JPS5832329Y2 - Ladder gutter ceramic filter - Google Patents

Description

[Detailed description of the invention] Industrial field of application The present invention relates to a ladder-type ceramic filter that is used as an intermediate frequency band-pass filter for wireless equipment, etc., in which a plurality of ceramic resonators are connected in series or in parallel. It is.

Structure of a conventional example and its problems First, a conventional ladder type ceramic filter of this type will be described with reference to FIGS. 1 to 4.

In the figure, 1 is a case, and terminals 4 are implanted in opposing side plates 2 and 3 of the case 1, respectively.

5 is an electrode plate having a protrusion 6; 7 and 8 are ceramic resonators mechanically held between the protrusions 6 of the electrode plate 5;

Further, 9 is an insulating plate that electrically insulates the electrode plate 5,
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Reference numeral 10 denotes a spacer, and as shown in FIG. 3, one end face has a sloped convex portion 12 fitted into a sloped recess 11 provided in the side plate 3 of the case 1. .

This spacer 10 is inserted by fitting the side plate 3 of the case 1 with the unevenness on the slope provided on the spacer 10, and the holding force applied to the ceramic resonators 7 and 8 by the protrusion 6 of the electrode plate 5 is It is press-fitted and fixed in an optimal manner.

Now, the ladder type ceramic filter having the conventional structure described above has the following drawbacks.

That is, the holding force of the ceramic resonators 7 and 8 must be adjusted by press-fitting the spacer 10 and then fixed.

Further, since the spacer 10 except for the convex portion is housed within the case 1, there is a limit to how short the entire length of the filter can be, making it difficult to reduce the size of the filter.

Purpose of the invention The present invention eliminates these conventional drawbacks. It is possible to fix the ceramic resonator without adjusting its holding force, and it also aims to reduce the overall length of the filter, thereby reducing its size. This paper proposes a ladder-type ceramic filter that attempts to reduce the

Structure of the Invention In order to achieve the above object, the ladder-type ceramic filter of the invention uses an insulating elastic body to hold the ceramic resonator uniformly, and also has a case that is oriented relative to each other in order to achieve further miniaturization. Recesses are formed in the side plates, and most of the insulating elastic body is housed in each of these recesses.

This configuration allows a ceramic resonator and an electrode plate.

The insulating plate can be held uniformly by the elastic force of the insulating elastic body, and there is no need to adjust the holding force while fixing it as in the conventional case. By storing it in the recesses formed inside the side plates on both sides, it is possible to reduce the size.

DESCRIPTION OF THE EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. 5 to 7, with the same numbers assigned to the same parts as described above.

In the figure, 13 is a case of the present invention, and recesses 16 are formed inside side plates 14 and 15 of the case 13, which face each other.

Further, 17 is an insulating elastic body, and is configured so that most of it can be accommodated in the recess 16 of the case 13.

The thickness of the insulating elastic body 17 is set so that the elastic force of the insulating elastic body 17 can be fully utilized when it is housed in the case 13 together with the electrode plate 5 ceramic resonators 7 and 8 and the insulating plate 9. .

By utilizing the elastic force of the insulating elastic body 17 in this manner, the ceramic resonators 7 and 8 can be fixed without having to adjust their holding force.

Moreover, even if the insulating elastic body 17 is used, most of it is accommodated in the recesses 16 formed in the side plates 14 and 15 of the case 13, so that the space for the insulating elastic body 17 is not taken up.

Effects of the invention As described above, according to the ladder-type ceramic filter of the invention, by using an insulating elastic body and utilizing its elastic force, it is possible to equalize the force that holds the ceramic resonator. The ceramic resonator can be held without adjusting the holding force.

In addition, even if the insulating elastic body is used, most of it is stored in the four parts formed on the case side plate, so the length of the filter can be shortened since it does not take up space for the insulating elastic body. This allows the structure to be made smaller without any deterioration in quality.

[Brief explanation of the drawing]

Fig. 1 is a top view showing a conventional ladder-type ceramic filter, Fig. 2 is a sectional view thereof, Fig. 3 is a perspective view of a spacer constituting the ceramic filter, Fig. 4 is a perspective view of the case, and Fig. 5 The figure is a top view of a ladder-type ceramic filter showing an embodiment of the present invention, FIG. 6 is a sectional view thereof, and FIG. 7 is a perspective view of a case constituting the ceramic filter of the present invention. 4...terminal, 5...electrode plate, 7,8...
... Ceramic resonator, 9 ... Insulating plate,
13...Case, 14.15...Side plate, 16...Recess, 17...Insulating elastic body.

Claims (1)

[Scope of utility model registration request] A plurality of ceramic resonators, electrode plates, and insulating plates are sequentially housed between the side plates of a case having opposing side plates in which terminals are implanted, and recesses are formed inside each of the side plates on both sides, A ladder-type ceramic filter that stores most of the insulating elastic material in each of these recesses.