JPH07135406A - Dielectric filter - Google Patents

Abstract

PURPOSE:To miniaturize dielectric filter and to reduce cost by adhering an insulating board on which a coupling capacitor or an inductor and input/output terminal electrodes are formed with a dielectric resonator. CONSTITUTION:Inner conductor terminals 3a,4a are soldered to coupling capacitor electrodes 8a, 8b via throughholes 8c, 8d. A 1st insulation board 7 is adhered to an open end face 6 of dielectric resonators R1, R2 and a 2nd insulation board 9 is adhered to the board 7. Then a coupling capacitor C2 is formed by the electrodes 8a,8b, a coupling capacitor C1 is formed by the electrodes 8a, 9a, and a coupling capacitor C3 is formed by the electrodes 8a, 9a to form the dielectric filter circuit. Furthermore, a shield to suppress leakage is provided between input/output terminal electrodes or a shield cover to cover the input/ output terminal electrodes is provided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dielectric filter in which an insulating substrate having a dielectric resonator coupling capacitor and the like formed thereon is bonded to the dielectric resonator.

[0002]

2. Description of the Related Art A conventional dielectric filter is shown in FIG.
As shown in FIG. 5, an electronic component attached to the dielectric resonator 11, for example, a coupling capacitor has soldered the capacitor 12 to the dielectric resonator 11 individually, and as shown in FIG. The air-core coil 13 was individually soldered to the dielectric resonator 11.

[0003]

Therefore, in the conventional dielectric filter, as shown in FIGS. 4 and 5, the dimension a for attaching the capacitor 12 or the air-core coil 13 to the dielectric resonator 11 is required. This hinders the miniaturization of the dielectric filter.

Therefore, according to the present invention, a coupling capacitor or the like, which is an auxiliary circuit of a dielectric resonator, is formed on an insulating substrate, and the insulating substrate is attached to the dielectric resonator, so that the dielectric is small and has a small number of parts. It is intended to provide a body filter.

[0005]

SUMMARY OF THE INVENTION The present invention is a dielectric filter comprising a plurality of dielectric resonators that are capacitor-coupled or inductor-coupled, and an insulating substrate having the coupling capacitor or inductor and input / output terminal electrodes formed thereon. Is attached to the dielectric resonator.

[0006]

According to the present invention, since the coupling capacitor or the inductor, which is an auxiliary circuit of the dielectric resonator, is formed on the insulating substrate and the insulating substrate is attached to the dielectric resonator, the total volume of the dielectric filter is reduced. Get smaller.

[0007]

Embodiments of the present invention will now be described with reference to the drawings. FIG. 1 shows a dielectric filter circuit according to an embodiment of the present invention, in which R1 and R2 are dielectric resonators and C
1, C2 and C3 are coupling capacitors, 1 is an input terminal, and 2 is an output terminal.

FIG. 2 is a specific example of the dielectric filter circuit shown in FIG. 1. R1 and R2 are λ / 4 dielectric resonators with one end open. Reference numerals 3 and 4 are resonator holes, and 3a and 4a are terminals of inner conductors formed in the resonator holes 3 and 4. 5 is an outer conductor,
6 is an open end face. The dielectric resonators R1 and R2 are coupled by connecting their outer conductors 5 and 5. Reference numeral 7 denotes a first insulating substrate such as an alumina substrate or a resin substrate on which comb-teeth-shaped coupling capacitor electrodes 8a and 8b are formed. Through holes 8c are formed in these coupling capacitor electrodes 8a and 8b. 8d is provided. Reference numeral 9 is a second insulating substrate such as an alumina substrate or a resin substrate, and coupling capacitor electrodes 9a and 9b are formed on both ends of the surface thereof. Input / output terminal electrodes 9c (not shown in the figure) and 9d are coupled capacitor electrodes 9a and 9b on both end faces.
And are provided respectively.

The members shown in FIG. 2 are combined as shown in FIG. 3 to form an integral dielectric filter. That is, the inner conductor terminals 3a and 4a are connected to the through holes 8c and 8d.
Via soldering to the coupling capacitor electrodes 8a, 8b, the first insulating substrate 7 is adhered to the open end faces 6 of the dielectric resonators R1, R2, and the second insulating layer 7 is attached to the first insulating substrate 7. The substrate 9 is adhered. The coupling capacitor C2 in FIG. 1 is formed by the coupling capacitor electrodes 8a and 8b, and the coupling capacitor C1 is coupled to the coupling capacitor electrode 8
a and the coupling capacitor electrode 9a, and the coupling capacitor C3 is formed by the coupling capacitor electrode 8b and the coupling capacitor electrode 9b to form the dielectric filter circuit of FIG.

In the above embodiment, the capacitors are formed by being divided into the first insulating substrate 7 and the second insulating substrate 9, but the first insulating substrate 7 and the second insulating substrate 9 are formed. 9 may have an integrated multilayer wiring structure.

Further, in the above embodiment, the case where only the capacitor electrode is formed on the insulating substrate is shown, but a coil pattern or the like can be formed. It can be applied to BPF, BEF, etc., and the number of stages is not limited.

Further, in the above embodiment, the input terminal electrode and the output terminal electrode are formed on both end surfaces of the insulating substrate 9, but they may also serve as the coupling capacitor electrodes 9a and 9b, or the insulating substrate. May be formed on the bottom surface of the.

Although the inner conductor terminals 3a and 4a are provided in the above embodiment, the inner conductor and the through-hole electrode may be directly soldered without providing the inner conductor terminals 3a and 4a.

Further, a shield for suppressing leakage may be provided between the input / output terminal electrodes, or a shield cover for covering the input / output terminal electrodes may be provided, and a portion other than the input / output terminal electrodes may be covered with a shield cover. May be.

[0015]

According to the present invention, since the coupling capacitor or the inductor, which is an auxiliary circuit of the dielectric resonator, is formed on a separate insulating substrate and the insulating substrate is attached to the dielectric resonator, the dielectric filter Can be downsized, the number of parts can be reduced, and the cost can be reduced.

[Brief description of drawings]

FIG. 1 is a dielectric filter circuit diagram according to an embodiment of the present invention.

FIG. 2 is an exploded perspective view of an embodiment embodying FIG.

FIG. 3 is an assembly diagram of FIG.

FIG. 4 is a front view of a conventional example.

FIG. 5 is a front view of another conventional example.

[Explanation of symbols]

 R1, R2 Dielectric resonator C1, C2, C3 Coupling capacitor 1 Input terminal 2 Output terminal 3, 4 Resonator hole 3a, 4a Inner conductor terminal 5 Outer conductor 6 Open end face 7 First insulating substrate 8a, 8b Coupling capacitor electrode 8c, 8d through hole 9 second insulating substrate 9a, 9b external coupling capacitor electrode 9c, 9d input / output terminal electrode

Claims (1)

[Claims] 1. A dielectric filter comprising a plurality of dielectric resonators that are capacitor-coupled or inductor-coupled, wherein an insulating substrate on which the coupling capacitors or inductors and input / output terminal electrodes are formed is attached to the dielectric resonators. A dielectric filter characterized by being combined.