JPS60257008A - Dielectric porcelain material for microwave - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a microwave dielectric ceramic material used for dielectric resonators and the like in applied equipment in the microwave field such as satellite receivers.

[Background technology and its problems]

In the microwave domain, the use of dielectric ceramics for dielectric resonators has been proposed and put to practical use, but with the recent advances in microwave technology, microwave equipment such as satellite receivers has become increasingly popular. The use of dielectric resonators in the field of technology continues to increase.

Conventionally, dielectric materials used for these dielectric resonators include BaO-TiO2-based porcelain, Ba0
-Porcelain in which a part of TiOz-based porcelain is replaced with other elements, or a combination of TiOz, whose dielectric constant changes with negative temperature, and a dielectric material whose permittivity changes with positive temperature, are generally used. However, all of these had practical problems, such as large dielectric loss and too large and large variations in the temperature coefficient (temperature stability) of the resonant frequency.

Therefore, in Japanese Patent Application No. 55-145001 (Japanese Unexamined Patent Publication No. 57-69607), the applicant proposed BaO- ' i 02 (3
, 9≦×≦4.1) 100 u)t
%, it was proposed to add and mix 1 to 26 ult% of ZnO. The dielectric ceramic in this prior application has the characteristics desired as a dielectric resonator used in the microwave field, that is, the relative dielectric constant ξr has a working frequency of IGHz.
It has a high dielectric constant of 30 to 40, which is suitable for ~20 GHz, and the temperature coefficient τtoppM7'c of the resonance frequency is +25
It has the advantage that the temperature coefficient value is small within the range of 0, and that the temperature coefficient value can be freely controlled around 0. However, the dielectric ceramic in this prior application still has some problems with respect to the dielectric loss tcLrLδ and the stability and reliability of the oscillation frequency, which is now severely required (
The dielectric loss tαle δ could not be sufficiently reduced.

[Purpose of the invention]

The present invention has been made in view of the above points, and its purpose is to reduce the temperature coefficient of the resonance frequency to -25〈τto
The object of the present invention is to provide a dielectric ceramic material for microwaves that can be controlled within the range of ppM/'C (+25 and centered around 0) and that can significantly reduce dielectric loss.

[Summary of the Invention] As a result of various experiments and studies, the present inventors found that the general formula BaTi
For 100 wt% of the composition expressed as 40G, 1
~26 wt% ZnO and 0.1-3.0 wt% Z
By mixing the present invention with rO2, we have discovered a dielectric ceramic material for microwave use that can achieve the above objectives, and the details will be clarified in the following examples.

[Embodiments of the invention]

The present inventors used TlO2 and BaCOs as raw materials for the main component BaTi 409, and the main component 100
With respect to wt%, ZrLO and ZrO! Dielectric ceramics were created by varying the amount of addition. When creating Tie!
The weight ratio of ZnO and BaC0a is fixed, and the weight ratio of ZnO and ZrOs to the main components is varied according to each composition, each of which is accurately weighed, and the materials of each composition are mixed with pure water using a centrifugal ball mill equipped with a resin ball. Thoroughly knead by wet mixing. After drying this mixture, it was calcined in the air at 1000°C for 5 hours, wet-pulverized in the centrifugal ball mill, thoroughly pulverized and sized, and then dried. /- to form a disk with a diameter of 7 m and a thickness of 51 g, and then in air for 10 hours, 11
Calcined at 70-1250'C. The dielectric porcelain thus obtained has a diameter of 5 mm.

A disk with a thickness of 2.8 chicks was cut to obtain sample pieces of each composition.

Each sample piece obtained by the above method was
i-Co Z organ (Q measurement method ICJ niche,
Relative permittivity ξr and dielectric loss tan at measurement frequency 13 GH, z
In addition to measuring a, -50"C to +6 in a constant temperature bath.
The temperature coefficient τ of the resonant frequency is determined by the above method in the range of 0°C.
toppM/''C was measured. Table 1 shows the results.

In addition, BaTi 40G (TlO2-61,8wt%
, B a COs -38,2wt%) 100 ur
For t%, ZruO is fixed at i i, o wt%,
The temperature coefficient r t when changing the amount of Zr0a added
appu/''(, Figure 1 shows the change in dielectric loss tan δ, when ZrOs is fixed at 1.9 wt% and the amount of ZnO added is varied with respect to 100 ult% of BaTi4O9. Figure 2 shows the change in the temperature coefficient τtoppM/'C. (The following is a margin) As is clear from Table 1 and Figure 1, ZrO2 is Q, l wt
% or less or more than 3.0wt%, tan δ is 3.0
The larger the value, the larger it will be, but this is 0.1 to 3. Within the range of Qwt%, tan δ is 3.0 or less, which is small enough to cause no practical problems, and especially in the range of 0.4 to 5 wt%, tan δ is
The a mil becomes significantly smaller than 2.6. Furthermore, as is clear from Table 1 and Figure 2, the weight ratio of ZrLO is 1
If it is less than 25 wt% or more than 25 wt%, the temperature coefficient τtoppM/"C of the resonance frequency becomes extremely large to an absolute value of about 25 or more, but this is 1.0 to 26.
Within the range of rt%, it falls within ±25, and the characteristic change shows linearity (if other materials are fixed),
The temperature coefficient can be freely controlled around O. In addition, the relative dielectric constant ξr of each sample piece is 3
The dielectric constant falls within the range of 3 to 37, and has a sufficiently high dielectric constant as a dielectric material for this type of microwave.

〔Effect of the invention〕

As described above, according to the present invention, it is possible to provide a microwave-use electric ceramic having a high dielectric constant, a small dielectric loss, and a temperature coefficient of a resonant frequency that can be controlled, and its industrial value is great.

[Brief explanation of drawings]

The drawings all show the changes in characteristics due to the dielectric ceramic according to the present invention, and Fig. 1 shows the dielectric loss δ and the temperature coefficient of resonance frequency τt o ppM/ when the ZrOg doping cap is changed.
FIG. 2 is a graph showing changes in the characteristics of the temperature coefficient when the amount of ZnO added is changed.

Claims (1)

[Claims] 100wt of composition represented by general formula BaTi 40g
% to shite, 1 to 26 wt% (1) ZnO and 0
．． 1 to 3. A dielectric ceramic material for microwave use, characterized in that it is made by adding and mixing Q wt% of Zr0z.