JPH07336109A - Dielectric filter - Google Patents

Abstract

PURPOSE:To provide a BEF(band elimination filter) type dielectric filter with small number of parts and small assembling man-hours and of small size. CONSTITUTION:Capacitance electrodes 1d, 1e are formed on one main plane of a block composite resonator 1 in which plural resonators are formed by resonator holes 1a, 1b provided on an inner conductor. The block composite resonator 1 is loaded on a multilayer substrate 2 on which an inductor 2 is formed by obtaining series resonance capacitance between the capacitance electrodes 1d, 1e and the resonator holes 1a, 1b.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a BEF type dielectric filter composed of a block composite resonator in which a series resonance capacitor is integrally formed on a dielectric block.

[0002]

2. Description of the Related Art Generally, an equivalent circuit of a BEF (Band Elimination Filter) type dielectric filter constituted by two resonators is shown in FIG. In the figure, R1 and R2 are resonators, Ce1 and Ce2 are series resonance capacitors of the resonators R1 and R2, respectively, and φ is an electrical angle π / 2 phase circuit. Also, FIG. 9 is an equivalent circuit of a similar BEF type dielectric filter, and the function of the phase circuit φ in FIG.
This is achieved by the inductor L and the stray capacitances C3 and C4.

Conventionally, in the case of realizing a BEF type dielectric filter having such an equivalent circuit, as shown in FIG. 7, discrete resonators R1 and R2 and a series resonance capacitance Ce are used as shown in FIG.
1, Ce2 and coupling terminals 32a and 32b are 2 each
I used them one by one. In the figure, L1 and L2
Are coil inductors and printed inductors, respectively, but either one is used. Also, 30 is a substrate, 31
Is a shield cover.

[0004]

However, in the conventional BEF type dielectric filter, the discrete resonator R is used.
Since 1, R2, the series resonance capacitors Ce1 and Ce2, and the coupling terminals 32a and 32b are used in proportion to the number of stages, the number of parts is large, the number of assembling steps is large, and the miniaturization is hindered.

Therefore, an object of the present invention is to provide a small BEF type dielectric filter having a small number of parts and a small number of assembling steps.

[0006]

Means for solving the problems of the present invention are as follows. 1. A plurality of resonator holes are formed in the dielectric block, inner conductors are provided in these resonator holes, one end face of the dielectric block constitutes an open end face, and one end face of the dielectric block is formed. On the open end face side, a capacitor electrode is formed at a portion corresponding to the resonator hole, and an outer conductor is mainly formed except for the periphery of the open end face and the capacitor electrode. A block composite resonator in which a series resonance capacitance is formed, a capacitance connection electrode connected to the capacitance electrode of the block composite resonator, an inductor connection land connected to the capacitance connection electrode, and an inductor connection A BEF-type dielectric filter comprising: an inductor provided between lands; and a substrate on which input / output electrodes continuously led out from the inductor connection land are formed.

2. A plurality of resonator holes are formed in the dielectric block, and inner conductors are provided in these resonator holes except for the dielectric bases provided in the vicinity of the openings. An open end is formed, and a capacitive electrode is formed on the open end side of one main surface of the dielectric block at a portion corresponding to the resonator hole. A block composite resonator in which a conductor is formed and a series resonance capacitance is formed between the inner conductor of the resonator hole and the capacitance electrode, and a capacitance connection electrode connected to the capacitance electrode of the block composite resonator, An inductor connection land connected to the capacitance connection electrode, an inductor provided between the inductor connection lands, and a substrate having an input / output electrode continuously derived from the inductor connection land B F-type dielectric filter.

[0008]

In the BEF type dielectric filter of the present invention, since the series resonance capacitance is formed integrally with the block composite resonator, the number of parts is small, the number of assembling steps is small, and the size is small.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a developed perspective view of a BEF type dielectric filter according to an embodiment of the present invention, which is a concrete embodiment of the equivalent circuit shown in FIG. In FIG. 1, reference numeral 1 is a block composite resonator, and this block composite resonator 1 has two resonators formed of resonator holes 1a and 1b formed in a dielectric block. In these resonator holes 1a and 1b,
An inner conductor is provided. On the open end surface 1c side of the block compound resonator 1 and on the back surface thereof, as shown in FIG. 2, at the portions corresponding to the resonator holes 1a and 1b, the capacitive electrodes 1d and 1d are provided.
e is formed. An outer conductor is mainly provided on the outer surface of the block composite resonator 1 except for the periphery of the open end surface 1c and the capacitance electrodes 1d and 1e. Then, series resonance capacitors Ce1 and Ce2 are formed between the capacitance electrodes 1d and 1e and the inner conductors of the resonator holes 1a and 1b, respectively. On the open end face 1c side, stray capacitances C3 and C4 are formed between the edges of the resonator holes 1a and 1b and the outer conductor, respectively.

