JPS61251202A - Dielectric filter - Google Patents

Abstract

PURPOSE:To apply simultaneously grounding and mechanical fixation between a dielectric resonator and a case by using a nearly U-shaped finger. CONSTITUTION:The type of material of the nearly U-shaped finger 13 is made selected as a material such as spring nickel silver because of the necessity of no rust and grounding. As the shape, two side faces 13-4 bent upper outward from both ends of a bottom 13-3 and prescribed number of claws formed by cutting the tip of each side face and prescribed number of tongue piece 13-2 curved inward at the middle are provided. In inserting the nearly U-shaped finger 13 mounted with a dielectric resonator 1 contacts the conductor film of the dielectric resonator 1 to attain grounding. In pressing the finger further from this state, since the claw 13-1 contacts the side face of the package case 2 with the reaction of the tongue 13-2 and the tongue 13-2 contacts the conductor film strongly respectively, the mechanical fixation and grounding are applied at the same time.

Description

[Detailed Description of the Invention] [Summary] In a dielectric filter having a metal case having a protrusion or recess on the inner wall for accommodating a dielectric resonator, an elastic metal plate is provided in the gap between the case and the dielectric resonator. Grounding and mechanical fixation were obtained by installing an approximately U-shaped finger with a tongue using a .

[Industrial application field]

The present invention relates to improvements in the structure of dielectric filters used, for example, in automobile wireless devices.

In general, the operating environment conditions for dielectric filters used in automobile wireless devices are very severe, and the temperature inside the trunk varies from +70 degrees in summer to -35 degrees in winter, so the range of change is approximately 105 degrees. As the temperature increases, vibrations and shocks are added to this.

Furthermore, if mass production of this wireless device is intended, the design and manufacture must be suitable for mass production, so the shape of the case, for example, will be different from that in the case of small quantity production.

Therefore, even when mass-produced, it is necessary to ensure that the dielectric filter exhibits predetermined electrical characteristics under the above environmental conditions.

(Prior Art) The present applicant has disclosed Utility Model Application No. 58-5758 as a case structure for a dielectric filter in which a dielectric resonator can be placed at a predetermined position within the case.

FIG. 3 shows an external view of a conventional example of a dielectric filter, and FIG. 4 shows a sectional view taken along line AA' in FIG.

FIG. 3(a) shows a case 2 with recesses 9 provided at the four corners on the outer wall of the case 2, the dimensions of which match the external dimensions of the dielectric resonator 1.
In b), convex portions 10 are provided at the four corners to match the external dimensions of the dielectric resonator 1, and in both cases, the dielectric resonator 1 can be easily placed at a predetermined position within the case.

However, in order to mass-produce automotive wireless devices, the dielectric filter must also be designed and manufactured for mass production. For example, if the case 2 is to be manufactured with the aim of reducing weight and mass production, aluminum die-casting is the easiest to mold. However, depending on the conditions of the molding machine, a draft angle will always occur, so case 2 is manufactured as shown in Figure 4. has a trapezoidal cross section, creating a wedge-shaped gap 12 between it and the dielectric resonator 1.

For this reason, even if the dielectric resonator 1 can be placed at a predetermined position,
If the conductor film of the dielectric resonator 1 and the case 2 are not properly grounded, the electrical characteristics of the dielectric filter will deteriorate. While adhering and fixing with a conductive adhesive 11, for example, a braided wire of a coaxial cable is stuffed into the gap 12 created between the conductive film 8 on the side surface of the dielectric resonator 1 and the inner side surface of the case 2. It was grounded on three sides.

[Problem that the invention seeks to solve]

However, as mentioned above, it is difficult to guarantee the specified adhesion strength of the conductively bonded parts over the entire range of harsh environmental conditions with a maximum temperature range of about 105 degrees and large vibrations and collisions, and The braided wire also moves.

That is, there are problems in that sufficient mechanical fixation is not achieved between the dielectric resonator and the case, and there is a possibility that the grounding may be incomplete.

[Means for solving problems]

The above-mentioned problem can be solved by placing a substantially U-shaped hook 13 with a tongue formed of an elastic metal plate in the gap 12 between the case 2 and the dielectric resonator 1. This problem is solved by the dielectric filter of the invention.

[Effect]

In the present invention, a gap 12 formed between the inner side surface of the case 2 and the side surface of the dielectric resonator 1 is provided with an elastic metal plate having an outwardly bent tab and an inwardly bent tongue piece. I installed a letter-shaped finger.

For this reason, the tongue piece strongly contacts the conductive film (for example, silver-deposited film) on the side surface of the dielectric resonator, and the claw strongly contacts the inner side surface of the case.

Therefore, the dielectric resonator and the case are mechanically fixed, and the conductive film on the side surface of the dielectric resonator contacts the side surface of the housing case to be grounded.

This eliminates deterioration of the electrical characteristics of the dielectric filter.

〔Example〕

The contents of the present invention will be specifically explained below with reference to illustrated embodiments. Note that the same reference numerals indicate the same objects throughout the drawings.

FIG. 1 is a cross-sectional view of the main part of an embodiment of the present invention, and FIG.
Figure 3 shows a perspective view of the generally U-shaped finger shown;

First, the material of the U-shaped finger 13 has spring properties and does not rust, and is made of nickel silver for springs, for example, since it is necessary to provide grounding.

As shown in Fig. 2, the shape is provided with two side surfaces 13-4 curved upward and outward from both ends of the bottom surface 13-3, and a claw 13-1 made by making a notch at the tip of each side surface. A predetermined number of tongue pieces 13-2 each curved inward are provided in the middle.

FIG. 1 shows a sectional view of essential parts of an embodiment of the present invention.

In the figure, when the approximately U-shaped finger 13 on which the dielectric resonator 1 is placed is inserted into the case, this finger 1
The tongue piece 13-2 provided on the side surface of the dielectric resonator 1 contacts the conductive film 8 of the dielectric resonator 1 and is grounded.

If the tab 13-1 is further press-fitted in this state, the tongue piece 13-
The reaction force of 2 is also added, and the Kodo 13-2
Since they are in strong contact with the conductor film 8, mechanical fixation and grounding can be achieved at the same time.

〔Effect of the invention〕

As explained in detail above, the use of the U-shaped fingers has the effect of simultaneously grounding and mechanically fixing the dielectric resonator and the case.

Therefore, there is no deterioration of the electrical characteristics of the dielectric filter.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of the main part of an embodiment of the present invention, and FIG. 2 is approximately U.
FIG. 3 is an external view of a conventional example, and FIG. 4 is a sectional view taken along line AA' in FIG. 3. In the figure, I is a dielectric resonator, 2 is a housing case, 8 is a conductive film, and 13 is a substantially U-shaped finger. 3rd...A-A'@Keizu Graduation 4-Bun

Claims (1)

[Claims] A dielectric resonator in which a conductive film is formed on a predetermined surface of a dielectric block, and a protrusion or recess that engages with the outer shape of the dielectric resonator on the inner wall, and the dielectric resonator is provided at a predetermined position. In a dielectric filter having a housing case capable of housing a body resonator, an elastic metal plate is provided in a gap (12) created between the housing case (2) and the dielectric resonator (1). A dielectric filter characterized in that a substantially U-shaped hooker (13) having a tongue piece formed using a dielectric filter is installed.