JPH03292002A - Dielectric filter - Google Patents

Abstract

PURPOSE:To miniaturize and to decrease the manhour required for assembling by adopting the constitution such that plural dielectric resonators are connected to the surface of a multi-layer substrates provided with a 1st capacitor, a 2nd capacitor, a 3rd capacitor and a strip line or an inductor. CONSTITUTION:Plural dielectric resonators 1 are placed to the surface of a multi-layer substrate 4 provided with an input output terminal 2 via a center metallic fixture 3, connected in parallel via 1st capacitors, the series connection comprising a 2nd capacitor 18, a strip line 23 (or an inductance 19) and a 3rd capacitor 20 on the multi-layer substrate 4 is connected in parallel with the 1st capacitor 17. The multi-layer substrate 4 is formed by a laminator comprising a 1st layer conductor pattern 5, a dielectric substance 6, a 2nd layer conductor pattern 7, a dielectric substance 8, a 3rd layer conductor pattern 9, a dielectric substance 10 and a 4th layer conductor pattern 11, and is provided with an input output terminal hole 2a, an input output terminal electrode 2b, a center metallic fixture hole 3a, and a center metallic fixture electrode 4b. Then the capacitors 17, 18, 20 and the strip line 23 (or inductance 19) are formed on the multi-layer substrate 4.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a dielectric filter used in communication systems and the like.

Conventional technology A conventional dielectric filter will be explained below.

As shown in FIGS. 5 and 6, in order to obtain filter characteristics in a predetermined band, a plurality of dielectric resonators 1 are connected to a first alumina bonded substrate 22 with input/output terminals 2 via a central metal fitting 3. The capacitor 17 is connected in parallel, and the series connection body of the second capacitor 18 on the rear transfer path board 21, the strip line 23, and the third capacitor 20 is connected in parallel with the first capacitor 17. It is.

Problems to be Solved by the Invention However, in the above-mentioned conventional configuration, the alumina bonded substrate 22 and the return pressure feed path board 21 are stacked in two stages, so the shape becomes large. It is difficult to maintain the parallelism of the parts, and the assembly process requires a large number of man-hours.

The present invention solves the above-mentioned conventional problems, and aims to provide a dielectric filter that can be miniaturized and require fewer assembly steps.

Means for Solving the Problems In order to achieve this object, the dielectric filter of the present invention has a plurality of dielectric resonators located on the surface side of a multilayer substrate, each of which has a first resonator formed by the conductor pattern of the multilayer substrate. A capacitor is connected in parallel with a second capacitor formed by the conductor pattern of the multilayer board and a strip line (
The third capacitor is connected in parallel to the first capacitor.

Effect: With this configuration, one multilayer substrate is used instead of two substrates, the alumina bonded substrate and the rear transfer path substrate, and the height of the dielectric filter can be reduced and the size of the dielectric filter can be reduced.

EXAMPLES Hereinafter, examples of the present invention will be described with reference to the drawings.

(First embodiment) As shown in FIGS. 1 and 4, a plurality of dielectric resonators 1
A multilayer board 4 equipped with input/output terminals 2 via a central metal fitting 3
The first capacitor 17 connects the second capacitor 18 of the multilayer board 4, the strip line 23, and the third capacitor 20 in series to the first capacitor 17. Connect in parallel. As shown in FIG. 2, the multilayer substrate 4 has a negative layer conductor pattern 5. Dielectric 6, second layer conductor pattern 7, dielectric 8. Third layer conductor pattern9. It is composed of a laminate of a dielectric 10 and a fourth layer conductor pattern 11, and is provided with an input/output terminal hole 2a, an input/output terminal electrode 2b, a center metal hole 3a, and a center metal electrode 3b.

