JP5934814B1 - Resonator and filter - Google Patents

Abstract

A resonator having high temperature stability applicable to a plurality of frequency bands and a filter using the resonator are provided. A resonator 10 according to the present invention includes an outer conductor 12 that forms a cavity 11 therein, and an inner conductor 13 provided in the cavity 11 of the outer conductor 12. The inner conductor 13 includes a movable body 133 that protrudes into the cavity 11, a distal end portion 131 that is a separate member from the movable body 133 and covers the distal end of the movable body 133 that projects into the cavity 11, and a movable body. 133 is a rod-like member arranged inside 133, provided with one end fixed to the tip 131 and the other end fixed to the moving body 133, and has a lower thermal expansion coefficient than the moving body 133. And a support bar 132. [Selection] Figure 3

Description

  The present invention relates to a resonator and a filter.

In a broadcasting station, a broadcast signal is transmitted from a transmitter to an antenna through a filter and radiated as a radio wave. For such a filter, a band pass filter (BPF: Band Pass Filter) is often used, and a signal in a predetermined frequency band included in a broadcast signal is allowed to pass, and other frequency components are allowed to pass. Suppress. Such a filter can be composed of a resonator using a cavity.
The characteristics such as the frequency band that the filter passes through are required not to deviate due to changes in temperature due to environmental temperature or heat generation (less temperature drift) and to have high temperature stability.

  Non-Patent Document 1 discloses an absolute temperature compensation for a tunable resonant cavity that has a narrow useful frequency range and shows a linear rule for temperature and frequency changes in the range of at least 30 ° C. near the reference temperature. A simple method for doing this is described.

S. A. S. A. Adeniran, "A New Technology for Absolute Temperature Compensation of Tunable Resonant Cavities" Pro, E (USA), December (December), 1985, Vol. 132, Part H (Pt. H), No. 7, p. 471.

By the way, the resonator is required to be compatible with use in a plurality of frequency bands and to have high temperature stability in these frequency bands.
An object of the present invention is to provide a resonator having high temperature stability that can be applied to a plurality of frequency bands, and a filter using the resonator.

For this purpose, a resonator to which the present invention is applied includes an outer conductor that forms a cavity therein, and an inner conductor provided in the cavity of the outer conductor, and the inner conductor is disposed in the cavity. A hollow member that protrudes into the hollow member and a member that is separate from the hollow member, a covering member that covers a tip of the hollow member that protrudes into the cavity, and a rod-like member that is disposed inside the hollow member There, the other end fixed to one end side with respect to the cover member with provided fixed relative to the hollow member, possess a support rod thermal expansion coefficient lower than that of the hollow member, the hollow member The tip of the resonator is characterized by being more easily elastically deformed than the base side of the hollow member .
Here, the covering member covers the distal end of the hollow member and an outer peripheral side surface of the distal end side, and the outer peripheral side surface of the hollow member supports the covering member slidably along the protruding direction. Can be characterized. In this case, the position of the covering member with respect to the hollow member is stabilized.
From another point of view, the hollow member includes an outer conductor that forms a cavity therein and an inner conductor that is provided in the cavity of the outer conductor, and the inner conductor protrudes into the cavity. And a hollow member that covers the tip of the hollow member that protrudes into the cavity, and a rod-like member that is disposed inside the hollow member, and covers one end side of the hollow member. The other end side is fixed to the member and fixed to the hollow member, and the support member has a thermal expansion coefficient lower than that of the hollow member. The position in the protruding direction is adjustable, and is fixed to the outer conductor at an intermediate position located between the one end and the other end of the support rod in the protruding direction. To be Kill. In this case, the resonance frequency can be adjusted while adjusting the temperature compensation amount.
From another point of view, the hollow member includes an outer conductor that forms a cavity therein and an inner conductor that is provided in the cavity of the outer conductor, and the inner conductor protrudes into the cavity. And a hollow member that covers the tip of the hollow member that protrudes into the cavity, and a rod-like member that is disposed inside the hollow member, and covers one end side of the hollow member. And a support rod having a lower coefficient of thermal expansion than that of the hollow member, and the inner conductor is disposed in the cavity. The support member is fixed to the outer conductor and supports the hollow member in a state where the hollow member penetrates, and the hollow member and the support member have a thread groove on each of the surfaces facing each other. And the thread grooves are engaged with each other. It can be the support for supporting the hollow member by. In this case, the resonance frequency of the resonator can be easily adjusted.
From another point of view, a filter to which the present invention is applied is connected to an input unit to which a signal is input, an output unit to which a signal is output, the input unit and the output unit, and internally. A resonator having an outer conductor that forms a cavity and an inner conductor provided in the cavity of the outer conductor, the inner conductor projecting into the cavity, and the hollow member Is a separate member, a covering member that covers the tip of the hollow member that protrudes into the cavity, and a rod-shaped member that is disposed inside the hollow member, and fixes one end side to the covering member. the other end side together provided fixed relative to the hollow member, possess a support rod thermal expansion coefficient lower than that of the hollow member, the distal end of said hollow member, than the root side of the hollow member off also characterized by easy elastic deformation It is a filter.

  According to the present invention, it is possible to provide a resonator having high temperature stability that can be applied to a plurality of frequency bands, and a filter using the resonator.

It is a figure explaining the filter in transmission of the signal for broadcasts. It is a perspective view of the filter in this Embodiment. (A) And (b) is the top view and sectional drawing explaining the structure of a resonator. It is a disassembled perspective view explaining the structure of an inner conductor. (A) thru | or (e) are sectional drawings explaining the member which comprises the structure of an inner conductor. (A) And (b) is the bottom view and top view explaining the structure of a moving body. (A) And (b) is a figure which shows a resonator in case a pass frequency band differs. (A) thru | or (c) is a figure explaining the temperature compensation in a resonator. (A) And (b) is a figure explaining the relationship between the pass frequency band and temperature compensation amount in a resonator. (A) And (b) is a figure for demonstrating the slide movement of a front-end | tip part. In a filter, it is a figure which shows the temperature change of the attenuation amount when the center frequency f0 is set to 474 MHz (low frequency band). In a filter, it is a figure which shows the temperature change of the attenuation amount when the center frequency f0 is set to 850 MHz (high frequency band). FIG. 6 is a diagram showing a temperature change of attenuation when a center frequency f0 is set to 863 MHz (high frequency band) in a single resonator. (A) thru | or (c) is a figure explaining the modification in this Embodiment. (D) thru | or (f) is a figure explaining the modification in this Embodiment.

Embodiments of the present invention will be described below in detail with reference to the accompanying drawings.
Here, a filter and a resonator will be described using a broadcast signal in a broadcast station as an example. However, the filter and the resonator are not limited to a broadcast signal, but are used to pass signals in a predetermined frequency band in other high-frequency signals. It may be a filter and a resonator.

<Filter 100>
FIG. 1 is a diagram for explaining a filter 100 in transmission of a broadcast signal.
The broadcast signal is transmitted from the transmitter 200 via the filter 100 to the antenna 300 and radiated from the antenna 300 as a radio wave.
The filter 100 is a band-pass filter (BPF) that passes a signal in a predetermined frequency band among broadcast signals input from the transmitter 200 and suppresses the passage of other frequency components.
In addition, since the filter and resonator in this Embodiment are not limited to the signal for broadcast as mentioned above, below, it describes with a signal.
Hereinafter, the frequency band to be passed is referred to as a pass frequency band.

