 13, and 14 are continuous. The casing 70 in which the casings 71, 72, 73, and 74 are continuously formed has a quadrilateral cross section (as shown in FIGS. 2A and 2B described later, side surfaces 71a and 71c, a lower surface 71b, and an upper surface). 71d), both ends are closed. The housing 70 is made of a conductive material and forms a shield (electric wall) against an electromagnetic field. That is, the filter 1 has a cavity structure.
FIG. 1 is a view of the inside of the filter 1 except for the upper surface of the housing 70.
And the filter 1 may be installed so that FIG. 1 may become the figure seen from the upper surface side, and may be installed in another direction. For example, you may install so that a longitudinal direction may become perpendicular | vertical.

The resonator 11 includes a resonator 21, a coupling member 31 disposed so as to face the resonator 21, and a coupling loop 41 that performs electric field coupling (capacitive coupling) to the resonator 21 and the coupling member 31.
The resonator 11 includes a connection component 51 connected to the coupling member 31 and an input terminal 61 connected to the connection component 51.
Furthermore, the resonator 11 includes a housing 71 that is a part of the housing 70 that houses the resonator 21, the coupling member 31, the coupling loop 41, the connection component 51, and the input terminal 61.

The resonator 12 includes a resonator 22 and a casing 72 that houses the resonator 22.
The resonator 13 includes a resonator 23 and a housing 73 that houses the resonator 23.

The resonator 14 includes a resonator 24, a coupling member 32 disposed so as to face the resonator 24, and a coupling loop 42 for electric field coupling (capacitive coupling) to the resonator 24 and the coupling member 32.
The resonator 14 includes a connection component 52 connected to the coupling member 32 and an input terminal 62 connected to the connection component 52.
Further, the resonator 14 includes a housing 74 that houses the resonator 24, the coupling member 32, the coupling loop 42, the connection component 52, and the output terminal 62.

When the resonators 11, 12, 13, and 14 are not distinguished from each other, they are referred to as a resonator 10.
When the resonators 21, 22, 23, and 24 are not distinguished from each other, they are referred to as resonators 20.
When the coupling members 31 and 32 are not distinguished from each other, they are referred to as coupling members 30. The coupling member 30 is an example of a capacitive coupling member.
When the coupling loops 41 and 42 are not distinguished from each other, they are expressed as a coupling loop 40. The coupling loop is an example of a capacity changing member.
When the connection parts 51 and 52 are not distinguished from each other, they are referred to as connection parts 50.
In addition to cases where the casings 71, 72, 73, and 74 are grouped together, they may be described as the casing 70 when they are not distinguished from each other.

The resonators 21, 22, 23, and 24 are made of conductive members. The resonators 21, 22, 23, and 24 are set to resonate at predetermined wavelengths (frequencies), respectively. The resonators 21, 22, 23, and 24 are arranged in a row in the housing 70.
The coupling members 31 and 32 are made of conductive members, and have a disk-like outer shape as an example. The coupling member 31 is disposed so that the flat surface faces the resonator 21. The coupling member 31 is electrically coupled to the resonators 21, 22, 23, and 24 via the resonators 21 that are arranged to face each other. The electrical coupling here is electric field coupling (capacitive coupling).
Similarly, the coupling member 32 is disposed such that a flat surface faces the resonator 24. The coupling member 32 is electrically coupled to the resonators 21, 22, 23, and 24 via the resonators 24 that are arranged to face each other. The electrical coupling here is also electric field coupling (capacitive coupling).

  In addition, the planar shape of the coupling members 31 and 32 may not be a circle but may be a polygon. Moreover, it may be a linear shape instead of a planar shape as shown in the figure. In addition, when it is a circle, it is suppressed that an electric field concentrates.

