JP2000022414A - Frequency setting method of dielectric resonator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a dielectric resonator and its frequency setting method where the setting of the frequency is changed without changing an internal structure and its shape and without much reducing the impedance. SOLUTION: A center conductor 1 is built in a dielectric body 2 by a lamination structure and a laminator is formed by sintering it. A hot terminal electrode 5 is formed to one end of the laminator and a ground terminal electrode 6 is formed to the other end. Both ends of the center conductor 1 connect to the hot terminal electrode and the ground terminal electrode 6. The center conductor 1 opposes to the ground electrodes 3, 4 provided on the laminator via the dielectric layer. A dielectric constant of a material 2a toward the hot terminal electrode 5 of the dielectric body 2 is selected to be relatively higher than that of a material 2b toward the ground terminal electrode 6. The resonance frequency is set by changing a ratio of the width of the high dielectric constant material 2a to that of the low dielectric constant material 2b in the lengthwise direction of the center conductor.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for setting the frequency of a dielectric resonator comprising a laminated body in which a center conductor is built in a dielectric body in a laminated structure and sintered.

[0002]

2. Description of the Related Art For example, in a dielectric resonator incorporated in a voltage controlled oscillator used for mobile communication such as a mobile phone, the resonance frequency of the dielectric resonator must be set in accordance with the difference in the frequency band used. Must. In the case of setting the resonance frequency of such a dielectric resonator in accordance with the application, conventionally, the internal structure and shape had to be changed in order to change the inductance of the center conductor.
For example, Japanese Unexamined Utility Model Publication No. Hei 5-8805 discloses an example in which conductors are provided on the upper and lower surfaces of a dielectric to increase the line length of the central conductor, and the conductors are connected inside the dielectric to form a central conductor. It is shown. Also, in order to reduce the size of the dielectric resonator, the wavelength is shortened by using a high dielectric constant material.

[0003]

However, as described above, in order to change the line length in order to change the inductance, it is necessary to change the internal structure and shape of the center conductor. There was a problem that it was not easy. Further, in the case where the wavelength is shortened by using a material having a high dielectric constant as the dielectric material, the impedance of the dielectric resonator decreases, which causes a decrease in Q.

The present invention has been made in view of the above problems, and provides a frequency setting method of a dielectric resonator that can change the frequency setting without changing the internal structure and shape and without significantly lowering the impedance. With the goal.

[0005]

A frequency setting method for a dielectric resonator according to the present invention comprises a laminated body in which a center conductor is built in a dielectric material in a laminated structure and sintered, and a hot terminal is connected to one end of the laminated body. The electrode has a ground terminal electrode at the other end, and the center conductor has both ends connected to the hot terminal electrode and the ground terminal electrode, and is opposed to a ground electrode provided on the laminate via a dielectric layer. A method of setting the frequency of the dielectric resonator, comprising a material having a relatively high dielectric constant sandwiched above and below the center conductor, and further having a low dielectric constant sandwiched between these high dielectric materials. A resonance frequency is set by disposing a material and changing a thickness ratio between the high dielectric constant material and the low dielectric material.

In the present invention, as the dielectric, a material having a relatively high dielectric constant is used on the center conductor side, and a material having a low dielectric constant is used on the ground electrode side. By changing the ratio of the thickness of the material, the resonance frequency can be changed without changing the structure of the center conductor or the entire shape.

[0007]

FIG. 1A is a perspective view showing an embodiment of a dielectric resonator according to the present invention, and FIG.
(C) is EE sectional drawing and FF sectional drawing of FIG. 1 (A), respectively. In these figures, reference numeral 1 denotes a central conductor embedded in a dielectric 2 in a laminated structure, and reference numerals 3 and 4 denote central conductors 1.
Ground electrodes 5, 5 and 6 formed on the lower surface and the upper surface of the laminated body composed of the central conductor 1 and the dielectric 2 are a hot terminal electrode and a ground terminal electrode formed at both ends in the longitudinal direction of the central conductor 1, respectively. A four-wavelength triplate resonator is formed.

In the dielectric 2, a portion 2a sandwiching the center conductor 1 vertically is made of a material having a relatively high dielectric constant, and a portion 2b on the ground electrode 3, 4 side sandwiching the high dielectric material 2a is relatively formed. It is made of a material having a low dielectric constant. Specifically, a Ba-Ti-Nd-based ceramic as a high dielectric constant material has a dielectric constant?
A low-permittivity material 2b having a dielectric constant of ε = 4 to 11 was used as the low-permittivity material 2b. And the laminated body was manufactured using the screen printing method.

