JP2541181Y2 - Dielectric filter - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dielectric filter, and more particularly, to a dielectric filter using a dielectric resonator that resonates in a dual mode.

[0002]

2. Description of the Related Art Conventionally, there has been a dielectric filter in which a plurality of dielectric resonators are arranged in a line in a metal case at intervals.

FIG. 7 is an illustrative view showing one example of a dielectric resonator used in such a conventional dielectric filter. The dielectric resonator 1 includes a quadrangular cylindrical outer conductor 2, and a cross-shaped dielectric 3 is fixed in the outer conductor 2. Therefore, the dielectric resonator 1 resonates in a dual mode.

Further, the outer conductor 2 of the dielectric resonator 1
Two partition plates 5a made of metal are provided at both ends of the opening 4
And 5b are fixed. These partition plates 5a and 5
“b” is for adjusting the strength of magnetic field coupling between the dielectric resonator 1 and the adjacent dielectric resonator. That is, when the width of the partition plates 5a and 5b is reduced, the area of the opening of the outer conductor 2 is increased, so that the magnetic field coupling between the dielectric resonator 1 and the adjacent dielectric resonator is increased. vice versa,
When the width of the partition plates 5a and 5b is increased, the area of the opening of the outer conductor 2 is reduced, so that the magnetic field coupling between the dielectric resonator 1 and the adjacent dielectric resonator is weakened.

In the dielectric filter using the dielectric resonator 1, when the dielectric resonator adjacent to the dielectric resonator 1 resonates in a single mode, the dielectric resonator 1 and the adjacent dielectric resonator are resonated. A magnetic field component required for the magnetic field coupling with the partition plates 5a and 5b is generated in a plane orthogonal to the main surfaces of the partition plates 5a and 5b and parallel to the width direction of the partition plates 5a and 5b, and unnecessary magnetic field coupling hardly occurs. Therefore, in this dielectric filter, the strength of the required magnetic field coupling can be adjusted by changing the width of the partition plates 5a and 5b of the dielectric resonator 1.

[0006]

However, in this dielectric filter, when the dielectric resonator adjacent to the dielectric resonator 1 resonates in dual mode, unnecessary magnetic field coupling occurs at a high level. That is, a magnetic field component unnecessary for magnetic field coupling between the dielectric resonator 1 and the adjacent dielectric resonator is generated by the partition plate 5.
partitioning plates 5a and 5b perpendicular to the main surfaces of a and 5b
Occurs in a plane parallel to the longitudinal direction of Therefore, the dielectric resonator 1 and the adjacent dielectric resonator are easily coupled by such unnecessary magnetic field coupling. Therefore,
In this dielectric filter, when the dielectric resonator adjacent to the dielectric resonator 1 resonates in dual mode, noise is generated, and desired filter characteristics cannot be obtained.

[0007] Therefore, a main object of the present invention is to provide a dielectric filter having a desired filter characteristic by suppressing unnecessary magnetic field coupling while securing necessary magnetic field coupling.

[0008]

SUMMARY OF THE INVENTION The present invention is a dielectric filter having a plurality of dielectric resonators coupled by a magnetic field, wherein a magnetic field component unnecessary for coupling between the dielectric resonators exists. Including a blocking member extending in a direction crossing the plane,
This is a dielectric filter in which dielectric resonators are coupled with a magnetic field through between the blocking members.

[0009]

A magnetic field component unnecessary for coupling between dielectric resonators is cut off by a plurality of cutoff members. On the other hand, a magnetic field component necessary for coupling between the dielectric resonators passes between the plurality of blocking members.

[0010]

According to the present invention, a desired filter characteristic can be obtained in a dielectric filter by suppressing unnecessary magnetic field coupling while securing required magnetic field coupling.

The above and other objects, features and advantages of the present invention will become more apparent from the following detailed description of embodiments with reference to the drawings.

[0012]

FIG. 1 is an illustrative view showing one embodiment of the present invention. This dielectric filter 10 includes a hollow rectangular parallelepiped case 12, for example. Case 12 is formed of, for example, a metal material. In this case 12, for example, four dielectric resonators 14 are fixed at intervals in the longitudinal direction.

The dielectric resonator 14 is particularly shown in FIGS.
As shown in FIG. 2, the outer conductor 16 includes, for example, a quadrangular cylindrical outer conductor 16. A cross-shaped dielectric 18 is fixed in the outer conductor 16, for example. Therefore, the dielectric resonator 14
Is a dual mode resonator that resonates in the TM mode.

The outer conductor 16 of each dielectric resonator 14
Two partition plates 20a and 20b made of, for example, a rectangular metal plate are provided on both sides in the width direction of the opposed opening portion.
Each is fixed.

A plurality of blocking members 2 made of metal extend from one partition plate 20a to the other partition plate 20b.
Are formed at intervals. In this case, the plurality of blocking members 22, 22,.
a and 20b are formed parallel to the width direction. Are formed integrally with the partition plates 20a and 20b and a metal plate.

On the other hand, at both ends of the case 12 in the longitudinal direction,
Input / output coaxial connectors 24a and 24b are provided, respectively. Further, these coaxial connectors 24a and 24b have antennas or loops 26a and 2
6b are respectively connected. In this case, these loops 26a and 26b are arranged in case 12 and are coupled to dielectric resonators 14 on both sides, respectively.

In the dielectric filter 10, a magnetic field required for coupling between the dielectric resonators 14 is generated in a plane perpendicular to the main surfaces of the partition plates 20a and 20b and parallel to the blocking member 22. Therefore, a magnetic field component necessary for coupling between the dielectric resonators 14 mainly passes through the slits 22 a between the blocking members 22.