The coupling loops 41 and 42 are made of a conductive member, and both ends thereof are connected to the housing 70 to form a loop.
The connection parts 51 and 52 are composed of conductive members. The connection component 51 propagates a signal from the input terminal 61 to the coupling member 31, and the connection component 52 propagates a signal from the coupling member 32 to the output terminal 62.
The input terminal 61 and the output terminal 62 are connectors, for example. In the input terminal 61, the inner conductor (core wire) of the connector is connected to the connection component 51, and the outer conductor of the connector is connected to the housing 71. The inner conductor and the outer conductor of the connector are insulated in a direct current manner. Similarly, at the output terminal 62, the inner conductor (core wire) of the connector is connected to the connection component 52, and the outer conductor of the connector is connected to the housing 74. The inner conductor and the outer conductor of the connector are insulated in a direct current manner.

The casings 71, 72, 73, and 74 constituting the casing 70 will be described.
The casing 71 is not closed on the resonator 12 side. The casing 71 is closed on the side opposite to the resonator 12 side. However, the input terminal 61 is provided so as to be connected from the outer side of the closed casing 71 to the inner connection component 51.
The casings 72 and 73 cover the side surfaces of the resonators 22 and 23, respectively. A partition wall 75 made of a conductive member is provided between the housing 72 and the housing 73. The partition 75 is provided with an opening 76 for electrically coupling the resonator 22 and the resonator 23. The electrical coupling here is magnetic field coupling. Note that there is no partition wall on the resonator 11 side of the casing 72, and there is no partition wall on the resonator 14 side of the casing 73.
Further, as in the case 71, the case 74 is not closed on the resonator 13 side. The casing 74 is closed on the side opposite to the resonator 13 side. However, the output terminal 62 is provided so as to be connected to the inner connection component 52 from the outside of the closed casing 74.
The side surfaces 71a, 71c, the lower surface 71b, and the upper surface 71d shown in FIGS. 2A and 2B are also made of a conductive material, and have a cavity structure as a whole.

  Note that the partition wall 75 between the resonator 12 and the resonator 13 may be omitted, and the partition wall between the resonator 11 and the resonator 12 or / and between the resonator 13 and the resonator 14. A partition wall similar to 75 may be provided. The partition wall may be provided in relation to the electrical characteristics of the filter 1.

  As the conductive member, aluminum, copper, brass, or the like having high conductivity can be applied. Moreover, what plated silver etc. on aluminum, copper, and brass is applicable.

  In the filter 1, the resonators 11, 12, 13, and 14 are each configured (manufactured) as a single unit, and these resonators 11, 12, 13, and 14 may be connected (assembled). ). The housing 70 may be configured (manufactured) as a whole, and the resonators 21, 22, 23, 24, the coupling members 31, 32, and the like may be configured (assembled) inside the housing 70. . In any case, a part of the housing 70 (housings 71, 72, 73, 74) may be removable to facilitate assembly.

The configurations of the resonators 21, 22, 23, 24, the coupling members 31, 32, and the coupling loops 41, 42 will be described in detail later with reference to FIG.
The resonator 11 is an example of a resonator at one end, and the resonator 14 is an example of a resonator at the other end. The coupling member 31 is an example of a capacitive coupling member, the coupling member 32 is an example of another capacitive coupling member, the coupling loop 41 is an example of a capacitance changing member, and the coupling loop 42 is an example of another capacitive changing member.

The operation of the filter 1 will be described.
The casing 70 (casings 71, 72, 73, 74), the outer conductor of the connector as the input terminal 61 and the outer conductor of the connector as the output terminal 62 are set to a reference potential, for example, a ground potential (GND). ing.

A signal is input to the input terminal 61 of the filter 1. Then, the signal propagates to the connection component 51 and the coupling member 31. Then, the signal is input from the coupling member 31 to the resonators 22, 23, and 24 through the resonator 21 that is coupled with an electric field (capacitance).
At that time, only wavelengths that resonate with the resonators 21, 22, 23, and 24 propagate.
Further, the propagated signal is input to the coupling member 32 that is capacitively coupled to the resonator 24. Then, it propagates through the connection component 52 and outputs from the output terminal 62.

