JPH0758515A - Dielectric resonator - Google Patents

Abstract

PURPOSE:To adjust freely an attenuation characteristic of a lower or a higher frequency of a pass band by improving a lower frequency characteristic of the pass band when the resonator is used for a band pass filter or easily adjusting a coupling characteristic between the resonators. CONSTITUTION:Internal electrodes 3a, 3b are formed on an inner peripheral face of throughholes 2a, 2b of a dielectric block 1, an external electrode 6 is formed on an outer sides of the dielectric block 1 except one face, and a dielectric substrate 8 with an external electrode 9 formed thereto is adhered to the outer face of the dielectric block 1 to the side to which no external electrode is formed at a gap (t). An attenuation pole is freely provided to a lower or a higher frequency of the pass band when the resonator is used for a band pass filter by setting or adjusting the gap (t) between the dielectric block 1 and the dielectric substrate 8.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dielectric resonator device formed by forming an internal electrode and an external electrode on a dielectric block.

[0002]

2. Description of the Related Art An external electrode is formed on the outer surface of a dielectric block formed by integrally molding or a dielectric block formed by joining dielectric members, and a plurality of internal electrodes are formed inside the internal electrode. A dielectric resonator device in which the resonator according to (1) is combline-coupled is used as, for example, a bandpass filter in the microwave band.

FIG. 15 shows the structure of a conventional dielectric resonator device using a integrally formed dielectric block. As shown in the figure, four surfaces S3, S4, S5, S6 that are continuous between the parallel first surface S1 and second surface S2 of the dielectric block.
Having a through hole 2a, 2b penetrating between the first surface S1 and the second surface S2, and the first dielectric block
The external electrode 6 is formed on each of the surface S1, the second surface S2, and the surfaces S3, S4, S5, S6. Through holes 2a, 2
On the inner peripheral surface of b, internal electrodes having open ends due to gaps are formed near the openings of the first surfaces S1 of the through holes 2a and 2b, respectively, and tip capacitances are formed in the gaps. Further, signal input / output electrodes 7a and 7b are formed on the outer surface of the dielectric block, and capacitively coupled to the resonator formed by the internal electrodes provided inside the through holes 2a and 2b. Thus, the two resonators having the internal electrodes form a dielectric resonator device in which the two resonators are comb-line coupled.

[0004]

FIG. 13 shows an equivalent circuit of a lumped constant circuit and a distributed constant circuit of the conventional dielectric resonator device shown in FIG. In FIG. 13, Cs
Is the tip capacitance formed in the gap between the internal electrodes provided on the inner peripheral surface of the through hole, and Ce is formed between the signal input / output electrodes 7a and 7b that are capacitively coupled with the vicinity of the open end of the internal electrode. This is the external coupling capacity. The characteristics of such a resonator device are as shown in FIG. In FIG. 14, the upper half is shown in FIG.
Shows the frequency characteristic of the admittance B of the circuit seen from the direction of the arrow, and the lower half shows the attenuation characteristic of the resonator circuit. In the case of such simple combline coupling, the admittance B becomes inductive at the resonance frequency fo and has a pole on the high frequency side.
Therefore, it has a bandpass filter characteristic with a center frequency of fo and an attenuation pole on the high frequency side.

Further, in FIG. 14, the coupling between the resonators is stronger at the low-frequency side portion and the passband portion, so that the low-frequency side attenuation characteristic becomes gentle.

As described above, in the conventional dielectric resonator device based on the simple comb line coupling, the attenuation characteristic on the high band side is excellent because it has the attenuation pole on the high band side of the pass band. The attenuation characteristic on the low frequency side of the band is not good. Therefore, when a large amount of attenuation is required on the low frequency side of the pass band, the number of stages of the resonator is increased, or the through hole for forming the internal electrode on the inner peripheral surface is formed into a step-like complex shape. If the structure is not adopted, the adjacent resonators cannot be capacitively coupled, and the characteristics on the low frequency side of the pass band cannot be easily improved.

An object of the present invention is to provide a dielectric resonator device which has a simple structure and has improved passband low-frequency characteristics when used as a bandpass filter.