FIG. 2 is a perspective view of filter 100 in the present embodiment.
As shown in FIG. 2, the filter 100 in the present embodiment includes a plurality of resonators 10.
More specifically, as an example, the filter 100 is configured by connecting six resonators 10 (respectively, the resonators are represented as resonators 10-1 to 10-6). The filter 100 includes an input terminal 20 as an example of an input unit that inputs a signal, and an output terminal 30 as an example of an output unit that outputs a signal. In addition, the filter 100 includes a fine adjustment screw 40 that is provided in each resonator 10 and allows fine adjustment of the resonance frequency of each resonator 10.

In the filter 100, the signal input to the input terminal 20 propagates between the resonators 10-1 to 10-6 and is output from the output terminal 30.
In the illustrated example, the input terminal 20 is connected to the resonator 10-1, and the output terminal 30 is connected to the resonator 10-6. Further, a coupling mechanism (not shown) is provided between each of the resonators 10-1 to 10-6, and is configured to propagate a signal. More specifically, the coupling mechanism includes the resonator 10-1 and the resonator 10-2, the resonator 10-2 and the resonator 10-3, the resonator 10-3 and the resonator 10-4. Between the resonator 10-4 and the resonator 10-5, and between the resonator 10-5 and the resonator 10-6.

  Here, a plurality of resonators 10 may be connected to each other by a coupling mechanism to obtain a predetermined pass frequency band, and a coupling mechanism may be provided between any of the plurality of resonators 10. . For example, unlike the illustrated example, a coupling mechanism may be provided between the resonator 10-1 and the resonator 10-6, and between the resonator 10-2 and the resonator 10-5.

In FIG. 2, the filter 100 is configured by connecting the resonators 10 in six stages (six). The number of connected resonators 10 affects the steepness of the pass frequency band. To explain further, the greater the number of stages of the resonator 10, the higher the steepness of the pass frequency band. On the other hand, as the number of stages increases, the loss increases. Therefore, the number of stages of the resonator 10 is set according to the required steepness of the pass frequency band. More specifically, for example, the filter 100 may be configured by one stage (one) resonator 10.
The steepness of the pass frequency band means that the width of the frequency band at the boundary between the pass frequency and the non-pass frequency is narrow.
Moreover, as said coupling mechanism, a well-known technique should just be applied and description is abbreviate | omitted here.

<Resonator 10>
FIGS. 3A and 3B are a plan view and a cross-sectional view illustrating the configuration of the resonator 10. More specifically, FIG. 3A is a plan view of the resonator 10, and FIG. 3B is a cross-sectional view taken along line IIIB-IIIB in FIG.
In FIG. 3A, the notation of the facing surface portion 121 is omitted. Moreover, in FIG.3 (b), the front-end | tip part 131 and the mobile body 133 are described as a side view instead of sectional drawing for convenience. 3A and 3B, the input terminal 20, the output terminal 30, the fine adjustment screw 40, or the coupling mechanism is not shown.

As shown in FIGS. 3A and 3B, the resonator 10 includes an outer conductor 12 that forms a cavity (cavity) 11 therein, and an inner conductor 13 that is provided in the cavity 11 formed by the outer conductor 12. And. Here, the outer conductor 12 constitutes a housing of the resonator 10.
Note that the resonator 10 is not limited to the arrangement shown in FIGS. 3A and 3B, and may be arranged upside down from the resonator 10 shown in FIG. 3B, for example. Alternatively, it may be arranged to be inclined with respect to the vertical direction.

<Outer conductor 12>
Next, the outer conductor 12 will be described with reference to FIGS. 3 (a) and 3 (b).
As shown in FIGS. 3A and 3B, the outer conductor 12 includes a facing surface portion 121, a side surface portion 122, and a support surface portion 123.
Here, as shown in FIG. 3B, the outer shapes of the opposing surface portion 121 and the support surface portion 123 of the outer conductor 12 are square. That is, the cavity 11 surrounded by the outer conductor 12 is a rectangular parallelepiped. The outer conductor 12 may have other shapes. For example, the bottom may be a rectangular parallelepiped or a cube. Further, the outer conductor 12 may be cylindrical or elliptical.

The support surface 123 is provided with a circular opening 124. Although details will be described later, the inner conductor 13 is provided in the opening 124.
Although illustration is omitted, when the input terminal 20, the output terminal 30, or the coupling mechanism is provided, for example, an opening is provided in the side surface portion 122 of the outer conductor 12, and the input terminal 20, the output terminal 30, or the coupling mechanism is provided. What is necessary is just to provide. Further, when the fine adjustment screw 40 is provided, for example, an opening may be provided in the support surface portion 123 and the fine adjustment screw 40 may be provided.

<Inner conductor 13>
FIG. 4 is an exploded perspective view illustrating the configuration of the inner conductor 13.
Next, the inner conductor 13 will be described with reference to FIGS. 3 and 4.
As shown in FIGS. 3A and 3B, the inner conductor 13 is a member whose outer shape is substantially cylindrical. The inner conductor 13 is provided in the opening 124 of the outer conductor 12. More specifically, the inner conductor 13 is provided so as to cover the opening 124 of the outer conductor 12 from the inside of the cavity 11, and is disposed so as to protrude into the cavity 11 formed by the outer conductor 12. The inner conductor 13 has both a function of an adjusting screw for setting a frequency band to be used and a function of suppressing a change in temperature (temperature drift) caused by a temperature change of the resonator 10 due to the environment and heat generation, that is, a function of temperature compensation. (Details will be described later).

  Here, the inner conductor 13 in the illustrated example is disposed in the cavity 11 so that the longitudinal direction (axial direction) is along the vertical direction. In the following description, the axial direction of the inner conductor 13 may be simply referred to as the axial direction. Further, in the axial direction of the inner conductor 13, the leading end side of the inner conductor 13 may be simply referred to as a leading end side, and the root side of the inner conductor 13 may be simply referred to as a root side. Further, the circumferential direction (circumferential direction) around the axis of the inner conductor 13 may be simply referred to as the circumferential direction.

As shown in FIG. 4, the inner conductor 13 includes a distal end portion 131, a support bar 132, a moving body 133, a support body 134, and a fixed plate 135.
Hereinafter, each of these constituent members constituting the inner conductor 13 will be described with reference to FIGS. 4 to 6.
Here, FIGS. 5A to 5E are cross-sectional views illustrating members constituting the configuration of the inner conductor 13. More specifically, FIG. 5 (a) is a cross-sectional view of the tip 131, FIG. 5 (b) is a cross-sectional view of the support bar 132, and FIG. 5 (c) is a cross-sectional view of the moving body 133. FIG. 5D is a sectional view of the support 134, and FIG. 5E is a sectional view of the fixing plate 135.
6A and 6B are a bottom view and a top view illustrating the configuration of the moving body 133. FIG. More specifically, FIG. 6A is a top view of the moving body 133, and FIG. 6B is a bottom view of the moving body 133.

<Tip 131>
As shown in FIG. 4, the tip 131 that is an example of a covering member is a disk-shaped member. In the illustrated example, the distal end portion 131 has a distal end side edge 131a and a root side edge 131b processed in an R shape.
As shown in FIG. 5A, the tip 131 includes a first recess 131c formed at the center of the tip side surface, a second recess 131d formed at the center of the root side surface, And a through hole 131e that allows the first recess 131c and the second recess 131d to continue in the axial direction.

