JPH06310922A - Dielectric ceramics resonator - Google Patents

Abstract

PURPOSE:To reduce manufacturing cost and to reduce the fluctuation of a resonance frequency by leading positively the heat generated from a dielectric ceramics resonance element externally for dissipation so as to reduce a temperature rise. CONSTITUTION:In the dielectric ceramics resonator 20 in which a dielectric ceramics resonator element 12 is fixed, for example, an thermal conductor 22 whose one terminal is in line contact or in face contact with an outer circumferential face 12a of the dielectric ceramic resonance element and whose other end is in face contact with an inner wall face 21 of an outer tube 21 of the resonator is used to immediately dissipate heat generated from the resonance element arranged in the inside to the outside of the resonator from an outer tube.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dielectric ceramic resonator having a dielectric ceramic resonant element inside.

[0002]

2. Description of the Related Art Conventionally, this kind of dielectric ceramic resonator has been used for a transmission channel filter used in a mobile communication base station of an automobile, a mobile phone base station, an MCA (multi-channel access) radio base station, or the like. Has been. As shown in FIG. 9, the resonator 10 has a dielectric ceramic resonance element 12 fixed inside the resonator 10 corresponding to high frequency power input via the coupling group antenna 11 on the input side. It was excited to cause resonance and output a signal of a predetermined frequency via the coupling group antenna 13 on the output side. Reference numeral 14 is a support base for supporting and fixing the dielectric ceramics resonance element 12, and 15
Is a dielectric ceramic rod for fine adjustment of the resonance frequency.

In the resonator 10, the input high frequency power causes the resonant element 12 to generate heat, which causes the resonator 10 to be heated.
The air inside is heated, the internal temperature rises, and the temperature of the outer tube 16 also keeps rising. It is known that the outer tube 16 linearly expands due to a temperature increase, and when the temperature extremely rises, the resonance frequency of the resonator 10 fluctuates due to the linear expansion of the outer tube 16. That is, for example, in FIG.
Invitation above, as shown in

[0004]

[Outer 1]

In the dielectric ceramic resonator, the distribution of the magnetic field H is as shown by the dotted line, and the distribution of the electric field E is as shown by the alternate long and short dash line, and the distribution direction is the distribution rotated in the direction of the arrow. Therefore, the coupling ring antenna 11
When high-frequency power is supplied from the outside via the resonance element 1,
2 Heat is generated inside and the temperature rises. Therefore, in the resonator 10, the outer tube 16 is manufactured by using an Invar alloy material having a very small linear expansion coefficient, or the outer tube 16 also has a temperature coefficient equivalent to that of the resonant element 12 (resonant frequency). The temperature coefficient of 1 was manufactured by using 0 [ppm / ° C.]), and the fluctuation of the resonance frequency due to the temperature rise was reduced to be within the predetermined standard value.

The resonator 10 having the above-described structure is basically of a type that can confine the heat generated in the dielectric ceramic resonator element 12 inside the resonator, and the resonance frequency fluctuates even when the temperature of the resonator element 12 rises. are those seldom rise, the resonant frequency characteristic is as shown in FIG. 11, the resonance frequency is 1415.03475 [MH _Z], a Q value at the time of the load Q _L is 2802, in Q value at no load Yes Q ₀
Was 27660.

[0007]

However, in the above dielectric ceramic resonator, an Invar alloy material having a very small linear expansion coefficient is used, or the temperature coefficient of resonance frequency is 0.
A material equivalent to a dielectric ceramics resonance element close to [ppm / ° C] is used, and in order to obtain an extremely high resonance sharpness (Q value), the inner wall surface 17 of the outer tube 16 is made of silver, gold, or the like having good conductivity. Since plating is performed, there is a problem that the manufacturing cost becomes high.

