CN204125790U - Wave frequency selects logical textiles thoroughly - Google Patents

Abstract

The utility model discloses an electromagnetic wave frequency selective transparent textile. The textile fabric includes a base layer and at least one periodic conductive pattern layer arranged on the base layer, and the base layer is a flexible fabric layer. The utility model utilizes the reasonable combination of the textile forming processing technology and the local metallization processing technology to design the frequency selective transparent textile, the band stop or band pass frequency can be designed, and has the characteristics of flexibility, flexibility and light weight. It can be applied to high-performance anti-radiation clothing, battlefield command tents and other products, and can adopt double-layer or multi-layer structure to strengthen the band-pass or band-stop function.

Description

Electromagnetic Frequency Selective Transparent Textiles

technical field

The utility model relates to a class of electromagnetic wave frequency selective transparent textiles. the

Background technique

The frequency selective surface is a spatial filter formed by a two-dimensional periodic array structure, which realizes band-pass filtering or band-stop filtering for electromagnetic waves. The formation structure of the frequency selective surface is divided into two types: through-hole type (slots of the same shape and size are periodically opened on the metal plate) and patch type (metal units of the same shape and size are periodically attached to the surface of the medium). The structural form shows obvious band-pass filtering characteristics and band-stop filtering characteristics respectively, and has important applications in many fields such as communication, antenna, and radar. the

Regarding frequency selective surfaces, there are many studies on basic theory and simulation calculations, as well as the design and characterization of frequency selective surfaces. However, the research on processing methods is relatively lacking, and the existing methods are more suitable for materials with relatively high rigidity. higher. For example, Chinese patent application 01010169471.7 discloses a dual-band array antenna based on a frequency-selective surface resonant unit, which can be applied to navigation and positioning, satellite antennas, and other applications that are sensitive to antenna profile height and quality; Chinese patent application 201110052236.6 designed a A stealth material compatible with radar and infrared, the stealth material is mainly composed of a radar absorbing structure layer (glass fiber reinforced FRP composite material) and an infrared stealth function layer (capacitive frequency selective surface), which is prepared by printing PCB technology The required frequency selection surface; Chinese patent application 201110443884.4 discloses a low-frequency frequency selection surface with a small unit size. By designing the conductive sheets in the upper and lower conductive layers of the PCB, the surface-surface coupling between the conductive sheets forms a larger Distributed capacitance significantly reduces the resonance frequency. From the analysis of existing patents, designers have adopted a variety of technologies to develop new frequency selective surfaces, especially composite structures, but they are limited to rigid materials, while ignoring the convenience and superiority of flexible fabrics to achieve frequency selective surface characteristics. the

For the research on the electromagnetic properties of textile materials, most of them focus on the aspects of conductivity, dielectric, antistatic, electromagnetic shielding, etc., while less research is done on their selective permeability to electromagnetic waves. As far as processing technology is concerned, designers often coat textiles or process fibers with electromagnetic shielding functions into fabrics to achieve the purpose of shielding electromagnetic waves as a whole, but they have not carried out research on how to achieve selective transparency of electromagnetic waves. Such as Chinese patent application CN200910054882.9 utilizes the method for electroless silver plating to form a layer of silver on the surface of polyester fabric, thereby endowing the fabric with electromagnetic shielding performance; Chinese patent application CN200910048743.5 utilizes the method for chemical copper plating to form a layer of copper on the surface of polyester fabric, Thereby endowing the fabric with electromagnetic shielding performance; Chinese patent 200810204134.X utilizes permalloy and clothing yarn to interweave fabrics to achieve electromagnetic shielding; US patent US19970943957 silver-plates nylon and other chemical fiber filaments to make conductive filament yarns, and then uses knitting The structure is woven into a highly conductive radiation-resistant knitted fabric. It is not difficult to find that the above-mentioned existing technologies all use certain processing methods to form an overall metal shielding structure, there is no periodic conductive pattern, and the electromagnetic wave transparency characteristics of band-pass or band-stop cannot be realized. the

Utility model content

The purpose of the utility model is to provide an electromagnetic wave frequency selective transparent textile, which overcomes the limitation that the existing electromagnetic functional textile lacks frequency selective transparent products. the

The electromagnetic frequency selective transparent textile provided by the utility model includes a base layer and at least one periodic conductive pattern layer arranged on the base layer;

The above-mentioned electromagnetic wave frequency selects transparent textiles, and the base layer is a flexible fabric layer;

