JPS6022446B2 - Materials for dielectric resonators - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to materials for dielectric resonators, particularly Ti02, Pr6
0,. , &0, Nd203, and POO.

The purpose of the present invention is to have a large dielectric constant (r),
When used as a dielectric resonator in the microwave frequency band, the no-load Q is large and the temperature coefficient of the resonant frequency (D)
The object of the present invention is to provide an excellent ceramic material for a dielectric resonator, which has a small value of 7f and whose 7f can be varied over a wide range by changing the composition. In the microwave frequency range, dielectrics have traditionally been used for impedance matching in microwave circuits and dielectric resonators.

In recent years, with advances in the technology of integrating microwave circuits, dielectric resonators made of dielectric ceramics with high permittivity and low loss have been used to stabilize the frequency of oscillators. Progress is being made actively to make this possible. Conventionally, these dielectric materials have been combined with porcelain of the porcelain-Ti02 system, porcelain in which part of it has been replaced with other elements, and porcelain with a negative temperature coefficient of yield. is often used. However, this has many practical problems because the dielectric constant is small and the no-load Q is small. The inventors conducted various studies on materials that do not have these drawbacks, and found that 34.5 to 8% by weight of Ti02 and 9 to 63% by weight
Weight % Pr60,. and 2.5-23.5% by weight of Heron○
and Pr60, . Less than 95% by weight of
It has been discovered that a ceramic material prepared by adding Pb○ in an amount not exceeding 10 parts by weight (not including 0) to 100 parts by weight of a ceramic composition substituted with 3 can be an excellent material for dielectric resonators. .

Hereinafter, details of the present invention will be explained based on Examples.

Starting materials include Tj02, Pr60. ,,Nd203,B
Using powdered raw materials of aC03 and POO, the required amount was weighed according to each composition, and pure water was placed together with the raw materials in a pole mill equipped with an agate stone and lined with rubber, and wet-mixed for 2 hours.

After drying the mixture, it was molded into a disc with a diameter of 5 mm and a thickness of 3 m at a pressure of 400 k9/kg, and calcined in air at 90,000 °C for 2 hours. As a result, carbonate roots were decomposed as CO2 gas. Thereafter, the calcined product was placed in the ball mill with pure water and wet-pulverized for two hours. After drying the bound pulverized material, add 3% by weight polyvinyl alcohol solution and sieve it through a 30 mesh sieve, and apply a pressure of 800 k9/2 to form a powder with a diameter of 2 mm and a thickness of about 8~12 mm.
Rib disks were molded and fired in air at a temperature within the range of 1200-150°C for 2 hours to obtain porcelain having the composition shown in the table below. The obtained ceramic was used as a microwave dielectric resonator, and the resonance frequency and no-load Q were measured. The dielectric constant was calculated from the resonance frequency and the size of the ceramic. The temperature dependence of the resonance frequency was measured in the range of -30C to 70QO, and 7r was determined. The resonant frequency was 2-30Hz.
In this table, sample numbers 1 to 24 indicate examples of the present invention, and sample numbers 25, 27, 29, 31, 3
2, 33, 34 show the case where Pb0 is not added, 26
, 28, and 30 indicate cases in which POO was present in an amount of 1% by weight or more.

As is clear from the above table, the yield ceramic of the present invention has a large no-load Q and a large power yield ratio in the microwave frequency band.

Furthermore, 7f can be varied over a wide range depending on the composition. Therefore, it is useful for stabilizing the temperature dependence of oscillators and resonators, and it is possible to create small, high-performance, and inexpensive microwave circuits. In the main component, if Ti02 is less than 34.5% by weight, or if the
is more than 23.5% by weight, Q is as low as 100 or less.

In addition, if the combined amount of praseodymium oxide and neodymium oxide is more than 6% by weight, or if the barium oxide is more than 2% by weight.
When the amount is less than 5% by weight, the dielectric constant is 4. Q is low when the combination of praseodymium oxide and neodymium oxide is 9% by weight. Further, if TiQ is 82% by weight or more, 7f becomes large, so these are excluded from the scope of the present invention. Regarding the additive P, if the amount added exceeds 10% by weight, the Q decreases significantly and the
The value of has become large again, and since there is no effect of increasing Q at 0% by weight, it is excluded from the scope of the present invention.

As is clear from the above description, the porcelain material of the present invention is
It has excellent properties as a ceramic for microwave dielectric resonators, and is of great industrial value.

Claims (1)

[Claims] 1 34.5-82% by weight titanium oxide (TiO_2)
and 9-63% by weight of praseodymium oxide (Pr_6O_
1_1) and 2.5-23.5% by weight of barium oxide (B
aO), and a part of the praseodymium oxide is replaced with neodymium oxide (Nd_2O_3),
Add 10 parts by weight of lead oxide (PbO) to 100 parts by weight of a ceramic composition whose substitution amount is 95% by weight or less of praseodymium oxide.
A material for a dielectric resonator, which contains an amount not exceeding part by weight (not including O).