The present invention has been made in view of the above problems, and can reduce the manufacturing cost and positively guide and dissipate the heat generated from the dielectric ceramics resonance element to the outside to reduce the temperature rise and to resonate. An object of the present invention is to provide a dielectric ceramic resonator capable of reducing frequency fluctuations.

[0009]

In order to achieve the above object, the present invention provides a dielectric ceramic resonator in which a dielectric ceramic resonant element is fixedly mounted. For example, one end of the dielectric ceramic resonant element has an outer peripheral surface. There is provided a dielectric ceramic resonator having a metallic heat conductor in line contact with the inner surface of the outer tube of the resonator, and a metal heat conductor inside the resonator.

[0010]

The heat conductor is arranged in line contact with the resonance element in consideration of the disturbance of the electric field distribution of the resonance element, and in surface contact with the outer tube so that heat from the resonance element is easily transmitted. The heat generated from the resonance element is transferred to the outer tube via the heat conductor, and the heat is immediately radiated to the outside of the resonator.

Therefore, the temperature rise inside the resonator can be reduced, and the fluctuation range of the resonance frequency due to the temperature characteristic fluctuation can be reduced.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment according to the present invention will be described with reference to the drawings of FIGS. FIG. 1 is a schematic perspective view for explaining the principle of the dielectric ceramic resonator according to the present invention.
Note that, in FIG. 1, the same components as those in FIG. 9 are denoted by the same reference numerals for convenience of description. In addition, in FIG.
A part of the outer tube 16 is cut out so that the inside of the resonator can be easily recognized.

In FIG. 1, the structure of this embodiment, which is different from the structure of the conventional example shown in FIG. 9, has a support base 1 inside a resonator 20.
Dielectric ceramics resonance element 12 supported and fixed on 4
Outer peripheral surface 12a and the inner wall surface 21 of the outer tube 21 of the resonator 20.
This is the point where, for example, a metallic heat conductor 22 that is in contact with each other is provided on a. As a result, even if heat is generated inside the dielectric ceramics resonance element 12 in response to high-frequency power input from the outside through a coupling group antenna (not shown), the heat is transmitted through the heat conductor 22 to the outer tube. It can be diverged from 21 to the outside.

However, when the heat conductor 22 is brought into surface contact with the outer peripheral surface 12a of the dielectric ceramics resonance element 12 as shown in FIG. 1, the distribution of the electric field E is the above-mentioned heat conductor as shown in FIG. It can be imagined that it will be pulled to the 22 side and disturbed. Therefore, in the present invention, as shown in the embodiment of FIG.
One end 22a of the heat conductor 22 contacting the outer peripheral surface 12a of the resonance element 12 is chamfered to be sharpened to form an acute angle.
The other end 22b is brought into line contact with the inner wall surface of the outer tube of the resonator (not shown). Therefore, the resonance frequency characteristic in the present embodiment is as shown in FIG. 4, the resonance frequency is 1414.96525 [MH _Z], a Q value at the time of the load Q _L is 2841, is the Q value at no load Q ₀ is 280
47, and the deterioration of the Q value is 1.4 compared with the case of FIG.
Within%, the frequency variation was within 0.05%.

As a result, in this embodiment, a heat conductor for actively dissipating the heat generated from the resonant element to the outside of the resonator is provided inside, and the disturbance of the electric field distribution of the resonant element is taken into consideration. , The heat conductor is brought into line contact with the resonance element, and the heat conduction from the resonance element is facilitated to be transferred to the outside. Since it is transmitted to the outer tube via the heat conductor, the temperature rise inside the resonator can be reduced,
The fluctuation range of the resonance frequency due to the temperature characteristic fluctuation can be reduced, and an inexpensive dielectric ceramic resonator with good stability can be manufactured.