Another object of the present invention is a dielectric resonance in which the coupling characteristics between the resonators can be easily adjusted to freely adjust the attenuation characteristics on the low band side or the high band side of the pass band. To provide a device.

[0009]

A dielectric resonator device according to a first aspect of the present invention has an outer surface continuous between a first surface and a second surface that are substantially parallel to each other, and has the first surface inside thereof. A dielectric block having a plurality of through holes penetrating between the first surface and the second surface, the outer surface of the dielectric block other than at least one outer surface parallel to the arrangement direction of the through holes. An external electrode is formed, an internal electrode is formed on each of the inner peripheral surfaces of the plurality of through holes, and a dielectric substrate on which the external electrode is formed is fixed on the outer surface of the dielectric block where the external electrode is not formed. It is arranged by keeping the gap.

According to a second aspect of the present invention, there is provided a dielectric resonator device having a plurality of dielectric members joined to each other and having a continuous outer surface between a first surface and a second surface which are substantially parallel to each other. First side and second
A dielectric block having a plurality of through holes penetrating between the surfaces is formed, and external electrodes are provided on other outer surfaces of the outer surface of the dielectric block except at least one outer surface parallel to the arrangement direction of the through holes. And forming internal electrodes on the inner peripheral surfaces of the plurality of through-holes, and forming a dielectric substrate on which external electrodes are formed on the outer surface of the dielectric block where the external electrodes are not formed with a constant gap. It will be arranged.

A dielectric resonator device according to a third aspect of the present invention is the device of the first or second aspect, wherein the gap is formed by an air layer.

A dielectric resonator device according to a fourth aspect is the dielectric resonator device according to the first or second aspect, wherein the gap is filled with a bonding material having a dielectric constant lower than that of the dielectric block.

[0013]

A dielectric resonator device according to the present invention comprises a dielectric block and a dielectric substrate, and the dielectric block has an outer surface continuous between a substantially parallel first surface and second surface. , A plurality of through holes penetrating between the first surface and the second surface are formed inside, and other outer surface of the dielectric block except at least one outer surface in the arrangement direction of the through holes External electrodes are formed on the inner surfaces of the plurality of through holes. An external electrode is formed on the dielectric substrate, and the dielectric substrate is arranged on the outer surface of the dielectric block on which the external electrode is not formed with a certain gap.

A dielectric resonator device according to a second aspect of the present invention comprises a dielectric block formed by joining a plurality of dielectric members and a dielectric substrate. The dielectric block is formed by joining a plurality of dielectric members. The outer surface of the dielectric block has an outer surface that is continuous between a substantially parallel first surface and a second surface, and has a plurality of through holes that penetrate between the first surface and the second surface. Outer electrodes are formed on the outer surfaces other than at least one outer surface in the arrangement direction of the through holes, and inner electrodes are formed on the inner peripheral surfaces of the plurality of through holes. External electrodes are formed on the dielectric substrate, and the dielectric substrate is arranged on the outer surface of the dielectric block on which the external electrodes are not formed with a constant gap.

An equivalent circuit of the two-stage dielectric resonator device is shown in FIG. In FIG. 10, Z is the impedance of the resonator formed by the internal electrodes, εr is the relative permittivity of the dielectric block, and L is the resonator length. Cs is the tip capacitance formed at the open end of the internal electrode. Resonance frequencies feven and fod of even and odd modes of such a resonator
d is shown by the following equation.

[0016]

[Equation 1]

[0017]

[Equation 2]

Here, Co is the speed of light. Therefore, the impedances Zeven, Zodd, the relative permittivities εreven, εrodd, and the tip capacities Cseven, Csodd for the even mode and the odd mode with respect to the gap t between the dielectric block and the dielectric substrate.
When the tendencies of feven and fodd are obtained from the respective tendencies of FIG. Thus, when the gap t is 0, f
There is a relationship of even <fodd, and as the gap t becomes wider,
While fodd rises gradually, feven rises relatively rapidly. Therefore, the gap t that has the relationship of feven = fodd
When o exists and the gap t is smaller than to, feven <fod
When d and the gap t are larger than to, the relationship of feven> fodd is established. On the other hand, the coupling value k between the resonators is expressed by the following equation.

