JPS58188189A - Radio wave absorber - 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 The present invention ('f1 Radio wave absorber 1 for removing radio wave interference caused by construction of concrete, steel frames, etc.) In recent years, with the development and spread of televisions, radar, etc. 1. In order to prevent the anti-reflection of radio waves caused by structures, ships, flying bottles, etc. In this case, the radio wave absorber 5 is required to be useful.

A variety of fabrics have been developed as absorbers for these radio waves, such as ferrite sintered bodies, composites of ferrite layers and carbon black layers, ferrite-poor carbon black mixtures, and There is one polymer synthetic tree with a cutter, etc., and one radio wave absorber (・1'1'7
Either the absorber has radio wave absorption characteristics that are immediately η, or in order to widen the frequency band that provides the radio wave absorption characteristics, r1, absorber 0) thickness or extremely 1 drop. In addition, in the absorber made of thin Japanese cedar, the sufficient f frequency band #. For example, Figure 1 shows the radio wave absorption characteristics of a composite ferrite that utilizes magnetic loss. The corresponding 'Z゛Lv power frequency band J15 is extremely narrow) (accompanied by difficulties in this process).

The present invention is 7'1)-Ruma Micro'! g1. In the region, the wide frequency ′■ (in the ri Q;
Wave absorption characteristics a) It provides a good yet thin radio wave absorber.

Figure 2 shows the cross-sectional structure when a conventional ferrite radio wave absorber is used in a competition, and the conductive structure 1) is an old radio wave absorber 260. Then, as shown in Figure 3 of Radio Waves, absorbing layer 3 and metamorphic@4 are stacked in 21 il and used by pasting it on a structure.

Another feature of the present invention is that the absorbent layer 3 of the above two layers has 2 to 70% by weight of steel fibers dispersed therein.
1゛LF (in the microwave region, which is the object of the present invention)
, /',' 7) does not show good absorption characteristics in the frequency band, and the strength decreases significantly in the 3 fl 41 J h, making it difficult to manufacture large-area absorbers.Basics of absorbing layers 1 weight 7r 1O ~ 80 wt%, phenolic resin 5
~80 heavy needles should be used in an appropriate amount of yH based on the weight of the entire absorbent layer. -7□7-4 and 5% by weight 1'', below, the moldability and inscription properties are between 8 and 8, and at least 5% by weight must contain phenol, Jney 4-ru. If the amount is less than 10 * weight (1 city wave absorption'l) property is sufficient, it is fi. Phenolic resin young 11, (1 ferrite exceeds 80 weight h, moldability?壬-Luff fiber C cutting diameter 10~Ianμ, length''
As a result of c1~5t・1 □□□ elbow, a uniform composition f! :Production - Good results were obtained with Rohi.Characteristics (dah point/diameter ratio is ~1.), d is suitable.

Next, h41″, the metamorphic layer (O,) laminated on the absorption layer 3 (I)-H face / -1 and resin 40 to 100% by weight,
-No a light O~60-i'j! 'This is from the iH staff, but the fiber is not included. Absorb to the top.
3. The metamorphic layer 4 can be manufactured separately and then glued together later, or can be integrally molded at the same time.

%'tJ? As for the steel fiber used in this case, for example, ty
The application was filed in No. 170397, 1985, and the metal fibers have a uniform length and have a uniform length. Figure 4 shows an example of the characteristics of the uninvented radio wave absorber.
I) Therefore, it is obvious that the radio wave absorption characteristics are excellent in a wide frequency band when compared with the conventional example shown in FIG. 1.This will be explained next using an example.

Example ferrite powder SONG 658% by weight, phenolic resin powder 28%
Double Ichi, average diameter 50μ, length 26 cicadas, length deviation measured by image analyzer June. ? Uniformly mix 60% by weight of stonyl fibers (0.1%C) and heat at 160°C and 200w at pressure 50 and 90-4.
*Plate A was press-molded into a shape of 200 m x 0.9 m to form an absorbent layer. Prepare a plate that is to become a metamorphic layer made from this, 20 pieces of 6-piece ferrite, and 80 pieces of phenolic resin, and prepare a plate that is made in the same manner as the absorption layer plate. Glue with adhesive, 3.
Radio wave absorbers with dimensions of 20 (IX200) were produced in a 9 m warehouse.

As shown in Figure 4, the anti-elbow coefficient was measured at RGF-Tz to 13 GHz. Show 1.

[Brief explanation of the drawing]

Figure 111 (1) Absorption characteristic diagram of conventional radio wave absorber, Figure 2 (
FIG. 9 is a cross-sectional view of an example of use of a conventional single-layer radio wave absorber; FIG. 14 is a diagram showing an example of use of the present invention; and FIG. 1: Structure, 2: '4 wave absorber, 3: vL wave absorption and absorption, 4
゛Change of emotions 1. A, A': Radio waves. Figure 1 Circulation, JI number ((z#r) Figure 3 Figure 4 Circulation number (QHx)

Claims (2)

[Claims] (1) Fluorite 10-80% by weight, phenolic resin 5
Go 80 Heavy legs Chikabutsu fCru absorption layer and phenolic resin 40-100
The weight is CH, 7E → I1-0 to 60 times CH, which is a metamorphic shadow that is composed of 2 Seishu and is a radio wave absorption characterized by f [B]. (2) The IFi wave absorber according to claim 1, wherein each of the steel fibers has a diameter of 10 to 100 μm and a length of 1 to 5 μm.