The heat conductor according to the present invention is not limited to the above embodiment, and for example, as shown in FIG. 5, the heat conductor 22 is formed in a wedge shape and has one end sharpened at an acute angle. 22a is brought into line contact with the outer peripheral surface 12a, and the other end 2
It is also possible to arrange 2b so as to make surface contact with the inner wall surface of the outer tube of the resonator (not shown) to reduce the temperature rise inside the resonator. In addition to this, for example, a configuration may be considered in which one end of the heat conductor is formed in one or a plurality of dot shapes and the dot contact is made with the outer peripheral surface of the resonant element. Further, a plurality of heat conductors can be arranged inside the resonator.

Further, in the present invention, if a fin for heat dissipation is attached to the outer tube 21 of the dielectric ceramic resonator 20, the efficiency of heat conduction to the outside is increased, and further, the effect of reducing the temperature rise. Can be improved.
Next, a specific configuration example of the dielectric ceramic resonator according to the present invention will be described based on the side sectional view of FIG. 6 and the AA sectional view of FIG. 7. Note that the same components as those in FIGS. 1 and 9 are denoted by the same reference numerals for convenience of description.

In these figures, in the dielectric ceramic resonator 20, the dielectric ceramic resonant element 12 is supported and fixed on a support 14 provided inside a cylindrical outer tube 21 having an inner diameter d and a height H. Two heat conductors 22 and 22 are fixed to the inner wall surface 21a of the outer tube 21 with screws 30 and 30 so that the heat conduction efficiency is good. The resonance element 12 is a cylinder having an outer diameter D ₁ and a height h, and has a hole 12b having a diameter D ₂ penetrating in the vertical direction in FIG. The outer tube 21 is made of copper.

The heat conductors 22 and 22 are the same as the resonance element 12 described above.
Together are symmetrically arranged via, as shown in FIG. 3, at the chamfered shape sharpened at an acute angle chamfered end 22a, it is made of a material, for example, B _S P (brass plates).
The one end 22a is in line contact with the outer peripheral surface 12a of the resonant element 12, and the other end 22b is in surface contact with the inner wall surface 21a. The heat conductors 22 and 22 are composed of a member having a height of 1, a width of w, a length of (d-D ₁ ) / 2, and a chamfered end 22a having a length of k.

In addition, when used in a mobile phone base station or the like, since it is necessary to change the resonance frequency for each channel, a dielectric ceramic for fine adjustment of the resonance frequency is provided above the center of the resonance element 12. A rod 15 is provided, and the ceramic rod 15 is fixed by a fixing nut 31 in the hole 12b of the resonance element 12 so as to be vertically movable, and adjusts the resonance frequency.

Signal input ends and output ends are provided at predetermined symmetrical positions of the outer tube 21, and coupling group antennas 32 and 33 are arranged at the input ends and output ends. The coupling ring antenna 32, 33
Is formed by forming a metal strip of copper or the like into a ring shape and is fixed to the inner wall surface 21a of the outer tube 21.
Connected to the center conductor of the mold connector.

Therefore, in the above embodiment, the resonator 20 is
Corresponding to the high frequency power input via the input side coupling loop antenna 32, the dielectric ceramics resonance element 12 fixed inside the resonator 20 is excited and resonates, and the output side coupling group. A signal of a predetermined frequency can be output via the antenna 33, and the heat of the resonant element 12 generated at that time can be radiated to the outside from the outer tube 21 via the heat conductors 22 and 22. As a result, the temperature rise inside the resonator can be reduced and the fluctuation range of the resonance frequency can be suppressed small.

Here, for example, the inner diameter d of the outer tube 21 is 76.
The resonance element 12 has a height of 9 [mm] and a height H of 71 [mm].
Outer diameter D ₁ of 38.6 [mm] and height h of 15 [mm]
The diameter D _{2 of the} hole 12b is 12.5 [mm], and the height l of the heat conductors 22, 22 is 8 [mm] and the width w is 5.
[Mm], the length k of the one end 22a of the chamfered portion is set to 6 [mm], further the resonance frequency 1500 [MH _Z], the temperature coefficient of the resonant frequency to 15 [ppm / ℃]. In this case, when high frequency power is supplied as an input signal to the input side coupling group antenna 32 of the resonator 20, the relationship between the temperature rise of the resonator 20 and the variation value of the resonance frequency is as shown in FIG. become. In addition, when the variation value of the resonance frequency is 0, it indicates that the resonance frequency is 1500 [MH _Z ] and there is no deviation amount.

