JPS59101902A - Dielectric filter - Google Patents

Abstract

PURPOSE:To make a filter attachable and detachable, and to improve an assembling workability and a maintenance property, etc. by sticking a metallic plate for fitting the filter, onto a face having an electric conductor film of a dielectric block. CONSTITUTION:A dielectric block 11 of a dielectric filter 10 is formed like a rectangular parallelepiped, a metallized electric conductor film 11a is provided on five faces except the upper face, and the film 11a becomes an external electric conductor. The filter 10 is formed as a BPF constituted of four stages having four resonance elements 12-15. A metallic plate 20 for fitting the filter is stuck to the bottom face of the block 11 by an adhesive means such as soldering, etc., and screw fitting holes 20c, 20d are penetrated and provided on projecting parts 20a, 20b of the plate 20. Since the plate 20 is fixed onto a device housing 21 with a screw, the filter 10 can be attached and detached easily, the assembling work is simplified, and the maintenance property is raised.

Description

DETAILED DESCRIPTION OF THE INVENTION (1) Technical Field of the Invention The present invention relates to a dielectric filter used in thermal welding devices in the VKIF band and UHF band, and particularly relates to a mounting structure for a dielectric filter and filter.

(2) Background of the Technology In general, filters used in portable radio equipment U called mobile radio equipment and in-vehicle radio equipment are required to be lightweight and less affected by temperature changes. For this reason, recently, dielectric filters, which are smaller, lighter, and less likely to liquefy at temperature than helical filters, are often used in these wireless devices.

This type of dielectric filter generally consists of a rectangular parallelepiped-shaped dielectric block, which has an external conductor film that is metallized on the bottom and side surfaces except for the top surface, and an internal conductor that has an axis in the vertical direction and is metallized on the inside surface. A band-pass filter (
It is configured as a BPF (W band pass filter).

Conventionally, this dielectric block was usually housed in a filter housing to form a dielectric filter, and this filter holder was often mounted in the wireless device housing together with various other electronic components. . However, in recent portable wireless devices and in-vehicle wireless devices, even smaller filters may be required, even if the characteristics of the filters are slightly sacrificed. In such a case, the 8% body block itself is attached to the housing of the wireless device as a dielectric filter without being housed in the filter housing. However, various problems remain with regard to the mounting structure of such a dielectric filter. In other words, this type of U electric body filter needs to be firmly fixed to the wireless device housing so as not to be affected by the negative effects 9 caused by vibrations, shocks, etc., which are environmental conditions specific to mobile wireless devices. On the other hand, it is desirable that the wireless device has a structure that can be easily attached to and detached from the device housing from the viewpoints of ease of operation, maintenance, etc. of the wireless device.

(3) Prior Art and Problems The conventional method for attaching the FM's fat cabinet frame 4/letter is to attach the surface of the dielectric block having the conductive film to the wireless device housing (
or a printed circuit board), or by using a presser metal fitting or the like, and similarly fixing it by soldering or the like. This type of mounting structure with solder allows the filter to be securely fixed to the device housing, and prevents vibrations of the device, negative effects such as @rock, etc.
It has the advantage of not being subject to any damage, but on the other hand, it has the following disadvantages.

(a) In order to avoid harmful effects on other mounted electronic components due to heating during soldering, it is necessary to first attach the dielectric filter to the device housing, and for this reason, the component installation procedure when assembling the device is difficult. Due to restrictions, assembly workability is not good.

(b) When it is necessary to remove the filter for test toning, maintenance replacement, repair, etc., the device housing and filter must be completely heated before being removed, which is very complicated and time-consuming, and this heating may cause other This tends to have a negative effect on mounted electronic components and is extremely difficult to maintain.

(c) For soldering, it is necessary to select materials for the device casing and the conductor film that are easy to solder to each other, and these materials are restricted.

(4) Purpose of the Invention In view of the above-mentioned conventional drawbacks, the present invention provides a dielectric filter having a structure that can be detachably attached to and securely fixed to a wireless device housing without requiring heating by soldering. The purpose is to

(5) Structure of the invention In order to achieve this object, according to the present invention,
A plurality of through holes are formed in a dielectric block at predetermined intervals, and conductors Pjkt are provided on five surfaces other than one surface including the opening of the through hole and on the inner surface of a predetermined hole of the through hole, and a conductor Pjkt is provided on the inner surface of a predetermined hole of the through hole. A combline type rust electric filter comprising an input/output exciter for connection, wherein a metal plate for mounting the filter is provided on the surface of the dielectric block having a conductive film. A filter is provided.

(6) Embodiments of the invention Hereinafter, embodiments of the invention will be described in detail based on the drawings.