  In addition, since the edge 131a on the front end side of the inner conductor 13 is processed into a round shape, a discharge may occur between the front end portion 131 and the outer conductor 12 (for example, between the opposing surface portion 121). It is suppressed. In the illustrated example, the shape of the edge 131a on the front end side of the inner conductor 13 is determined so that the electric field strength is 3.0 kV / mm or less. Thereby, the filter 100 can handle a high-power signal.

<Support bar 132>
As shown in FIG. 4 and FIG. 5B, the support bar 132 has a columnar shape, which is a so-called bar-shaped member. The support bar 132 includes a main body 132a and first and second screw holes 132b and 132c formed on both end surfaces of the distal end side and the root side, respectively.
Although the support bar 132 is a columnar bar here, it may have other shapes such as a prismatic bar. More specifically, the cross-sectional shape of the support bar 132 is not limited to a circle, and may be any shape such as an ellipse or a polygon.

<Moving object 133>
As shown in FIG. 4, the moving body 133, which is an example of a main body and a hollow member, is a bottomed cylindrical member that forms a space 133 a inside itself, that is open at the distal end side and covered at the root side. The moving body 133 includes a slide support portion 133b located on the distal end side, and a fixed portion 133c located on the root side of the slide support portion 133b. Here, while the thread groove 133t is formed along the circumferential direction on the outer peripheral surface of the fixed portion 133c, the screw groove 133t is not formed on the outer peripheral surface of the slide support portion 133b. The fixed portion 133c is an example of a region where the thread groove 133t is formed.

  Moreover, as shown in FIG. 4, the slide support part 133b includes a slit 133e extending in the axial direction from the distal end side. In the illustrated example, a plurality of (six) slits 133e are formed apart from (arranged) in the circumferential direction. In other words, the slide support part 133b is configured to include a plurality (six) of small piece parts 133f by forming a plurality (six) of slits 133e. The small piece parts 133f are formed so as to be spaced apart (arranged) from each other in the circumferential direction.

  Moreover, as shown in FIG.5 (c), the moving body 133 is provided with the 3rd recessed part 133m formed in the center of the surface by the side of a base, and the through-hole 133n which makes the 3rd recessed part 133m and the space 133a continue. .

The slide support portion 133b has an outer diameter that matches (corresponds to) the outer diameter of the fixed portion 133c. Moreover, the slide support part 133b is provided with the enlarged diameter part 133d with a large diameter of the space 133a formed inside compared with the to-be-fixed part 133c. Therefore, the slide support portion 133b is thinner in the radial direction than the fixed portion 133c, and is more easily elastically deformed in the radial direction.
Here, as shown in FIG. 6A, each of the plurality of small piece parts 133f is movable in the radial direction of the slide support part 133b as it is elastically deformed (see the arrow in the figure). More specifically, the slide support portion 133b is configured such that its outer diameter can be changed (shrinkable).

Returning to FIG. 4 again, the fixed portion 133c of the present embodiment has a portion in which the screw groove 133t is formed and a portion in which the screw groove 133t is not formed in the circumferential direction. That is, the thread groove 133t is discontinuous in the circumferential direction.
Further description will be made with reference to FIG. 6B. The fixed portion 133c includes a threaded portion 133g and a flat portion 133h at positions adjacent to each other in the circumferential direction. Here, the threaded portion 133g is a region where the screw groove 133t is formed in the fixed portion 133c, while the flat portion 133h is a region where the screw groove 133t is not formed in the fixed portion 133c. The flat portion 133h is an example of a discontinuous portion where the thread groove 133t is not continuous.

  The flat portion 133h is a portion corresponding to a so-called D-cut, and is a flat portion formed on the outer peripheral surface of the fixed portion 133c. In other words, the flat portion 133h is a substantially planar region whose longitudinal direction extends along the axial direction. Here, the flat portion 133h can be regarded as a portion having less unevenness than the screw portion 133g, for example. Further, the flat portion 133h can be regarded as a region that does not generate a force for fixing the moving body 133 to the support 134. In other words, the operation of forming the flat portion 133h is facilitated when the longitudinal direction of the flat portion 133h is along the axial direction.

Now, as shown in FIG.6 (b), the to-be-fixed part 133c is equipped with the multiple (4 pieces) screw part 133g and the flat part 133h by arranging in the circumferential direction alternately. In the illustrated example, each of the threaded portions 133g is disposed at a position facing each other across the central axis of the moving body 133. In addition, each of the flat portions 133h is disposed at a position facing each other across the central axis of the moving body 133. Further, as the circumferential length in the illustrated example, the flat portion 133h is longer than the screw portion 133g.
As shown in the example in the figure, in the moving body 133, a plurality (four) of flat portions 133h are arranged in the circumferential direction, so that, for example, one circumferential length is equal to the sum of the four flat portions 133h. Compared with a configuration in which a flat portion (not shown) is formed, the electrical connection between the moving body 133 and the support body 134 can be stably maintained. In addition, the relative position between the moving body 133 and the support body 134 can be suppressed.

<Support 134>
As shown in FIGS. 4 and 5 (d), the support 134 is a cylindrical member that forms a space 134a therein, is partially covered on the tip side, and is open on the root side.
The support 134 includes a through hole 134b formed at a center corresponding to the outer diameter of the moving body 133 at the center of the tip side surface. The support 134 includes a thread groove 134t that is formed along the circumferential direction on the inner peripheral surface of the through hole 134b and meshes with the thread groove 133t of the moving body 133. The screw groove 134t is an example of another screw groove.

Further, the support 134 includes a flange portion 134c formed on the outer peripheral surface on the base side, and a thread groove 134d penetrating the flange portion 134c in the axial direction. Further, in the illustrated example, the support 134 has an edge 134e on the distal end side in the axial direction processed into a round (R) shape.
Furthermore, the support body 134 includes a plurality of screw holes 134f on the surface covering the tip side. The screw hole 134f is formed along the circumferential direction on the surface facing the space 134a. The screw hole 134f is formed to extend from the root side toward the tip side.

Here, as shown in FIG. 4 and FIG. 5 (d), the thread groove 134 t is not formed on the outer peripheral surface of the support 134.
Further, a thread groove 134t is formed on the inner peripheral surface of the through hole 134b formed in the support body 134, while the inner peripheral surface of the support body 134 located on the root side of the through hole 134b is The thread groove 134t is not formed. Note that the inner diameter of the space 134a in the illustrated example is larger than the inner diameter of the through hole 134b.
Furthermore, the thread groove 134t formed in the inner peripheral surface of the through hole 134b is continuously formed in the circumferential direction. More specifically, the inner peripheral surface of the through hole 134b does not have a discontinuous portion of the thread groove 133t in the circumferential direction, unlike the fixed portion 133c of the moving body 133.

<Fixed plate 135>
As shown in FIGS. 4 and 5 (e), the fixed plate 135 is an annular plate member. The inner diameter of the fixed plate 135 is formed with a dimension corresponding to the outer diameter of the movable body 133.
The fixed plate 135 includes a thread groove 135t that is formed along the circumferential direction on the inner peripheral surface 135a and that meshes with the thread groove 133t of the moving body 133. The thread groove 135t is continuously formed in the circumferential direction.
The fixing plate 135 includes a plurality of through holes 135b penetrating in the axial direction along the circumferential direction. The through holes 135b are formed at positions facing the screw holes 134f of the support 134, respectively.

