JPS6110324Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a filter, for example, a stripline filter using a dielectric resonant element.

Conventionally, as a filter used in the VHF band,
There are those that use LC resonance and those that use helical resonance. Q is a filter that uses LC resonance.
However, filters using helical resonance have the drawback of being large in size. Therefore, recently, stripline filters in which a plurality of resonant electrodes are formed on the surface of a dielectric substrate are often used. This strip line filter is formed by printing silver or the like on the surface of a dielectric substrate and then baking it. However, in such a strip line filter, it is not possible to arbitrarily increase or decrease the number of resonant electrodes or change the degree of coupling after manufacturing. Furthermore, it is desired that the above-mentioned strip line filter be made smaller in size so that it can be incorporated into a device.

A coaxial TEM resonator was also developed in which an inner guide shaft and an electrode film serving as an outer conductor were formed on the inner and outer surfaces of a cylindrical ceramic dielectric, but as the frequency decreased, the axial length of the cylindrical dielectric decreased. It must be made longer;
Due to manufacturing technology, it has been difficult to form a long and uniform cylindrical ceramic dielectric.

Therefore, the main purpose of this invention is to provide a filter that allows the number of resonant electrodes of the filter to be increased or decreased as desired, the degree of coupling can be freely adjusted, and the shape of the filter is reduced.

In summary, this invention provides at least one dielectric resonator including an electrode film formed on at least the opposing main surface of a dielectric element, excluding at least the opposing side surfaces, and Attach to the mounting surface of the case via an insulating spacer so that the electrode membrane surface is perpendicular to the mounting surface of the case. And at least 1 which should be Shodan
An input side capacitive coupling element is coupled to one side electrode film of two dielectric resonators, and an output side capacitive coupling element is coupled to the other side electrode film of at least one dielectric resonator to be the final stage. It is composed of

The above objects and other objects and features of the present invention will become clearer from the detailed description given below with reference to the drawings.

FIG. 1 is an external perspective view showing an example of a dielectric resonant element included in an embodiment of this invention. In the figure, first, a dielectric material 11 having a rectangular cross-sectional shape and a rod shape is prepared. This dielectric 11 is made of ceramic or the like having a dielectric constant ε of about 90. Electrode films 12, 13, 14 are formed on the dielectric 11 except for the side surfaces facing each other in the longitudinal direction and the end surface of one side.
is formed. That is, in FIG. 1, an electrode film 12 made of, for example, silver or copper is formed on the upper main surface, and an electrode film 13 is similarly formed on the lower main surface.
is formed. Then, this dielectric resonant element 1 is
In order to make a 1/4 wavelength resonant element, a short-circuiting electrode film 1 is provided on one side end surface to short-circuit electrode films 12 and 13.
4 is formed. Note that this dielectric resonant element 1 is
When used as a 1/2 wavelength resonant element, the short-circuit electrode film 14 is not formed.

2 is a plan view showing an example of a stripline filter using the dielectric resonant element shown in FIG. 1, and FIG. 3 is a plan view of the stripline filter shown in FIG. 2 cut along the line -. FIG.

In the figure, a case 2a is made of a metal material and has a box shape with an open top. For example, two partition walls 21 and 22 are formed inside the case 2a to partition the interior in the longitudinal direction, and these partition walls 21 and 22 allow the three resonant elements 1a to be arranged as a first stage, an intermediate stage, and a final stage. Storage portions 25 to 27 are formed for storing 1 to 1c. Further, on one side of the partition walls 21 and 22, cutouts 23 and 24 are formed for accommodating chip capacitors 42 and 43, which will be described later. The storage parts 25 to 27 are made of an insulator such as plastic or low dielectric constant ceramic,
Insulating spacers 3a to 3c each having a main surface having substantially the same shape as the side surface of the dielectric resonant elements 1a to 1c and having a relatively thin thickness are arranged, respectively. The dielectric resonant elements 1a to 1c are fixed to the case 2a via the spacers 3a to 3c.

