JPS5935486B2 - Porcelain materials for dielectric resonators - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to dielectric resonator materials, particularly TiO2, pr6o1
1, relates to a ceramic material for dielectric resonators composed of Nd2oS and BaO components.

Below, titanium oxide, praseodymium oxide, neodymium oxide, and barium oxide are respectively TiO2, Pr6O,...
It is expressed as Nd203, BaO. The purpose of the present invention is to have a large dielectric constant (ε0), a large unloaded Q when used as a dielectric resonator in the microwave frequency band, a small temperature coefficient (τf) of the resonant frequency, and change the composition. In particular, the present invention aims to provide an excellent ceramic material for dielectric resonators that can vary τf over a wide range.

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

In recent years, as technology for integrating microwave circuits in particular has progressed, high dielectric constants,
Miniaturization by using dielectric resonators using dielectric ceramics with low loss is actively being promoted. Conventionally, these dielectric materials include BaO-Ti0! In many cases, a combination of porcelain based ceramics, porcelain in which a part of porcelain is replaced with other elements, and dielectric porcelain whose temperature coefficient of permittivity is negative is used. However, these have a small dielectric constant, a small force, and a small no-load Q, which causes many practical problems. As a result of the applicant's investigation of materials that do not have these drawbacks, TiQ! of 34.5-82% by weight! and 9-6
A ceramic material for a dielectric resonator which is excellent in a ceramic material consisting of 3% by weight of pr6ol1 and 2.5 to 23.5% by weight of BaO, in which 100% by weight of the 6o11 portion is replaced by p up to 95% by weight. I found out that. The present invention will be explained below based on Examples.

Starting materials include TiO2, pr6o11, Nd2o3, B
A CO3 powder raw material was weighed according to each composition, and put into a ball mill equipped with an agate stone and lined with rubber with pure water, and wet-mixed overnight. After drying the mixture, it was formed into a cylindrical shape at a pressure of 400 kgr/(-771) and calcined in air at 900°C for 2 hours.Then, the calcined product was placed in the ball mill with pure water and wet-pulverized for one day. After drying the obtained pulverized product, a 3% by weight polyvinyl alcohol solution was added, and then 30% by weight of polyvinyl alcohol solution was added.
Granulate with a mesh sieve, 8001<9/(1-J model)
Formed into a cylindrical shape with a diameter of 207 nm and a thickness of approximately 8 to 12 mm at a pressure of Vf, and heated at 12,000 C to 1,500 C in air.
It was fired for 2 hours at a temperature of 0.degree. C. 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 -3°C to 70°C, and τf was determined. The resonant frequency was 2-3 GHz. As is clear from the table, the dielectric ceramic of the present invention has a large no-load Q and a large dielectric constant in the microwave frequency band.

Furthermore, τf 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 makes it possible to create small-sized, high-performance, and inexpensive microwave circuits. TiO2 is 3
In cases where BaO is less than 4.5% by weight, or when BaO is less than 23.5% by weight,
%, Q is as low as 100 or less.

In cases where the combined amount of praseodymium oxide and neodymium oxide is more than 23.5% by weight, or when barium oxide is more than 2.5% by weight,
If it is less than % by weight, the dielectric constant is small. If the combined amount of praseodymium oxide and neodymium oxide is less than 9.5% by weight, Q is low ~ All the results of the working materials shown in the table were obtained using reagent special grade raw materials, but the inventors Industrial raw materials containing about 5% by weight of lanthanum oxide, samarium oxide, and cerium oxide were used as raw materials for braceodymium and neodymium oxide, but it was confirmed that there were no practical problems in terms of characteristics.

In addition, in producing the porcelain material of the present invention, even if each constituent component is used alone as a starting material, or if a part of the constituent components is mixed in advance, essentially The result remains the same. What enhances the industrial value of the present invention is that a mixture of praseodymium oxide and neodymium oxide can be obtained at low cost as a form close to that of natural products.

As described above, the porcelain material according to the present invention has very excellent characteristics as a porcelain for microwave dielectric resonators.
It has great industrial utility value.

Claims (1)

[Claims] 1 34.5-82% by weight titanium oxide, 9-62% by weight praseodymium oxide, 2.5-23.5% by weight
In porcelain materials consisting of barium oxide of
A ceramic material for a dielectric resonator characterized by substitution of up to 5% by weight.