[0019]

[Equation 3]

Therefore, the change of the coupling value k with respect to the change of the gap t is as shown in the upper part of FIG. Thus, when the gap t is narrower than to, inductive coupling occurs and the gap t becomes to.
A wider case will result in capacitive engagement.

As a result, the admittance B when the circuit in the arrow direction in the equivalent circuit shown in FIG.
As shown at the top of. Here, B1 is the frequency characteristic when the gap t is small and inductively coupled, and B2 is the gap t.
Shows frequency characteristics when is large and capacitively coupled. In this example, if the resonance frequency of the resonator when the gap t is small is fo1, as shown by A1 in the lower part of FIG. 12, an attenuation pole occurs on the high frequency side of the pass band and the gap t is large. If the resonance frequency of the resonator is set to fo2, an attenuation pole is generated on the low frequency side of the pass band, and the attenuation characteristic on the low frequency side is improved.

As described above, the center frequency of the pass band can be changed and the position of the attenuation pole can be moved according to the size of the gap t, whereby the attenuation characteristic on the high band side or the low band side of the pass band can be selected. Can be improved.

The gap may be an air layer as in claim 3, and the dielectric block for joining the dielectric block and the dielectric substrate may be bonded as in claim 4. It is also possible to fill the gap with a bonding material having a dielectric constant lower than the dielectric constant.

[0024]

1 is an external perspective view of a dielectric resonator device according to a first embodiment of the present invention.

In FIG. 1, reference numeral 1 is a dielectric block, and 8 is a dielectric substrate, both of which are joined with a predetermined gap maintained. Two through-holes 2a and 2b are formed in the dielectric block 1, internal electrodes are formed on the inner peripheral surfaces of the two through-holes 2a and 2b, and are formed on the outer surfaces of the dielectric block 1 and the dielectric substrate 8. Form the external electrode 6. Thus, the dielectric resonator device used as the bandpass filter including the two-stage resonator is configured.

2A and 2B are views showing the internal structure of the dielectric block shown in FIG. 1, where FIG. 2A is a front view and FIG.
13 is a sectional view taken along line XX in FIG.
As shown in the figure, the parallel first surface S of the dielectric block 1
Four surfaces S3, S4, which are continuous between the first surface S1 and the second surface S2
S5, S6, the first surface S1, the second surface S2, the surface S3,
The external electrodes 6 are formed on substantially the entire surfaces of S5 and S6 and the peripheral portion of the surface S4.
Is formed. The surface S4 has internal electrodes 3a, 3
Electrodes 13a and 13b that are capacitively coupled with the vicinity of the open end of b are formed. Through holes 2a and 2b penetrating between the first surface S1 and the second surface S2 are formed inside, and the through holes 2a and
Internal electrodes 3a, 4a, 3b, 4b having open ends 5a, 5b due to a gap are formed near the openings of the first surface S1 of the through holes 2a, 2b on the inner peripheral surface of 2b, respectively. With this configuration, the tip capacitance Cs is formed at the open ends 5a and 5b, and the two resonators formed by the internal electrodes 3a and 3b are combline coupled.

3A and 3B are views showing the structure of the dielectric substrate 8 shown in FIG. 1, where FIG. 3A is a top view and FIG. 3B is a front view.
(C) is a bottom view. External electrodes 9 are provided on the peripheral portion of the upper surface of the dielectric substrate 8 and the other five surfaces excluding this upper surface. Further, signal input / output electrodes 12a and 12b are formed from the upper surface of the dielectric substrate 8 to the bottom surface via the side surfaces. The bottom surface (surface S4) of the dielectric block shown in FIG.
When they are joined to each other, capacitance is formed between the signal input / output electrodes 12a, 12b and the electrodes 13a, 13b on the bottom surface of the dielectric block, and as a result, the open ends of the signal input / output electrodes 12a, 12b and the internal electrodes 3a, 3b. A constant external coupling capacitance is formed between the area and the vicinity.