  That is, the filter 1 passes only a signal having a wavelength (resonance wavelength) resonating with each of the resonators 21, 22, 23, and 24 from a signal input to the input terminal 61 and outputs the signal from the output terminal 62. At this time, if the resonance wavelengths of the resonators 21, 22, 23, and 24 are set in accordance with the range of wavelengths desired to pass, a band-pass filter that passes signals in the range (band) of wavelengths desired to pass is obtained. .

The coupling loop 41 is provided to face the resonator 21 and the coupling member 31. Then, the capacitance between the coupling loop 41 and the resonator 21 and / or the coupling member 31 is changed by changing (adjusting) the distance between the coupling loop 41 and the resonator 21 and / or the coupling member 31. Is done. Then, the coupling amount in the resonator 11 is changed. That is, the electrical characteristics of the resonator 11 are changed.
Similarly, the coupling loop 42 is provided to face the resonator 24 and the coupling member 32. Then, the capacitance between the coupling loop 42 and the resonator 24 and / or the coupling member 32 is changed by changing (adjusting) the distance between the coupling loop 42 and the resonator 24 and / or the coupling member 32. Is done. Then, the coupling amount in the resonator 14 is changed. That is, the electrical characteristics of the resonator 14 are changed.
In this way, the electrical characteristics of the filter 1 are changed.
This will be described in detail later.

  As described above, the coupling member 31 and the resonator 21 are electric field (capacitance) coupled, and the resonator 24 and the coupling member 32 are electric field (capacitance) coupled. ) Is cut.

(Resonator 11)
FIG. 2 is a diagram illustrating the resonator 11 in detail. 2A is a top view and FIG. 2B is a side view. 2A and 2B, the surfaces of the casing 71 are referred to as side surfaces 71a, 71c, a lower surface 71b, and an upper surface 71d. Furthermore, a surface on which the input terminal 61 of the housing 71 is provided is a side surface 71e. In FIG. 2A, the upper surface 71d of the casing 71 is removed as in FIG. In FIG. 2B, the side surface 71a of the housing 71 is removed from the paper surface of FIG.
The evaluation of the group delay time shown in FIGS. 4 and 5 was performed assuming that the resonator 11 is surrounded by the casing 71. Therefore, the side surface 71f is assumed to be on the resonator 12 side. Therefore, in FIGS. 2A and 2B, the side surface 71f is shown.

  As shown in FIGS. 2A and 2B, the resonator 21 is a rod-shaped member having a rectangular cross section and rounded corners. And the rectangular center part is a circular cavity so that a rod-shaped member may become hollow. The cavity is provided through the rod-shaped resonator 21 in the longitudinal direction. The cross-sectional shape of the resonator 21 need not be a rectangle with rounded corners, but may be a polygon.

One end of the resonator 21 is electrically (directly) connected (short-circuited) to the lower surface 71 b of the housing 71. The other end of the resonator 21 is released (opened). As described above, the casing 71 is set to the reference potential.
The resonator 21 that is a rod-shaped member is set to ¼ (¼λg) of the wavelength λg in the tube surrounded by the casing 71. The frequency fg with respect to the wavelength λg is the frequency fg in the tube.
That is, the resonator 21 resonates at a wavelength having a length from the short end to the open end of ¼λg.
The same applies to the other resonators 22, 23, and 24.
Here, the resonator 20 is a hollow rod-shaped member, but may be a member having another shape.

  Then, one surface in the longitudinal direction of the rectangular cross section of the resonator 21 faces the flat surface of the disk-shaped coupling member 31.