<Relationship of each member in the inner conductor 13>
Next, the positional relationship between the members constituting the inner conductor 13 in a state where the inner conductor 13 is assembled will be described with reference to FIGS. 3 to 5.
First, the distal end portion 131 is disposed so as to cover the opened distal end side of the moving body 133. At this time, the tip 131 is provided at the tip of the moving body 133 so that the position in the axial direction can be displaced.

Specifically, the slide support part 133 b of the moving body 133 is inserted into the second recess 131 d of the tip part 131. Thereby, the slide support part 133b is supported so that the front-end | tip part 131 can be slid in an axial direction.
Although not described above, the inner diameter of the second recess 131d of the distal end portion 131 and the outer diameter of the slide support portion 133b are in a state where the slide support portion 133b is inserted (arranged) in the second recess 131d. It is a dimension that the tip portion 131 is restricted from moving in the radial direction and is movable in the axial direction.
Further, as described above, the small piece portion 133f is elastically deformed in the radial direction, whereby the resistance when the slide support portion 133b slides in the axial direction is reduced.
In other words, the relative position of the tip 131 with respect to the slide support 133b is stabilized by inserting the slide support 133b of the moving body 133 into the second recess 131d of the tip 131.

The tip 131 and the moving body 133 are fixed to both ends of the support bar 132 via bolts (fixers, not shown).
Specifically, a bolt (not shown) is disposed penetrating from the distal end side (first concave portion 131c side) of the distal end portion 131 through the through hole 131e to the second concave portion 131d side. Then, the tip end 131 is fixed (connected) to the support rod 132 by inserting the tip of the bolt into the first screw hole 132 b formed on the tip side of the support rod 132.
Further, another bolt (not shown) is disposed penetrating from the base side (the third recess 133m side) of the moving body 133 through the through hole 133n to the space 133a side. The moving body 133 is fixed to the support bar 132 by inserting the tip of this bolt (not shown) into the second screw hole 132 c formed on the base side of the support bar 132.

  The support bar 132 is fixed to the moving body 133 via a bolt (not shown). The support bar 132 is fixed to the end of the moving body 133 opposite to the slide support portion 133b, in other words, to the bottom side of the moving body 133. Here, the bottom of the moving body 133 is not limited to a portion that covers one end of the moving body 133 formed as a hollow member, but is a part of the moving body 133, and is the center in the longitudinal direction of the moving body 133. Any part may be used as long as it is located on the opposite side of the slide support part 133b.

In addition, the movable body 133 is provided so that the base side is inserted into the support body 134 and the position in the axial direction with respect to the support body 134 can be displaced.
Specifically, the base side of the moving body 133 is inserted into the through hole 134 b of the support body 134. Here, the thread groove 133t formed on the outer peripheral surface of the movable body 133 is engaged with the screw groove 134t formed on the inner peripheral surface of the through hole 134b of the support body 134. In this state, the relative position in the axial direction of the moving body 133 and the support body 134 is changed by rotating the moving body 133 in the circumferential direction.

In the present embodiment, the support 134 is provided in the cavity 11, and the moving body 133 is supported on the distal end side of the support 134. As a result, the amount of the movable body 133 protruding outward from the support surface portion 123 of the outer conductor 12 is suppressed.
In addition, the support 134 can be understood as a configuration that covers the outer periphery (a part of the moving body 133) on the base side of the moving body 133. As described above, the support 134 covers a part of the moving body 133, so that the area in which the thread groove 133t formed in the moving body 133 is inserted into the cavity 11 is suppressed.

Further, as described above, the movable body 133 is formed with the flat portion 133h, and the thread groove 133t of the movable body 133 is not partially continuous in the circumferential direction, whereas the thread groove 134t of the support body 134 is formed. Is formed in an annular shape continuously in the circumferential direction. Thus, unlike the example shown in the figure, for example, the displacement in the axial direction that can occur when the configuration in which the thread groove 134t of the support 134 is not partially continuous in the circumferential direction is suppressed.
To explain further, in such a configuration in which the thread groove 134t of the support body 134 is not continuous, the thread groove 134t of the support body 134 is formed depending on the mounting angle as a result of rotating the movable body 133 in the circumferential direction. The part where the screw groove 133t of the moving body 133 is not formed (flat part 133h) may be in a state of facing each other. In this case, the thread groove 133t and the thread groove 134t do not mesh with each other, and there is a possibility that the relative position in the axial direction between the support body 134 and the movable body 133 is shifted. In the present embodiment, the thread groove 134t of the support 134 is continuously formed in the circumferential direction so as to suppress the positional deviation in the axial direction.

  Now, in the state where the base side of the moving body 133 is inserted into the support body 134 and the position adjustment in the axial direction of the moving body 133 (details will be described later) is completed, the fixed plate 135 is fixed to the moving body 133 and the support body 134. Is attached. As a result, displacement of the moving body 133 relative to the support body 134 is suppressed.

Specifically, the fixed plate 135 is attached to the moving body 133 inserted into the space 134a through the through hole 134b, and the screw groove 133t of the moving body 133 and the screw groove 135t of the fixed plate 135 are engaged with each other. Then, with the screw groove 133t and the screw groove 135t engaged with each other, a bolt (not shown) is inserted through the through hole 135b of the fixing plate 135 and then inserted into the screw hole 134f of the support 134 and fixed. To do. This suppresses the moving body 133 from moving (rotating) in the circumferential direction via the fixed plate 135 and the bolt.
In addition, as shown in FIG.3 (b), the support body 134 and the fixing plate 135 are fixed in the state spaced apart in the axial direction. Therefore, the moving body 133 is in a state where it is fixed with a so-called double nut. The fixed plate 135 is an example of a rotation suppressing member.

Although not described above, the inner conductor 13 is fixed to the outer conductor 12 via the support 134.
Specifically, as shown in FIG. 3 (b), a bolt (not shown) is inserted into a screw hole (not shown) formed in the support surface portion 123 of the outer conductor 12, and the support for the inner conductor 13 is further inserted. It is inserted into a thread groove 134d formed in 134 and fixed. As a result, the support 134 (inner conductor 13) is fixed to the outer conductor 12.

<Material>
Next, an example of the material constituting the resonator 10 will be described.
The outer conductor 12 is made of a metal that is a conductive material, specifically, aluminum (Al), iron (Fe), copper (Cu), or the like.
Further, members other than the support bar 132 and the fixed plate 135 in the inner conductor 13, that is, the tip 131, the moving body 133, and the support 134 are metals that are conductive materials, specifically, aluminum, iron, copper Etc. Moreover, you may comprise by performing the plating process with silver (Ag) etc. with respect to these metals.