FIG. 4 is a sectional view taken along the line AA shown in FIG. As shown in the figure, internal electrodes 3a and 3b are formed on the inner peripheral surfaces of the through holes 2a and 2b of the dielectric block 1, respectively. Further, the dielectric substrate 8 is bonded to the bottom surface of the dielectric block 1 via the bonding material 10, and an air layer having a gap t is formed between the bottom surface of the dielectric block 1 and the dielectric substrate 8. When the dielectric substrate is joined to the dielectric block, the electrodes 13a and 13b on the dielectric block side and the signal input / output electrodes 12a and 12b on the dielectric substrate side are joined via a conductive material. Good.

Next, FIG. 5 shows the structure of a dielectric resonator device according to a second embodiment of the present invention.

The difference from the first embodiment is that the gap between the dielectric block 1 and the dielectric substrate is filled with a bonding material for bonding the two. Reference numeral 10 in the figure is a bonding material for bonding between the dielectric block 1 and the dielectric substrate 8, and is made of, for example, a synthetic resin material having a dielectric constant lower than that of the dielectric block 1 and the dielectric substrate 8. Even with this configuration,
The coupling property between the two resonators can be adjusted by the size of the gap t.

Next, FIG. 6 is an external perspective view of a dielectric resonator device according to a third embodiment of the present invention. Unlike the example shown in FIG. 1, in this example, signal input / output electrodes are formed on the dielectric block side. In FIG. 6, 1 is a dielectric block, and 8 is a dielectric substrate, which are joined with a predetermined gap maintained. The dielectric block 1 has two through holes 2
a and 2b are formed, and these two through holes 2a and 2b are formed.
An inner electrode is formed on the inner peripheral surface of the above, and an outer electrode 6 is formed on the outer surface of the dielectric block 1 and the dielectric substrate 8. Signal input / output electrodes 7a and 7b are formed on the outer surface of the dielectric block 1.
Is formed and capacitively coupled to the resonator by the internal electrodes provided inside the through holes 2a and 2b.

7A and 7B are views showing the internal structure of the dielectric block shown in FIG. 6, where FIG. 7A is a front view and FIG.
13 is a sectional view taken along line XX in FIG.
As shown in the figure, the parallel first surface S of the dielectric block 1
Four surfaces S3, S4, which are continuous between the first surface S1 and the second surface S2
S5, S6, the first surface S1, the second surface S2, the surface S3,
The external electrodes 6 are formed on substantially the entire surfaces of S5 and S6 and the peripheral portion of the surface S4.
Is formed. Through holes 2a and 2b penetrating between the first surface S1 and the second surface S2 are formed inside the through hole 2
Internal electrodes 3a, 4a, 3b, 4b having open ends 5a, 5b due to a gap are formed on the inner peripheral surfaces of a, 2b near the openings of the first surface S1 of the through holes 2a, 2b, respectively. With this configuration, the tip capacitance Cs is formed at the open ends 5a and 5b, and the two resonators formed by the internal electrodes 3a and 3b are combline coupled.

8A and 8B are views showing the structure of the dielectric substrate 8 shown in FIG. 6, in which FIG. 8A is a top view, FIG. 8B is a front view, and FIG.
(C) is a bottom view. External electrodes 9 are provided on the other five surfaces of the dielectric substrate 8 except for the peripheral portion of the upper surface.

Next, FIG. 9 shows the structure of a dielectric resonator device according to a fourth embodiment of the present invention.

FIG. 9 is a sectional view taken along a plane orthogonal to the two through holes. Unlike the third embodiment, in this example, the external electrodes 9 are formed on the entire outer peripheral surface of the dielectric substrate 8.
Even in this case, by adjusting the size of the air layer t, it is possible to change the coupling between the two resonators and form the attenuation pole on the high band side or the low band side of the pass band.

In each of the above-mentioned embodiments, the dielectric resonator device having the two-stage resonator is taken as an example, but the present invention can be similarly applied to the case of three or more stages. Also,
In each of the above-described embodiments, the second surface S2 of the dielectric block is used as the short-circuit surface, and a plurality of λ / 4 are formed in the dielectric block.
Although an example of configuring the resonator is shown, the first surface S1 and the second surface S
A λ / 2 resonator may be configured with both surfaces of 2 as a short-circuit surface. Further, both surfaces of the first surface S1 and the second surface S2 may be open surfaces to form a λ / 2 resonator.