A second capacitor 18, a strip line 23, and a third capacitor 20 are constructed by the first layer conductor pattern 5, the second layer conductor pattern 7, and the dielectric 6 sandwiched therebetween. Here, the second capacitor 18 and the third capacitor 2
0 is formed by the facing capacitance between the second layer conductor pattern 5 and the second layer conductor pattern 7, and the capacitance can be adjusted on the second layer conductor pattern 5.

Moreover, the pattern 7 of the strip line 23 is formed by the second layer conductor pattern, and the ground electrode 2 which is the opposing surface
4 is formed on the -th layer conductor pattern 5. A first capacitor 17 is constituted by the third layer conductor pattern 9, the fourth layer conductor pattern 11, and the dielectric material 10 sandwiched therebetween. In addition, by using a high dielectric constant material for the dielectric 6 and the dielectric 10 and using a low dielectric constant material for the dielectric 8, unnecessary prevents capacitive coupling.

As described above, according to this embodiment, the first capacitor, the second capacitor
The configuration in which multiple dielectric resonators are connected to the front side of the multilayer substrate 4, which includes a capacitor, a third capacitor, and a strip line, facilitates assembly, reduces assembly man-hours, and reduces the height of the dielectric filter. It can be made smaller.

(Second Embodiment) A second embodiment of the present invention will be described below with reference to the drawings.

The structure shown in FIGS. 1 and 4 differs from the first embodiment of the present invention in that an inductance 19 is provided in place of the strip line 23 of the first embodiment.

As shown in FIG. 3, the multilayer substrate 4 includes a negative layer conductor pattern 12. Dielectric 13. Second layer conductor pattern 14. Consisting of a laminate of a dielectric 15 and a third layer conductor pattern 16,
Input/output terminal 2a, input/output terminal electrode 2b, and center metal fitting hole 3
a and a center metal electrode 3b are provided.

A second capacitor 18 is formed by the second layer conductor pattern 12.
This constitutes an inductance 19 and a third capacitor 20, and the capacitance can also be adjusted. The second layer conductor pattern 14, the third layer conductor pattern 16, and the dielectric material 15 sandwiched between them
constitutes the first capacitor 17. In addition, by using a material with a high dielectric constant for the dielectric 15 and a material with a low dielectric constant for the dielectric 13, unnecessary capacitive coupling between the first layer conductor pattern 12 and the second layer conductor pattern 14 can be avoided. To prevent.

As described above, the first capacitor, the second capacitor,
With a configuration in which multiple dielectric resonators are connected to the surface side of a multilayer board equipped with a third capacitor and inductance,
Assembly is also easier, the number of assembly steps can be reduced, and the height of the dielectric filter can be lowered to make it more compact.

Effects of the Invention As is clear from the above description of the embodiments, a plurality of dielectric resonators are provided on the surface side of a multilayer substrate provided with a first capacitor, a second capacitor, a third capacitor, and a strip line or inductance. By connecting the
This makes it possible to realize an excellent dielectric filter that is compact and can reduce assembly man-hours.

[Brief explanation of drawings]

FIG. 1 is a front view showing the structure of a dielectric filter according to a first embodiment and a second embodiment of the present invention, and FIG.
FIG. 3 is a perspective view showing the structure of a multilayer board according to the second embodiment of the present invention; FIG.
The figure is an equivalent circuit diagram of an embodiment of the present invention, FIG. 5 is a front view showing the configuration of a conventional dielectric filter, and FIG. 6 is a conventional circuit diagram. 1...Dielectric resonator, 2...Input/output terminal, 3...Center metal fitting, 4...Multilayer board.

Claims (2)

[Claims] (1) A plurality of dielectric resonators are located on the surface side of the multilayer board, each connected in parallel with a first capacitor formed by the conductor pattern of the multilayer board, and a second capacitor formed by the conductor pattern of the multilayer board. A dielectric filter in which a series connection body of a capacitor, a strip line, and a third capacitor is connected in parallel to the first capacitor. (2) The dielectric filter according to claim 1, further comprising an inductance in place of the strip line.