The flexible fabric is made of a non-conductive textile material through pure spinning of a single fiber or a blend of multiple fibers;

The non-conductive textile material is cotton, hemp, wool, silk, polyester, polytrimethylene terephthalate fiber, polybutylene terephthalate fiber, nylon, acrylic fiber, ultra-high molecular weight polyethylene fiber, polypropylene fiber , vinylon, glass fiber, aramid fiber, sulfone fiber, viscose fiber, acetate fiber and cupro ammonia fiber at least one. the

The periodic conductive pattern layer is formed by repeated arrangements of conductive unit patterns in local areas. the

The above-mentioned electromagnetic wave frequency selects transparent textiles, and the unit pattern is any one of the following 1)-4):

1) Centrally connected figure, said centrally connected figure is a Jerusalem cross unit;

2) Ring unit graphics, the ring unit graphics are circular rings, square rings or hexagonal rings, etc.;

3) Solid unit graphics, the solid unit graphics are rectangles, circles or polygons, etc.;

4) A combination of unit graphics in 1)-3). the

The conductive unit pattern in the local area is composed of a conductive part and a non-conductive part, and the conductive part and the non-conductive part can be interchanged. For example, the unit pattern of the outer square and the inner circle can be such that the inner circular part is conductive and the rest of the outer part is non-conductive; it can also be interchanged so that the inner circular part is non-conductive and the rest of the outer part is conductive. The frequency selective surface formed by repeated stacking of the former is a patch type, and the frequency selective surface formed by repeated stacking of the latter is a through-hole type. the

The electromagnetic wave frequency selective transparent textile of the utility model can be prepared by the following method: through local metallization processing, repeated piles of the unit pattern are formed at the local position of the base layer to form a frequency selective surface, thereby having an electromagnetic wave band-pass or band-pass resistance function. The local metallization processing method can be computer embroidery, conductive paint printing, laser etching of metal foil, cloth bronzing, local electroplating, local electroless plating or local magnetron sputtering and other preparation methods. the

The utility model utilizes the reasonable combination of the textile forming processing technology and the local metallization processing technology to design the frequency selective transparent textile, the band-resistance or band-pass frequency can be designed, and has the characteristics of flexibility, flexibility and light weight. It can be applied to high-performance anti-radiation clothing, battlefield command tents and other products, and can adopt double-layer or multi-layer structure to strengthen the band-pass or band-stop function. the

Description of drawings

Fig. 1 (a) is the schematic diagram of the ring patch type frequency selection see-through textile in the utility model embodiment 1;

Fig. 1 (b) is the schematic diagram of the ring through-hole type frequency selection see-through textile in the utility model embodiment 1;

Fig. 1 (c) is the filter performance curve of two kinds of frequency selection see-through textiles in the utility model embodiment 1;

Fig. 2 (a) is the schematic diagram of square ring patch type frequency selection see-through textile in embodiment 2 of the present utility model;

Fig. 2 (b) is the schematic diagram of square ring perforated type frequency selection see-through textiles in Embodiment 2 of the utility model;

Fig. 2 (c) is two kinds of frequency selection see-through textile filter performance curves in the utility model embodiment 2;

Fig. 3 (a) is the schematic diagram of the cross patch type frequency selection see-through textile surface in the utility model embodiment 3;

Fig. 3 (b) is the schematic diagram of the surface of the cross-hole type frequency selection see-through textile in Example 3 of the utility model;

Fig. 3(c) is the filtering performance curve of two kinds of frequency selective transparent textiles in Example 3 of the present utility model. the

The marks in the figure are as follows:

1 base layer, 2 circular conductive units, 3 square circular conductive units, 4 cross-shaped conductive units. the

Detailed ways

The utility model will be further described below in conjunction with the accompanying drawings, but the utility model is not limited to the following embodiments. the

The following examples adopt the local metallization process of conductive paint printing, choose plain weave polyester fabric as the base layer, the warp and weft yarn count is 389dtex/144f, the warp and weft density is 234×210 threads/10cm, and the square meter weight is 197g/m ² , The circular, square and cross-shaped periodic conductive patterns were respectively selected, and two types of frequency selective surfaces, patch type and through-hole type, were processed and prepared for each conductive pattern. The specific parameters are shown in Table 1.

Table 1 Structural parameters of three kinds of conductive units (circular ring, square ring and cross)

The specific process of the conductive paint printing selected by the utility model is as follows:

(1) Determine the printing process and prepare the printing paste: use the conventional paint printing process, according to 80g copper-coated silver powder coating particles, 350g adhesive 707, 450g emulsified paste A state paste, 50g urea, 25g cross-linking agent EH, 45g cold water Ratio for mixing. After testing, the conductivity of the conductive paste was 5.2×10 ⁶ S/m.

(2) Flat screen plate making, printing conductive patterns: select polyester silk mesh cloth, according to the designed pattern structure, use the photosensitive plate making method to make a flat screen with SP number 42, select a net dynamic flat screen printing machine, install and adjust Screen and scraper, to ensure normal operation, use a squeegee to scrape the printing paste three times along the warp or weft direction of the fabric, control the thickness of the paint to 60μm, and print the conductive paste on the fabric through the mesh of the pattern to form a conductive sex pattern. the

(3) Baking and color fixation: go through three processes of re-baking (baking on the primer), steaming (102°C, 5min, using a reduction steamer), baking (130°C, 3min) to reinforce the color, and further Finished products. the

Embodiment 1, circular frequency selection transparent textiles

According to the frequency selective surface theory, the ring-shaped conductive unit is designed (the spacing of the array period Dx=Dy=12mm, the outer diameter R is 5mm, and the inner diameter r is 3mm), and the above-mentioned paint printing process is used for processing and preparation, and two kinds of surfaces are obtained with periodicity. The frequency selective see-through textile of the circular pattern is schematically shown in Figure 1(a) and 1(b). It can be seen from this figure that the frequency-selective see-through textile of this embodiment includes a base layer 1 and a period set on the base layer 1 The periodic conductive pattern layer is formed by the repeated arrangement of circular conductive units 2 . the

When the electromagnetic wave is vertically incident, the transmission coefficient curves of the two textiles to the electromagnetic wave are obtained, as shown in Fig. 1(c). It can be seen that the resonant frequency of the two curves is around 13 GHz, and they have good complementarity. For the ring patch type, the peak value of the transmission coefficient is -43.35dB, and the shielding effectiveness reaches the maximum value; the transmission coefficient is less than -10dB in the frequency range of 12.4GHz to 14.1GHz, and the band-stop effect is better, while in other frequency bands, it shows The larger the transmission coefficient, the smaller the shielding effectiveness. For the ring through-hole type, the peak value of the transmission coefficient is -0.028dB, there is almost no shielding effect, and all electromagnetic waves can pass through; the transmission coefficient is greater than -10dB in the frequency range of 12.3GHz to 13.7GHz, and the band-pass effect is better. In the frequency band, the transmission coefficient is small and the shielding effectiveness is large. The two frequency-selective transparent textiles exhibit the characteristics of band-stop filters and band-pass filters respectively, and have great application prospects in the fields of radar wave detection, battlefield command tents, and microwave weapons of specific bands. the

Embodiment 2, square ring frequency selective transparent textiles

According to the theory of frequency selective surface, the square annular conductive unit is designed (the spacing of the array period Dx=Dy=20mm, the outer side length a is 13mm, and the inner side length b is 6mm). The frequency-selective transparent textile of the square ring pattern, its schematic diagram is as shown in Figure 2 (a) and 2 (b), as can be seen from this figure, the frequency-selective transparent textile of this embodiment includes a base layer 1 and a base layer located on the base layer 1 A periodic conductive pattern layer, the periodic conductive pattern layer is formed by repeated arrangement of square ring conductive units 3 . the

When the electromagnetic wave is vertically incident, the transmission coefficient curves of the two textiles to the electromagnetic wave are obtained, as shown in Fig. 2(c). It can be seen that the resonant frequency of the two curves is around 9.5 GHz, and they have good complementarity. For the square ring patch type, the peak value of the transmission coefficient is -38.22dB, and the shielding effectiveness reaches the maximum value; the transmission coefficient is less than -10dB in the frequency range of 8.8GHz to 10.4GHz, and the band-stop effect is better, while in other frequency bands, it shows The larger the transmission coefficient, the smaller the shielding effectiveness. For the square ring through-hole type, the peak value of the transmission coefficient is -0.078dB, there is almost no shielding effect, and all electromagnetic waves can pass through; the transmission coefficient is greater than -10dB in the frequency range of 8.9GHz to 10.3GHz, and the band-pass effect is better. In the frequency band, the transmission coefficient is small and the shielding effectiveness is large. The two frequency-selective transparent textiles exhibit the characteristics of band-stop filters and band-pass filters respectively, and have great application prospects in the fields of radar wave detection, battlefield command tents, and microwave weapons of specific bands. the

Embodiment 3, cross-shaped frequency selection transparent textiles

According to the frequency selective surface theory, the cross-shaped conductive unit is designed (the spacing of the array period Dx=Dy=20mm, the length c is 16mm, and the width d is 8mm), and the above-mentioned paint printing process is selected for processing and preparation, and two kinds of surfaces with periodic cross-shaped patterns are obtained. The frequency selective see-through textile of the present embodiment comprises a base layer 1 and a periodic conductive pattern arranged on the base layer 1 as shown in Figure 3(a) and 3(b). Layer, the periodic conductive pattern layer is formed by repeated arrangement of cross-shaped conductive units 4 . the

When the electromagnetic wave is vertically incident, the transmission coefficient curves of the two textiles to the electromagnetic wave are obtained, as shown in Fig. 3(c). It can be seen that the resonant frequency of the two curves is around 9.8 GHz, and they have good complementarity. For the cross patch type, the peak value of the transmission coefficient is -35.07dB, and the shielding effectiveness reaches the maximum; in the frequency range of 8.9GHz to 10.5GHz, the transmission coefficient is less than -10dB, and the band-stop effect is better, while in other frequency bands, it shows transmission The larger the coefficient, the smaller the shielding effectiveness. For the cross hole type, the peak value of the transmission coefficient is -0.419dB, there is almost no shielding effect, and all electromagnetic waves can pass through; the transmission coefficient is greater than -10dB in the frequency range of 9.0GHz to 10.5GHz, and the band-pass effect is better, while in other frequency bands , it shows that the transmission coefficient is small and the shielding effectiveness is large. The two frequency-selective transparent textiles exhibit the characteristics of band-stop filters and band-pass filters respectively, and have great application prospects in the fields of radar wave detection, battlefield command tents, and microwave weapons of specific bands. the

It can be seen from the above examples that the textiles with six different periodic conductive patterns all exhibit ideal frequency selective transparency characteristics, but the resonance frequency points are slightly different, which is because the shape and size of the periodic conductive patterns on the fabric surface are different. The difference, the textile with the target resonant frequency can be obtained by optimizing the design. the

The electromagnetic wave frequency selection transparent textile of the utility model can be designed and produced by relatively mature processing technology, and is flexible and free, and has various patterns; the textile has the characteristics of light weight, softness and easy bending, so that it has potential application value in many fields , For example, it can be used in the design and development of high-performance anti-radiation clothing, battlefield command tents, flexible filters and other products. the

Claims (6)

1. An electromagnetic frequency selective transparent textile, characterized in that: the textile comprises a base layer and at least one periodic conductive pattern layer arranged on the base layer. the 2. The electromagnetic frequency selective transparent textile according to claim 1, characterized in that: the base layer is a flexible fabric layer. the 3. The electromagnetic wave frequency selective transparent textile according to claim 2, characterized in that: the flexible fabric layer is made of a non-conductive textile material through pure spinning of a single fiber or blending of multiple fibers; The non-conductive textile material is cotton, hemp, wool, silk, polyester, polytrimethylene terephthalate fiber, polybutylene terephthalate fiber, nylon, acrylic fiber, ultra-high molecular weight polyethylene fiber, polypropylene fiber , vinylon, glass fiber, aramid fiber, sulfone fiber, viscose fiber, acetate fiber and cupro ammonia fiber at least one. the 4. The electromagnetic wave frequency selective transparent textile according to claim 1, characterized in that: the periodic conductive pattern layer is formed by repeated arrangements of conductive unit patterns in local areas. the 5. The electromagnetic wave frequency selective transparent textile according to claim 4 is characterized in that: the unit figure is any one of the following 1)-4): 1) Centrally connected figure, said centrally connected figure is a Jerusalem cross unit; 2) Ring unit graphics, the ring unit graphics are circular rings, square rings or hexagonal rings; 3) Solid unit graphics, the solid unit graphics are rectangles, circles or polygons; 4) A combination of unit graphics in 1)-3). the 6 . The electromagnetic frequency selective transparent textile according to claim 5 , wherein the conductive unit pattern in the local area is composed of a conductive part and a non-conductive part. 6 . the