On the other hand, the support bar 132 has a coefficient of thermal expansion (linear) compared to the outer conductor 12, the tip 131, the moving body 133, the support 134, and the fixed plate 135 (hereinafter sometimes referred to as the outer conductor 12). (Expansion coefficient) is made of a small material. For example, the support bar 132 is made of a metal material having a smaller coefficient of thermal expansion than aluminum, iron, copper, or the like constituting the outer conductor 12, specifically, Invar (registered trademark) (invariable steel), carbon steel, or the like. Is done.
The support bar 132 only needs to have a smaller amount of deformation due to temperature change than the outer conductor 12 or the like, and may be configured by a combination of the above materials.
The fixing plate 135 is made of a metal (specifically, aluminum, iron, copper, etc.) in the present embodiment. However, the fixing plate 135 only needs to be surely fixed, and other materials (specifically, other than metal) May be a resin or the like.

<Adjustment of Resonant Frequency of Resonator 10>
FIGS. 7A and 7B are diagrams showing the resonator 10 when the pass frequency bands are different. More specifically, FIG. 7A shows a case where the frequency band is low (low frequency band), and FIG. 7B shows a case where the frequency band is high (high frequency band).
As shown in FIG. 7A, the cavity 11 in the outer conductor 12 has a side length Lr and a height Hr. The dimensions of each member constituting the inner conductor 13 are the outer diameter D1 of the tip 131, the outer diameter D2 of the moving body 133, the outer diameter D3 of the support body 134, and the outer diameter D4 of the fixed plate 135.
Further, the distance h1 is from the support surface portion 123 of the outer conductor 12 to the tip of the tip portion 131 of the inner conductor 13, and the distance h2 is from the tip of the tip portion 131 of the inner conductor 13 to the facing surface portion 121 of the outer conductor 12. The axial distance from the tip of the support 134 to the tip of the support bar 132 is h3, and the axial distance from the tip of the support 134 to the root of the support bar 132 is h4. The axial distance from the tip of the support 134 to the tip of the tip 131 is h5, and the axial distance from the support surface 123 to the tip of the support 134 is h6.
In the present embodiment, the low frequency band may be denoted as LF and the high frequency band as HF.

Next, the adjustment of the resonance frequency in the resonator 10 will be described with reference to FIG.
First, the dimensions of the resonator 10 will be described.
In the resonator 10 according to the present embodiment, the length Lr, the height Hr, the outer diameter D1 of the tip 131, the outer diameter D2 of the moving body 133, and the outer diameter of the main body of the support 134 are surrounded by the outer conductor 12. D3 and the outer diameter D4 of the fixed plate 135 are the same (fixed) even if the frequency band to be used is different.
On the other hand, the distances h1 to h6 are changed based on the frequency band to be used. More specifically, in the resonator 10 according to the present embodiment, the frequency band to be used can be changed by setting the distance h1. Although details will be described later, in the resonator 10 according to the present embodiment, by adjusting the distance h1, the temperature drift of the frequency is suppressed in the frequency band to be used.

  The cavity 11 of the resonator 10 has, for example, a side length Lr of 120 mm and a height Hr of 150 mm. The outer diameter D1 of the tip 131 is 45 mm, the outer diameter D2 of the moving body 133 is 35 mm, the outer diameter D3 of the main body of the support 134 is 50 mm, and the outer diameter D4 of the fixing plate 135 is 46 mm.

Now, the distance h1 (LF) in the low frequency band shown in FIG. 7A is set larger than the distance h1 (HF) in the high frequency band shown in FIG. 7B. That is, the distance h2 (LF) in the low frequency band is smaller than the distance h2 (HF) in the high frequency band.
And in this Embodiment, the frequency band to be used can be changed by making variable the distance h1 from the support surface part 123 of the outer conductor 12 to the front-end | tip of the front-end | tip part 131. FIG.

Here, the distance h1 is obtained based on the frequency band to be used by simulation (electromagnetic field analysis). In addition, the distance h1 is obtained based on the amount of deformation (details will be described later) of the outer conductor 12 due to thermal contraction or thermal expansion accompanying a change in temperature in a frequency band to be used and a predetermined temperature range.
The distances h2 to h6 are determined by setting the distance h1. From this, any of the distances h2 to h6 may be obtained by simulation, and the distance h1 may be determined based on the result.

<Method for adjusting resonator 10>
Now, a method for adjusting the resonator 10 will be described.
First, as a premise, when the resonator 10 is adjusted, the fixed plate 135 is not attached to the moving body 133 and the support body 134.
When the frequency band in which the resonator 10 is used is determined, the inner conductor 13 is arranged so that the distance h1 obtained in advance by simulation is obtained while adjusting the position of the moving body 133 in the axial direction. At this time, the distance h1 is adjusted by rotating (twisting) the movable body 133 in the circumferential direction.
The distance h1 is determined by the sum of the distance h5 and the distance h6. The distance h6 is a fixed value determined by the dimensions of the support 134. Therefore, for example, the inner conductor 13 is arranged at a position obtained by simulation while measuring the distance h5 while twisting the moving body 133.

Then, in the state where the position adjustment of the moving body 133 in the axial direction is completed, the fixing plate 135 and the bolt (not shown) are attached to the moving body 133 and the support body 134 as described above. As a result, displacement of the moving body 133 relative to the support body 134 is suppressed.
Thus, the resonator 10 is set, and the correspondence to the frequency band in which the resonator 10 is used is completed.

In the filter 100 shown in FIG. 2, the distances h1 of the resonators 10-1 to 10-6 may be set to be different from each other depending on the characteristics of the filter 100 such as the pass frequency band.
When the frequency band in which the resonator 10 is used is readjusted, the fixed plate 135 and the bolt (not shown) are removed, the movable body 133 is rotated in the circumferential direction and arranged at a desired position, and then the movable body 133 is fixed again via the fixing plate 135 and bolts. Thus, the resonator 10 in the present embodiment can easily change the frequency band.

<Mechanical vibration>
As described above, in the present embodiment, the thread groove 133t and the thread groove 134t are formed on the outer peripheral surface of the moving body 133 and the inner peripheral surface of the through hole 134b of the support member 134, respectively, and are engaged with each other. At the same time, the fixing plate 135 fixes them.
This makes it possible for the resonator 10 to withstand mechanical vibration while electrical contact between the inner conductor 13 and the outer conductor 12 is ensured. That is, the earthquake resistance of the resonator 10 (filter 100) is improved, and the contact resistance between the inner conductor 13 and the outer conductor 12 is reduced. Further, by rotating the inner conductor 13, the moving body 133 moves smoothly in the axial direction and the position thereof is fixed. Therefore, adjustment of the protrusion amount (see distance h5) of the moving body 133 and The moving body 133 can be fixed easily.

Here, unlike the present embodiment, as a structure for variably supporting the inner conductor 13, a mode in which a so-called finger (not shown) that is an elastic deformation supporting member fixed to the outer conductor 12 is used can be considered. . More specifically, by supporting the inner conductor 13 while pressing the outer periphery of the inner conductor 13 with this finger, electrical contact between the inner conductor 13 and the outer conductor 12 is ensured through the finger, and the inner conductor The position of 13 can be changed smoothly.
However, in the aspect using this finger, the outer peripheral surface of the inner conductor 13 is pressed by the elastic force of the finger, and the inner conductor 13 is fixed by the frictional force between the outer peripheral surface and the finger. When is added, the position of the inner conductor 13 may be shifted. Therefore, it is necessary to fix the inner conductor 13 with another fixing member or the like.
Therefore, in the present embodiment, compared to this finger mode, the region where the outer peripheral surface of the moving body 133 and the inner peripheral surface of the through hole 134b of the support 134 are opposed to each other so as to withstand mechanical vibration. The screw grooves 133t and 134t are provided on the surface.