Further, in FIG. 1, 2 is a multilayer substrate,
On the surface of the multilayer substrate 2, coil connection lands 2a, 2
b is provided, and input / output electrodes 2c and 2d extending from the side surface to a part of the back surface of the multilayer substrate 2 are provided continuously with the coil connection lands 2a and 2b. Coil connection land 2a,
The coil inductor 3 is connected to 2b. In addition, capacitive connection electrodes 2e and 2f are provided on the surface of the multilayer substrate 2. The capacitance electrodes 1d and 1e of the block composite resonator 1 are connected to the capacitance connection electrodes 2e and 2f. Further, the coil connection land 2b and the capacitance connection electrode 2f are, as shown in FIG. 3, an intermediate layer of the multilayer substrate 2 and a short-circuit electrode 2g.
Connected by. The same applies to the coil connection land 2a and the capacitance connection electrode 2e. Then, the coil connection lands 2a, 2b, the input / output electrodes 2c, 2
A ground electrode is mainly provided on the multilayer substrate 2 except for d and the periphery of the capacitance connection electrodes 2e and 2f. In addition, 4 is a shield cover.

The members shown in FIG. 1 are assembled as shown in FIG. In this case, the coil inductor 3 is connected to the coil connection lands 2a and 2b, and the capacitance electrodes 1d and 1e of the block composite resonator 1 are connected to the capacitance connection electrodes 2e and 2f of the multilayer substrate 2, respectively. The outer conductor of the block composite resonator 1 and the ground electrode of the multilayer substrate 2 are also connected. A shield governor 4 is provided on the open end surface 1c side of the block composite resonator 1 so as to cover the coil inductor 3.

The embodiment shown in FIGS. 1 to 4 is shown in FIG.
As shown in FIG. 2, the series resonance capacitors Ce1 and Ce2 are the inner conductors of the resonator holes 1a and 1b of the block composite resonator 1 and the capacitance electrodes 1d and 1d.
Since it is formed between each of them and e, it is not necessary to separately connect an individual capacitor, and therefore the coupling terminal in the conventional example is also unnecessary, and the dielectric filter is downsized.

FIG. 5 is an exploded perspective view of another embodiment. This embodiment also embodies the equivalent circuit shown in FIG. Figure 5
In the figure, 11 is a block compound resonator, and this block compound resonator 11 has two resonators which are resonator holes 11a and 11b formed in the dielectric block.
Inner conductors are provided in the resonator holes 11a and 11b except for the ring-shaped dielectric bodies 11h and 11i provided near the openings. These ring-shaped dielectric bodies 11h and 11i form the open ends of the two resonators.

Capacitor electrodes 11d and 11e are formed on the open end side and the back surface of the block composite resonator 11 at the portions corresponding to the resonator holes 11a and 11b, as in the first embodiment. . An outer conductor is mainly provided on the outer surface of the block composite resonator 11 except for the periphery of the capacitor electrodes 11d and 11e. Then, this outer conductor is slightly inserted into the openings of the resonator holes 11a and 11b.

Further, as shown in FIG. 2, between the capacitance electrodes 11d and 11e and the inner conductors of the resonator holes 11a and 11b, as shown in FIG. 2, series resonance capacitances Ce1 and Ce2 are provided.
Are formed respectively. Also, the resonator holes 11a and 11b
Ring-shaped dielectric body 11h provided near the opening of
Stray capacitors C3 and C4 (see FIG. 9) are formed between the inner conductor and the outer conductor with 1i interposed.

