JPH11243301A - Coaxial dielectric filter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a dielectric filter which simply adjusts an arrangement relation in assembly parts, also increases the degree of freedom in the direction of taking out a signal and is miniaturized. SOLUTION: This filter contains a linear cutoff waveguide 1, two or more coaxial dielectric resonators 21 and 22 arranged coaxially or almost coaxially in the waveguide 1 at an interval a rod-shaped input side antenna 32 whose front end side approaches or is inserted into an input side inner conductor of the resonator 21 arranged on an input side and a rod-shaped output side antenna 42 whose front end approaches or is inserted into an output side inner conductor of the resonator 22 arranged on an output side. In such a case, each end plane on adjacent sides of the mutually adjoining resonators 21 and 22 has an inclination plane having a gradient with respect to a vertical cross-section in the lengthwise direction of the waveguide 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a coaxial dielectric filter used for signal regeneration and clock signal extraction in a regenerative repeater for optical communication, and more particularly, to easily adjust the arrangement relationship of assembled parts. The present invention relates to an improvement in a coaxial dielectric filter which can be performed and has a greater degree of freedom in a signal extraction direction, thereby achieving miniaturization.

[0002]

2. Description of the Related Art FIG. 6 is an equivalent circuit diagram of a typical dielectric filter using a coaxial dielectric resonator. FIG. 7 is a diagram showing a conventional coaxial type dielectric filter using a capacitor. It is a top view showing the structure of a dielectric filter. In a typical coaxial dielectric filter, as shown in the equivalent circuit diagram of FIG.
Components such as capacitors (C1, C2, C3) (or inductors) are provided between the coaxial dielectric resonators (between stages) and to obtain electrical coupling between the coaxial dielectric resonators and the output connector. Have been placed. In the coaxial dielectric filter according to the conventional example, the capacitor is formed by a technique such as thick film printing on a substrate of alumina or the like in order to obtain a desired electrical coupling, and as shown in FIG. )
Connected using connection leads. In FIG. 7, reference symbol a denotes a coaxial dielectric resonator, b denotes an input / output capacitor,
c is an interstage capacitor, d is a metal case provided with a recessed housing part d 'which constitutes a part of the cutoff waveguide, e is an input connector, f is an output connector, and g is a capacitor connection lead. Each is shown.

When a coaxial dielectric filter having a narrow pass band is to be manufactured as a dielectric filter, a capacitor having an extremely small capacitance is required. In the above-mentioned electrical coupling method using a substrate such as alumina, since it is extremely difficult to realize a capacitor or the like having a small capacitance, there is a disadvantage that a coaxial dielectric filter having a narrow pass bandwidth cannot be mass-produced. Was.

Therefore, the present applicant has already proposed a coaxial dielectric filter in which the structure is simplified by adopting a new electrical coupling method which does not use components such as capacitors (Japanese Patent Laid-Open No. Hei 8 (1996) -1996). -88504).

That is, this coaxial dielectric filter is
As shown in FIGS. 8 (A) to 8 (C), a linear cut-off conductor formed of a housing portion d 'provided in a metal case d and a metal lid d "for closing the open side of the housing portion d'. A waveguide tube and two coaxial types arranged coaxially or substantially coaxially at a distance in the cut-off waveguide and provided with an outer conductor and an inner conductor on the outer peripheral surface a2 and the inner peripheral surface a3 of the cylindrical main body a1. A dielectric resonator a, a;
The base end is supported by an input-side connector e fixed to the input side wall surface of the cut-off waveguide, and the front end is approached or inserted into the input-side inner conductor of a coaxial dielectric resonator a disposed on the input side. A rod-shaped input-side antenna i and an output side of a coaxial dielectric resonator a whose base end is supported by an output-side connector f fixed to the output side wall surface of the cut-off waveguide and disposed on the output side. The main part is constituted by a rod-shaped output-side antenna j whose leading end is close to or inserted into the conductor.

In this coaxial dielectric filter, the electrical coupling corresponding to C1 and C3 shown in FIG. 6 is performed by connecting the distal end of a rod-shaped input antenna i whose base end is supported by an input connector e to the coaxial line. By inserting or inserting into the input-side inner conductor of the dielectric resonator a, the distal end of the rod-shaped output antenna j whose base end is supported by the output connector f is connected to the coaxial dielectric resonator. Each of them can be obtained by being close to or inserted in the inner conductor on the output side of a. In addition, the amount of electrical coupling can be changed by changing the proximity or insertion amount of the rod-shaped input antenna i and the output antenna j that are close to or inserted into the inner conductor of the coaxial dielectric resonators a. Thus, the distance or area between the inner conductors of the coaxial dielectric resonators a, a and the respective antennas i, j changes, which can be changed. For this reason, the amount of electrical coupling (capacitance) is changed by changing the proximity or insertion amount of the rod-shaped input-side antenna i and output-side antenna j that are close to or inserted into the inner conductor of each coaxial dielectric resonator a. C1 and C3 can be adjusted. In addition, when the antenna tip side is brought close to the inner conductor of the coaxial dielectric resonator, the amount of electrical coupling is smaller than when the antenna tip side is inserted. It is possible to increase the value by setting the inner diameter of the cylindrical portion small.

The electric coupling corresponding to C2 shown in FIG. 6 is performed when the coaxial dielectric resonators a and a are arranged in the cut-off waveguide, and the opposing sides of the coaxial dielectric resonators a and a are arranged. Can be given by increasing the distance between the open surfaces. The amount of electrical coupling is exponentially attenuated by increasing the distance between the coaxial dielectric resonators a, a in the cutoff waveguide, and the opposing coaxial dielectric resonators a, By changing the distance a, the amount of electric coupling (capacitance and / or inductance) C2 between the coaxial dielectric resonators a can be adjusted.

As described above, according to the coaxial dielectric filter developed by the present applicant, the structure of the filter can be simplified since a new electrical coupling method that does not use components such as a capacitor is employed. Since the number of points can be reduced, a narrow-band coaxial dielectric filter can be easily and inexpensively manufactured.

In the above-mentioned coaxial dielectric filter incorporating two coaxial dielectric resonators, a coaxial dielectric resonator a and an input antenna i are arranged on the input side.
Between the two coaxial dielectric resonators a and a, and between the coaxial dielectric resonator a and the output antenna j arranged on the output side. The desired characteristics are realized when the values are taken. That is, when even one of these balances is broken, the characteristic value of the obtained coaxial dielectric filter changes.

When balancing the degree of electrical coupling at three locations, the adjustment between two coaxial dielectric resonators is higher than the adjustment between a coaxial dielectric resonator and each antenna. Accuracy is required. This is because, as described above, when the distance between the coaxial dielectric resonators is increased, the amount of electrical coupling is exponentially attenuated as described above. This is because the adjustment of the distance between the shaped dielectric resonators greatly affects the balance of the degree of electrical coupling.

[0011]

The coaxial dielectric resonator incorporated in the coaxial dielectric filter is, for example, made of barium or titanium-based oxide ceramics, and has a rectangular external cross section and a cylindrical portion. A cylindrical main body a1 having a circular cross section, and a conductive layer made of a thick film silver paste or the like provided on the inner and outer peripheral surfaces of the cylindrical main body a1 (the conductive layer provided on the inner peripheral surface is an inner conductor, The conductive layer provided on the outer peripheral surface is referred to as an outer conductor) to form a main part (see FIG. 8C), and both end surfaces in the length direction are vertical surfaces. Has no electrically conductive layer and is electrically open.

Also, the individual coaxial dielectric resonators before adjustment incorporated in the coaxial dielectric filter have variations in conditions during the manufacture of the dielectric material (for example, variations in processing dimensions, or during molding and firing). (Variation in density, etc.), inherent variations such as the dielectric constant and dielectric loss of the dielectric and the conductor loss of the outer conductor. Therefore, before being assembled in the coaxial dielectric filter, the end faces of the manufactured coaxial dielectric resonators are individually shaved and pre-adjusted to make their resonance frequencies uniform. The length dimensions of the dielectric resonator are of course irregular.

For this reason, when arranging each coaxial dielectric resonator in the cut-off waveguide, it is difficult to adjust the distance due to the irregular length of each coaxial dielectric resonator. In addition, there is a problem that a coaxial dielectric filter having a target characteristic value cannot be obtained even if the distance setting between the coaxial dielectric resonators is slightly deviated.

SUMMARY OF THE INVENTION The present invention has been made in view of such a problem. An object of the present invention is to provide a coaxial dielectric filter which can easily adjust the positional relationship in an assembled part, and further provide a signal filter. An object of the present invention is to provide a coaxial dielectric filter capable of increasing the degree of freedom in a take-out direction and reducing its size.