<Suppression of decrease in Qu value>
As described above, the threaded groove 133t is provided on the outer peripheral surface of the moving body 133. That is, the moving body 133 is formed in a male screw shape. As a result, the surface resistance of the entire inner conductor 13 is increased, and as a result, the Qu value can be lowered.
Therefore, a flat portion 133h is provided on the outer peripheral surface of the moving body 133 of the present embodiment. Since the flat portion 133h is formed, the Qu value is compared with a configuration in which the flat portion 133h is not formed, that is, a configuration in which the threaded portion 133g is formed over the entire periphery of the fixed portion 133c of the moving body 133. Is suppressed.

  In addition, the following can be considered as a mechanism for suppressing the decrease in the Qu value by forming the flat portion 133h, for example. That is, when the flat portion 133h is formed, the surface area of the moving body 133 (fixed portion 133c, inner conductor 13) is reduced, and the electrical path in the axial direction is reduced. This is due to the skin effect, and as a result, the electrical resistance of the entire inner conductor 13 is reduced, and a decrease in the Qu value is suppressed. That is, a good Qu value can be obtained, and as a result, the passage loss can be reduced.

Here, the simulation result about forming the thread groove 133t in the outer peripheral surface of the moving body 133 and forming the flat part 133h is demonstrated. First, unlike the present embodiment, when the screw groove 133t is not formed on the outer peripheral surface of the moving body 133, that is, when the moving body 133 is formed in a columnar shape, the Qu value is about 9500.
Further, unlike this embodiment, when the thread groove 133t is formed on the entire circumference of the moving body 133, that is, when the thread groove 133t is formed on the outer peripheral surface of the moving body 133 and the flat portion 133h is not formed, the Qu value is obtained. Was about 7500.
On the other hand, when the threaded groove 133t is formed on the outer peripheral surface of the moving body 133 of the present embodiment, that is, the moving body 133 and the flat portion 133h is formed, the Qu value is about 8100.
From this simulation result, it was confirmed that the formation of the flat portion 133h suppresses the decrease in the Qu value compared to the case where the flat portion 133h is not formed.

<Temperature compensation>
8A to 8C are diagrams for explaining temperature compensation in the resonator 10. FIG. 8A is a diagram showing the resonator 101 in which the inner conductor 13 is fixed to the outer conductor 12 unlike the present embodiment, and FIG. 8B is the present embodiment, and the inner conductor 13 is FIG. 8C is a diagram illustrating the temperature drift of the resonator 10 as a configuration that can move with respect to the outer conductor 12, and FIG. 8C illustrates the temperature drift of the frequency f using the S parameter S11.
8A and 8B, the white arrow and the black arrow indicate the outside when the resonator 10 changes from the temperature T0 to the temperature (T0−ΔT), that is, when the temperature decreases. The change (direction of contraction) of the conductor 12 and the inner conductor 13 is shown.

Next, temperature compensation that suppresses frequency temperature drift will be described with reference to FIG.
First, a resonator 101 different from the present embodiment shown in FIG. 8A will be described. In the resonator 101, the inner conductor 13 is fixed to the support surface portion 123 of the outer conductor 12. The resonator 101 is not provided with the tip 131, the support bar 132, the moving body 133, the support 134, and the fixed plate 135, and the position of the inner conductor 13 cannot be adjusted.
In this case, when the temperature changes from the temperature T0 to the temperature (T0−ΔT), the outer conductor 12 and the inner conductor 13 contract according to the coefficient of thermal expansion and move in the direction of the white arrow in the figure. At this time, the size of the cavity 11 is reduced, and the distance h1 is also reduced. As a result, as shown in FIG. 8C, the center frequency f0 is shifted to the center frequency f0 ′. This is the temperature drift of the frequency.

  Next, the resonator 10 in the present embodiment shown in FIG. 8B will be described. In the resonator 10, as described above, the tip 131 of the inner conductor 13 is provided so as to be slidable in the axial direction with respect to the moving body 133. Further, the tip 131 is connected to the support bar 132. As described above, the thermal expansion coefficient of the support bar 132 is smaller than the thermal expansion coefficient of the outer conductor 12 and the like.

Therefore, in the configuration shown in FIG. 8B, as in the configuration shown in FIG. 8A, when the temperature T0 changes to the temperature (T0−ΔT), the outer conductor 12 contracts due to thermal contraction (white). Move in the direction of the pull arrow). Further, the moving body 133 and the support body 134 also contract in the axial direction (moves in the direction of the white arrow).
Here, the support bar 132 also contracts in the axial direction. However, since the thermal expansion coefficient of the support bar 132 is small, the support bar 132 has a shorter contraction length (deformation amount) in the axial direction than the moving body 133. Due to the difference in deformation amount, the support bar 132 moves in the direction in which the tip 131 of the inner conductor 13 is pushed (entered) into the cavity 11 (moves in the direction of the black arrow). In other words, the support rod 132 having a small coefficient of thermal expansion is pushed out inside the inner conductor 13.

Therefore, even if the moving body 133 and the support body 134 contract (move in the direction of the white arrow) due to thermal contraction, the tip 131 of the inner conductor 13 is pushed (entered) into the cavity 11 by the support bar 132. Since it is moved in the direction (moved in the direction of the black arrow), it is possible to suppress the distance h1 from becoming smaller.
As a result, the center frequency f0 is not shifted to the center frequency f0 ′, and the center frequency f0 is maintained.

  Now, in the configuration shown in FIG. 8B, when the temperature changes from the temperature T0 (T0 + ΔT), that is, when the temperature rises, the above description is reversed. That is, the outer conductor 12 expands and moves in a direction in which the tip 131 of the inner conductor 13 is pushed out (exited) from the inside of the cavity 11 by the support rod 132 having a small coefficient of thermal expansion as the moving body 133 expands. To do. That is, an increase in the distance h1 is suppressed. Thus, the center frequency f0 is not shifted and the center frequency f0 is maintained.

Thus, when the temperature is lowered by making the coefficient of thermal expansion of the support rod 132 smaller than that of the outer conductor 12 and the moving body 133, the direction in which the tip of the inner conductor 13 is pushed into the cavity 11 (black) When the temperature rises in the direction of the colored arrow), the temperature drift of the frequency is suppressed by moving the tip of the inner conductor 13 in the direction of pushing out from the cavity 11 (the direction of the white arrow). .
The amount by which the inner conductor 13 moves with respect to the cavity 11 due to the temperature change is set so that the temperature shift of the frequency is suppressed in a predetermined temperature range such as −10 ° C. to 45 ° C., for example. .

<Relationship between frequency band and temperature compensation amount>
FIGS. 9A and 9B are diagrams for explaining the relationship between the pass frequency band and the temperature compensation amount in the resonator 10. More specifically, FIG. 9A shows a case where the frequency band is low (low frequency band), and FIG. 9B shows a case where the frequency band is high (high frequency band).
Next, the relationship between the frequency band and the temperature compensation amount in the resonator 10 will be described with reference to FIG. In other words, the change in the amount of temperature compensation accompanying the movement of the moving body 133 in the resonator 10 in the axial direction will be described.

