JPS5949649B2 - Materials for dielectric resonators - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides materials for dielectric resonators, particularly BaO, ZnO, N
This relates to dielectric resonator materials composed of b2O5, CaO, and ZrO2 components, and the unloaded Q of the element body is
and the dielectric constant ε is large, and the temperature stability of the resonance frequency γf
The purpose of this invention is to provide a material that can constitute a microwave dielectric resonator with excellent properties.

Conventionally, in the microwave region, dielectric materials have been applied to impedance matching of microwave circuits, dielectric resonators, and the like.

In recent years, especially as the integration technology of microwave circuits has progressed, there has been an active effort to use dielectric ceramics with high dielectric constant, low loss, and low cost to stabilize the frequency of oscillators and to miniaturize them. progress is being made. Conventionally, these dielectric materials include BaO-TiO2-based porcelain, porcelain in which part of it is replaced with other elements, and TiO2, which has a negative dielectric constant that changes with temperature, and TiO2, which has a positive dielectric constant that changes with temperature. A combination of dielectric ceramic and dielectric ceramic is often used. but,
These have many practical problems, such as large dielectric loss, large variations in temperature change in dielectric constant, and too high stability of resonance frequency.

As a result of various studies conducted by the applicant regarding materials that do not have these drawbacks, the general formula xBa0-yZn0・ZNb2
In the composition represented by O5, 0.5≦X≦0.75
, 0.1≦y≦0.3, 0.1≦z≦0.3 (where x
+y+z=1) found that porcelain with a composition within the range of
1-110274).

However, the temperature stability γf of the resonant frequency is quite large, and research has been carried out to improve this stability. The present invention is based on that result. The dielectric resonator material according to the present invention includes BaO, Zn
By further adding CaO and ZrO2 to O and Nb2O5, it was possible to improve the temperature stability γf of the resonant frequency without reducing the no-load Q (Qu) and the dielectric constant ε. be.

Its characteristics are (11) (y, BaO-yZ
In the composition formula n0・ZNb205)+WCa0−ZrO2, 0.5≦X≦0.75, 0.1≦y≦0.3
, 0.1≦z≦0.3, x+y+z=1, 0<w≦0.
It is characterized by having a composition within the range of 9. Hereinafter, the present invention will be explained based on Examples. First, BaC
O3, CaCO3, ZNO, Nb2O5 and ZrO2
The starting materials were weighed according to each composition and wet-mixed with pure water in a ball mill equipped with an agate ball and lined with rubber.

This mixture was dried and then placed in air for 1200 min.
After calcining at °C for 5 hours, it was wet-pulverized in the ball mill. After taking out the crushed slurry from the ball mill and drying it, it was formed into a disk with a diameter of 256 at a pressure of 700 kg/Cwi, which was then fired in air at a temperature within the range of 1460 to 136 d'C for 2 hours. Porcelain having the composition shown in the table was obtained. Then, a disk-shaped porcelain sample with dimensions of 5 mm in diameter and 2 mm in thickness was cut out from each piece of porcelain, and used in a dielectric resonator for microwaves, and the resonant frequency was measured by the Trutub method. This resonant frequency (approximately 11 GHz)
The dielectric constant ε was measured from the and the diameter, and the no-load Q (Qu) was measured using the band reflection method.

The temperature stability γf of the resonance frequency was determined by placing each sample in a temperature bath and measuring the change in trap frequency as the temperature changed from -30°C to +700C. The results are shown in the table below. As is clear from the table, the dielectric ceramic material of the present invention has a large no-load Q, a relatively large dielectric constant, and is excellent in resonance frequency and temperature stability in the microwave region. I understand that there is something.

Samples 6, 7, and 8 with compositions outside the scope of the present invention did not sinter well into porcelain, and did not have sufficient mechanical strength to be used as a dielectric resonator. In this case, the no-load Q is small and the temperature change in the resonant frequency is large, so it is excluded from the scope of the present invention. Furthermore, it was confirmed that the porcelain according to the present invention has a small dielectric loss even in the low frequency range and a small temperature change in the dielectric constant, so it is an excellent material for ceramic capacitors.

Claims (1)

[Claims] 1 General formula (1-w) (xBaO・yZnO・zNb_
In the composition represented by 2O_5)+wCaO・ZrO_2, 0.5≦X≦0.75, 0.1≦y≦0.3,
0.1≦z≦0.3, x+y+z=1,0<w≦0.9
A dielectric resonator material characterized by having a composition within the range of .