The coupling loop 41 is, for example, a linear member, and is made of a linear conductive material that can be easily bent here. The coupling loop 41 has one end and the other end connected to the lower surface 71 b of the housing 71. That is, both ends of the coupling loop 41 are set to the reference potential. The length of the coupling loop 41 is set to approximately ½λg with respect to the guide wavelength of the frequency to be passed.
The coupling loop 41 is set so as to be coupled to the resonator 21 and the coupling member 31 by an electric field (capacitance). That is, on the coupling member 31 side, one end portion of the coupling loop 41 that rises from the lower surface 71b rises to the center of the coupling member 31, and extends to the side surface 71c along the coupling member 31 (surface opposite to the resonator 21). It is bent to face. Next, it proceeds parallel to the lower surface 71 b until it passes through the coupling member 31, and when it passes through the coupling member 31, it is bent toward the resonator 21. And it progresses in parallel with lower surface 71b so that the side of resonator 21 may be met. And it is bent toward the lower surface 71 b in the middle of the side surface of the resonator 21. The other end of the coupling loop 41 is connected to the lower surface 71b.
That is, as shown to Fig.2 (a), as for the coupling loop 41, the part parallel to the lower surface 71b is L-shaped.

When the coupling loop 41 is connected to the reference potential and the length between the end portions is ½λg, the coupling loop 41 is coupled not by electromagnetic coupling but by electric field (capacitance).
The coupling loop 41 may be provided so as to be coupled to the resonator 21 and the coupling member 31 by an electric field (capacitance). Therefore, the L-shaped portion of the coupling loop 41 may not be parallel to the lower surface 71b. Further, the coupling loop 41 does not have to have the shape shown in FIGS. 2A and 2B, and may have another shape.

Since the coupling loop 41 is made of a linear conductive material, the distance between the resonator 21 and the coupling member 31 can be changed later. That is, the side (L-shaped part) that is not connected to the lower surface 71 b of the coupling loop 41 is pushed and deformed toward the resonator 21 and the coupling member 31, so that the distance between the resonator 21 and the coupling member 31 is increased. The distance between the resonator 21 and the coupling member 31 can be increased by being closer or by being deformed so as to be separated from the resonator 21 and the coupling member 31 side.
That is, after assembling the resonator 11, the capacitance between the resonator 21 and / or the coupling member 31 is changed by deforming the coupling loop 41 by temporarily removing the upper surface 71 d while observing the electrical characteristics. Therefore, the coupling amount in the resonator 11 can be changed. As a result, even if the electrical characteristics vary due to variations in processing accuracy and assembly accuracy of each member, the electrical characteristics can be changed by a relatively easy method of deforming the linear conductive material. .

FIG. 3 is an equivalent circuit of the resonator 11 and the filter 1. 3A shows the resonator 11, and FIG. 3B shows the filter 1.
As shown in FIG. 3A, the resonator 11 is configured such that a capacitor C <b> 1 having a fixed capacitance and a capacitor C <b> 2 having a variable capacitance are connected in parallel to the resonator 21. The capacitor C1 is a capacitance between the resonator 21 and the coupling member 31, and the capacitor C2 is a capacitance between the resonator 21 and the coupling member 31 via the coupling loop 41.
A signal input to the input terminal 61 propagates to the coupling member 31 and propagates to the resonator 21 via the capacitor C1. Similarly, a signal input to the input terminal 61 propagates to the resonator 21 via the capacitor C <b> 2 configured by the coupling loop 41.

  By changing the distance between the coupling loop 41 and the resonator 21 or / and the coupling member 31, the capacitance of the capacitor C2 is changed. Thereby, the coupling amount in the resonator 11 is changed.

