JP2561473Y2 - Dielectric resonator - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dielectric resonator for use in a high-frequency filter, a high-frequency oscillator and the like.

[0002]

2. Description of the Related Art A conventional coaxial quarter-wavelength dielectric resonator has a resonance hole extending from one end face to the other end face of a dielectric block, and an inner conductor provided on the inner peripheral surface of the resonance hole. An outer conductor provided on the side surface of the dielectric block, a short-circuit conductor (end-surface conductor) connecting the inner conductor and the outer conductor at the other end surface of the dielectric block, and one for connecting the inner conductor to an external circuit. A lead terminal or a coupling capacitor inserted into the resonance hole from the end face side and connected to the inner conductor.
In the case of forming a half-wavelength type dielectric resonator, the short-circuit conductor is omitted.

[0003]

The length of the dielectric resonator, that is, the length of the resonance hole, is a value obtained by dividing the speed of light Co by the product of 4 and the square root of the relative permittivity εr and the resonance frequency fo. . Therefore, whether to change the resonant frequency changes the length of the dielectric resonator, it is necessary to change the dielectric constant epsilon _r, it has been difficult to easily change the resonance frequency.
In addition, since the resonance frequency is related to the length of the dielectric resonator, there is a limit to miniaturization.

Therefore, an object of the present invention is to reduce the size when the resonance frequency is the same as the conventional one, and to reduce the resonance frequency when the size is the same as the conventional one. An object of the present invention is to provide a dielectric resonator capable of easily adjusting a resonance frequency.

[0005]

In order to achieve the above object, the present invention has first and second end faces facing each other and a side face between them, and the first end face and the second end face extend from the first end face. comprising a dielectric block co to reach the end surface of 2 Juana is formed, the inner conductors provided on the inner peripheral surface of the resonator holes and an outer conductor provided on a side surface of the dielectric block In the dielectric resonator, an outer conductor-free portion having a shape surrounded by the outer conductor is provided on the side surface, and is used for resonance frequency adjustment so as to project in a peninsula shape into the outer conductor-free portion. A conductor is provided, and the resonance frequency adjusting conductor is provided.
Extends parallel to the first and second end faces.
The present invention relates to a dielectric resonator characterized by being formed .

[0006]

When the position of the portion where the outer conductor is not formed is changed from the first end face of the dielectric block toward the second end face, it has been found that the resonance frequency fo changes as shown in FIG. Since the resonance frequency changes depending on the size and the position of the portion where the outer conductor is not formed, the resonance frequency is adjusted by selectively removing the adjustment conductor. The portion where the outer conductor is not formed has an action of changing the fundamental wave and the higher harmonic, and it is considered that the resonance frequency changes by this. Resonance frequency
The number adjustment conductor extends parallel to the first and second end faces.
Therefore, the selective removal of the conductor for adjusting the resonance frequency
When advanced from the end, the distance between the removed portion and the first end surface
Substantially no change in distance occurs. Therefore, the resonance frequency
The number varies mainly depending on the area of the removed portion. Follow
Change of the resonance frequency due to the removal of the resonance frequency adjustment conductor.
Of the resonance frequency can be estimated relatively accurately.
Adjustment becomes easy.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A quarter-wave coaxial dielectric resonator according to an embodiment of the present invention will be described below with reference to FIGS. This dielectric resonator has a length of about 8.3 m made of dielectric porcelain.
m, the length of each side is about 4.0 mm. The dielectric block 1 includes a first end face (open end face) 2, a second end face (short-circuit end face) 3 opposed thereto, and four side faces 4a, 4a,
b, 4c, 4d, and a circular resonance hole 5 formed from the first end face 2 to the second end face 3. An inner conductor 6 is provided on the inner peripheral surface of the resonance hole 5, and four side surfaces 4a are provided.
4d is provided with an outer conductor 7, and the second end face 3 is provided with an end face conductor (short-circuit conductor) 8 for connecting the inner conductor 6 and the outer conductor 7. The inner conductor 6, the outer conductor 7, and the end surface conductor 8 are conductor films formed by applying and baking or plating a conductive paste.

An outer conductor non-formed portion 9 surrounded by an outer conductor 7 is provided on the side surface 4a of the dielectric block 1. The width W of the outer conductor unformed portion 9 is about 1.0 mm, the length in the direction in which the resonance hole 5 extends is about 0.5 mm, and the distance L from the first end face 2 to the center of the outer conductor unformed portion 9 is It is about 5.0 mm. In the outer conductor non-formed portion 9, a resonance frequency adjusting conductor 10 continuous with the outer conductor 7 like a peninsula is arranged.
Lead terminal 1 for connecting dielectric resonator to external circuit
Numeral 0 is inserted into the resonance hole 5, comes into contact with the inner conductor 6, and is fixed by solder (not shown). In this embodiment, the circuit board 1
The outer conductor 7 is connected to the conductor layer 12 on the solder layer 1 by soldering (not shown), and the lead terminals 10 are soldered to the conductor layer 13 (not shown).
Connected by The contact position P1 of the lead terminal 10 closest to the first end face 2 with respect to the inner conductor 6 is approximately 2.3 mm from the position P0 of the first end face 2.