In addition, external connection terminals 61 formed of coaxial connectors, for example, are provided through both side surfaces of the case 2a.
62 is provided. A chip capacitor 41 serving as input-side capacitance coupling means is provided between the center conductor of the external connection terminal 61 and the electrode film 12a of the dielectric resonant element 1a. That is, one electrode of the chip capacitor 41 is connected to the center conductor of the external connection terminal 61, and the other electrode is directly connected to the electrode film 12a of the dielectric resonant element 1a. Also,
The electrode of a chip capacitor 42 is directly electrically connected between the electrode film 13a of the dielectric resonant element 1a and the electrode film 12b of the dielectric resonant element 1b, and the chip capacitor 42 is connected to the cutout formed in the partition wall 21. It is stored in the section 23. Similarly, the electrode film 13b of the dielectric resonant element 1b and the dielectric resonant element 1c
A chip capacitor 43 is connected between the electrode film 12c and the electrode film 12c.
are directly electrically connected, and this chip capacitor 43 is housed in the cut-out portion 24 of the partition wall 22. Furthermore, the electrode film 13c of the dielectric resonant element 1c
A chip capacitor 44 is connected between the center conductor of the external connection terminal 62 and the center conductor of the external connection terminal 62 .

A cover 2b is provided on the upper surface of the case 2a. This cover 2b is made of the same metal material as the case 2a, has a predetermined distance from the upper surface of each dielectric resonant element 1a to 1c, and is formed by bending both sides thereof so as to cover the case 2a. Then, the partition wall 2 of the case 2a is placed on the top surface of the cover 2b.
A plurality of through holes 28 are bored in corresponding portions 1 and 22. Solder is poured into the through holes 28, and the cover 2b is fixed to the upper surface of the partition walls 21 and 22.

In this way, a stripline filter is configured, and by inputting, for example, a VHF signal between the external connection terminal 61 and the case 2a, a signal within a predetermined frequency range is generated between the external connection terminal 62 and the case 2a. You can get VHF signal.

In this way, since the individually formed dielectric resonant elements 1a to 1c are arranged within the case 2a, the number of dielectric resonant elements 1 can be increased or decreased as desired. Further, when changing the frequency, it is sufficient to use a dielectric resonant element having a length corresponding to the frequency, and when it is desired to increase the degree of coupling between each dielectric resonant element 1a to 1c, electrostatic It is only necessary to increase the capacity, and the degree of freedom as a strip line filter can be increased. Furthermore, if it is desired to increase the Q of each dielectric resonant element, the cross-sectional area of the dielectric may be increased. Furthermore, as a feature of this embodiment,
Electrode film 12a of each dielectric resonant element 1a to 1c
12c to 13a to 13c are arranged so as to be perpendicular to the mounting surface of the case 2a, respectively, and chip capacitors 42 and 43 are directly electrically connected between each of the dielectric resonant elements 1a to 1c. As a result, the overall shape can be made smaller compared to those connected by lead wires or the like.

In addition, in the above-mentioned embodiment, the case where three dielectric resonant elements 1, 1a to 1c are provided, was explained, but only one dielectric resonant element 1 is provided, and one side electrode film of the dielectric resonant element 1 is provided. A chip capacitor on the input side may be connected, and a chip capacitor on the output side may be connected to the electrode film on the other side.

In this case, the dielectric resonator to be the first stage and the dielectric resonator to be the final stage are constituted by one dielectric resonator.

As described above, according to this invention, a dielectric resonant element is prepared that includes an electrode film formed on at least the opposing main surface of a dielectric element, excluding at least the opposing side surfaces, and The electrode film is attached to the mounting surface of the case via an insulating spacer so that it is perpendicular to the mounting surface of the case, and the input capacitance coupling means is coupled to the electrode film on one side of the dielectric resonant element, and the electrode on the other side is connected to the mounting surface of the case. By configuring the filter by coupling the output side capacitance coupling means to the membrane, the number of dielectric resonant elements can be increased or decreased as desired. Further, since the frequency and the degree of coupling can be easily changed, the degree of freedom as a filter can be increased.

[Brief explanation of the drawing]

FIG. 1 is an external perspective view showing an example of a dielectric resonant element included in an embodiment of this invention. FIG. 2 is a plan view showing an example of a stripline filter using the resonant element shown in FIG. 1. FIG. 3 is an external perspective view of the strip line filter shown in FIG. 2, cut along line -. In the figure, 1 is a dielectric resonant element, 11 is a dielectric, 12, 13, 14 are electrode films, 2a is a case,
2b is a cover, 41 to 44 are chip capacitors, and 61 and 62 are external connection terminals.

Claims (1)

[Claims for Utility Model Registration] A case, at least one unit disposed on the mounting surface of the case;
two insulating spacers, including a dielectric element and an electrode film formed on at least opposing main surfaces of the dielectric element excluding at least opposing side surfaces, the electrode film surface facing toward the mounting surface of the case; at least one dielectric resonator mounted on the mounting surface of the case via the insulating spacer in a perpendicular manner; A filter comprising: a capacitive coupling element; and an output capacitive coupling element coupled to the other electrode film of the at least one dielectric resonator to be the final stage.