JPH0495401A - Polarized type dielectric filter - Google Patents

Abstract

PURPOSE:To reduce number of components by using an internal capacitance between input/output electrode and an inner conductor in a resonance hole and between a polarized electrode and the inner conductor inside a dielectric black as a coupling capacitance with an external circuit and a polarized capacitance. CONSTITUTION:Input/output electrodes 10a, 10b are formed to positions opposite to resonance holes 5a, 5e respectively at a 1st stage and a final stage. An inner conductor 6 in the resonance holes 5a, 5e and the input/output electrodes 10a, 10b are in capacitive coupling via a dielectric block 2 and resulting capacitance C1, C4 are used for a Qe capacitance for external circuit coupling. Moreover, polarized electrodes 11a, 11b are in capacitive coupling with the inner conductor 6 in the resonance holes 5b, 5d via the dielectric block 2. Then capacitance C2, C3 are used as the polarized capacitance and the resonance holes 5a, 5b and the resonance holes 5d, 5e are in polarized capacitance coupling.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a polarized dielectric filter comprising a dielectric block having resonator holes.

<Prior Art> Conventionally, there has been a polarized filter as shown in the equivalent circuit diagram of FIG. This polar filter has a total of four resonant elements A and -A4. Qe capacitors C,,C, for coupling to an external circuit (not shown) are connected to the first and final stage resonant elements A,,A4, and the first and final stage resonant elements A,,A4 are connected to Qe capacitors C,,C, for coupling to an external circuit (not shown). , and the resonant elements A, , A adjacent to these.

Polar capacitances Cx and Cs are provided between them.

A polarized dielectric filter 40 shown in an exploded perspective view of FIG. 7 is an example of a polarized filter constituting the above-mentioned equivalent circuit.

That is, this polar dielectric filter 40 includes a dielectric block 41 made of a dielectric material such as ceramic. This dielectric block 41 has a short-circuit side end face 42 and an open side end face 43, and resonator holes 44a to 44d, which are through holes, are formed in parallel between these end faces 42 and 43. An inner conductor 45 is formed on the inner peripheral surface of each resonator hole 44a, . . . , and an outer conductor 46 is formed on the entire circumference of the side surface of the dielectric block 4I.

A short-circuit electrode film (not shown) that short-circuits the inner conductor 45 and the outer conductor 46 is formed on the short-circuit side end surface 43 . As a result, each resonator hole 44a to 44d has a resonant element A, to A4.
is configured. Note that between the resonator holes 44a to 44d, coupling holes 4 for coupling the respective resonance elements A1 to A4 are provided.
7. ... is formed.

This dielectric block 41 has a resin pin 48 and a wiring board 49.
, and a metal case 50 are attached.

The resin pin 48 is constructed by coating the metal pin 51 with resin, and has two types: an input/output pin and a polar pin.

The input/output resin pins 48a are inserted into the first and final stage resonator holes 44a and 44d, and the polarized resin pins 48b are inserted into the intermediate stage resonator holes 44b and 44c from the open end surface 43, respectively. As a result, the metal pin 51 of the input/output resin bottle 48a and the resonator holes 44a, 4 of the first and final stages are connected to each other.
It is electrically coupled to the inner conductor 45.45 of 4d by the Qe capacitance C,,C, and the polarized resin pins 48b, 48b
metal pins 51, 51 and intermediate stage resonator holes 44b, 44
It is electrically coupled to the inner conductor 45.45 of c through polar capacitors 11C,,C,.

The wiring board 49 connects each resin pin 4 via a through pole 52.
It is connected and fixed to the tips of metal pins 5I of 8a and 48b. A wiring pattern 53 is formed between the through holes 52. This wiring pattern 53 connects the input/output resin bottle 48a and the adjacent polarized resin pin 48b.

Furthermore, a metal case 50 for grounding and for preventing leakage of electromagnetic energy is fitted onto the dielectric block 41 from the open end surface 43 side.

A disconnection sheet 54 is interposed between the wiring board 49 and the metal case 50.

<Problems to be Solved by the Invention> By the way, in the polarized dielectric filter 40 described above, the resin pins 48a, 48b for input/output and polarization are used for coupling with an external circuit and for polar capacitive coupling. Since a wiring board 49 is required, there is a problem in that the number of parts increases and the cost increases.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a polarized dielectric filter that can reduce costs.