1 to 5 are diagrams for explaining an embodiment of a dielectric block according to the present invention.

FIG. 1 and FIG. 2 are diagrams showing a first embodiment of the present invention.
This figure is a perspective view of the dielectric filter, and FIG. 2 is a diagram showing the dielectric filter shown in the first diagram attached to the casing of a wireless device. In both figures, reference numeral 10 indicates the entire dielectric filter, 11 is a dielectric block, 12, 13, 14, 15 are through holes, 16, 17 is an exciter for connecting with an external circuit, and 20 is an exciter for connecting to an external circuit. Metal plate for filter installation, 20c, 20
d indicates each screw mounting hole. The dielectric block 11 is formed in the shape of a rectangular parallelepiped, and conductor films (indicated by cross hatching in the figure) lla are provided on each of the other five surfaces (side surfaces and bottom surface) except for the top surface, which are metalized by a method such as thick film firing. These conductor films 11a are formed as external conductors. Furthermore, the block 11 has a plurality of through holes 12,
13, 14, and 15 are formed, and on the inner surface of these through holes,
A conductor g formed in the same manner as the external conductor film, respectively.
(Indicated by crosshatching in the figure) 12a, 13a, 1
4a.

15a are provided, and these conductor films are formed as internal conductors. This allows the through hole 12.13°14.1
5 is formed as a wavelength resonant element (resonant hole) that resonates at a frequency of t% wavelength (the depth of the hole is the depth of the internal conductor film). The exciter bodies 16 and 17 are made of metal rods, and are inserted into non-metallized holes 18 and 19, respectively, and are connected to an external circuit and connected to the resonant elements (resonance holes) 12 and 15, respectively, in an electric field. provided to be coupled. Therefore, this dielectric filter is formed into a four-stage band pass filter (BPF) having four resonant elements 12, 13, 14, and 15.

Now, a metal plate 20 for attaching a filter is fixed to the bottom surface of the dielectric block 11 by adhesive means such as soldering. Then, the protrusions 20 a, 20 of the metal plate 20
Screw mounting holes 20c and 20d are provided through the hole b. This screw mounting hole 20c.

20d may be formed as a screw hole or simply an insertion hole for inserting a screw. Figure 2 shows screw mounting hole 2.
0 c, 20 d f are formed in the insertion holes, and the dielectric filter lO is shown in a state u attached to the recess 22 provided in the wireless device housing 21. In other words, in this case, recess 2
A threaded hole is provided in the bottom wall 22a of 2, and a tightening screw 23.2 is provided.
The metal plate 20 is fixed on the bottom wall 22a by screwing them into screws on the bottom wall 22a through the insertion holes 20c and 20d from above, respectively. In addition, when the screw mounting holes 20 c and 20 d are formed as screw holes, an insertion hole is provided in the bottom wall 22 a of the recess 22 and the tightening screw 2
3.24 from below through the insertion hole of the bottom wall 22a and screwed into the screws 20c, 20d of the metal plate 20, the metal plate 20 is attached to the bottom wall 22 in the same manner as in the above case and 1T3J.
fixed on a. Therefore, screw mounting holes 20c and 20d
K To select whether to form a screw attachment or an insertion hole,
The decision may be made based on which case makes it easier to tighten the tightening screws 23 and 24, taking into consideration the overall shape of the device housing 21, the mounting positions of other electronic components, and the like. Arranging the filter IO in the recess 22 of the device housing 21 in this way is preferable in view of the characteristics of the filter IO, since electric field interference with other electronic components is prevented by the side wall 22b of the recess 22a. Furthermore, since various recesses for mounting other electronic components are formed in this type of device housing 21, the recess 22 can be formed at the same time as these recesses. Therefore, there is almost no disadvantage in terms of manufacturing costs. Of course, the filter 10 may be attached to the flat surface of the device housing 21. Since the metal plate 20 is fixed in full contact with the device casing 21, the filter 10 can be mounted without any problems regarding grounding characteristics.

With this configuration, the dielectric filter of this embodiment is extremely easy to attach and detach, and there is no need to heat it as required when soldering, so it can be easily attached to other electronic devices when assembling the wireless device. It can be installed at the end after the components have been mounted, which is extremely convenient when it becomes necessary to install a dielectric filter different from the originally planned dielectric filter due to the frequency of use, etc. . Of course,
Even if you install it first, you can easily replace it with another filter. Therefore, this embodiment, which has such a structure that can be easily attached and detached, can simplify the assembly work of the wireless device and improve maintainability.