  First, as described above, the distance h1 (LF) in the low frequency band is set to be larger than the distance h1 (HF) in the high frequency band. Accordingly, the distance h3 (HF) in the high frequency band is smaller than the distance h3 (LF) in the low frequency band. In addition, the distance h4 (HF) in the high frequency band is larger than the distance h4 (LF) in the low frequency band.

Next, in the arrangement shown in FIGS. 9A and 9B, consider the case where the resonator 10 changes from the temperature T0 to the temperature (T0−ΔT), that is, the temperature decreases. Although the amount of deformation is smaller than that of the moving body 133, the support rod 132 contracts due to this temperature drop.
Here, the distance h3 (HF) in the high frequency band is smaller than the distance h3 (LF) in the low frequency band. Therefore, even if the temperature is decreased by the same temperature (ΔT), the deformation amount of the distance h3 is smaller in the case of the shorter high frequency band. As a result, the change in the distance h1 is suppressed more in the high frequency band than in the low frequency band. In other words, the higher the frequency band, the greater the action in the direction of canceling out the influence of thermal deformation, and as a result, the amount of temperature compensation increases.

Note that a change in temperature compensation amount can also be captured from the viewpoint of the arrangement of the moving body 133.
First, the moving body 133 is in a state where the support body 134 supports the middle in the axial direction (intermediate position in the axial direction). For this reason, when the moving body 133 contracts as the temperature decreases, the base end of the moving body 133 moves in the direction toward the distal end (moves in the direction of the white arrow).
Here, as shown in FIGS. 9A and 9B, the distance h4 (HF) in the high frequency band is larger than the distance h4 (LF) in the low frequency band. In other words, the length on the base side of the moving body 133, that is, the length in the axial direction from the end on the base side of the moving body 133 to the tip of the support body 134 is longer in the high frequency band. Therefore, even if the temperature is decreased by the same temperature (ΔT), the amount of change in the length on the root side becomes larger in the high frequency band. As a result, the base-side end of the moving body 133 moves more in the direction toward the distal end in the case of the high frequency band.

  At this time, the support rod 132 fixed to the base end of the moving body 133 is pushed into the cavity 11 in the high frequency band compared to the low frequency band in the end portion 131. Move more in the direction of entry. As a result, the change in the distance h1 is suppressed more in the high frequency band than in the low frequency band. In other words, the higher the frequency band, the greater the action in the direction of canceling out the influence of thermal deformation, and as a result, the amount of temperature compensation increases.

<Sliding movement of tip 131>
FIGS. 10A and 10B are diagrams for explaining the sliding movement of the distal end portion 131. FIG. More specifically, FIG. 10A shows a case where the temperature is higher than the temperature when the resonator 10 is adjusted, and FIG. 10B shows a case where the temperature is lower than the temperature when the resonator 10 is adjusted. Indicates. Further, the frequency bands in FIGS. 10A and 10B are the same.
Next, the sliding movement of the tip 131 will be described with reference to FIG.

First, in the present embodiment, the tip 131 is connected to the moving body 133 and the support bar 132 as described above. Then, temperature compensation is performed by changing the distance in the axial direction between the tip 131 and the moving body 133 by the support rod 132.
More specifically, as shown in FIGS. 10A and 10B, the surface 131r of the distal end portion 131 on the moving body 133 side (the root side) and the distal end portion 131 of the movable body 133 according to the temperature. The distance from the side (tip side) surface 133r changes. Note that this distance is larger when the temperature is low (see FIG. 10B).

Here, when the axial distance between the distal end portion 131 and the moving body 133 is changed, as described above, the second recessed portion 131d (see FIG. 5A), which is the inner peripheral surface of the distal end portion 131, is used. The tip portion 131 slides while being supported by the outer peripheral surface of the slide support portion 133b of the moving body 133.
In the present embodiment, unevenness such as a thread groove 133t is not formed on the outer peripheral surface of the slide support portion 133b. Further, the slide support portion 133b is elastically deformed in the radial direction. As a result, the sliding movement of the distal end portion 131 can be performed smoothly. The smooth movement of the slide ensures that the temperature compensation is performed, and as a result, the resonance frequency can be easily adjusted. Further, due to the elastic deformation of the slide support portion 133b, the electrical connection between the distal end portion 131 and the moving body 133 is stably maintained.
The axial length of the support bar 132 can be determined based on the distance required in the axial direction between the tip 131 and the moving body 133 in order to perform desired temperature compensation.

<BPF characteristics>
FIG. 11 is a diagram illustrating a change in temperature of the attenuation amount in the filter 100 when the center frequency f0 is set to 474 MHz (low frequency band).
FIG. 12 is a diagram showing a change in temperature of the attenuation amount in the filter 100 when the center frequency f0 is set to 850 MHz (high frequency band).
In FIGS. 11 and 12, a filter 100 in which six resonators 10 are connected is used as shown in FIG.

Next, the measurement result of the temperature change of the attenuation amount in the filter 100 shown in FIG. 2 will be described with reference to FIGS. 11 and 12.
Here, in FIG. 11 and FIG. 12, as the filter 100, a configuration in which six resonators 10 shown in FIG. 3 are connected is used (see FIG. 2). Here, in FIGS. 11 and 12, the temperature is changed in order of 23 ° C., −10 ° C., 45 ° C., and 23 ° C.

  As shown in FIG. 11, in the case of the low frequency band in which the center frequency f0 is set to 474 MHz, the attenuation amount hardly changes in the above temperature range, and the fluctuation (temperature drift) of the passing frequency band (470 to 478 MHz). Is hardly seen.

  Further, as shown in FIG. 12, in the case of a high frequency band in which the center frequency f0 is set to 850 MHz, the attenuation amount shows a slight fluctuation in the above temperature range, but the pass frequency band (846 to 856 MHz). Fluctuation (temperature drift) is hardly seen.

  11 and 12, the filter 100 using the resonator 10 shown in FIG. 3 has a high temperature in a temperature range of −10 ° C. to + 45 ° C. in a wide band with a center frequency f0 of 474 MHz to 850 MHz. It was confirmed that stability was obtained.

<Resonator characteristics>
FIG. 13 is a diagram showing the temperature change of the attenuation when the center frequency f0 is set to 863 MHz (high frequency band) in the resonator 10 alone.
Next, the measurement result of the temperature change of the attenuation amount in the resonator 10 alone shown in FIG. 3 will be described with reference to FIG.
In FIGS. 11 and 12, the filter 100 in which six resonators 10 are connected is used, whereas in FIG. 13, only one resonator 10 is configured. Similarly to FIGS. 11 and 12, the temperature is changed in order of 23 ° C., −10 ° C., 45 ° C., and 23 ° C.

As shown in FIG. 13, in the above temperature range, the attenuation amount hardly changes and temperature drift is hardly observed. Therefore, high temperature stability of the resonator 10 is obtained.
As described above, the resonator 10 can handle a high-power signal and is downsized.

<Modification>
FIGS. 14A to 14C and FIGS. 15D to 15F are diagrams for describing modifications of the present embodiment.
Next, a modification of the present embodiment will be described with reference to FIGS. 14 and 15. In the following description, the same components as those described above are denoted by the same reference numerals, and detailed description thereof is omitted.
In the above, the filter 100 of the present embodiment has been described with reference to FIGS. 1 to 13, but various modifications can be considered for the filter 100.

