CN113279105B

CN113279105B - Elastic tunable frequency selection fabric and preparation method thereof

Info

Publication number: CN113279105B
Application number: CN202110043240.XA
Authority: CN
Inventors: 肖红; 陈剑英; 张恒宇; 王焰; 梁高勇; 代国亮; 孟令卿; 施楣梧
Original assignee: Institute of Quartermaster Engineering Technology Institute of Systems Engineering Academy of Military Sciences
Current assignee: Institute of Quartermaster Engineering Technology Institute of Systems Engineering Academy of Military Sciences
Priority date: 2021-01-13
Filing date: 2021-01-13
Publication date: 2022-12-02
Anticipated expiration: 2041-01-13
Also published as: CN113279105A

Abstract

The invention discloses an elastic tunable frequency selection fabric and a preparation method thereof. The elastic tunable frequency selection fabric is a frequency selection fabric which is formed by a periodic array of conductive units and dielectric units, has stretching elasticity and adjustable and controllable resonance frequency within a certain frequency range, the sizes, the intervals, the shapes and the electromagnetic parameters of the conductive units and the dielectric units of the elastic tunable frequency selection fabric are changed in the stretching process, and the resonance frequency is changed along with the change; after the external force is removed, when the initial state is recovered, the resonant frequency is recovered to the original position. The elastic tunable frequency selective fabric can be stretched to a specific size according to the unit size corresponding to the designed resonant frequency, so that the frequency selectivity can be regulated, the intelligent regulation and control of the frequency response characteristic of the frequency selective fabric are realized, the fabric has the flexibility and the flexibility, and the elastic tunable frequency selective fabric can be widely applied to products such as electromagnetic protection, radar covers, communication tents, flexible explosion-proof tanks and the like.

Description

Elastic tunable frequency selection fabric and preparation method thereof

Technical Field

The invention relates to an elastic tunable frequency selective fabric and a preparation method thereof, belonging to the technical textile field.

Background

The Frequency Selective Surface (FSS) is formed by a periodic array of conductive elements and dielectric elements, mainly including a patch type and an aperture type, and corresponds to a spatial filter for selectively transmitting or reflecting electromagnetic waves at a resonant Frequency point. The FSS prepared by the traditional processing means only has single resonant frequency because the electromagnetic property and the structure of the material are fixed, and cannot be regulated and controlled according to the external electromagnetic environment. However, with increasingly complex external electromagnetic environments and variable working states, the FSS with a single resonant frequency cannot meet working requirements, and the frequency selection effect of the FSS is seriously affected by the machining precision. The FSS with the tunable function can make up errors caused by the limitation of the processing precision and can also make proper regulation and control aiming at the external complex electromagnetic environment.

By using mechanical action or external voltage control and the like, the size of the conductive units, the distance between the periodic units and the electromagnetic parameters of the substrate material can be changed, the FSS with the tunable function can be prepared, and the dynamic response to the external electromagnetic environment is realized. For example, in the chinese patent 201710201798.X, a varactor is introduced between cells, and the equivalent capacitance in the cells is changed by excitation of an external voltage, so that the resonance frequency is continuously adjustable; chinese patent 201821154808.5 introduces switching diodes between units, and the electrical size of the units is changed by on-off control of the diodes, so that switching of the FSS between transmission and cut-off states is realized; chinese patent 201910262624.3 utilizes a thermal modulation mechanism to heat a Barium Strontium Titanate (BST) thin film, and realizes frequency tuning of terahertz by changing the dielectric constant of a substrate material. The above patents are merely illustrative of the properties, but do not provide much description of other properties such as flexibility and strength. For applications of electromagnetic protection, personal communication and the like, the FSS is required to realize a tunable function, and meanwhile, the FSS is expected to have a certain curvature or flexibility to be applied to common lamination of various curved surfaces. The Chinese patent 201910309529.4 uses a polyimide or polyester film as a base material, and the prepared flexible FSS can be bent, is simpler in process and better in performance compared with an FSS with a curved surface structure, but does not relate to a tunable function; the Chinese patent 201921561654.6 is a flexible FSS prepared on a glycol phthalate substrate and using graphene as a conductive unit, and tuning in the microwave and even terahertz field is realized by applying bias voltage. However, the graphene prepared by the method generally adopts a vapor deposition method, and the prepared graphene sheet layer has more defects, and the preparation of large-size graphene sheets is difficult and the cost is high. The preparation of flexible FSS is not a lot of patents, but it is not difficult to see that most of the preparation is to prepare conductive units on a flexible substrate, so that the functions of flexibility, bending and the like are emphasized, and the tunable function of FSS is less applied.

