JP2800323B2 - High frequency resonator - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high-frequency resonator used in a microwave frequency region, such as a filter or an oscillator for a wireless communication device such as a mobile phone, a mobile phone, and a cordless phone.

2. Description of the Related Art High-frequency resonators used in the microwave frequency range, such as filters and oscillators, generally confine microwaves having a predetermined resonance frequency in a dielectric block formed of a high dielectric constant material, and perform a predetermined operation. It is configured so that an effect can be obtained.

FIGS. 4 (a) and 4 (b) show a coaxial dielectric resonator conventionally used as this kind of high-frequency resonator.

The coaxial dielectric resonator has a size of 1/4 corresponding to 1/4 of one wavelength.
A microwave having a wavelength is set as a resonance frequency (resonance line wavelength) and has a dielectric block 51 formed in a cylindrical shape.
An internal electrode 52 is formed on the inner peripheral surface of the dielectric block 51, and an external electrode 53 is formed on the outer peripheral surface of the dielectric block 51.

FIG. 5 shows an example of a high-frequency resonator to which a microstrip line is applied.

The high-frequency resonator has a resonance frequency (resonance line wavelength) of a microwave that is an integral multiple of one wavelength, and a strip-shaped first block is formed on the surface of the dielectric block 54 formed in a flat plate shape.
In addition, third internal electrodes 55a and 55c and a ring-shaped second internal electrode 55b are formed, and an external electrode 56 is formed on the back surface of the dielectric block 54. In this high-frequency resonator, the Q value is improved by forming the second internal electrode 55b in a ring shape.

FIG. 6 shows another conventional example of a high frequency resonator to which a microstrip line is applied.
A first internal electrode 57a in a strip shape and a second internal electrode 57b in a ring shape are formed on the surface of 54, and a slit 58 is formed in the internal electrode 57b in the ring shape. In the high-frequency resonator, the internal electrode is
Since the open ends 59a and 59b of 57b are formed, a half wavelength can be used as the resonance line wavelength.

Problems to be Solved by the Invention In the above-described coaxial dielectric resonator, the structure is simple, but the shape and dimensions are restricted to some extent by the high dielectric constant material used as the material of the dielectric block 51, so that the degree of freedom in design is limited. It is narrow and has limitations in miniaturization. That is, since the resonance frequency confined in the dielectric block 51 is determined by the shape and size of the dielectric block 51, it is necessary to increase the size of the dielectric block 51 when the resonance frequency is relatively low even in the microwave frequency region. As a result, there is a problem that the dielectric block 51 is increased in size and fine adjustment of the resonance frequency becomes difficult.

On the other hand, in a high-frequency resonator to which a microstrip line is applied, since a free print pattern can be formed on the surface of the dielectric block 54, the degree of freedom of design is large, and metallization is well known in a thick film printing technology. Therefore, it can be manufactured at low cost.

However, in the high-frequency resonator, since one surface of the conductor portion is exposed to the outside and is in contact with air, the effective dielectric constant is low, radiation loss occurs, the influence of the external environment is liable, and reliability is reduced. There was a problem of lack.

In addition, since the effective relative dielectric constant is low as described above, it is necessary to form the dielectric block 54 large, and there has been a problem that it is difficult to achieve a green form.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and has as its object to provide a high-frequency resonator that can be further reduced in size and size and has a high degree of design freedom.

Means for Solving the Problems In order to achieve the above object, in a high-frequency resonator according to the present invention, an internal electrode is buried inside a dielectric block, and an external electrode is formed on a surface of the dielectric block. On the other hand, the internal electrode has an open end and is formed in a substantially loop shape in plan view with insulation from the external electrode maintained, and portions near the open end overlap with each other with a dielectric portion interposed therebetween. Is a first feature.

An internal electrode is buried inside the dielectric block, an external electrode is formed on the surface of the dielectric block, and the internal electrode has an open end and is formed in a substantially loop shape in plan view, The second end indicates that the open end or the vicinity of the open end is electrically connected to a plurality of electrode pieces through connection electrodes, respectively, and that the plurality of electrode pieces are stacked on each other with a dielectric portion interposed therebetween. The feature is.

Further, in the high-frequency resonator according to the second aspect, a part of the external electrode is cut and divided into a ground electrode and a capacitance adjusting electrode, and a connection electrode is extended to extend the capacitance adjusting electrode. The third feature is that the power supply is electrically connected to the power supply.

Action According to the above configuration, the loop-shaped internal electrode in a plan view is in a state formed without a gap inside the dielectric block,
Radiation loss is small, and there is no influence from the outside world, and a decrease in effective relative permittivity is prevented.