Further, in the dielectric filter 10, a magnetic field unnecessary for coupling between the dielectric resonators 14 is generated by the partition plate 20.
It occurs in a direction perpendicular to the main surfaces of a and 20b and perpendicular to the blocking member 22. Therefore, this dielectric filter 1
In the case of 0, unnecessary magnetic field components are generated by the blocking members 22, 22,.
Is shut off by That is, a magnetic field component unnecessary for coupling between the dielectric resonators 14
Can hardly pass through each dielectric resonator 14.
Trapped inside.

Therefore, in this dielectric filter 10, unnecessary magnetic field coupling can be suppressed while securing required magnetic field coupling, and desired filter characteristics can be obtained.

FIG. 4 is a front view of an essential part showing a modification of the embodiment shown in FIG. In the embodiment shown in FIG. 4, the length of the blocking member 22 or the slit 22 a in the longitudinal direction of the partition plates 20 a and 20 b is not particularly changed as compared with the embodiment shown in FIG. It is formed diagonally.

FIG. 5 is a front view of an essential part showing another modification of the embodiment shown in FIG. In the embodiment shown in FIG. 5, in particular, the length of the blocking member 22 or the slit 22a in the longitudinal direction of the partition plates 20a and 20b is not changed as compared with the embodiment shown in FIG.
Are formed obliquely.

FIG. 6 is a front view of a main part showing still another modification of the embodiment shown in FIG. In the embodiment shown in FIG. 6, a slit 23 is formed at an intermediate portion of the blocking member 22 in comparison with the embodiment shown in FIG.

In the embodiment shown in FIGS. 4, 5 and 6,
Since the blocking member intersects with the surface where the unnecessary magnetic field component is present, the unnecessary magnetic field component is generated by the blocking members 22, 22,.
・ ・ It is cut off at Therefore, unnecessary magnetic field coupling can be suppressed while securing required magnetic field coupling, and desired filter characteristics can be obtained.

The dielectric resonator shown in FIGS. 4 and 5
14 is compared with the dielectric resonator 14 shown in FIGS.
And a part or all of the blocking member 22 has a certain angle.
The partition plates 20a, 2
0b and perpendicular to the blocking member 22.
The field components have a certain
It passes through the slit 22a between the blocking members 22 at the level.
Further, in the dielectric resonator 14 shown in FIG.
Compared with the dielectric resonator 14 shown in FIG.
By forming a slit 23 in the portion,
Since a part has been removed, it is shown in FIGS.
As in the embodiment, the main surfaces of the partition plates 20a and 20b are orthogonal to the main surfaces.
And all of the magnetic field components orthogonal to the blocking member 22 are blocked.
Without interruption, between the blocking members 22 at a certain level
Pass through the slit 22a. Therefore, FIGS.
FIG. 1 shows one of the dielectric resonators 14 shown in FIG.
A dielectric material applied to a part of the dielectric resonator 14 of the embodiment shown in FIG.
When the filter 10 is configured, the partition plates 20a, 20b
Magnetic field component perpendicular to the main surface and perpendicular to the blocking member 22
Slit 22a between blocking members 22 at a certain level
Between the dielectric resonators 14 that are not adjacent to each other.
In other words, dielectric resonators 14 that should not be coupled together should
Are magnetically coupled, so-called jump coupling occurs. That
Therefore, a finite attenuation pole is generated in the attenuation region of the waveform passing through the filter.
You. The position of this attenuation pole depends on the strength of the
Control appropriately depending on the position where the bond occurs.
Can be In this case, passing through the dielectric filter 10
Spurious due to TM111 mode etc. generated near the band
By generating an attenuation pole at the position of the
Canceling out ass and suppressing the level of spurious resonance
Becomes possible.

In each of the above-described embodiments, the blocking member 22 is integrally formed of a metal plate together with the partition plates 20a and 20b.
And 20b, or may be constituted by a long and thin electrode formed on a plate, such as a ceramic substrate, which is difficult to block a magnetic field.

The blocking member 22 or the slit 22a
, The degree of magnetic field coupling between the dielectric resonators 14 can be changed. In this case, if the width of the blocking member 22 is reduced or the width of the slit 22a is increased, a magnetic field component unnecessary for coupling passes through the slit 22a to some extent. become weak.

[Brief description of the drawings]

FIG. 1 is an illustrative view showing one embodiment of the present invention;

FIG. 2 is a perspective view showing a dielectric resonator used in the embodiment shown in FIG.

FIG. 3 is a sectional view taken along line III-III in FIG. 2;

FIG. 4 is a front view of an essential part showing a modification of the embodiment shown in FIG. 1;

FIG. 5 is a main part front view showing another modified example of the embodiment shown in FIG. 1;

FIG. 6 is a main part front view showing still another modification of the embodiment shown in FIG. 1;

FIG. 7 is a perspective view showing a dielectric resonator used in a conventional dielectric filter as a background of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Dielectric filter 12 Case 14 Dielectric resonator 16 External conductor 18 Dielectric 20a, 20b Partition plate 22 Blocking member 22a Slit

Claims (1)

(57) [Scope of request for utility model registration] 1. A dielectric filter having a plurality of dielectric resonators coupled by a magnetic field, wherein the dielectric filter extends in a direction intersecting a plane where a magnetic field component unnecessary for coupling between the dielectric resonators exists. It includes a blocking member, between said dielectric resonators through between the blocking member is coupled with the magnetic field, the dielectric filter.