As is apparent from FIG. 8, in the case of the present embodiment, the relationship shown in b is established, and the temperature of the resonant element 12 rises as compared with the case of a in which the heat conductor is not arranged. Even though the heat inside the resonator can be dissipated to the outside, it is possible to reduce the temperature rise inside the resonator, thereby keeping the fluctuation range of the resonance frequency small and keeping the above resonance frequency within the desired standard value. it can.

In the above embodiments, the case of using a metallic heat conductor has been described, but the present invention is not limited to this, and for example, a heat conductor such as a heat pipe filled with a liquid that vaporizes at a predetermined temperature. By using, it is possible to obtain the same effect as that of the above embodiment. Instead of the heat conductor, it is also possible to use, for example, a blower for sending in air.

[0026]

As described above, according to the present invention, in the dielectric ceramic resonator in which the dielectric ceramic resonant element is fixedly mounted, one end is on the outer peripheral surface of the dielectric ceramic resonant element and the other end is Since the heat conductors that come into contact with the inner wall surfaces of the outer tube of the resonator are provided inside the resonator, the manufacturing cost of the resonator can be reduced and the heat generated from the dielectric ceramics resonance element can be positively transferred to the outside. It is possible to induce and diverge to reduce the temperature rise and reduce the fluctuation of the resonance frequency.

[Brief description of drawings]

FIG. 1 is a schematic perspective view for explaining the principle of a dielectric ceramic resonator according to the present invention.

FIG. 2 is a perspective view showing an embodiment of a dielectric ceramics resonance element and a heat conductor according to the present invention.

FIG. 3 is a perspective view showing another embodiment of the dielectric ceramics resonance element and the heat conductor according to the present invention.

FIG. 4 is a diagram showing resonance frequency characteristics in the embodiment of FIG.

FIG. 5 is a perspective view showing another embodiment of the dielectric ceramics resonance element and the heat conductor according to the present invention.

FIG. 6 is a side sectional view of a specific structural example of a dielectric ceramic resonator according to the present invention.

7 is a cross-sectional view taken along the line AA of FIG.

FIG. 8 is a diagram showing a relationship between a temperature rise of the resonator shown in FIGS. 6 and 7 and a variation value of a resonance frequency.

FIG. 9 is a schematic perspective view for explaining the principle of a conventional dielectric ceramic resonator.

FIG. 10 is a perspective view of a dielectric ceramics resonance element.

FIG. 11 is a diagram showing a resonance frequency characteristic in FIG. 9.

[Explanation of symbols]

 10, 20 Dielectric ceramics resonator 11, 13, 32, 33 Coupling group antenna 12 Dielectric ceramics resonance element 12a Peripheral surface of dielectric ceramics resonance element 14 Support stand 15 Dielectric ceramics rod 16,21 Outer tube 21a Outer tube Inner wall surface 22 Heat conductor

Claims (3)

[Claims] 1. A dielectric ceramic resonator in which a dielectric ceramic resonant element is fixedly provided, one end of which is the outer peripheral surface of the dielectric ceramic resonant element, and the other end of which is the inner wall surface of the outer tube of the resonator. A dielectric ceramic resonator comprising a contacting heat conductor inside thereof. 2. The dielectric ceramic resonator according to claim 1, wherein the heat conductor makes line contact or surface contact with the inner wall surfaces of the dielectric ceramic resonator element and the resonator outer tube. 3. The dielectric ceramic resonator according to claim 1, wherein the thermal conductor is a metallic or non-metallic conductor.