As shown in FIG. 3B, the filter 1 has resonators 11, 12, 13, and 14 arranged in a line. The resonator 14 has the same structure as that of the resonator 11, but has a structure opposite to the signal traveling direction. The resonator 14 is connected to the output terminal 62 instead of the input terminal 61.
For example, in mobile communication, an AISG signal for controlling a phase shifter or the like may be superimposed on a high-frequency coaxial cable in order to save the cable wiring work. Such a case is shown in FIG. When the AISG signal is superimposed on a high-frequency coaxial cable, it is modulated into an AM wave of about 2 MHz. Since this signal wave has a lower frequency than the signal passing through the filter 1, the signal wave is separated from the input terminal 61 portion and transmitted to the output terminal 62 portion through a different path from the filter 1. Then, it is added to the signal that has passed through the filter 1. That is, since the AISG signal is a frequency that does not belong to the pass band of the filter 1, the AISG signal is transmitted through a different (different) path from the filter 1 via the inductances L 1 and L 2. The inductances L1 and L2 are provided in order to suppress passage of signals having a higher frequency than the AISG signal (for example, signals passing through the filter 1).
Here, the AISG signal is added to the signal that has passed through the filter 1, but it may be transmitted as it is to the control device for the AISG signal.

FIG. 4 is a diagram showing the group delay time in the resonator 11. In general, since the coupling amount can be evaluated by the group delay time, the group delay time will be described here. In FIG. 4, the resonator 11 having the coupling loop 41 to which the first embodiment is applied (with a coupling loop) and the resonator 11 having no coupling loop 41 to which the first embodiment is not applied (no coupling loop). It shows. The vertical axis represents the group delay time (ns), and the horizontal axis represents the frequency (f / fg) normalized by a predetermined frequency fg (wavelength λg).
The resonator 11 without the coupling loop 41 is obtained by removing the coupling loop 41 in FIGS. 2 (a) and 2 (b). That is, the other configuration of the resonator 11 without the coupling loop 41 is the same as that of the resonator 11 shown in FIGS.
As shown in FIG. 4, the resonator 11 having the coupling loop 41 has a smaller group delay time in the vicinity of the frequency fg than the resonator 11 having no coupling loop 41. This indicates that the amount of coupling in the resonator 11 has increased. That is, the resonator 11 has the coupling loop 41, so that the coupling amount increases. The resonator 11 having the coupling loop 41 is tightly coupled (tightly coupled), and the resonator 11 not having the coupled loop 41 is loosely coupled (sparsely coupled).
Therefore, when the coupling loop 41 is provided, the distance between the resonator 21 and the coupling member 31 can be set wider than when the coupling loop 41 is not provided. As a result, the power durability is also improved.

  FIG. 5 is a diagram illustrating the group delay time when the distance between the coupling loop 41, the resonator 21, and the coupling member 31 is changed in the resonator 11 to which the first embodiment is applied. Here, as shown in FIG. 2A, the distance between the coupling loop 41 and the resonator 21 and the distance between the coupling loop 41 and the coupling member 31 are both changed by Δt. As shown in FIG. 2A, Δt is defined as + in the direction in which the distance between the coupling loop 41 and the resonator 21 and the coupling member 31 decreases (approaches) and − in the direction in which the distance increases (moves away). Note that ± Δt is set by moving the L-shaped portion of the coupling loop 41.

As shown in FIG. 5, when Δt is + (approaching), the group delay time is shorter in the vicinity of the frequency fg than when Δt is 0. This indicates that the amount of coupling in the resonator 11 has increased (the coupling has become dense).
On the other hand, when Δt is − (goes away), the group delay time is longer in the vicinity of the frequency fg than when Δt is 0. This indicates that the amount of coupling in the resonator 11 has decreased (coupling has become sparse).

As described above, the coupling amount in the resonator 11 is changed by changing the distance between the coupling loop 41 and the resonator 21 and the coupling member 31. That is, the electrical characteristics of the resonator 11 are changed.
Here, the distance to the coupling loop 41 is changed for both the resonator 21 and the coupling member 31, but the distance to the coupling loop 41 is changed for one of the resonator 21 or the coupling member 31. Alternatively, a part of the coupling loop 41 may be bent or deformed. What is necessary is just to set the distance of the coupling loop 41 with respect to the resonator 21 or / and the coupling member 31 so that it may become the coupling amount to obtain | require.
Although not described here, the same applies to the resonator 14.