Further, since the internal electrode has an open end and is formed in a state where insulation from the external electrode is maintained, and a portion near the open end overlaps with a dielectric portion interposed therebetween, the open end The capacitance is formed in the overlapping portion of the above, the resonance line wavelength is shortened, and the resonator can be made thinner and smaller.

Further, when the open ends of the internal electrodes are electrically connected to the plurality of electrode pieces via the connection electrodes, respectively, and the plurality of electrode pieces are stacked on each other with the dielectric portion interposed therebetween, the overlapping ends may occur. Since the capacitance is formed at the electrode portion, the capacitance is further increased, and thus the resonance line wavelength can be further shortened.

Further, a part of the external electrode is cut and divided into a ground electrode and a capacitance adjustment electrode, and the connection electrode is extended and electrically connected to the capacitance adjustment electrode, thereby forming an electrostatic capacitor. The capacitance can be finely adjusted, and the resonance frequency can be finely adjusted.

Embodiment Hereinafter, an embodiment according to the present invention will be described in detail with reference to the drawings.
In the following embodiment, the case where the resonance frequency (resonance line wavelength) of the resonator is 1/2 wavelength is shown.

1 (a) and 1 (b), reference numeral 1 denotes a high-frequency resonator as one embodiment of the present invention, in which an internal electrode 3 is buried inside a dielectric block 2 having a substantially rectangular parallelepiped shape. An external electrode 4 is formed on the surface of the substrate 2.

The dielectric block 2 is formed by sintering a high frequency dielectric ceramic made of a high dielectric constant material.

The internal electrode 3 has open ends 5a and 5b and is formed in a substantially loop shape in plan view. Further, the internal electrode 3
A portion in the vicinity of one open end 5b is bent in an inclined cross section and overlapped with a portion in the vicinity of the other open end 5a with the dielectric portion 6 interposed therebetween. The overlapped portion (indicated by a hatched portion 7 in the figure) A capacitance is formed. The metal conductor forming the internal electrode 3 may be Ag, Pd, Pt, Au, Cu, Co, Ni, or an alloy containing at least one or more of these in consideration of microwave conductivity, productivity, and the like. Ni, Ni
System alloys, Co, and Co system alloys are limited to non-magnetic materials).

Thus, in the example of the present invention, the internal electrode 3 has the open end.
5a, 5b, and is formed in a state where insulation from the external electrode 4 is maintained, and the portions near the open ends 5a, 5b overlap each other with the dielectric portion 6 interposed therebetween.
Capacitance is formed at the overlapping portion 7 (hatched portion) of 5b, and it is possible to resonate with a short resonance line wavelength of 波長 wavelength or less, so that the resonator can be made thinner and smaller.

Further, since the internal electrode 3 is formed in a substantially loop shape and is buried in the dielectric block 2, the internal electrode 2 is completely surrounded by the dielectric block 2. Therefore, compared to a high-frequency resonator using a conventional microstrip line, a radiation loss is reduced, and a high-frequency resonator having a high effective relative permittivity and without being affected by the outside is obtained with excellent reliability. be able to.

FIGS. 2 (a) and 2 (b) show a second embodiment in which a substantially loop-shaped internal electrode 9 having open ends 8a and 8b is formed in the same plane. I have. The first connection electrode 10a is provided near the one open end 8a.
Are connected in the vertical direction in the figure, and a pair of upper and lower first electrode pieces 11a and 12a are connected in a stacked manner near both ends of the first connection electrode 10a with the dielectric portion 13 interposed therebetween. A second connection electrode 10b is vertically connected to the other open end 8b,
In the vicinity of both ends of the second connection electrode 10b, a pair of upper and lower second
The electrode pieces 11b and 12b are formed so as to be stacked on the first electrode pieces 11a and 12a with the dielectric portion 13 interposed therebetween.

In the resonator formed in this manner, the portion between the first electrode pieces 11a and 12a and the second electrode pieces 11b and 12b, and the portion near the open end 8a of the internal electrode 9 and the second electrode pieces 11b and The capacitance is formed in a multilayer shape between the capacitor and the resonator 12b (indicated by a hatched portion 14 in the figure), so that a further miniaturized resonator can be obtained as compared with the first embodiment.

FIGS. 3A and 3B show a third embodiment. In this high-frequency resonator, a part of the external electrode 15 is cut and divided into an earth electrode 16 and capacitance adjusting electrodes 17a and 17b.

This high-frequency resonator is connected to a first open end 8a and a first open end 8b of the internal electrode 9 in the vicinity of the first open end 8b.
The second connection electrodes 18a and 18b extend and are electrically connected to the capacitance adjusting electrodes 17a and 17b. Further, as in the second embodiment, a pair of upper and lower first electrode pieces 11a and 12a and a pair of upper and lower second electrode pieces 11b and 12b are connected to the first and second connection electrodes 17a and 17b. Have been.