[0015]

That is, according to the present invention, a linear blocking waveguide and a coaxial or substantially coaxial coaxial waveguide are arranged in the blocking waveguide at a distance along the length thereof. Two or more coaxial dielectric resonators arranged, a rod-shaped input antenna whose tip side is close to or inserted into the input-side inner conductor of the coaxial dielectric resonator arranged on the input side,
A coaxial dielectric filter having a rod-shaped output antenna whose tip side is close to or inserted into the output side inner conductor of the coaxial dielectric resonator arranged on the output side is premised on coaxial dielectric filters adjacent to each other. At least one adjacent end surface between the body resonators forms an inclined surface having a slope with respect to a cross section perpendicular to the length direction of the cutoff waveguide.

According to the coaxial dielectric filter according to the first aspect of the present invention, at least one adjacent end face between the coaxial dielectric resonators adjacent to each other has a length of the cut-off waveguide. Since two or more coaxial dielectric resonators are arranged in the cut-off waveguide, the distance between adjacent coaxial dielectric resonators is formed because the inclined surface having a gradient with respect to a cross section perpendicular to the direction is formed. When performing the adjustment, the coaxial dielectric resonator provided with the inclined surface is not only moved in the length direction of the cutoff waveguide, but also moved in the width direction of the cutoff waveguide. It is possible to adjust the distance to the dielectric resonator.

That is, the moving direction of the coaxial dielectric resonator for adjusting the degree of electrical coupling between the adjacent coaxial dielectric resonators is not only the length direction of the cut-off waveguide but also its width direction. Therefore, the operation of adjusting the degree of electrical coupling between adjacent coaxial dielectric resonators can be simplified as compared with the conventional coaxial dielectric filter.

Since the end faces of the coaxial dielectric resonators facing the distal ends of the input-side and output-side antennas have a vertical plane shape as described above, the conventional coaxial dielectric filters have the same shape. The input and output directions of the signal are basically in the length direction of the cutoff waveguide (that is, the arrangement direction of the coaxial dielectric resonators).

For this reason, the length dimension of the coaxial dielectric filter is inevitably long, which is not suitable for miniaturization.
Since the input and output directions of the signal are also specified in the length direction, the degree of freedom in circuit design in a package on which the coaxial dielectric filter is mounted is correspondingly low. The invention according to claim 2 relates to a coaxial dielectric filter capable of achieving miniaturization and improvement in the degree of freedom in circuit design.

That is, the invention according to claim 2 is based on the coaxial dielectric filter according to the invention described in claim 1,
At least one of the input end face of the coaxial dielectric resonator disposed on the input side and the output end face of the coaxial dielectric resonator disposed on the output side has a lengthwise direction of the cut-off waveguide. A slope with respect to the cross-section perpendicular to the cross-section, and parallel to the length direction of the blocking waveguide and at the input side and / or
Alternatively, the input-side and / or output-side antenna of the input-side and / or output-side antenna may be directly or via an input-side and / or output-side connector on the wall of the cut-off waveguide opposite to the inclined surface of the coaxial dielectric resonator disposed on the output side. The base end side is supported, and the distal end side of the input side and / or the output side antenna is close to the approximate center of the inclined surface of the coaxial dielectric resonator arranged on the input side and / or the output side, and The input and / or output direction of the signal at the side and / or output side antenna is perpendicular or substantially perpendicular to the length direction of the cut-off waveguide.

According to the second aspect of the present invention, the coaxial dielectric filter disposed on the input side and the output side of the coaxial dielectric resonator disposed on the input side. At least one of the output-side end surfaces of the body resonator forms an inclined surface having a slope with respect to a cross section perpendicular to the length direction of the blocking waveguide, and is parallel to the length direction of the blocking waveguide. And the input side and / or the output side connector of the coaxial dielectric resonator disposed on the input side and / or the output side directly or via the input side and / or the output side connector on the cut-off waveguide wall surface facing the inclined surface. Since the base end side of the output side antenna is supported, the size of the coaxial dielectric filter in the length direction can be reduced, so that the filter can be downsized. Signal input and Because it can arbitrarily set the output direction, the coaxial dielectric filter it is possible to greatly improve the circuit design flexibility in the package to be mounted.