[Second Embodiment]
The filter 1 to which the second embodiment is applied differs from the filter 1 to which the first embodiment shown in FIG. 1 is applied in the configuration of the resonator 12 and the resonator 13.
FIG. 6 is a diagram illustrating an example of the configuration of the filter 1 to which the second exemplary embodiment is applied.
The filter 1 to which the second embodiment is applied includes four resonators 11, 12, 13, and 14, similarly to the filter 1 to which the first embodiment is applied. These resonators 11, 12, 13, and 14 are connected in a row so that the casings 71, 72, 73, and 74 included in the resonators 11, 12, 13, and 14 are continuous. The casing 70 in which the casings 71, 72, 73, and 74 are continuously formed has a quadrilateral cross section (enclosed by both side surfaces, a lower surface, and an upper surface as in the first embodiment). , Both ends are closed. The housing 70 is made of a conductive material and forms a shield (electric wall) against an electromagnetic field. That is, the filter 1 has a cavity structure.
FIG. 6 is a view of the inside of the filter 1 except for the upper surface of the housing 70.

Portions similar to those of the filter 1 of the first embodiment shown in FIG. 1 such as the resonators 11 and 14 are denoted by the same reference numerals and description thereof is omitted. And the resonators 12 and 13 different from the filter 1 of 1st Embodiment are demonstrated.
Similar to the resonator 12 in the filter 1 of the first embodiment shown in FIG. 1, the resonator 12 includes a resonator 22. The resonator 12 includes a coupling member 33 and a coupling loop 43, similarly to the resonator 11 and the resonator 14. Furthermore, the resonator 12 includes a connection component 53 connected to the coupling member 33.
The resonator 13 includes a resonator 23 as in the resonator 13 in the filter 1 according to the first embodiment shown in FIG. The resonator 13 includes a coupling member 34 and a coupling loop 44 similarly to the resonator 11 and the resonator 14. Furthermore, the resonator 13 includes a connection component 54 connected to the coupling member 33.

  Here, the resonator 22 is an example of a first resonator, the resonator 23 is an example of a second resonator, the coupling member 33 is an example of a first capacitive coupling member, and the coupling member 34 is a second capacitive coupling member. The coupling loop 43 is an example of a first capacity changing member, and the coupling loop 44 is an example of a second capacity changing member.

The coupling member 33 is provided so as to face the resonator 22 from the resonator 13 side, and the resonator 22 and the coupling member 33 are electric field (capacitive) coupled. Furthermore, the coupling loop 43 is provided at a position where electric field (capacitance) coupling is performed with respect to the resonator 22 and the coupling member 33, and the distance from the resonator 22 and / or the coupling member 33 can be changed.
Similarly, the coupling member 34 is provided so as to face the resonator 23 from the resonator 12 side, and the resonator 23 and the coupling member 34 are electric field (capacitive) coupled. Further, the coupling loop 44 is provided at a position where electric field (capacitance) coupling is performed with respect to the resonator 23 and the coupling member 34, and the distance from the resonator 23 and / or the coupling member 34 can be changed.
Further, the coupling member 33 and the coupling member 34 are connected by connecting parts 53 and 54 connected to each other. The connection parts 53 and 54 are connected through an opening 76 provided in the partition wall 75 between the resonators 12 and 13.
The connecting parts 53 and 54 are separate parts, but may be a single part.

  As described above, in the second embodiment, the resonators 12 and 13 are coupled by the coupling members 33 and 34 and the connection parts 53 and 54, and the coupling amount is changed by the coupling loops 43 and 44. That is, the coupling amount is changed depending on the distance between the coupling loop 43 and the resonator 12 or / and the coupling member 33. Similarly, the coupling amount is changed by the distance between the coupling loop 44 and the resonator 13 or / and the coupling member 34. It should be noted that both the distance between the coupling loop 43 and the resonator 12 or / and the coupling member 33 and the distance between the coupling loop 44 and the resonator 13 or / and the coupling member 34 may be changed. It may be changed.