Most of traditional textile materials are wave-transparent materials, and light and flexible Frequency Selective Fabric (FSF) with certain Frequency Selective characteristics and electromagnetic functions can be prepared by utilizing local metallization. As in chinese patent 201410473103.X, the prepared planar frequency selective surface has a filtering characteristic by performing a local metallization treatment on the surface of the fabric; the Chinese patent 201510970380.6 adopts a carpet tufting loom to prepare a three-dimensional periodic structure, is simple to prepare and can realize large-scale production. Most of researches on textile-based FSS mainly focus on preparation and performance researches, and few researches on tunable textile-based FSS are carried out.

Disclosure of Invention

The invention aims to provide an elastic Tunable Frequency Selective Fabric (TFSF) and a preparation method thereof, which overcome the defects that the resonant Frequency of the existing textile base Frequency Selective surface is single, cannot be regulated and controlled according to the external electromagnetic environment and the difference of Frequency Selective characteristics caused by the defect of insufficient processing precision.

The elastic tunable frequency selection fabric provided by the invention is formed by a periodic array of conductive units and dielectric units;

the tunable frequency selective fabric has elastic and stretchable performance and recoverable performance;

under the action of an external force, the elastic tunable frequency selection fabric is elastically deformed, and in the elastic deformation process, the size and the conductivity of a conductive unit, the size of a medium unit and the distance between the conductive unit and the medium unit of the elastic tunable frequency selection fabric are changed, so that the resonance frequency is changed along with the change; after the external force is removed, when the tunable frequency selection fabric returns to the initial state, namely the size and the conductivity of the conductive unit, the size of the dielectric unit and the distance between the conductive unit and the dielectric unit return to the initial state, the resonant frequency of the tunable frequency selection fabric returns to the original position, and thus the adjustment and control of the resonant frequency of the elastic tunable frequency selection fabric are realized;

the conductive unit is composed of a conductive yarn aggregate or a conductive coating;

the medium unit is composed of a common yarn aggregate.

Based on the elastic tunable frequency selection fabric, the fabric can be stretched to a specific size according to the unit size corresponding to the designed resonance frequency, so that frequency selectivity regulation and control are performed, the intelligent regulation and control of the frequency response characteristic of the frequency selection fabric are realized, and the fabric has the flexibility and the flexibility; the method can not only respond and regulate and control the external complex and changeable electromagnetic environment, but also make up for the difference of frequency selection characteristics caused by insufficient processing precision.

In the above elastic tunable frequency selective fabric, the periodic array refers to that the conductive units and the dielectric units are periodically arranged at a pitch of 0.1mm to 100 mm;

the elastically tunable frequency selective fabric may be stretched to 200% of its length;

the resonance frequency of the elastic tunable frequency selection fabric can be regulated and controlled within the range of 300 MHz-100 GHz.

In the above elastic tunable frequency selective fabric, the conductive unit is a central connection type unit, a ring, a solid, or a composite type unit formed by the above shapes;

the central connection type is a tripolar shape, an anchor shape or a Yelu cooling cross shape;

the ring is a circular ring, a square ring or a hexagonal ring;

the solid is rectangular, circular or polygonal.

In the above elastic tunable frequency selective fabric, the conductive yarn is a single spun yarn formed by metal fiber, metallized fiber, organic electromagnetic functional fiber, carbon fiber or intrinsic conductive polymer fiber, or a blended yarn obtained by core-spun, doubling or blended spinning with other common textile fibers;

the conductive coating is formed by conductive ink or conductive slurry;

the conductive ink or the conductive paste is formed of a conductive paste containing metal powder, a carbon-based conductive paste, or a conductive polymer.

Specifically, the metal fiber is any one of stainless steel fiber, iron fiber, copper fiber, iron-cobalt alloy, nickel fiber, cobalt fiber and permalloy fiber;

the metallized fiber is a fiber with a metal layer plated on the surface, and comprises silver-plated fiber, nickel-plated fiber and copper-plated fiber;

the organic electromagnetic functional fiber is a fiber added with conductive powder or magnetic powder in an organic polymer fiber matrix, and comprises carbon black, graphene conductive fiber, graphite conductive fiber, polyaniline, polythiophene conductive polymer conductive fiber, organic ferrite, carbonyl iron and other magnetic fibers;

the intrinsic conductive polymer fiber can be one of polyaniline, polypyrrole and polythiophene conductive polymer fibers.

In the elastic tunable frequency selection fabric, the common yarn is a pure spun yarn, a core-spun yarn or a yarn doubling yarn obtained by spinning cotton, hemp, wool, terylene, chinlon, polypropylene fiber, acrylic fiber, vinylon, aramid fiber and/or viscose fiber.

The invention provides three types of elastic tunable frequency selective fabrics, which are as follows:

the first is an elastic three-dimensional fabric formed by fixedly connecting the conductive unit and the dielectric unit on a plane elastic dielectric fabric substrate;

connecting the conductive unit and the medium unit to the plane elastic medium fabric substrate in a way of vertical pile or loop pile by adopting an electric weaving gun, a tufting carpet weaving machine or a manual sample preparation way;

the planar elastic media fabric substrate may be stretched unidirectionally or bidirectionally;

the height of the raised piles or the loop piles is 0.01 mm-10 mm;

the planar elastic media fabric substrate is stretchable to 200% in a planar direction;

and during stretching, the conductive yarn is not broken or separated, and the conductivity of the stretched conductive yarn is not lower than 10S/m.

The second type is a woven elastic plane fabric which is woven by the conductive yarn with elasticity and the common yarn with elasticity according to a specific tissue structure and can be stretched unidirectionally or bidirectionally;

the conductive yarn and the common yarn are made to have elasticity by adding elastic fibers;

the elastic fiber is spandex, self-curling bi-component elastic fiber or polyolefin elastic fiber;

the weave structure can be divided into a weave structure of a woven fabric or a weave structure of a knitted fabric;

the weave structure of the woven fabric comprises plain weave, twill, applique and jacquard;

the texture structure of the knitted fabric comprises plain knitting, rib knitting, links, intarsia or plating;

the woven elastic flat fabric may be stretched to 200%;

The third is a post-finishing type elastic plane fabric obtained by attaching the conductive coating to an elastic medium fabric substrate in a structure of the conductive unit through a post-treatment mode;

preparing the conductive coating on the elastic medium fabric substrate by adopting a screen printing, ink-jet printing, digital printing, magnetron sputtering, electroplating, chemical plating, thermal transfer printing or gold stamping mode,

the elastic media fabric substrate may be stretched unidirectionally or biaxially;

the elastic media fabric substrate base is stretchable to 200% in a planar direction;

when the conductive coating is stretched, the conductive coating does not crack or fall off, and the sheet resistance of the conductive coating in a stretched state is not higher than 1000 omega/□.

The elastic tunable frequency selective fabric can be prepared according to the following method:

selecting conductive ink and slurry of medium yarns which have no influence on electromagnetic waves and conductive yarns with electromagnetic functions, and testing to obtain electromagnetic parameters such as conductivity (sheet resistance) or dielectric constant of the conductive ink and slurry; according to the frequency characteristics required by use, the shape and the size of the conductive unit are designed through theoretical calculation by combining the electromagnetic parameters of the yarn, and optimization is carried out; calculating the corresponding relation between the elastic deformation quantity and the change of the resonant frequency; and selecting corresponding TFSF types and preparation methods thereof according to the designed structure, unit shape and size and the physical and mechanical properties of the medium yarns, the conductive yarns and the conductive substances for weaving.

The elastic tunable frequency selection fabric has the adjustability of the resonant frequency, and the position of the resonant frequency can be changed according to actual requirements. By theoretically calculating the corresponding relation between the sizes, the intervals, the shapes and the electromagnetic parameters of the conductive units and the dielectric units and the resonance frequency, the electrical size of the material can be changed by stretching the fabric to a certain deformation, and the regulation and control performance of the resonance frequency can be realized. Therefore, the fabric can be stretched to a specific size according to the unit size corresponding to the designed resonant frequency, frequency selectivity regulation and control are carried out, and intelligent regulation and control of the frequency response characteristic of the frequency selective fabric are realized.

The invention prepares the frequency selective fabric with tunable function by using a textile processing means, can stretch in different sizes to adapt to complicated and changeable electromagnetic environments, and overcomes the defect of single resonant frequency of the traditional textile-based FSS. Meanwhile, by means of the flexibility of the textile material, the defects that the traditional FSS is hard and is not easy to be compounded with a curved surface are overcome, the defect that a high-precision FSS cannot be prepared by a textile processing means is overcome, the intelligent electromagnetic textile which is light, flexible, stretchable and tunable is realized, and the intelligent electromagnetic textile has the advantages of sample preparation diversity, low cost and batch preparation.

Drawings

FIG. 1 is a schematic diagram of an elastic three-dimensional TFSF according to the present invention, wherein FIG. 1 (a) is a dimensional configuration before stretching; FIG. 1 (b) shows a dimensional form after stretching.

FIG. 2 is a schematic representation of a woven elastic flat TFSF according to the present invention, wherein FIG. 2 (a) is the dimensional configuration before stretching; fig. 2 (b) shows the dimensional configuration after stretching.

FIG. 3 is a schematic representation of a post-finished elastic flat TFSF according to the present invention, wherein FIG. 3 (a) is the dimensional configuration before stretching; fig. 3 (b) shows the dimensional configuration after stretching.

Fig. 4 is a schematic view of a patch-type elastic TFSF in which the conductive unit is a square ring, prepared in example 1 of the present invention.

Fig. 5 is a schematic view of an aperture-type elastic three-dimensional TFSF in which the conductive element prepared in example 2 of the present invention is square.

Fig. 6 is a schematic view of a woven elastic flat TFSF in which conductive elements are cross-shaped, prepared in example 3 of the present invention.

Fig. 7 is a schematic view of a woven elastic flat TFSF with a conductive element of square shape prepared in example 4 of the present invention.

Fig. 8 is a schematic diagram of a post-processed elastic planar TFSF with a circular aperture as a conductive element prepared in example 5 of the present invention.

Fig. 9 is a schematic diagram of a post-finishing type elastic flat TFSF in which a conductive unit prepared in embodiment 6 is a combination of a cross and a circular ring.

FIG. 10 is a graph of the electromagnetic reflectance of an elastic three-dimensional TFSF prepared in example 1 of the present invention, with frequency on the abscissa f and in GHz; ordinate S ₁₁ Is the reflection coefficient in dB.

FIG. 11 is a graph of the electromagnetic reflectance of an elastic three-dimensional TFSF prepared in example 2 of the present invention, with frequency on the abscissa f and in GHz; ordinate S ₁₁ Is the reflection coefficient in dB.

FIG. 12 is a graph of the electromagnetic transmission coefficient of a woven elastic plane TFSF prepared in example 3 of the present invention with frequency on the abscissa f in GHz; ordinate S ₂₁ The transmission coefficient is given in dB.

FIG. 13 is a plot of the electromagnetic transmission coefficient of a woven elastic planar TFSF prepared in example 4 of the present invention, with frequency on the abscissa f and in GHz; ordinate S ₂₁ The transmission coefficient is given in dB.

FIG. 14 is a graph of the electromagnetic transmission coefficient of a post-finished elastic flat TFSF prepared in example 5 of the present invention, with f on the abscissa, in frequency unitsIs GHz; ordinate S ₂₁ Is the transmission coefficient in dB.

FIG. 15 is a plot of the electromagnetic reflectance of a TFSF post-finished elastic sheet prepared in accordance with example 6 of the present invention, with frequency on the abscissa f and in GHz; ordinate S ₂₁ The transmission coefficient is given in dB.

Detailed Description

The experimental procedures used in the following examples are all conventional procedures unless otherwise specified.

Materials, reagents and the like used in the following examples are commercially available unless otherwise specified.

Fig. 1 is a schematic diagram of an elastic three-dimensional TFSF formed by bonding a conductive element 1 and a dielectric element 2 to a planar elastic dielectric fabric substrate 3, wherein the conductive element 1 and the dielectric element 2 can be connected to the planar elastic dielectric fabric substrate 3 in a pile or loop manner by using an electric weaving gun, a tufted carpet weaving machine or a hand-made sample manner; the height of the raised pile or the loop pile can be 0.01 mm-10 mm; the planar elastic dielectric fabric substrate 3 can be stretched in a unidirectional or bidirectional manner, and in the stretching process, the sizes, the intervals, the shapes and the electromagnetic parameters of the conductive units 1 and the dielectric units 2 of the elastic three-dimensional TFSF are changed, as shown in fig. 1 (b), the resonance frequency is changed along with the change; after the external force is removed, when the initial state is recovered, the resonant frequency is recovered to the original position.

FIG. 2 is a schematic diagram of a woven elastic flat TFSF woven from conductive elements 1 and dielectric elements 2, specifically a woven elastic flat fabric capable of being stretched in one or two directions and woven from conductive yarns having elasticity and ordinary yarns having elasticity according to a specific weave structure; the conductive yarn and the common yarn are made to have elasticity by adding elastic fibers; the woven elastic plane TFSF can be stretched unidirectionally or bidirectionally, and in the stretching process, the size, the spacing, the shape and the electromagnetic parameters of the conductive unit 1 and the dielectric unit 2 of the woven elastic plane TFSF are changed, as shown in fig. 2 (b), the resonance frequency is changed along with the change; after the external force is removed, when the initial state is recovered, the resonant frequency is recovered to the original position.

Fig. 3 is a schematic diagram of a post-processing type elastic flat fabric TFSF obtained by attaching a conductive coating to an elastic medium fabric substrate in a structure of a conductive unit 1 through a post-processing manner, specifically, the conductive coating can be prepared on the elastic medium fabric substrate in a manner of screen printing, ink jet printing, digital printing, magnetron sputtering, electroplating, chemical plating, thermal transfer printing or gold stamping, the elastic medium fabric substrate can be stretched in a unidirectional or bidirectional manner, and during the stretching process, the sizes, the intervals, the shapes and the electromagnetic parameters of the conductive unit 1 and the medium unit 2 of the post-processing type elastic flat fabric TFSF change, and as shown in fig. 3 (b), the resonance frequency changes along with the change; after the external force is removed, when the initial state is recovered, the resonant frequency is recovered to the original position.

Example 1 preparation of Patch-type elastic three-dimensional TFSF

As shown in fig. 4, a schematic diagram of a patch-type elastic TFSF with a square conductive unit is prepared by an electric weaving gun. The conductive unit is woven by 40/2 polyester silver-plated yarns, the medium unit is woven by 40/2 polyester yarns, and the plane substrate medium is cotton/spandex elastic fabric. And coating glue containing water-soluble polyurethane on the back surface of the planar substrate medium after weaving, and heating and drying for curing. The conductive element of the frequency selective fabric was a square ring with m =10mm, n =6mm, d =15mm, and a nap height H =6mm, and when the sample was biaxially stretched to 20%, the resonance frequency was shifted from 15.41GHz to 13.87GHz as shown in fig. 10.

Example 2 preparation of pore-size elastic steric TFSF

As shown in fig. 5, the conductive element is a schematic diagram of a square aperture-type elastic three-dimensional TFSF prepared by a computer carpet weaving machine. The conductive unit is woven by stainless steel yarn with the content of 100%, the medium unit is woven by polyester yarn with the content of 50tex, and the plane substrate medium is cotton/spandex elastic fabric. And after weaving, coating glue containing water-soluble polyurethane on the back of the planar substrate medium, and heating and drying to solidify the glue. The conductive elements of the frequency selective fabric are square rings, where m =12, d =16mm, h =3mm. When the specimen was stretched to 20% simultaneously in both directions, the resonant frequency shifted from 15.47GHz to 13.20GHz, as shown in FIG. 11.

Example 3 preparation of a woven elastic Flat TFSF

As shown in fig. 6, the conductive elements are a schematic diagram of a cross-shaped woven elastic flat TFSF. And weaving the intarsia fabric by adopting a sample loom. The warp yarn is 21/2S cotton/spandex core-spun yarn, the weft yarn is terylene/spandex elastic yarn, the weft yarn for weaving the conductive unit is 50/2S silver-plated terylene/spandex blended yarn, and the weft yarn is silver-plated terylene/spandex elastic yarn. The conductive elements are cross-shaped, with m =9mm, n =2mm, and d =12mm. When the strain is 60% in the weft direction in the frequency band of 2-18GHz, the resonant frequency can be changed from 16.67GHz to 11.54GHz, as shown in FIG. 12.

Example 4 preparation of a textured elastic Flat TFSF

Fig. 7 is a schematic diagram of a woven elastic planar TFSF with square conductive elements. The computerized flat knitting machine adopting the island fine 14 needles adopts a special plating yarn nozzle, wherein the ground yarn adopts 50tex terylene/spandex yarn, the surface yarn adopts 40tex stainless steel/spandex elastic yarn with the content of 50 percent, and local plating tissues are woven. The locally plated sites form conductive cells, where m =6mm, d =16mm. In the frequency band of 14-18GHz, when the warp and weft are stretched along the warp and weft direction to the deformation of 5% of the original length, the resonant frequency is moved from 16.94GHz to 16.56GHz, as shown in FIG. 13.

Example 5 preparation of post-finished elastic Flat TFSF

Fig. 8 is a schematic diagram of a post-conditioning type elastic plane TFSF. An 80tex cotton/spandex core-spun yarn is used for weaving plain weave on a 14-needle island fine computerized flat knitting machine, an elastic substrate is woven, and the thickness of the fabric after off-machine weaving is 0.2mm. The conductive ink with 4% of graphene content is prepared by taking N-methyl pyrrolidone as a solvent, and the viscosity of the conductive ink is 2000mPa & s. And forming the conductive coating with periodic arrangement on the surface of the fabric by adopting an ink-jet printing mode. During the stretching, the resistance change is small. The conductive unit is in a square ring shape, and the size of the conductive unit is m =13.5mm, n =2mm, and D =18mm. The resonant frequency can be changed from 9.14GHz to 5.68GHz in the 2-12GHz band, with 60% strain in the biaxially oriented fabric, as shown in fig. 14.

Example 6 preparation of post-finished elastic Flat TFSF

Fig. 9 is a schematic diagram of a post-finishing elastic flat TFSF. The gram weight is 200g/m ² The plain woven fabric is stretched to 1.5 times of the original length and fixed by a frame, so that the surface is smooth. A mask is prepared according to the designed structure, wherein the conductive part is hollowed out. Covering and fixing the mask on the prepared knitted fabric, plating nickel on the surface by adopting a magnetron sputtering method, wherein the hollowed position of the mask is a conductive unit, and the position covered by the mask is a non-conductive unit. The conductive unit is a composite structure of a circular ring and a cross shape, wherein r ₁ ＝7.5mm，r ₂ =5.5mm, m =8mm, n =2mm, d =17.5mm. After the conductive coating is cured, the conductive coating is detached from the frame, and the surface of the fabric shrinks after the conductive coating is removed from the frame. There are two distinct resonance peaks before and after stretching and the resonance frequency shifts to lower frequencies with stretching as shown in fig. 15.

Claims

1. An elastic tunable frequency selective fabric is formed by a periodic array of conductive units and dielectric units;

the periodic array refers to the periodic arrangement of the conductive units and the medium units according to a pitch of 0.1mm to 100mm;

the medium unit is composed of a common yarn aggregate;

the elastically tunable frequency-selective fabric may be stretched to 200% of its length;

the resonance frequency of the elastic tunable frequency selection fabric is adjustable and controllable within the range of 300MHz to 100GHz;

the elastic tunable frequency-selective fabric is any one of the following 1) to 3):

1) The elastic tunable frequency selection fabric is an elastic three-dimensional fabric formed by fixedly connecting the conductive unit and the dielectric unit on a planar elastic dielectric fabric substrate;

during stretching, the conductive yarn is not broken or separated, and the conductivity of the stretched conductive yarn is not lower than 10S/m;

2) The elastic tunable frequency selection fabric is a woven elastic plane fabric which is woven by the elastic conductive yarns and the elastic common yarns according to a specific tissue structure and can be stretched in a single direction or two directions;

3) The elastic tunable frequency selection fabric is a post-finishing type elastic plane fabric obtained by attaching the conductive coating to an elastic medium fabric substrate in a structure of the conductive unit in a post-processing mode;

during stretching, the conductive coating does not crack or fall off, and the sheet resistance of the conductive coating in a stretching state is not higher than 1000 omega/□;

under the action of an external force, the elastic tunable frequency selection fabric is elastically deformed, and in the elastic deformation process, the size and the conductivity of a conductive unit, the size of a medium unit and the distance between the conductive unit and the medium unit of the elastic tunable frequency selection fabric are changed, so that the resonance frequency is changed along with the change; after the external force is removed, when the tunable frequency selection fabric returns to the initial state, that is, the size and the conductivity of the conductive unit, the size of the dielectric unit and the distance between the conductive unit and the dielectric unit return to the initial state, the resonant frequency of the tunable frequency selection fabric returns to the original position, so that the adjustment and control of the resonant frequency of the elastic tunable frequency selection fabric are realized.

2. The resiliently tunable frequency selective fabric of claim 1, wherein: the conductive unit is a central connection type unit, a ring, a solid or a composite type unit formed by the shapes;

the central connection type is a three-pole shape, an anchor shape or a yarrow cooling cross shape;

the ring is a circular ring, a square ring or a hexagonal ring;

the solid is rectangular, circular or polygonal.

3. The elastically tunable frequency selective fabric of claim 1 or 2, wherein: the conductive yarn is single spun yarn formed by metal fiber, metallized fiber, organic electromagnetic functional fiber, carbon fiber or intrinsic conductive polymer fiber, or blended yarn obtained by core-spun, doubling or blended spinning with other common textile fiber;

the conductive coating is formed by conductive ink or conductive slurry;

4. The resiliently tunable frequency selective fabric of claim 3, wherein: the metal fiber is any one of stainless steel fiber, iron fiber, copper fiber, iron-cobalt alloy, nickel fiber, cobalt fiber and permalloy fiber;

the organic electromagnetic functional fiber is a fiber with conductive powder or magnetic powder added in an organic polymer fiber matrix, and comprises carbon black, graphene conductive fiber, graphite conductive fiber, polyaniline and polythiophene conductive polymer fiber, organic ferrite and carbonyl iron;

the intrinsic conductive polymer fiber is polyaniline, polypyrrole or polythiophene conductive polymer fiber.

5. The elastically tunable frequency selective fabric of claim 4, wherein: the common yarn is pure spun yarn, core-spun yarn or doubling yarn obtained by spinning cotton, hemp, wool, terylene, chinlon, polypropylene fiber, acrylic fiber, vinylon, aramid fiber and/or viscose fiber.

6. The elastically tunable frequency selective fabric of claim 1, wherein: connecting the conductive unit and the medium unit to the plane elastic medium fabric substrate in a way of vertical pile or loop pile by adopting an electric weaving gun, a tufting carpet weaving machine or a manual sample preparation way;

the height of the raised piles or the loop piles is 0.01mm to 10mm;

the planar elastic media fabric substrate is stretchable to 200% in a planar direction.

7. The elastically tunable frequency selective fabric of claim 1, wherein: the conductive yarn and the common yarn are made to have elasticity by adding elastic fibers;

the weave structure is a woven fabric weave structure or a knitted fabric weave structure;

the woven elastic flat fabric may be stretched to 200%.

8. The resiliently tunable frequency selective fabric of claim 1, wherein: preparing the conductive coating on the elastic medium fabric substrate by adopting a screen printing, ink-jet printing, digital printing, magnetron sputtering, electroplating, chemical plating, thermal transfer printing or gold stamping mode,

the elastic media fabric substrate is elongatable in a planar direction up to 200%.

9. A preparation method of an elastic tunable frequency selection fabric comprises the following steps:

the elastically tunable frequency selective fabric is according to any one of claims 1 to 8;

selecting medium yarns which do not influence electromagnetic waves and the conductive yarns with electromagnetic functions or ink or slurry with conductivity, and testing to obtain electromagnetic parameters of the medium yarns, the conductive yarns or the ink or the slurry with the electromagnetic functions, wherein the electromagnetic parameters comprise conductivity, sheet resistance and dielectric constant;

according to the required frequency characteristic, in combination with the electromagnetic parameters, the shape and the size of the conductive unit are designed through theoretical calculation and optimized;

calculating the corresponding relation between the elastic deformation quantity and the change of the resonant frequency;

and selecting the type of the corresponding elastic tunable frequency selection fabric according to the designed structure, unit shape and size and the physical and mechanical properties of the medium yarns, the conductive yarns and the ink or the sizing agent for weaving.