<Means for Solving the Problems> In order to achieve the above object, the present invention provides dielectric blocks that are provided in a bottomed shape from the short-circuit side end face to the opposite end face, and are arranged in parallel to each other. At least three resonator holes, an inner conductor formed on the inner surface of the resonator hole, an outer conductor formed on the side surface of the dielectric block, and a t
and a short-circuiting electrode film that short-circuits the inner conductor and the outer conductor, and input/output electrodes are provided on the opposing end faces at positions facing the resonator holes of the first and final stages, and the resonator holes of the intermediate stage. A polar electrode is formed at a position facing at least one of the holes, and the polar electrodes or the polar electrode and the input/output electrode are electrically connected. Configured filter.

<Operation> According to the above configuration, the input/output electrode and the polarized electrode are capacitively coupled to the inner conductor of the resonator hole facing them through the dielectric block. Therefore, this capacitance becomes a connection capacitance with an external circuit and a polar capacitance.

<Example> Hereinafter, the present invention will be described in detail based on an example shown in the drawings. FIG. 1 is a perspective view of an embodiment of the present invention, and FIG. 2 is a sectional view thereof.

This polarized dielectric filter 1 includes a dielectric block 2 made of a dielectric material such as ceramic, and the upper end face in FIG. 2 is a short-circuit side end face 3. Further, bottomed resonator holes 58 to 5e are provided from the short-circuit side end surface 3 to the opposing end surface 4. Resonator holes 5a to 5e are arranged in parallel to each other. Each resonator hole 5a to 5e
An inner conductor 6 is formed on the entire inner circumferential surface of. An outer conductor 7 is formed around the entire side surface of the dielectric block 2. Furthermore, a short-circuit electrode film 8 is formed on the short-circuit side end surface 3 to short-circuit the inner conductor 6 and the outer conductor 7.

As a result, a total of five resonant elements A, -A are configured for each of the resonator holes 5a to 5e. In addition, each resonator hole 58~
A slit 9.5e is provided between the slits 9.5e to couple the resonant elements A and -A5. ...is being formed.

On the other hand, on the opposing end surface 4, input/output electrodes 10a, 1ob,
Polar electrodes 11a, Ilb, and a ground electrode 12 are formed. That is, the input/output electrode 10a, I Ob
are the resonator holes 5a and 5 of the first stage and the last stage, respectively.
It is formed at a position facing e. Input/output electrode ID
a and I Ob are formed to extend from the end portion 14 to the longitudinal side surface (lower side surface in FIG. 1).

The polar electrodes 11a and Ilb are connected to the resonator holes 5a and 5e.
are formed at positions facing the adjacent resonator holes 5b and 5d, respectively. And these polar electrodes 11a, 1
lb and the input/output electrodes 10a and 10b are connected by line electrodes 13.13.

The grounding section 12 is connected to the above-mentioned electrode 1 on the opposite end surface 4.
It is formed electrically separated from 0a, 10b, lla, 11b, and 13. The opposing end surface 4 includes these electrodes 10a, 10b, and lla.

1 lb, 12,13.13.

In the polarized dielectric filter 1, the resonator hole 5a
, 5e and the input/output electrodes 10a, 10b are capacitively coupled via the dielectric block 2, and these capacitances C, ,
C, is a Qe capacitor for external circuit coupling.

In addition, the polarized electrodes 11a and 1 lb are connected to the resonator hole 5b.
, 5d are capacitively coupled to the inner conductor 6 of the dielectric block 2 via the dielectric block 2. These capacitances Ct and C3 become polar capacitances, and polar capacitive coupling occurs between the resonator holes 5a, 5b and 5d5e. An equivalent circuit diagram of this polarized dielectric filter is shown in FIG.

This polarized dielectric filter 1, as shown in FIG.
It is connected on the wiring board 20. In other words, input/output electrode]
Oa, 10b and the outer conductor 7 are connected to the cover turn 21.
A dielectric filter 1 is placed on the wiring board 20 so as to face the ground pattern 21 and the ground pattern 22 . Then, the input/output electrodes 10a, IOb, the input/output cover turn 21, and the outer conductor 7 and the ground pattern 22 are soldered.

As described above, in this embodiment, the dielectric filter I can be placed directly on the wiring board 20 and connected, that is, it can be surface mounted. Furthermore, the opposing end surface 4 is connected to the input/output electrode 10.
a, 10b, . . . , etc., so that there is no leakage of electromagnetic field energy. Therefore, there is no need to use the conventional metal case 50, and the number of parts is further reduced.

Furthermore, in the case of this embodiment, the input/output electrode 10a.

10b is formed to extend to the side surface, and the connection between the dielectric filter l and the external circuit can be performed by flow soldering, making the connection work easier.