FIG. 7 is a diagram in which two resonators 12 and 13 are extracted from the filter 1 to which the second embodiment shown in FIG. 6 is applied.
In order to show a state in which the amount of coupling between two resonators 12 and 13 shown in FIG. 8 to be described later is evaluated, the resonators 12 and 13 shown in FIG. It is assumed that the 14th side is surrounded by a casing.

  FIG. 8 is a diagram showing the group delay time in two coupled resonators 12 and 13. In FIG. 8, the resonators 12 and 13 (with coupling members and coupling loops) to which the second embodiment is applied and the resonators 12 and 13 (with coupling members and couplings) to which the second embodiment is not applied. No loop). The vertical axis represents the group delay time (ns), and the horizontal axis represents the frequency (f / fg) normalized by a predetermined frequency fg (wavelength λg). The interval between the resonator 22 and the coupling member 33 and the interval between the resonator 23 and the coupling member 34 are constant.

The resonators 12 and 13 to which the second embodiment is applied include coupling members 33 and 34, connection parts 53 and 54, and coupling loops 43 and 44. Therefore, in FIG. 8, they are expressed as “with a coupling member and with a coupling loop”.
On the other hand, the resonators 12 and 13 to which the second embodiment is not applied include the coupling members 33 and 34 and the connection parts 53 and 54, but do not include the coupling loops 43 and 44. Therefore, in FIG. 8, it is expressed as “with a coupling member and without a coupling loop”.

  As shown in FIG. 8, in the resonators 12 and 13 (with the coupling member and with the coupling loop) to which the second embodiment is applied, the resonators 12 and 13 (the coupling member) to which the second embodiment is not applied. The interval between two frequencies that appear separately is wider than (with and without coupling loop). This is because the resonators 12 and 13 to which the second embodiment is applied (with a coupling member and with a coupling loop) are the resonators 12 and 13 to which the second embodiment is not applied (with a coupling member and a coupling loop). This indicates that the amount of coupling between the resonators 12 and 13 is larger than that of (No). That is, the resonators 12 and 13 (with the coupling member and the coupling loop) are tightly coupled (tight coupling), and the resonators 12 and 13 (with the coupling member and no coupling loop) are loosely coupled (loosely coupled). ).

In the resonators 12 and 13 (with the coupling member and with the coupling loop) to which the second embodiment is applied, the distance between the coupling loop 43 and the resonator 12 or / and the coupling member 33, the coupling loop 44, and The amount of coupling between the resonators 12 and 13 is changed by changing both or one of the distances from the resonator 13 and / or the coupling member 34. In this way, the electrical characteristics of the two connected resonators 10 are changed.
Two connected resonators 10 may also be referred to as resonators.

FIG. 9 is a diagram illustrating a modification of the two resonators 12 and 13. In FIG. 8, a coupling loop 43 that couples an electric field (capacitance) to the resonator 12 and the coupling member 33 and a coupling loop 44 that couples an electric field (capacitance) to the resonator 13 and the coupling member 34 are provided.
In the modification of the resonators 12 and 13 shown in FIG. 9, a coupling loop 45 coupled to the resonator 12, the coupling member 33, the resonator 13, and the coupling member 34 is provided.
Note that, as described above, the length of the coupling loop 45 between the two ends connected to the reference potential is set to ½λg. Therefore, when it is difficult to obtain coupling to the resonator 12, the coupling member 33, the resonator 13, and the coupling member 34 with the coupling loop 45 having a length of 1 / 2λg, as illustrated in FIG. , 13 may be provided with coupling loops 43 and 44, respectively.