In this dielectric resonator, the resonance frequency before the adjustment conductor 10 is removed by polishing is the target frequency (886 MHz).
z). Therefore, while gradually removing the adjusting conductor 10 by polishing, the resonance frequency is measured. When the target frequency is reached, the adjusting conductor 10 is removed.
Stop polishing.

When the relationship between the size of the lateral width W of the outer conductor unformed portion 9 and the resonance frequency was examined, the results shown in FIG. 3 were obtained. Note that the distance L from the first end surface 2 to the center of the outer conductor non-formed portion 9 was maintained at 4.0 mm, the vertical width was maintained at 0.5 mm, and only the horizontal width W was changed. As can be seen from FIG. 3, the resonance frequency f0 can be reduced to about 2 by changing the width W.
Can be changed by 3 MHz. The resonance frequency f0 in the case where the portion 9 where the outer conductor was not formed was not provided was 900 MHz.

The width W of the outer conductor unformed portion 9 is 1.0 m.
When the change in the resonance frequency f0 when only the distance L from the first end face 2 was changed while maintaining the length m and the vertical width at 0.5 mm, the result shown in FIG. 4 was obtained. As is clear from this, in the region closer to the first end surface 2 than the position P1 on the side surface 4a corresponding to the position where the lead terminal 10 is in contact with the inner conductor 6, the resonance frequency f0 has the outer conductor unformed portion 9 Although it is slightly higher than the case where it is not provided, the resonance frequency f0 becomes lower in the region closer to the second end face 3 than the position P1.

As shown by the dotted line in FIG. 5, the adjusting conductor 10 was removed, and the change in the removed area and the frequency were examined.
The result shown in FIG. 6 was obtained. As is apparent from this result, the resonance frequency decreases as the removal area increases.

[0013]

[Modifications] The present invention is not limited to the above-described embodiment, and for example, the following modifications are possible. (1) In the embodiment, the outer conductor non-formed portion 9 is the exposed surface of the dielectric block 1, but another dielectric or insulator or the like may be attached here. When a dielectric material having a different relative permittivity is attached to the outer conductor non-formed portion 9, the resonance frequency can be adjusted. (2) In the embodiment, the outer conductor non-formed portion 9 is provided only on one side surface 4a.
A part corresponding to the outer conductor non-formed portion 9 can be provided in d. When mounting on the circuit board 1, the side surface 4
It is desirable to provide the outer conductor non-formed portion 9 in addition to c. (3) One electrode terminal of the coupling capacitor can be connected to the inner conductor 6 instead of the lead terminal 10. (4) The dielectric block 1 can be made cylindrical. (5) The end face conductor 8 can be omitted to provide a half-wavelength type dielectric resonator.

[0014]

As is apparent from the above, according to the present invention, by providing the portion where the outer conductor is not formed, the resonance frequency can be changed without changing the length of the resonance hole.
Furthermore, the desired resonance frequency can be obtained with high precision by gradually removing the adjusting conductor. Also, the resonance frequency
The adjusting conductor extends parallel to the first and second end faces.
Then, the amount of change in the resonance frequency by removing this is
Resonant frequency can be estimated relatively accurately and desired resonance frequency can be easily determined.
Can be obtained.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing a state in which a dielectric resonator according to an embodiment of the present invention is mounted on a circuit board.

FIG. 2 is a perspective view showing the dielectric resonator of FIG. 1 before a lead terminal is attached.

FIG. 3 is a diagram illustrating a relationship between a width of a portion where an outer conductor is not formed and a resonance frequency.

FIG. 4 is a diagram illustrating a relationship between a position of a portion where an outer conductor is not formed and a resonance frequency.

FIG. 5 is a plan view of a dielectric resonator.

FIG. 6 is a diagram showing the relationship between the removal area of the adjustment conductor and the amount of change in the resonance frequency.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Dielectric block 5 Resonance hole 6 Inner conductor 7 Outer conductor 9 Outer conductor unformed portion 10 Adjustment conductor

Claims (1)

(57) [Scope of request for utility model registration] A first end face facing the first end face and a side face between the first end face and the second end face;
Comprising of a dielectric block that is co-Juana is formed to reach the end surface, the inner conductors provided on the inner peripheral surface of the resonator hole, and a outer conductor provided on a side surface of the dielectric block In the dielectric resonator, an outer conductor-free portion in a shape surrounded by the outer conductor is provided on the side surface, and the outer conductor-free portion is formed so as to protrude into a peninsula shape into the outer conductor-free portion. A vibration frequency adjusting conductor is provided, and the resonance frequency adjusting conductor is provided on the first and second end faces.
A dielectric resonator formed so as to extend in parallel with the dielectric resonator.