Next, the invention according to claim 3 relates to the invention in which a coaxial dielectric resonator mounted on the coaxial dielectric filter according to claim 1 or 2 is specified.

That is, a third aspect of the present invention is based on the coaxial dielectric filter according to the first or second aspect of the present invention, wherein the coaxial dielectric resonator is provided between the outer peripheral surface of the cylindrical main body and the coaxial dielectric resonator. It is a half-wavelength coaxial dielectric resonator in which an outer conductor and an inner conductor are provided on the inner peripheral surface.

In the coaxial dielectric filter according to the first to third aspects of the present invention, the linear cut-off waveguide has a receiving portion in which the coaxial dielectric resonator is disposed. The main part composed of a main body and a lid member that closes the open side of the storage part is applied. For the waveguide main body having the above housing portion, a thick metal body such as duralumin may be cut and formed, or a steel plate having a thickness of about 0.8 mm or silver plating or the like may be formed on the surface. This may be configured by bending the applied steel sheet. Also, ABS resin, acrylonitrile resin,
The above-mentioned waveguide is formed in a plastic case obtained by injection-molding butadiene resin, styrene resin, etc. into a case shape, with a nickel base plating on a surface of a plastic material, and metal plating such as silver plating as a surface finish. The main body may be configured.

[0025]

Embodiments of the present invention will be described below in detail with reference to the drawings.

This coaxial dielectric filter is shown in FIG.
As shown in (B), a linear cut-off waveguide 1 and two coaxial dielectric resonators (1/1) arranged coaxially or substantially coaxially at a distance in the cut-off waveguide 1. Two-wavelength resonators) 21 and 22, an input connector 31 fixed to a wall surface at one end in the length direction of the cutoff waveguide 1, and a base end supported by the input connector 31 and provided on the input side. A rod-shaped input antenna 3 whose leading end is close to or inserted into the input-side inner conductor of the disposed coaxial dielectric resonator 21
2, an output connector 41 fixed to a wall surface at the other end in the length direction of the cutoff waveguide 1, and a coaxial dielectric whose base end is supported by the output connector 41 and disposed on the output side. The main part thereof is constituted by a rod-shaped output-side antenna 42 whose tip side is close to or inserted into the output-side inner conductor of the resonator 22.

First, the blocking waveguide 1 is shown in FIGS.
As shown in FIG. 1B, an aluminum metal case 11 provided with a substantially rectangular accommodating portion 10 and an aluminum metal cover 1 for closing an upper opening of the metal case 11 are provided.
And 2. In addition, as a constituent material of the blocking waveguide 1, in addition to aluminum, its alloy, brass, a gold-plated plastic material, and the like are exemplified.

The coaxial dielectric resonators 21 and 22
As shown in FIG. 1 (A), a tubular body made of a dielectric material such as lead titanate or barium titanate and having a rectangular external section and a circular cylindrical section is provided. The main part is composed of the inner peripheral surface of the main body and the silver conductive film provided on the outer peripheral surface, and the adjacent end surfaces between the resonators are cut obliquely so that each end surface is cut off. Each of the inclined surfaces has a slope with respect to a cross section α perpendicular to the longitudinal direction of the waveguide 1, and the inclined angle θ of each inclined surface is 60 degrees with respect to the longitudinal direction of the cut-off waveguide 1. Each time is set.

When assembling the coaxial dielectric filter, first, the input antenna 32 is attached to the metal case 11 via the input connector 31 and the distance between the input antenna 32 and the input antenna 32 is adjusted. An input-side coaxial dielectric resonator (a half-wavelength resonator) 21 is arranged, and the coaxial dielectric resonator 21 is fixed to the housing 10 via an appropriate adhesive.

Next, the fixed coaxial dielectric resonator 21
Is arranged next to the output side, and the distance adjustment for adjusting the degree of electrical coupling between the coaxial dielectric resonators 21 and 22 is performed.

When performing this distance adjustment, the coaxial dielectric resonator 22 provided with the inclined surface as shown in FIG.
In addition to moving the cut-off waveguide 1 in the length direction as well as in the width direction of the cut-off waveguide 1 (see the dashed-dotted line in FIG. 2A), the gap between the cut-off waveguide 1 and the coaxial dielectric resonator 21 on the adjacent side is not affected. The distance between them can be adjusted. That is, the position of the fixed coaxial dielectric resonator 21 is adjusted while first moving the coaxial dielectric resonator 22 provided with the inclined surface in the length direction, and then the coaxial dielectric resonator 21 is moved. The fine adjustment between the coaxial dielectric resonators 21 and 22 can be performed by moving the dielectric resonator 22 in the width direction. For this reason, as shown in FIG. 2 (B), the coaxial dielectric resonator 21 and the conventional coaxial dielectric filter 21 only perform the movement adjustment in the length direction.
The work of adjusting the degree of electrical coupling between the 22 is simplified and the adjustment accuracy can be improved.

Since the coaxial dielectric resonator 22 is moved in the width direction, a slight displacement in the width direction with respect to the fixed coaxial dielectric resonator 21 occurs (that is, the coaxial dielectric resonator 21 is moved). The coaxial dielectric resonator 22 is disposed substantially coaxially with the resonator 21), but it has been confirmed that the influence of the displacement on the filter characteristics is extremely small. Also, the coaxial dielectric resonator 2
It has also been confirmed that there is almost no problem with the generation of spurious due to the fact that the end surfaces on the adjacent sides of the first and second 22 form an inclined surface if the following conditions are satisfied. That is,
As shown in FIGS. 2C and 2D, the length of the coaxial dielectric resonator is L, and the length of the inclined surface in the resonator arrangement direction is δ (the inclined surface is coaxial as shown in FIG. 2D). Δ = δ1 + δ2 when provided at both ends of the dielectric resonator)
When the condition that δ / L is less than 1/5 is satisfied, the generation of the spurious can be avoided.

In this way, the coaxial dielectric resonator 22
Is appropriately fixed to the housing portion 10 of the metal case 11 via an adhesive, and the output side antenna 42 is shaved to have a length suitable for adjustment with the coaxial dielectric resonator 22. Is attached to the metal case 11 via the output side connector 41 to complete this coaxial dielectric filter.

Although two coaxial dielectric resonators 21 and 22 are applied in this embodiment, three or more coaxial dielectric resonators may be incorporated. Further, in this embodiment, the inclination angle θ of the adjacent end surface of each coaxial dielectric resonator is set to 60 degrees, but the same applies when the inclination angle is set to 45 degrees or 70 degrees. The effect has been confirmed. In some cases, an inclined surface is formed only at the end face on the adjacent side of the coaxial dielectric resonator 22, and the end face on the adjacent side of the coaxial dielectric resonator 21 has a vertical surface shape as in the prior art. You may apply as it is.

FIG. 3 is a plan view of a coaxial dielectric filter according to another embodiment in which the signal input direction is perpendicular or substantially perpendicular to the length direction of the cutoff waveguide.

That is, this coaxial dielectric filter is:
The input end face of the coaxial dielectric resonator 21 arranged on the input side is cut obliquely, and the input end face is cut with respect to a cross section perpendicular to the length direction of the cutoff waveguide 1. A coaxial dielectric resonator 2 which forms an inclined surface having a gradient, and which is parallel to the length direction of the cut-off waveguide 1 and arranged on the input side;
1, a base end side of the input side antenna 32 is supported via an input side connector 31 on a wall surface of the cut-off waveguide facing the inclined surface, and a distal end side of the input side antenna 32 is arranged on the input side. Except that the input direction of a signal to the input side antenna 32 is perpendicular or substantially perpendicular to the length direction of the cut-off waveguide 1 in the vicinity of the approximate center of the inclined surface of the shaped dielectric resonator 21. This is substantially the same as the coaxial dielectric filter shown in FIGS. 1 (A) and 1 (B). The inclination angle θ of each inclined surface is 6 degrees with respect to the length direction of the cutoff waveguide 1.
Each is set to 0 degrees.

In this coaxial dielectric filter, similarly to the coaxial dielectric filter shown in FIGS. 1A and 1B, a conventional coaxial dielectric filter which only adjusts the movement in the length direction. Coaxial dielectric resonator 21 compared to a body filter,
This has the advantage that the work of adjusting the degree of electrical coupling between the 22 is simplified and the adjustment accuracy is improved.

Further, in this coaxial dielectric filter, the input side connector 31 is provided on the wall of the cut-off waveguide opposite to the inclined surface of the coaxial dielectric resonator 21 disposed on the input side.
, The base end of the input-side antenna 32 is supported, so that the size in the length direction of the coaxial dielectric filter can be reduced, and the filter can be downsized.
The input direction of the signal at the input antenna is the cut-off waveguide 1.
Has the advantage that the degree of freedom in circuit design in a package in which this coaxial dielectric filter is mounted can be greatly improved because it is perpendicular or substantially perpendicular to the length direction of the filter. .

Also in this embodiment, the inclination angle θ of the end face on the adjacent side of each of the coaxial dielectric resonators 21 and 22 and the input end of the coaxial dielectric resonator 21 arranged on the input side. Although the inclination angle θ of the outer surface is set to 60 degrees,
Similar effects have been confirmed when the angle is set to 5 degrees or 70 degrees.

FIGS. 4 and 5 show a coaxial dielectric according to another embodiment in which the signal input direction and the signal output direction are perpendicular or substantially perpendicular to the length direction of the cutoff waveguide. It is a top view of a body filter.

That is, the coaxial dielectric filter shown in FIG. 4 has a coaxial dielectric resonator 21 arranged on the input side.
Both the input side end face and the output side end face of the coaxial dielectric resonator 22 disposed on the output side are cut obliquely so that the input side end face and the output side end face are cut off. Each of the inclined surfaces has a slope with respect to a cross section perpendicular to the longitudinal direction of the waveguide 1, and is arranged on the input side and the output side in parallel with the longitudinal direction of the cutoff waveguide 1. Each of the input antenna 32 and the output antenna 42 is provided on the cut-off waveguide wall surface of each of the coaxial dielectric resonators 21 and 22 facing the inclined surface via an input connector 31 and an output connector 41. The ends are supported, and the distal ends of the input-side antenna 32 and the output-side antenna 42 are close to the approximate centers of the inclined surfaces of the coaxial dielectric resonators 21 and 22 disposed on the input and output sides. , Input side antenna 3
2 except that the signal input direction in FIG. 2 and the signal output direction in the output side antenna 42 are perpendicular or substantially perpendicular to the length direction of the cutoff waveguide 1, respectively.
This is substantially the same as the coaxial dielectric filter shown in FIGS. The inclination angle θ of each inclined surface is set to 60 degrees with respect to the length direction of the cutoff waveguide 1.

In this coaxial dielectric filter, as in the case of the coaxial dielectric filter shown in FIG. 3, the operation of adjusting the degree of electrical coupling between the coaxial dielectric resonators 21 and 22 is simplified. In addition, there is an advantage that the adjustment accuracy can be improved, and the size of the filter can be reduced and the degree of freedom in circuit design in a package in which the coaxial dielectric filter is mounted can be greatly improved. .

In the coaxial dielectric filter shown in FIG. 5, the input-side antenna 32 and the input-side connector 31, and the output-side antenna 42 and the output-side connector 41 are formed on the same side wall surface of the cut-off waveguide. FIG. 4 except for
Is substantially the same as the coaxial dielectric filter shown in FIG.

[0044]

According to the coaxial dielectric filter according to the first and third aspects of the present invention, at least one adjacent end face between the coaxial dielectric resonators adjacent to each other is provided with a cut-off waveguide. Since two or more coaxial dielectric resonators are arranged in the cut-off waveguide because the inclined surface has a slope with respect to a cross section perpendicular to the length direction, the distance between adjacent coaxial dielectric resonators is reduced. When the distance adjustment is performed, the coaxial dielectric resonator provided with the inclined surface is not only moved in the length direction of the cut-off waveguide but also in the width direction of the cut-off waveguide. Adjustment of the distance to the coaxial dielectric resonator becomes possible.

In other words, the moving direction of the coaxial dielectric resonator for adjusting the degree of electrical coupling between adjacent coaxial dielectric resonators is not only the length direction of the cut-off waveguide but also its width direction. In this case, there is an effect that the operation of adjusting the degree of electrical coupling between adjacent coaxial dielectric resonators can be simplified as compared with the conventional coaxial dielectric filter, and the adjustment can be performed. It also has the effect of improving accuracy.