[0037]

According to the present invention, by setting or adjusting the gap between the dielectric block and the dielectric substrate,
When used as a band pass filter, the attenuation pole can be freely provided on the low band side or high band side of the pass band, and the attenuation characteristics on the low band side or high band side of the pass band width can be easily improved. . Moreover, it is possible to easily change the center frequency of the pass band and the position of the attenuation pole by setting or adjusting the gap, and to obtain dielectric resonator devices having different characteristics by using members made from the same mold. You can

[Brief description of drawings]

FIG. 1 is an external perspective view of a dielectric resonator device according to a first embodiment of the present invention.

2A and 2B are diagrams showing a configuration of a dielectric block in FIG. 1, where FIG. 2A is a front view, FIG. 2B is a sectional view taken along line XX in FIG. 2A, and FIG.

3 is a diagram showing a configuration of a dielectric substrate in FIG.
(A) is a top view, (B) is a front view, and (C) is a bottom view.

FIG. 4 is a cross-sectional view taken along the line AA of the dielectric resonator device shown in FIG.

FIG. 5 is a sectional view of a main portion of a dielectric resonator device according to a second embodiment of the present invention.

FIG. 6 is an external perspective view of a dielectric resonator device according to a third embodiment of the present invention.

7A and 7B are diagrams showing a configuration of a dielectric block in FIG. 6, where FIG. 7A is a front view, FIG. 7B is a sectional view taken along line XX in FIG. 7A, and FIG.

8 is a diagram showing a configuration of a dielectric substrate in FIG. 6,
(A) is a top view, (B) is a front view, and (C) is a bottom view.

FIG. 9 is a sectional view of a main part of a dielectric resonator device according to a fourth embodiment of the present invention.

FIG. 10 is an equivalent circuit diagram of a resonator device including two-stage combline-coupled resonators.

FIG. 11 is a diagram showing an example of changes in the resonance frequencies of the even mode and the odd mode and changes in the coupling value between the resonators with respect to the size of the gap.

FIG. 12 is a diagram showing frequency characteristics of two resonator devices having different gaps.

FIG. 13 is an equivalent circuit diagram of a two-stage dielectric resonator device with combline coupling, which is expressed using a lumped constant circuit and a distributed constant circuit.

FIG. 14 is a diagram showing frequency characteristics of a conventional dielectric resonator device.

FIG. 15 is an external perspective view showing the configuration of a conventional dielectric resonator device.

[Explanation of symbols]

 1-Dielectric block 2a, 2b-Through hole 3a, 3b-Internal electrode (resonator) 4a, 4b-Internal electrode 5a, 5b-Open end 6-External electrode 7a, 7b-Signal input / output electrode 8-Dielectric Substrate 9-External Electrode 10-Bonding Material 11-Air Layer 12a, 12b-Signal Input / Output Electrode 13a, 13b-Electrode

Claims (4)

[Claims] 1. A dielectric block having an outer surface continuous between a substantially parallel first surface and a second surface, and having a plurality of through holes penetrating between the first surface and the second surface formed therein. An external electrode is formed on the outer surface of the dielectric block other than at least one outer surface parallel to the direction of arrangement of the through holes, and an inner electrode is formed on the inner peripheral surface of the plurality of through holes. A dielectric resonator device in which a dielectric substrate on which external electrodes are formed is arranged on the outer surface of the dielectric block on which the external electrodes are not formed and which is formed respectively, with a constant gap. 2. A plurality of dielectric members are joined to each other to have a continuous outer surface between a substantially parallel first surface and a second surface, and the inside penetrates between the first surface and the second surface. While forming a dielectric block having a plurality of through holes to form an external electrode on the outer surface of the dielectric block other than at least one outer surface parallel to the array direction of the through holes, the external electrode, Internal electrodes are respectively formed on the inner peripheral surfaces of the plurality of through holes, and a dielectric substrate having external electrodes formed thereon is arranged on the outer surface of the dielectric block where the external electrodes are not formed with a constant gap. Dielectric resonator device. 3. The method according to claim 1, wherein the gap comprises an air layer.
Alternatively, the dielectric resonator device according to item 2. 4. The dielectric resonator device according to claim 1, wherein the gap is filled with a bonding material having a dielectric constant lower than that of the dielectric block.