JPS5879302A - Resistive terminator - Google Patents

Abstract

PURPOSE:To obtain a resistive terminator having a great reflection loss and excellent heat resistance, by using a sintered body adding bismuth oxide to cobalt. zinc ferrite. CONSTITUTION:Cobalt.zinc ferrite consisting of cobalt oxide, oxide iron oxide and zinc generally has a great magnetic loss, but many holes and is subject to water absorption and in using the material as a resistive terminator, the characteristics have a large dispersion depending on the adsorbed water content. In adding a little of bismuth oxide to this ferrite, however, the ferrite can very deusely be sintered, allowing to offer a high heat resistance and reflection loss to a resistive terminator using this ferrite. The characteristics of examples of execution of this invention are listed in table.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a non-reflection terminator used in microwave and #LWI.

In microwave and millimeter wave circuits, some reflected electromagnetic waves may interfere with the incident waves, resulting in standing waves.

In order to eliminate these standing wave tubes, microwave circuit devices usually use a non-reflection terminator in front of the shorting plate to completely absorb the incident electromagnetic waves.For low-power devices, a resistive film or the like is used. Alternatively, a non-reflective terminator, which has the same insulating properties and strength, is made by combining iron powder with styrene resin or epoxy resin.

However, these non-reflective terminators (Fi) convert the absorbed electromagnetic waves into heat. The resin in the container deteriorates due to chemical decomposition.For example, if a microwave with a power of 15W or more is applied, the temperature reaches 1200°C or more, so the above-mentioned non-reflection terminator cannot be used in many cases. Therefore, an excellent non-reflection terminator that is heat resistant and has large reflection loss is the best choice! SUMMARY OF THE INVENTION An object of the present invention is to provide a non-reflective terminator that has excellent heat resistance and large reflection loss.

That is, the present invention is a non-reflective terminator made of a sintered body of cobalt-zinc ferrite made of cobalt oxide, zinc oxide, and iron oxide, with the addition of an oxidized bissmith tube.

Oxide magnetic materials and ferrite are generally used widely as component materials for coils, transformers, etc., but they are all required to have low loss. Furthermore, in the microwave band, yttricum/iron-based garnet, manganese magnesium 7-elite, etc. are used as non-reciprocal element materials, but these are also required to have low loss. However, on the contrary, a material with high loss is desired for a non-reflection terminator. The material properties required for a non-reflection terminator include large dielectric loss and large magnetic wholesale loss, and the non-reflection terminator as a device is required to have characteristics such as large reflection loss.

Cobalt 7elite is a common manganese ferrite among the camphorite 7elites. It is difficult to sinter, and only a sintered body with many pores can be obtained.
Such a sintered body with many pores easily absorbs water, and when it is used as a non-reflection terminator, the characteristics will vary greatly depending on the amount of water deposited. and replace
Furthermore, we found that adding bismuth oxide allows for dense sintering, and that a large reflection loss can be obtained when all non-reflection terminators are manufactured using this 〇 The following is an explanation based on an example ◎ Example-1 Cobalt oxide, iron oxide, zinc oxide pipe jllll&.

After weighing according to the component ratio shown in Table 2, they were mixed in a ball mill, pre-calcined at SOO℃, and after mixing with a binder, one IIttIJ body with a size of 27 cod horns x 7 cm was created. The results of firing the body tube at 1250℃ for 5 hours are shown in Table 1s1, and the results of firing at 1300℃ for 5 hours are shown in Table 2.In addition, in the constant characteristic method, short-circuit WRJ-611 at the end of the measurement circuit. A waveguide was connected, a resistor was set in the center of the tube wall, and the oscillator was swept at a frequency of 5.9 to 6.4 GHz. The water absorption rate was determined by boiling the sample in water for 1 hour and drying it for a specified time. It was determined by comparing 0-layer lids.

No. ill! ! As shown in Table 11 and Table 2, the reflection loss of the non-reflection terminator made using cobalt/zinc 7 & light is the same as that of other 7.
Compared to the case where wing lights were used, it was larger by 9&9. However, because the sintering conditions were not dense under the above firing conditions, the medium water content was large and the variation in properties was noticeable.0 Tables 1 and 2 The insulation resistance of the sample shown in is 8810' from 3×1♂Ω country.
The insulation resistance of the sample LOF@lOa-rich composition is small.Next, bismuth oxide was added to d% of the sample of the composition shown in Table 1 under the above conditions. A sample was made using
It is shown in Table 3.

As shown in Table 3, using a sintered tube made of cobalt-zinc 7E2ite with bismuth oxide added results in a non-reflective termination with excellent reflection loss characteristics and a lower water absorption rate than the values in Table 1, %, and Table 2. A vessel is obtained. It is also possible to add other additives to promote sintering.

[Brief explanation of the drawing]

The shape of the non-reflection terminator used in the measurements of the present invention is shown. Figure 1 7

Claims (1)

[Claims] A non-reflective terminator characterized in that it is made of a sintered body made of cobalt oxide, iron oxide, zinc oxide, and vinylite added with binumuth oxide.