JP2553138Y2 - Dielectric filter - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a dielectric filter in which resonators are capacitively coupled to each other by a capacitor electrode formed on a coupling substrate, and the resonator and input and output terminals are coupled by external capacitance. In particular, the present invention relates to an improvement in a connection structure of input and output terminals which can reduce costs by standardizing parts and improve productivity by reducing assembly man-hours.

[0002]

2. Description of the Related Art As an example of a dielectric filter using a plurality of dielectric coaxial resonators, there is one having a structure shown in FIGS. The dielectric filter 20 is configured by arranging a plurality of dielectric coaxial resonators 22 in parallel on a grounding case plate 21 and mounting a box-shaped case cover (not shown). A coupling substrate 23 is provided in front of the dielectric resonator 22, and a capacitor electrode 24 is formed on an upper surface of the coupling substrate 23. A coupling terminal (not shown) of the dielectric resonator 22 is connected to each of the capacitor electrodes 24.
They are capacitively coupled. Further, external connection terminals 25 are provided on the capacitor electrodes 24 'at both ends of the coupling substrate 23.
Is connected, and the external connection terminal 25 and the resonators 22 at both ends are externally coupled by a capacitor. Further, one end of a coil 26 is connected to the capacitor electrode 24 ′ at one end of the coupling substrate 23, and the other end of the coil 26 is connected to the grounding case 21. Also,
Since the coupling substrate 23 needs to be supported in a floating state so as not to contact the grounding case plate 21, an insulating spacer substrate 27 is provided between the case plate 21 and the coupling substrate 23.
Are arranged and both are bonded and fixed.

Here, when connecting the external connection terminal 25 and the coil 26, in order to secure this connection space, conventionally, an end 23a of the coupling board 23 is formed to be slightly extended, and this end is formed. A connection capacitor electrode 24 'is formed in the portion 23a. By the way, since the end 23a of the coupling board 23 is floating from the case plate 21, when the coil 26 is connected thereto, the coil 26 is fixed on the case plate 21 with the resin 28. ing. When the external connection terminal 25 is to be connected, a clip-like holding portion 25a is integrally formed by bending it, and the end portion 23a is held and fixed by the holding portion 25a, so that soldering can be easily performed. In addition to this, misalignment and the like are prevented.

[0004]

However, since the conventional dielectric filter 20 employs a structure in which the external connection terminal 25 having a special shape having the holding portion 25a is separately formed, the component cost is reduced accordingly. There is a problem that rises. In addition, since the work of sandwiching the coupling board 23 by the sandwiching portion 25a of the external connection terminal 25 is required, there is also a problem that the number of work steps is increased by that much and the productivity is low.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned conventional problems. A dielectric filter which can reduce the cost of parts by standardizing external connection terminals, and can reduce the number of working steps by eliminating the need for sandwiching work. It is intended to provide.

[0006]

SUMMARY OF THE INVENTION Accordingly, in the present invention, a plurality of resonators are disposed on a case, a coupling substrate is disposed on the case via a spacer substrate, and an electrode formed on the coupling substrate is provided. In the dielectric filter, the resonators are connected to each other, an extension portion protruding outward from the coupling substrate is integrally formed on the spacer substrate, and the extension portion is capacitively coupled to an electrode of the coupling substrate. A connection electrode is formed, and an external connection terminal is connected to the connection electrode.

[0007]

According to the dielectric filter of the present invention, an extension protruding from the coupling substrate is formed on the spacer substrate, a connection electrode is formed on the extension, and an external connection terminal is connected to the connection electrode. Therefore, since it is only necessary to arrange the external connection terminals on the connection electrodes of the spacer substrate,
It is possible to eliminate the need for the holding portion as in the case where the external connection terminal is connected to the coupling board floating from the conventional grounding case. As a result, the external connection terminals can be standardized, and the cost of parts can be reduced accordingly. In addition, since the work of sandwiching the coupling board between the external connection terminals can be eliminated, the number of work steps can be reduced, and the productivity can be improved.

[0008]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 to 4 illustrate a dielectric filter according to an embodiment of the present invention. In the figure, reference numeral 1 denotes a dielectric filter of the present embodiment, which is constituted by arranging four dielectric coaxial resonators 3 in parallel on a grounding case plate 2 and mounting a box-shaped case cover (not shown). Have been. Each of the dielectric coaxial resonators 3 has a through hole 4 a formed in the axis of a rectangular parallelepiped dielectric block 4, an inner peripheral surface of the through hole 4 a, and an open end surface 4 of the dielectric block 4.
The conductive film is formed by coating a conductive film on each of the outer surfaces except b.

The through holes 4a of the dielectric resonators 3
Inside, a cylindrical coupling terminal 5 is press-fitted, and a connection piece 5a of the coupling terminal 5 projects outward from the open side end face 4b. Further, a strip-shaped coupling substrate 6 is disposed in front of the dielectric resonator 3, and a capacitor electrode 7 is provided on the upper surface of the coupling substrate 6, and a back electrode (not shown) is provided on both ends of the lower surface. Are formed respectively. The connection piece 5a of each resonator 3 is connected to each capacitor electrode 7, whereby adjacent resonators 3 are capacitively coupled.

A spacer substrate 8 having substantially the same width as that of the ground case plate 2 and the coupling substrate 6 is provided between the ground case plate 2 and the coupling substrate 6. It is supported in a floating state. The spacer substrate 8 is made of an insulating material such as resin or alumina. The spacer substrate 8 and the case plate 2 are fixed with an adhesive, and the spacer substrate 8 and the coupling substrate 6 are fixed with a resin.

Further, one end face 8a in the longitudinal direction of the spacer substrate 8 coincides with one end face 6a of the coupling board 6, and external connection terminals 9 are provided between the one end faces 6a, 8a of the two boards 6,8. Is inserted at one end 9a. This one end 9a is connected to the back surface electrode of the coupling substrate 6, and an external coupling capacitance is formed by the electrode and the capacitor electrode 7 facing the substrate 6 with the capacitor electrode 7 interposed therebetween. Further, the other end 9b of the external connection terminal 9 is bent and formed in a stepped manner, and the other end 9b protrudes outward from the recess 2a of the case plate 2.

An extension 8b is formed integrally with the other end of the spacer substrate 8 in the longitudinal direction, and the extension 8b extends outward from the other end surface 6b of the coupling substrate 6. A connection electrode 10 is formed on the upper surface of the extension 8b.
b, and is connected to the back surface electrode of the coupling substrate 6. Thereby, an external coupling capacitance is formed between the connection electrode 10 and the capacitor electrode 7. One end 11a of the coil 11 is connected to the connection electrode 10,
The other end 11b is connected to the case plate 2.

Further, one end 12a of an external connection terminal 12 is connected to the connection electrode 10 of the spacer substrate 8, and the other end 12b protrudes outward from the recess 2a of the case plate 2. The terminal 12 has the same dimensions and the same shape as the terminal 9.

Next, the operation and effect of this embodiment will be described. According to the present embodiment, the extension 8b is integrally formed on the spacer substrate 8, and the connection electrode 10 is formed on the extension 8b, and the external connection terminal 12 is connected to this. It is only necessary to make the shape, and the conventional specially shaped holding portion can be eliminated. As a result, the cost can be reduced because the terminal components can be standardized. Further, in the present embodiment, since the conventional operation of sandwiching the external connection terminal can be omitted, the number of work steps can be reduced by that much, and the productivity can be improved. Further, the dielectric filter 1 of the present embodiment
When assembling, components such as the external connection terminal 12 and the coil 11 are sequentially arranged at predetermined positions, and cream solder is applied to these connection portions, and a batch process by reflow soldering becomes possible. Performance can be further improved.

[0015]

As described above, according to the dielectric filter of the present invention, an extension extending outward from the coupling substrate is integrally formed on the spacer substrate, and a connection electrode is formed on the extension. Since the external connection terminal is connected to the connection electrode, the external connection terminal can be standardized, and the parts cost can be reduced, and the number of work steps can be reduced to improve productivity.

[Brief description of the drawings]

FIG. 1 is a perspective view illustrating a dielectric filter according to an embodiment of the present invention.

FIG. 2 is a plan view showing the dielectric filter of the embodiment.

FIG. 3 is a front view showing the dielectric filter of the embodiment.

FIG. 4 is a side view showing the dielectric filter of the embodiment.

FIG. 5 is a perspective view showing a conventional dielectric filter.

FIG. 6 is an equivalent circuit diagram of a general dielectric filter.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Dielectric filter 2 Grounding case plate 3 Dielectric coaxial resonator 6 Coupling board 7 Capacitor electrode 8 Spacer board 8b Extension 10 Connection electrode 12 External connection terminal

Claims (1)

(57) [Scope of request for utility model registration] A plurality of resonators are arranged on a case, a coupling substrate is disposed on the case via a spacer substrate, and the resonators are connected to electrodes formed on the coupling substrate. In the dielectric filter, an extension portion extending outward from the coupling substrate is formed integrally with the spacer substrate, and a connection electrode capacitively coupled to an electrode of the coupling substrate is formed on the extension portion, and the connection electrode A dielectric filter, wherein an external connection terminal is connected to the filter.