FIG. 3 is a longitudinal sectional view showing a second embodiment of the present invention. Note that in FIGS. 3 to 5, the same parts as in FIG. 1 described above are given the same reference numerals as in FIG. 1, and their explanation will be omitted. In FIG. 3, reference numeral 10' indicates the entire dielectric filter, and 25 indicates a metal plate fixed to the bottom surface of the block 11 in the same manner as in the first embodiment (FIG. 1).

The metal plate 25 is provided with screws 25a and 25b corresponding to the through holes 12 and 15, respectively. The dielectric filter 10' is fixed to the device housing by screwing screws (not shown) into the screw fittings 25a, 25b from below in the same manner as in the first embodiment. This second
As is clear from FIG. 3, in this embodiment, the parts corresponding to the protrusions 20a and 20b of the metal plate 20 in the first embodiment can be omitted, so the mounting space is smaller than in the first embodiment. It has the advantage of being

FIG. 4 is a longitudinal sectional view showing a third embodiment of the present invention. In the figure, the reference numeral 10'' indicates the entire dielectric filter;
26 is the block 1 in the same manner as in the first embodiment described above.
The metal plate fixed to the bottom of 1 is shown. Attachment screws 26 a and 26 b are provided on the lower surface of the metal plate 26 and project downward. After inserting the mounting screws 26a and 26b into mounting holes (not shown) provided in the device housing, the filter lO" is tightened by screwing nuts (not shown) into the mounting screws 26a and 26b. Fixed to the device housing.

This third embodiment also has the same advantages as the second embodiment.

FIG. 5 is a longitudinal sectional view showing a fourth embodiment of the present invention. In the figure, reference numeral 101 indicates the entire dielectric filter,
Reference numeral 27 indicates a metal plate fixed to the bottom surface of the block 11 in the same manner as in the 111 embodiment. Projections 2 are provided on the upper surface of the metal plate 27 to fit into the through holes 12 and 15 of the block 11, respectively.
Mounting screws 27a are provided at 7c and 27de and extend below the protrusion.

A metal plate 27b is provided on one side of the metal plate 27.

The installation procedure of this fourth embodiment is the same as that of the aforementioned third embodiment. This fourth embodiment has the same advantages as the second embodiment described above, and also has the advantage that the protrusions 27c and 27d serve to position the block 11, and when the metal plate 27 is a thin plate, the mounting screw 27 There is an advantage that a, 27 b can be provided stably.

It should be noted that the present invention is not limited to the above embodiment, and for example, the metal plates (20, 25, 26, 27) are
It is also possible to configure a dielectric filter by fixing it to the side surface of the metal plate, and it is also possible to deform the shape of the metal plate itself into various shapes as necessary.

(7) Effects of the Invention As explained in detail above, the dielectric filter of the present invention is provided by fixing a metal plate for filter attachment to the surface of the dielectric block having the conductive film. It is possible to attach and detach the wireless device, which has great effects such as improving the ease of assembly and maintenance of the wireless device.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of a first embodiment of a dielectric filter according to the present invention, FIG. 2 is a longitudinal cross-sectional view showing the dielectric filter of FIG. 1 attached to a housing of a wireless device, and FIG. FIG. 5 is a longitudinal sectional view showing the second, third and fourth embodiments of the present invention, respectively. 10, 10', 10', 10''...Dielectric filter of the present invention, 11...Dielectric block, lla.
・・Conductor film (outer conductor), 12.13, 14.15・・
・Through holes (resonance holes), 12a, 13a, 14a,
L5h=・Conductor film (internal conductor), 16.17... Exciter, 20.25.26.27... Metal plate, 20
c, 20 d...screw mounting hole, 21...casing of wireless device, 22...recess in device casing, 23.24...
・Tightening screw, 25 a, 25 b...screw attacher,
26a, 26b, 27a, 27b - mounting screws, 2
7c, 27d...Protrusions of the metal plate (27). Figure 1 Figure 2 Nnn o 20c18 20 11a
19 2υdFigure 3Figure 4Figure 5

Claims (1)

[Scope of Claims] 1. A number of through holes are formed at predetermined intervals in - dielectric blocks, and five surfaces other than one surface containing the opening of the through hole and a predetermined location of the through hole are formed. In a combline type dielectric filter, a conductive film is provided on the inner surface of the hole, and an input/output excitation body is provided for connection to an external circuit.
An electrically shielding filter characterized in that a metal plate for attaching the filter is provided on the surface of the dielectric block having the conductive film. 2. The dielectric filter according to claim 1, wherein the metal plate is provided with screw mounting holes. 3. The dielectric filter according to claim 1 VC, wherein a mounting screw can is provided on the metal plate. 4. A projection is provided on the surface of the metal plate facing the conductor film, and the projection is formed to be insertable into a through hole in the conductor film and extends to the opposite side of the projection. The dielectric filter according to claim 3, which is provided with a screw.