Further, in FIG. 5, reference numeral 22 denotes a multi-layer substrate, and one end surface side of the surface thereof has capacitance connecting electrodes 12e, 1
2f is provided separately from the ground electrode. In the intermediate layer 22a (separated and shown in parentheses) of the multi-layer substrate 22, the pattern inductor 13, the connection lands 12a and 12b, and the connection lands 12a and 12b are led out, and the side surface and the back surface are provided. Input / output electrode 1 up to a part
2c and 12d are provided. In addition, the capacitive connection electrodes 12e and 12f of the multilayer substrate 22 and the connection lands 12a and 12
b are connected by through holes.
The capacitive connection electrode 12 is formed on the outer surface of the multilayer substrate 22.
The ground electrode is mainly provided except for the periphery of the electrodes e, 12f and the input / output electrodes 12c, 12d.

As shown in FIG. 6, the block composite resonator 11 and the multilayer substrate 22 shown in FIG. 5 are connected with the capacitance electrodes 11d and 11e and the capacitance connection electrodes 12e and 12f, and the outer conductor and the ground electrode, respectively. Be integrated.

In this embodiment, since the open end of the resonator is provided in the vicinity of the opening of the resonator hole, the open end face 1c in the first embodiment is covered with the outer conductor and the leakage of the electromagnetic field is reduced. In addition, the cover 4 in the first embodiment can be eliminated, and the multilayer substrate 22 forming the pattern inductor 13 and the block composite resonator 11 have substantially the same size. Becomes

[0019]

According to the present invention, since the series resonance capacitance is formed integrally with the block composite resonator, the number of parts and the number of assembling steps are reduced. Further, since the series resonance capacitor is integrally formed, the filter can be downsized. Therefore, the cost can be reduced.

[Brief description of drawings]

FIG. 1 is an exploded perspective view of an embodiment of the present invention.

2 is a sectional view taken along line XX of the block composite resonator shown in FIGS. 1 and 5. FIG.

FIG. 3 is an enlarged view of a YY cross section of the multilayer substrate shown in FIG.

FIG. 4 is an assembly form diagram of the members shown in FIG.

FIG. 5 is an exploded perspective view of another embodiment of the present invention.

6 is an external view of the assembly of the members shown in FIG.

7 is a developed perspective view of a conventional example

FIG. 8 is a general equivalent circuit diagram of a BEF type dielectric filter.

FIG. 9 is an equivalent circuit diagram of another BEF type dielectric filter.

[Explanation of symbols]

1, 11 Block compound resonator 1a, 1b, 11a, 11b Resonator hole 1c Open end face 1d, 1e, 11d, 11e Capacitance electrode Ce1, Ce2 Series resonance capacity C3, C4 Stray capacity 2, 22 Multilayer substrate 2a, 2b Connection land 2c, 2d, 12c, 12d Input / output electrodes 2e, 2f, 12e, 12f Capacitance connection electrode 2g Short circuit electrode 3, 13 Coil inductor 4 Cover 11f, 11g Dielectric base material 11h, 11i Ring-shaped dielectric base material 22a Intermediate layer

Claims (2)

[Claims] 1. A plurality of resonator holes are formed in a dielectric block, inner conductors are provided in these resonator holes, and one end surface of the dielectric block constitutes an open end surface, On the open end face side of one main surface, a capacitor electrode is formed at a portion corresponding to the resonator hole, and an outer conductor is mainly formed except the open end face and the periphery of the capacitor electrode, and an inner conductor of the resonator hole is formed. And a capacitance electrode, a block composite resonator in which a series resonance capacitance is formed, a capacitance connection electrode connected to the capacitance electrode of the block composite resonator, and an inductor connection connected to the capacitance connection electrode A BEF-type dielectric filter including a land, an inductor provided between the inductor connection lands, and a substrate on which input / output electrodes continuously derived from the inductor connection land are formed. 2. A plurality of resonator holes are formed in a dielectric block, and inner conductors are provided in these resonator holes except for a dielectric base material provided in the vicinity of the openings. The base material constitutes the open end of the resonator, and a capacitor electrode is formed on the open end side of one main surface of the dielectric block at a portion corresponding to the resonator hole, and the dielectric block surrounds the capacitor electrode. Except that the outer conductor is mainly formed, and the block composite resonator in which a series resonance capacitance is formed between the inner conductor of the resonator hole and the capacitance electrode is connected to the capacitance electrode of the block composite resonator. A capacitor connecting electrode, an inductor connecting land connected to the capacitor connecting electrode, an inductor provided between the inductor connecting lands, and an input / output electrode continuously derived from the inductor connecting land; BEF type dielectric filter has.