First, in the above description, it has been described that the flat portion 133h extends linearly along the axial direction, but the present invention is not limited to this.
For example, like the moving body 1330 illustrated in FIG. 14A, a configuration including a screw portion 1330g and a flat portion 1330h that is not continuous in the axial direction may be employed.
Further, for example, like a moving body 1331 shown in FIG. 14B, the screw portion 1331 g and a flat portion 1331 h formed in a spiral shape so as to turn on the outer peripheral surface of the moving body 1331 are provided. Also good.

In the above description, a plurality of flat portions 133h are formed along the circumferential direction. However, the present invention is not limited to this.
For example, the structure provided with the one flat part 1332h in the circumferential direction like the mobile body 1332 shown in FIG.14 (c) may be sufficient. In the moving body 1332, one screw portion 1332 g is formed in the circumferential direction. In addition, as the circumferential length in the illustrated example, the threaded portion 1332g is longer than the flat portion 1332h.
Although illustration is omitted here, the number of the threaded portion 133g and the flat portion 133h may be 2, 3, or 5 or more, respectively. Regardless of the number of screw parts 133g and flat parts 133h, the total length of all screw parts 133g and the sum of all flat parts 133h may be equal in the circumferential length, or either one of them May be long.

  In the above description, it has been described that the flat portion 133h is a flat surface, but the present invention is not limited to this. Although illustration is omitted, the flat portion 133h may be configured as a surface having a curved surface or unevenness, for example, as long as the thread groove 133t is not formed.

In the above description, the slide support portion 133b is provided with a plurality of slits 133e in the circumferential direction. However, the present invention is not limited to this. Although illustration is omitted, for example, a configuration including one slit 133e may be used.
Or the structure which is not provided with the slit 133e like the mobile body 1334 shown in FIG.15 (d) may be sufficient. In this configuration, the outer diameter of the slide support portion 1334b can be changed by, for example, forming the slide support portion 1334b with a member having a high elastic modulus or a thin shape.

In the above description, it has been described that the inner conductor 13 includes the distal end portion 131, the support rod 132, the moving body 133, the support body 134, and the fixed plate 135. However, the present invention is not limited to this.
For example, it is good also as a structure which is not provided with the support body 134 like the inner conductor 130 shown in FIG.15 (e). In the resonator 103 that does not include the support 134, an opening 1240 into which the inner conductor 130 is inserted is formed in the support surface portion 1230 of the outer conductor 1210. Further, a thread groove 1241t is formed on the inner peripheral surface 1241 of the opening 1240.
Then, the screw groove 1241t of the opening 1240 and the screw groove 133t of the screw portion 1335g of the moving body 1335 mesh with each other, so that the moving body 1335 can withstand mechanical vibration and the position of the moving body 1335 in the axial direction can be adjusted. It becomes possible to adjust.

  Or it is good also as a structure which is not provided with the support bar 132 like the inner conductor 140 shown in FIG.15 (f). In the resonator 105 that does not include the support bar 132, the distal end portion 1316 and the moving body 1336 are configured as an integral member, not as separate members. Unlike the inner conductor 140 shown in FIG. 15 (f), the tip 131 is configured with the moving body 133 as a separate member, such as the tip 131 and the moving body 133. It may be configured to be fixed to each other by a fixing tool.

  Furthermore, although illustration is abbreviate | omitted, the structure which does not equip the outer peripheral surface of the mobile body 133 with the thread groove 133t may be sufficient. That is, for example, unlike the above-described inner conductor 13 or the like, a moving body (not shown) that does not include the thread groove 133t, a distal end portion 131 provided at the distal end of the movable body, and the movable body and the distal end portion 131, respectively. An inner conductor (not shown) may be configured so as to include a support bar 132 having both ends connected to each other.

Although various embodiments and modifications have been described above, it is of course possible to combine these embodiments and modifications.
Further, the present disclosure is not limited to the above-described embodiment, and can be implemented in various forms without departing from the gist of the present disclosure.

DESCRIPTION OF SYMBOLS 10, 10-1-10-6 ... Resonator, 11 ... Cavity (cavity), 12 ... Outer conductor, 13 ... Inner conductor, 100 ... Filter, 131 ... Tip part, 132 ... Support rod, 133 ... Moving body, 133b ... Slide support part, 133c ... Fixed part, 133g ... Screw part, 133h ... Flat part, 134 ... Support, 135 ... Fixing plate

Claims (5)

An outer conductor that forms a cavity inside;
An inner conductor provided in the cavity of the outer conductor,
The inner conductor is a hollow member that protrudes into the cavity;
A cover member that is a separate member from the hollow member and covers a tip of the hollow member that protrudes into the cavity;
It is a rod-shaped member disposed inside the hollow member, and is provided with one end fixed to the covering member and the other end fixed to the hollow member, and has a thermal expansion coefficient higher than that of the hollow member. have a and a lower support rod,
The resonator according to claim 1, wherein the distal end side of the hollow member is more easily elastically deformed than a base side of the hollow member . The covering member covers the distal end of the hollow member and the outer peripheral side surface of the distal end side,
The resonator according to claim 1, wherein the outer peripheral side surface of the hollow member supports the cover member so as to be slidable along the protruding direction. An outer conductor that forms a cavity inside;
An inner conductor provided in the cavity of the outer conductor;
With
The inner conductor is a hollow member that protrudes into the cavity;
A cover member that is a separate member from the hollow member and covers a tip of the hollow member that protrudes into the cavity;
It is a rod-shaped member disposed inside the hollow member, and is provided with one end fixed to the covering member and the other end fixed to the hollow member, and has a thermal expansion coefficient higher than that of the hollow member. With a low support rod
Have
The hollow member is
The position in the protruding direction within the cavity is adjustable,
In a direction the projection, at an intermediate position located between said other end and said one end of said support rod, co exciter, characterized in that it is fixed relative to the outer conductor. An outer conductor that forms a cavity inside;
An inner conductor provided in the cavity of the outer conductor;
With
The inner conductor is a hollow member that protrudes into the cavity;
A cover member that is a separate member from the hollow member and covers a tip of the hollow member that protrudes into the cavity;
It is a rod-shaped member disposed inside the hollow member, and is provided with one end fixed to the covering member and the other end fixed to the hollow member, and has a thermal expansion coefficient higher than that of the hollow member. With a low support rod
Have
The inner conductor is fixed to the outer conductor in the cavity, and has a support body that supports the hollow member in a state in which the hollow member has penetrated.
Said hollow member and said support member has a screw groove on each of the opposed surfaces to each other, co-acoustic transducer of the support by the screw groove each other meshes is characterized in that for supporting the hollow member. An input section to which signals are input;
An output unit for outputting a signal;
An outer conductor connected to the input unit and the output unit and forming a cavity therein, and a resonator having an inner conductor provided in the cavity of the outer conductor;
The inner conductor is
A hollow member provided projecting into the cavity;
A cover member that is a separate member from the hollow member and covers a tip of the hollow member that protrudes into the cavity;
It is a rod-shaped member disposed inside the hollow member, and is provided with one end fixed to the covering member and the other end fixed to the hollow member, and has a thermal expansion coefficient higher than that of the hollow member. have a and a lower support rod,
The filter, wherein the distal end side of the hollow member is more easily elastically deformed than the base side of the hollow member .

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