Further, in the case of this embodiment, the coupling between the resonant elements A and -A is performed by a slit 9 formed in the short-circuit side end face 3. Due to its structure, the slit 9 may have a metal film similar to the short-circuiting electrode film 8 formed on its inner surface. Therefore, the outer surface of the dielectric block 2 of this embodiment has a ground electrode 12.
It is now possible to cover almost the entire surface with a metal film such as the short-circuit electrode film 8, etc., and these electrodes can be formed by plating,
Manufacturing is becoming even easier.

Each resonator hole 5a in the polarized dielectric filter I
Adjustment (adjustment of Qe capacity, polar capacity, stray capacity, etc.)
are input/output electrodes 10a and lOb.

This is done by slightly scraping off the polarized electrodes 11a, 1lb and the ground electrode 12.

By the way, in the above embodiment, the polar electrodes lla,
1 lb and the input/output electrodes 10a and I Ob are connected by line electrodes 13.13, but an embodiment in which they are connected by insulated leads as shown in FIGS. 4 and 5 is also conceivable.

On the opposing end face 4 of this polarized dielectric filter 30, input/output electrodes 10a are provided at the same positions as in the previous embodiment.

10b, polar electrode 11a, Ilb, ground electrode 1
2 is formed. And a polar electrode 11a.

11b are connected by a semi-rigid cable S. In this embodiment, the same or similar parts as in the previous embodiment are given the same reference numerals.

In this polarized dielectric filter 30, the resonator hole 5
Qe capacitances C,,C, for external circuit coupling are generated between a, 5e and input/output electrodes 10a, IOb, and
Polar capacitances Cx, C3 are generated between the polar electrodes 11a, 1 lb and the inner conductors 6 of the resonator holes 5b, 5d.

Since the polar electrodes 11a and 1 lb are connected by the semi-rigid cable S, there is a polar capacitive coupling between the resonator holes 5b and 5d.

An equivalent circuit diagram of this polarized dielectric filter 30 is shown in FIG.

In addition, in the case of this embodiment, the slit 9 can also be formed on the opposite end surface 4 side, as shown by the imaginary line.

In each of the above embodiments, the slit 9 connects the resonant element A1. This was carried out in a polarized dielectric filter l, 30 in which A t... was coupled, but a polarized dielectric filter in which resonant elements A , , A , , . . . were coupled through coupling holes. It goes without saying that this can also be implemented in filters.

Furthermore, in each of the above embodiments, the resonator holes 5a,...
Although the present invention was carried out using a polarized dielectric filter 1.30 having five .

<Effects of the Invention> As described above, according to the present invention, the internal capacitance of the dielectric block generated between the input/output electrode and the polarized electrode and the inner conductor of the resonator hole can be reduced by coupling with the external circuit. Capacity and polar capacitance could be made. This eliminates the need for separate parts such as conventional capacitive coupling resin pins and wiring boards, which reduces the number of parts and allows the polarized dielectric filter to be manufactured at low cost.

[Brief explanation of the drawing]

1 to 3 relate to one embodiment of the present invention, in which FIG. 1 is a perspective view, FIG. 2 is a sectional view, and FIG. 3 is an equivalent circuit diagram. 4 to 6 relate to a second embodiment of the present invention,
FIG. 4 is a perspective view, FIG. 5 is a sectional view, and FIG. 6 is an equivalent circuit diagram. 7 and 8 relate to a conventional example, with FIG. 7 being an exploded perspective view and FIG. 8 being an equivalent circuit diagram. l...Dielectric filter 2...Dielectric block 3...Short-circuit side end face 4...Opposing end face 5a to 5e...Resonator hole 6...Inner conductor 7...Outer conductor 8... ... Short-circuit electrode film 10a, 10b... Input/output electrode 11a, l lb - Polar electrode

Claims (1)

[Claims] (1) At least three resonator holes (5 a to 5
e) and an inner conductor (6) formed on the inner surface of the resonator hole (5a to 5e).
) and an outer conductor (7) formed on the side surface of the dielectric block (2).
The inner conductor (6) is formed on the short-circuit side end face (3), and the outer conductor (
A short-circuiting electrode film (8) for short-circuiting the input/output electrodes (10a, 7) is provided on the opposing end surface (4) at positions facing the resonator holes (5a, 5e) of the first stage and the final stage.
, 10b), and an intermediate stage resonator hole (
a polarized electrode (11a, 11b) is formed at a position facing at least one of the electrodes (5b, 5c, 5d);
These polar electrodes (11a, 11b) or the input/output electrodes (10a, 10b)
) is electrically connected to the polarized dielectric filter.