In the first embodiment, the coupling loop 40 has been described as a linear conductive material as an example. In addition to a linear conductive material, the coupling loop 40 may be configured by bending a plate-shaped or bar-shaped member, or may be configured by cutting out. The coupling loop 40 only needs to be able to change the distance to the resonator 20 and / or the coupling member 30 after the resonator 11 is assembled.
Then, a long hole may be provided in the housing 70, and the coupling loop 40 may be fixed to the long hole. By changing the fixed position within the range of the long hole, the capacity of the coupling loop 40 can be changed depending on the distance to the resonator 20 and / or the coupling member 30. That is, the coupling amount in the resonator 10 can be changed.

In the first embodiment and the second embodiment, the coupling loop 40 and the resonator 20 or / and the coupling member 30 are changed by changing the distance between the coupling loop 40 and the resonator 20 or / and the coupling member 30. The capacity between was changed. Instead of the distance, the area where the coupling loop 40 and the resonator 20 or / and the coupling member 30 face each other may be changed. For example, the area facing the resonator 20 and the coupling member 30 may be changed by twisting the coupling loop 40 as a plate-shaped member.
In addition, various modifications may be made without departing from the spirit of the present invention.

DESCRIPTION OF SYMBOLS 1 ... Filter 10, 11, 12, 13, 14 ... Resonator, 20, 21, 22, 23, 24 ... Resonator, 30, 31, 32, 33, 34 ... Coupling member, 40, 41, 42, 43 44, 45 ... coupling loop, 50, 51, 52, 53, 54 ... connection parts, 61 ... input terminal, 62 ... output terminal, 70, 71, 72, 73, 74 ... casing, 75 ... partition wall, 76 ... Aperture, λg ... wavelength, fg ... frequency

Claims (6)

A resonator that resonates at a predetermined wavelength;
A capacitive coupling member capacitively coupled to the resonator;
A resonator comprising: a capacitive change member capable of capacitively coupling to the resonator and the capacitive coupling member and capable of changing a capacitance with respect to the resonant body or a capacitance with respect to the capacitive coupling member. The capacity changing member is
The resonator according to claim 1, wherein one end and the other end are connected to a reference potential, and a distance to the resonator or the capacitive coupling member is changeable.   The resonator according to claim 2, wherein the capacitance changing member has a length from the one end to the other end set to ½ of the wavelength. A first resonator and a second resonator, each resonating at a predetermined wavelength;
A first capacitive coupling member capacitively coupled to the first resonator;
A second capacitive coupling member capacitively coupled to the second resonator;
Capacitively coupled to the first resonator, the second resonator, the first capacitive coupling member, and the second capacitive coupling member, the first resonator, the second resonator, the first A capacity changing member capable of changing a capacity of at least one of the first capacitive coupling member and the second capacitive coupling member;
The first capacitive coupling member and the second capacitive coupling member are disposed between the first resonator and the second resonator and are electrically connected to each other. Resonator. The capacity changing member is
A first capacitance changing member that is capacitively coupled to the first resonator and the first capacitive coupling member, and capable of changing a capacitance with respect to the first resonator or a capacitance with respect to the first capacitive coupling member;
A second capacitance changing member that is capacitively coupled to the second resonator and the second capacitive coupling member, and capable of changing a capacitance of the second resonator or a capacitance of the second capacitive coupling member; The resonator according to claim 4. A plurality of resonators, each resonating at a predetermined wavelength and arranged in a row;
An input terminal connected to a resonator at one end of the plurality of resonators and receiving a signal;
An output terminal connected to a resonator at the other end of the plurality of resonators and outputting a signal,
The resonator at the one end is
A resonator and a capacitive coupling member capacitively coupled to the resonator,
The resonator at the other end is
Another resonator and another capacitive coupling member that capacitively couples with the other resonator,
Capacitively coupled to the resonator and the capacitive coupling member, capacitively coupled to the resonator or the capacitive coupling member, and capacitively coupled to the other resonator and the other capacitive coupling member, and A filter comprising at least one of another resonator or another capacitance changing member capable of changing a capacitance with respect to the other capacitive coupling member.

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