This manufacturing process is as follows. First, a silver paste that is to be the ground electrode 3 for the base film is printed on the base film surface to be manufactured in multiple pieces,
Dried. Thereafter, printing and drying of a paste containing ceramics, which is the low dielectric constant material 2b, were repeated until the paste reached a predetermined thickness. Next, printing and drying of a paste containing ceramics as the high dielectric constant material 2a were repeated until a predetermined thickness was obtained. After that, printing of silver paste to become the center conductor 1,
Drying was performed. Thereafter, printing and drying of a paste containing ceramics, which is a high dielectric constant material 2a above the center conductor 1, were repeated the same number of times as the previous time. Then, the low dielectric constant material 2b
Printing and drying of the paste containing ceramics was repeated. Then, a silver paste as the ground electrode 4 on the upper surface was printed and dried. In this printing, for the center conductor 1 and the ground electrodes 3 and 4, for the number of chips to be manufactured,
The pattern was arranged vertically and horizontally. By cutting and firing the laminated body laminated as described above, a laminated body corresponding to each chip was produced. Then, a hot terminal electrode 5 and a ground terminal electrode 6 were formed on both ends of the laminate by baking and plating.

In the manufactured dielectric resonator, the length L1 in the longitudinal direction of the center conductor 1 of the dielectric 2 shown in FIG.
mm, and the length L2 of the ground electrodes 3 and 4 was 2.8 mm. Also, a high dielectric constant material 2a sandwiching the central conductor 1 from the central conductor 1
H1 of the upper and lower portions of the substrate and the thickness H of the low dielectric constant material 2b
2 was changed as in the examples of FIGS. 1, 2A and 2B. The width W1 of the chip shown in FIG.
mm, and the width W2 of the center conductor 1 was 0.4 mm.

FIG. 2 (C) shows the dielectric constant ε of the high dielectric constant material 2a = 80, the dielectric constant ε = 7 of the low dielectric constant material 2b, and the thickness H1 of the high dielectric constant material 2a and the low dielectric constant material 2b. , H2
FIG. 9 is a characteristic diagram showing a result of measuring a change in resonance frequency without substantially changing the thickness of the entire dielectric 2 while changing the resonance frequency. F1 in FIG. 2C is the resonance frequency when H1 = H2 = 400 μm (in the cases of FIGS. 1A to 1C),
f1 = 3.3 GHz. F2 is H1 = 50
0 μm, H2 = 250 μm (FIG. 2B)
And f2 = 2.8 GHz. F3 is the resonance frequency when H1 = 250 μm and H2 = 550 μm (FIG. 2A), and f3 = 3.
It was 9 GHz.

As described above, by changing the ratio of the thickness of the central conductor 1a without changing the overall thickness of the high dielectric constant material 2a and the low dielectric constant material 2b and the structure of the central conductor 1,
, And the capacitance between the ground electrodes 3 and 4 can be changed to change the resonance frequency.

In practicing the present invention, a structure in which a ground electrode is provided also on the side surface of the laminate may be employed, or a structure in which the ground electrodes 3, 4 and the ground electrode on the side surface are covered with a dielectric layer and protected. Good. The hot terminal electrode 5 may not be provided on the entire end face, but may have a width enough to cover the exposed portion of the central conductor 1.

[0014]

According to the present invention, as the dielectric having the built-in center conductor, a material having a relatively high dielectric constant is used on the side of the center conductor, and a material having a low dielectric constant is used on the side of the ground electrode. Since the resonance frequency is changed by changing the ratio of the thickness of the material to the low dielectric constant material, the resonance frequency can be changed without changing the shape of the entire laminate and the structure of the center conductor. For this reason, it is easy to respond to the frequency change.
Further, by using a low dielectric constant material for the dielectric on the ground electrode side, it is possible to avoid a significant decrease in impedance and a decrease in Q.

[Brief description of the drawings]

FIG. 1A is a perspective view showing an embodiment of a dielectric resonator according to the present invention, and FIGS. 1B and 1C are EE sectional view and FF sectional view of FIG. is there.

FIGS. 2A and 2B are cross-sectional views showing another embodiment of a dielectric resonator according to the present invention, and FIG. 2C is a diagram showing resonance with respect to a change in thickness of a high dielectric constant material and a low dielectric constant material. FIG. 4 is a frequency characteristic diagram showing a change in frequency.

[Explanation of symbols]

1: center conductor, 2: dielectric, 2a: high dielectric constant material, 2
b: low dielectric constant material, 3, 4: ground electrode, 5: hot terminal electrode, 6: ground terminal electrode

Claims (1)

[Claims] 1. A laminated body in which a center conductor is embedded in a dielectric body in a laminated structure and sintered, wherein the laminated body has a hot terminal electrode at one end and a ground terminal electrode at the other end. A method of setting the frequency of a dielectric resonator having both ends connected to the hot terminal electrode and the ground terminal electrode and facing a ground electrode provided on the laminate via a dielectric layer, It is composed of a material having a relatively high dielectric constant so as to be sandwiched above and below the conductor, and a low dielectric material is arranged so as to sandwich these high dielectric materials. A frequency setting method for a dielectric resonator, wherein a resonance frequency is set by changing a thickness ratio.