According to the coaxial dielectric filter according to the second and third aspects of the present invention, the coaxial dielectric resonator disposed on the input side has the input end surface and the coaxial dielectric resonator disposed on the output side. At least one of the output-side end faces of the shaped dielectric resonator forms an inclined surface having a slope with respect to a cross section perpendicular to the length direction of the cutoff waveguide, and the lengthwise direction of the cutoff waveguide To the cut-off waveguide wall of the coaxial dielectric resonator disposed on the input side and / or the output side which is parallel to the input side and / or via the input side and / or the output side connector, Since the base side of the antenna on the side and / or the output side is supported, the size in the length direction of the coaxial dielectric filter can be reduced, and the filter can be downsized. Signal input at antenna And output directions because it can arbitrarily set, has the effect of this coaxial dielectric filter it is possible to greatly improve the circuit design flexibility in the package to be mounted.

[Brief description of the drawings]

FIG. 1A is a plan view of a coaxial dielectric filter according to an embodiment with a cover removed, and FIG. 1B is a plan view of a metal cover.

FIG. 2A is an explanatory diagram of a work of adjusting a distance between coaxial dielectric resonators in a coaxial dielectric filter according to an embodiment, and FIG. 2B is a coaxial dielectric according to a conventional example. FIG. 2C and FIG. 2D are diagrams for explaining the operation of adjusting the distance between the coaxial dielectric resonators in the filter. FIGS. 2C and 2D show the length L of the coaxial dielectric resonator and the length of the inclined surface in the resonator arrangement direction. FIG. 4 is an explanatory diagram showing a dimension δ.

FIG. 3 is a plan view of a coaxial dielectric filter according to another embodiment with a lid removed.

FIG. 4 is a plan view of a coaxial dielectric filter according to another embodiment with a lid removed.

FIG. 5 is a plan view of a coaxial dielectric filter according to another embodiment with the lid removed.

FIG. 6 is an equivalent circuit diagram of a typical dielectric filter using a coaxial dielectric resonator.

FIG. 7 is a plan view of a conventional coaxial dielectric filter using a capacitor, in which the lid is removed.

8 (A) is a plan view of a conventional coaxial dielectric filter without using a capacitor or the like with a lid removed, FIG. 8 (B) is a plan view of a metal lid, and FIG. 8 (C) is the above coaxial type dielectric filter; FIG. 2 is a schematic perspective view of a coaxial dielectric resonator mounted on a dielectric filter.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 cut-off waveguide 11 metal case 21 coaxial dielectric resonator 22 coaxial dielectric resonator 31 input connector 41 output connector 32 input antenna 42 output antenna

Claims (3)

[Claims] 1. A linear cut-off waveguide, and two or more coaxial dielectric resonators disposed coaxially or substantially coaxially within the cut-off waveguide at a distance along its length. A rod-shaped input-side antenna whose tip is close to or inserted into the input-side inner conductor of the coaxial dielectric resonator disposed on the input side, and the output-side inner conductor of the coaxial dielectric resonator disposed on the output side A coaxial dielectric filter having a rod-shaped output antenna whose tip side is close to or inserted into the coaxial dielectric resonator, wherein at least one adjacent end face between coaxial dielectric resonators adjacent to each other has the cut-off waveguide. A coaxial dielectric filter, characterized in that the inclined surface has a slope with respect to a cross section perpendicular to the longitudinal direction of the tube. 2. The waveguide of claim 1, wherein at least one of an input end face of the coaxial dielectric resonator disposed on the input side and an output end face of the coaxial dielectric resonator disposed on the output side is cut-off waveguide. A coaxial dielectric which forms an inclined surface with a slope relative to a cross section perpendicular to the length of the tube, and which is arranged parallel to the length of the cut-off waveguide and on the input and / or output side A base end side of the input side and / or the output side antenna is supported directly or via an input side and / or an output side connector on a wall surface of the blocking waveguide opposite to the inclined surface of the resonator. And / or the tip side of the output side antenna is close to substantially the center of the inclined surface of the coaxial dielectric resonator disposed on the input side and / or the output side,
2. The coaxial dielectric according to claim 1, wherein the input and / or output direction of the signal at the input side and / or the output side antenna is perpendicular or substantially perpendicular to the length direction of the cut-off waveguide. filter. 3. The coaxial dielectric resonator according to claim 1, wherein said coaxial dielectric resonator is a half-wave coaxial dielectric resonator in which an outer conductor and an inner conductor are provided on an outer peripheral surface and an inner peripheral surface of a cylindrical main body. Claim 1
Or the coaxial dielectric filter according to 2.