In the high-frequency resonator thus formed, a portion between the first electrode pieces 11a and 12a and the second electrode pieces 11b and 12b with the dielectric portion 18 interposed therebetween, and a portion near the open end 8a of the internal electrode 9 And the second electrode pieces 11b, 12b, and the capacitance adjusting electrodes 17a, 1
Capacitances are formed between the first electrode piece 11a and the second electrode piece 11b (shown by hatched portions 20 in the figure), and the size can be further reduced. Moreover, the external electrode 15 is cut (trimmed) so that a desired capacitance is obtained.
Since the capacitance adjusting electrodes 17a and 17b are formed,
It is possible to obtain a high-frequency resonator whose capacitance has been finely adjusted.

The present invention is not limited to the above embodiment, but can be modified without departing from the scope. For example, the number of electrode pieces is not limited, and
Also, in the third embodiment, the open end 8b may be configured to overlap with the dielectric portion interposed therebetween as in the first embodiment.

Effect of the Invention As described in detail above, the high-frequency resonator according to the present invention has an internal electrode formed with an open end and insulated from the external electrode, and a portion near the open end. Since they overlap each other with the dielectric part in between, capacitance is formed at these overlapping parts, making it possible to shorten the resonance line wavelength, making it thinner and smaller than conventional high-frequency resonators. Can be achieved.

The internal electrodes are formed in a substantially loop shape,
Since the internal electrodes are embedded in the dielectric block, the internal electrodes are completely surrounded by the dielectric block. Therefore, compared to a conventional high frequency resonator using a Myslo strip line, radiation loss is reduced, and a high-frequency resonator having a high effective relative permittivity and being excellent in reliability without being affected by the outside is obtained. be able to.

Further, the open end or the vicinity of the open end of the internal electrode is electrically connected to a plurality of electrode pieces via the connection electrodes, respectively.
In addition, since the plurality of electrode pieces are stacked on each other with the dielectric portion interposed therebetween, a multilayer capacitance forming portion is formed inside the dielectric block, and it is possible to further shorten the resonance line wavelength, The size and thickness can be further reduced.

Further, a part of the external electrode is cut and divided into an earth electrode and a capacitance adjusting electrode, and a connection electrode is extended and electrically connected to the capacitance adjusting electrode,
Fine adjustment of the capacitance can be performed, fine adjustment of the resonance frequency can be easily performed, and a high-frequency resonator with little variation in the resonance frequency can be obtained.

[Brief description of the drawings]

FIG. 1A is a plan view showing an embodiment of the high-frequency resonator according to the present invention, FIG. 1B is a sectional view taken along line AA of FIG. 1A, and FIG. FIG. 2B is a plan view showing the second embodiment, FIG. 2B is a sectional view taken along the line BB of FIG. 2A, FIG. 3A is a plan view showing the third embodiment, FIG. 4 (b) is a cross-sectional view taken along line CC of FIG. 3 (a), FIG. 4 (a) is a perspective view showing a conventional example, and FIG. 4 (b) is a cross-sectional view taken along line XX of FIG. 4 (a). FIG. 5 is a perspective view showing another conventional example, and FIG. 6 is a perspective view showing still another conventional example. 2 …… Dielectric block, 3,9 …… Internal electrode, 4, 15 …… External electrode, 5a, 5b, 8a, 8b …… Open end, 6,13,18 …… Dielectric part, 10a, 18a… ... 1st connection electrode (connection electrode), 10b, 18b ... 2nd connection electrode (connection electrode), 11a, 12a ... 1st electrode piece (electrode piece), 11b, 12b ... 2nd electrode One piece (electrode piece), 16: Ground electrode, 17a, 17b: Capacitance adjustment electrode.

Claims (3)

(57) [Claims] An internal electrode is buried inside a dielectric block, and an external electrode is formed on a surface of the dielectric block, while the internal electrode has an open end and is insulated from the external electrode. A high-frequency resonator, wherein the resonator is formed in a substantially loop shape in a plan view while being kept, and portions near the open end overlap each other with a dielectric portion interposed therebetween. 2. An internal electrode is buried inside the dielectric block, and an external electrode is formed on the surface of the dielectric block, while the internal electrode has an open end and is formed in a substantially loop shape in plan view. The open end or the vicinity of the open end is electrically connected to a plurality of electrode pieces via connection electrodes, respectively, and the plurality of electrode pieces are stacked on each other with a dielectric portion interposed therebetween. Characteristic high-frequency resonator. 3. A method according to claim 1, wherein a part of the external electrode is cut and divided into an earth electrode and a capacitance adjusting electrode, and a connecting electrode is extended and electrically connected to the capacitance adjusting electrode. The high-frequency resonator according to claim 2, wherein: