CN105337026B - A kind of method for weaving of the micro-strip array antenna based on Woven Distance Fabric - Google Patents

Abstract

The invention discloses a weaving method of a microstrip array antenna based on a woven spacer fabric, which includes weaving textile fibers and epoxy resin on a spacer loom and solidifying and forming a composite material; measuring the dielectric constant and Loss tangent; Calculate the basic size of the microstrip antenna radiating element based on the obtained dielectric properties of the composite material, and then design the antenna array unit size, calculate and design the structure and size of the impedance matching network, and weave the microstrip array on the loom according to the above size The basic structure of an antenna. Woven spacer fabrics have the characteristics of good structural integrity, high hollowness, and light weight. Therefore, the antenna obtained in the present invention not only has good structural integrity and anti-delamination ability, but also has very light weight and excellent electromagnetic radiation characteristics; the reliability and comprehensive performance of the antenna can be greatly improved, and it can be used in aerospace, transportation, etc. , information and other fields have broad application prospects.

Description

A Weaving Method of Microstrip Array Antenna Based on Woven Spacer Fabric

technical field

The invention relates to a microstrip antenna capable of bearing external force and receiving transmitted signals, especially a microstrip antenna system designed based on spacer fabric.

Background technique

Antennas are an essential component of communication systems and are widely used in civil and military fields. As an essential communication device, a large number of antennas are installed on the aircraft. The early antennas are protruding structures, which are easy to be damaged and affect the aerodynamic performance of the aircraft. Therefore, the traditional protruding antennas are not used in the modern aerospace field, but the antennas with a planar structure lying flat on the surface of the fuselage. However, this kind of antenna is still not a part of the fuselage and cannot play the role of bearing stress. At the same time, in low-frequency band communication, the size of the antenna will increase with the increase of the wavelength, and the reliability of its structure will decrease accordingly. In order to accommodate the antenna As the size increases, the structural integrity of the fuselage must be compromised.

As the most widely used material in the field of modern aerospace, fiber composite reinforced materials have the characteristics of high specific strength and good fatigue resistance. However, most fiber-reinforced composite materials use a layered structure, and its biggest disadvantage is that it is easy to delaminate. If the antenna structure is based on this composite material, it may be delaminated with the composite material after impact and lose its function. The U.S. Air Force Laboratory (AFRL) conducted a series of research work in the 1990s and developed a third-generation aerial antenna system. The basic idea is to integrate the antenna into the composite material structure of the aircraft skin to achieve the purpose that the antenna will not be damaged as long as the material is not damaged.

Textile-reinforced composites can overcome the disadvantage of delamination, so they have a wide range of applications in the aerospace field. Among them, the spacer fabric is light in weight and has good impact resistance. Compared with the traditional microstrip antenna, it is lighter in weight and has smaller dielectric loss. If the antenna is combined with the spacer fabric to make the antenna a part of the spacer composite reinforcement material, the antenna The reliability and survivability of the system can be greatly improved, which is very important for aerospace equipment, especially for long-term use of aircraft.

Contents of the invention

The technical problem to be solved by the present invention is to provide a structurally integrated antenna array structure by using the unique performance and advantages of the textile structure combined with the design principle of the antenna array, so as to solve the problem of low gain performance in the current single antenna structure.

The present invention solves the technical problem: a weaving method for a microstrip array antenna based on a woven spacer fabric is provided, comprising the following steps:

Step 1: Preparation process:

Step 1): weaving spacer fabrics on spacer looms, and curing and forming composite materials with epoxy resin; measuring the dielectric constant and dielectric loss of the composite materials;

Step 2): According to the dielectric constant of the composite material, design the basic size of the radiating unit of the microstrip antenna, and weave the basic structure of the microstrip antenna on the spacer loom according to the size, and the calculation formulas are shown in the following 1-1 to 1-7 : where f _r is the center frequency, ε _r is the dielectric constant of the composite material, h is the thickness of the composite material, c is the speed of light in vacuum, W and L are the width and length of the radiation element, λ ₀ is the free-space wavelength, WG and LG is the width and length of the finished microstrip antenna, and the spacing between the radiation elements is 0.6 times λ ₀ ;

LG=L+0.2λ _g formula 1-6;

WG=W+0.2λ _g formula 1-7;

Step 3): Select the conductive yarn according to the calculation result, so that its diameter is less than the minimum width of the matching network transmission line, choose warp yarn as three layers, the uppermost layer is the radiation element structure layer woven by conductive yarn; the lower layer is the warp and weft fabric layer, The warp and weft yarn layer plays the role of supporting the radiation element; the bottom layer is a grounding layer woven with conductive yarns; the warp and weft yarn fabric layer and the grounding layer are hollow structures composed of spacer yarns;

The second step: Weaving multiple line arrays:

Step a): For the design of the multi-element linear array antenna, its basic structure preform includes three layers of yarns, the uppermost layer of yarns weaves the radiation elements, the width of the yarn layer is equal to the width of the antenna element, and the lower layer is the warp and weft yarn fabric layer, The bottom layer is the grounding layer woven with conductive yarns. The yarns of the radiation element layer and the grounding layer are conductive yarns. In addition, several conductive wires are added at the position of the feeder line. Above; the weft yarn is two layers, the lower weft yarn is made of conductive yarn, and the rest of the warp and weft yarns are high-strength and high-modulus yarns;

Step b): Use a shuttle wound with conductive yarns to weave the antenna unit. When the shed is opened, the two layers of weft yarns respectively pass through the opened sheds of the warp and weft yarn layer and the grounding layer, while the shuttle passes through the gap between the radiation element layer and the upper layer. The shed formed by the yarn, and then the heddle is changed, the warp and weft yarn layer is interwoven with the ground floor layer and the spacer yarn respectively, and the above weaving process is repeated. When reaching the feeder network, the feeder is woven into the feeder; Control the width of the feeding transmission line; the weaving of the subsequent antenna elements is the same;

Or, the second step: weaving the multivariate square matrix:

Step a): Use two shuttles to weave two rows of antenna elements at the same time, the weaving process is the same as the above multi-element linear array;

Step b): Dip the antenna preform welded with the coaxial connector with the above-mentioned epoxy resin to make a microstrip array antenna.

Preferably, the volume content of the textile fiber in step 1) of the first step accounts for 40%-50% of the total volume of the textile fiber and epoxy resin.

Preferably, the high-strength and high-modulus yarn in step a) of the second step is glass fiber, aramid fiber or basalt fiber.

Preferably, the feeding network feeds the woven antenna array by means of coaxial feeding or edge feeding. For multi-element line arrays, the coaxial connector probe is welded to the final 50ohm impedance transmission line, and the coaxial connection The base of the device is welded to the bottom conductive yarn; for the multi-element square array, the coaxial connector probe is used to pass through the fabric and welded to the center of the feeder network, and the base of the coaxial connector is welded to the bottom conductive yarn.

The spacer fabric structure used in the present invention has the advantages of light weight, not easy to be delaminated, excellent impact resistance, and small dielectric loss. The method of interweaving the conductive thread and the warp and weft yarns is used to weave the antenna, so that the antenna and the spacer structure are combined into one Intact whole, which improves the survivability of the antenna.

Compared with the prior art, the present invention has the following advantages and positive effects:

1. The radiation element and ground plate of the microstrip antenna of the present invention will not be separated from the matrix part under the action of external force or the internal stress caused by resin shrinkage during processing;

2. The radiating element and the grounding plate of the microstrip antenna of the present invention can be designed in the inner layer of the three-dimensional structure as required, thereby being protected by the outer composite material and greatly improving its anti-damage ability;

3. The spacer fabric structure has strong adaptability and can adapt to surfaces with various curvatures;

4. The spacer fabric structure has the advantages of light weight and high specific strength, which can improve the mechanical properties of the microstrip antenna;

5. Due to the use of automatic weaving technology and pre-formed resin transfer forming, the product cost is low and the quality is stable, which is conducive to popularization and use;

6. Without dipping treatment, this antenna structure can also be used on flexible structures to send and receive and process signals, such as smart textiles;

7. The basic radiation unit is fixed, and the antenna gain is improved without changing the composite material;

8. Compared with the unit microstrip antenna, the multi-element can still work after several units are damaged, which improves the survivability of the entire antenna;

9. Since the structure is composed of multiple radiating elements, it is easier to achieve conformal fit on the surface than the element antenna.

10. Compared with traditional fabrics, spacer fabrics have smaller dielectric constant and lower dielectric loss, and the performance of the microstrip antenna made is better.

Description of drawings

Fig. 1 is the structural representation of woven spacer fabric;

Figure 2 is a side view of a woven spacer fabric;

Figure 3 is a front view of a woven spacer fabric;

Fig. 4 is the schematic diagram of binary linear microstrip array antenna;

FIG. 5 is a schematic diagram of a four-element square microstrip array antenna.

Detailed ways

In order to make the present invention more comprehensible, preferred embodiments are described in detail below with accompanying drawings.

Embodiment 1: Binary linear microstrip array antenna based on glass fiber spacer fabric

(1) Choose E glass fiber provided by Zhejiang Jushi Group as the fiber composite reinforcement, choose JL-235 resin and JH-242 curing agent provided by Changshu Jiahua Co., Ltd., and choose Wuxi Liz Precision Electrical Wire Co., Ltd. Copper stranded wire is the raw material.

(2) The working frequency of the antenna designed in this embodiment is 1.5 GHz, and the dielectric constant of the prepared spacer glass fiber composite material is calculated as 1 by back-calculation. According to empirical formulas 1-1 to 1-7, binary The size parameters of the linear microstrip array antenna are shown in Figure 4. Where W and L are the width and length of the radiating element 4 respectively, WG and LG are the width and length of the finished microstrip antenna, FL is the length of the microstrip line, and FD is the width of the microstrip line.

(3) Weaving the prefabricated part of the binary linear microstrip array antenna. The design basic structure preform includes three layers of yarn, the uppermost layer of yarn weaves the radiation element 4, the width of the yarn layer is equal to the width of the antenna element, the lower two layers of yarn weave the upper and lower layers of yarn of the woven spacer fabric, and the uppermost layer The bottom layer of yarn is copper stranded wire, and several copper stranded wires are added at the position of the feeder wire. The number of wires is determined by the width of the feeder wire and is located above all 3 layers of warp yarns; the weft yarn 2 is two layers, and the lower layer weft yarn 2 is used Copper stranded wire, the rest of the warp and weft yarns are glass fibers. Every weft insertion, the warp and weft yarn layer, the ground floor layer and the spacer yarn 1 are interweaved once respectively. When the weaving direction reaches 10mm, start to use the shuttle to weave the antenna radiation element 4, select the uppermost yarn, and use a copper stranded wire The shuttle is used to insert the weft, passing through the raised warp yarn 3, every time the shuttle inserts weft, it beats up once, after completing the 40.8mm of the first half of the radiation element 4, when it reaches the feeding network, continue to weave the second half of the radiation element 4 and the antenna structure, and the subsequent unit weaving method is the same. The probe of the coaxial connector (JSMA-KFD40) is welded to the feeding point of the radiation element 4, and the base of the coaxial connector is welded to the lower copper wire of the antenna prefabricated part.

(4) The above-mentioned microstrip antenna preform is made into a composite material microstrip antenna by a hand lay-up method.

Embodiment 2: Quaternary square microstrip array antenna based on glass fiber spacer fabric

(1) Aramid fiber is selected as the fiber composite reinforcement with a fineness of 167tex; nylon silver-plated yarn is selected as the conductive yarn with a fineness of 20tex.

(2) The operating frequency of the single radiating element 4 microstrip antenna designed in this embodiment is 2.4 GHz, the density and thickness of the spaced aramid fiber composite material are the same as in Embodiment 1, and its dielectric constant ε _r = 1.8, according to Empirical formulas 1-1 to 1-7 can be used to calculate the size parameters of the single radiating element 4 microstrip antenna, as shown in Figure 5. Where W and L are the width and length of the radiating element 4 respectively, WG and LG are the width and length of the finished microstrip antenna, FL is the length of the microstrip line, and FD is the width of the microstrip line.

(3) Weaving a single radiating element 4 microstrip antenna preform. The weaving method is the same as (3) in the first embodiment, the radiation element 4 and the grounding plate are made of nylon silver-plated yarn, and the rest are made of aramid fiber.

Embodiment 3: Binary linear microstrip array based on low dielectric glass fiber spacer fabric

(1) The fiber with low dielectric properties selected in this embodiment is E glass fiber, and its fineness is 300tex. The conductive fiber, resin and curing agent selected are the same as in Embodiment 1.

(2) The working frequency of the antenna designed in this embodiment is 1.5 GHz, the thickness of the prepared spacer glass fiber composite material is 2 mm, and its dielectric constant ε _r = 2, which can be calculated according to empirical formulas 1-1 to 1-7 The size parameters of the single radiating element 4 microstrip antenna are shown in Figure 4. Where W and L are the width and length of the radiating element 4 respectively, WG and LG are the width and length of the finished conformal carrying microstrip antenna, FL is the length of the microstrip line, and FD is the width of the microstrip line.

(3) Weaving a single radiating element 4 microstrip antenna preform. Weaving method is the same as embodiment 1.

(4) The above-mentioned microstrip antenna preform is made into a composite material microstrip antenna by a hand lay-up method.

Compared with Example 1, the spacer fabric composite material antenna prepared in this example has smaller thickness, and greatly improved mechanical bearing capacity and stability.

Claims (4)

1. a weaving method based on the microstrip array antenna of woven spacer fabric, comprises the following steps: Step 1: Preparation process: Step 1): weaving spacer fabrics on spacer looms, and curing and forming composite materials with epoxy resin; measuring the dielectric constant and dielectric loss of the composite materials; Step 2): According to the dielectric constant of the composite material, design the basic size of the radiating unit of the microstrip antenna, and weave the basic structure of the microstrip antenna on the spacer loom according to the size, and the calculation formulas are shown in the following 1-1 to 1-7 : where f _r is the center frequency, ε _r is the dielectric constant of the composite material, h is the thickness of the composite material, c is the speed of light in vacuum, W and L are the width and length of the radiation element (4) respectively, and λ ₀ is the free space wavelength , WG and LG are the width and length of the finished microstrip antenna, and the spacing between the radiation elements (4) is 0.6 times λ ₀ ; LG=L+0.2λ _g formula 1-6; WG=W+0.2λ _g formula 1-7; Step 3): Select the conductive yarn according to the calculation result so that its diameter is less than the minimum width of the matching network transmission line, select the warp yarn (3) as three layers, and the uppermost layer is the radiation element (4) structural layer woven by conductive yarn; the lower layer It is the warp and weft yarn fabric layer, and the warp and weft yarn layer plays the role of supporting the radiation element (4); the bottom layer is the grounding floor layer woven by conductive yarn; the warp and weft yarn fabric layer and the grounding floor layer are composed of spacer yarns (1) hollow structure; The second step: Weaving multiple line arrays: Step a): For the design of the multi-element linear array antenna, its basic structural preform includes three layers of yarns, the uppermost layer of yarns weaves the radiation element (4), the width of the yarn layer is equal to the width of the antenna element, and the lower layer is warp and weft yarns The fabric layer, the bottom layer is the grounding layer woven with conductive yarn, the radiation element (4) layer and the grounding layer yarn are conductive yarns, and a number of conductive wires are added at the position of the feeder line, and the number is determined by the width of the feeder line Determined to be located on all warp yarns (3) layers; the weft yarn (2) is two layers, the lower weft yarn (2) uses conductive yarn, and the rest of the warp and weft yarns are high-strength and high-modulus yarns; Step b): use a shuttle wound with a conductive yarn to weave the antenna unit, when the shed is opened, the two layers of weft yarns (2) respectively pass through the opened shed of the warp and weft yarn layer and the ground layer, and at the same time the shuttle passes through the radiation element ( 4) The shed formed by the layer and the spacer yarn (1) on the upper layer, after which the healds are changed, the warp and weft yarn layers are interwoven with the ground floor layer and the spacer yarn (1) respectively, and the above weaving process is repeated. When reaching the feeder network, weave into Feed line; the warp yarns (3) on the left and right sides of the feed line are used to control the width of the feed transmission line with conductive yarns; the follow-up antenna unit weaving is the same; Or, the second step: weaving the multivariate square matrix: Step a): Use two shuttles to weave two rows of antenna elements at the same time, the weaving process is the same as the above multi-element linear array; Step b): Dip the antenna preform welded with the coaxial connector with the above-mentioned epoxy resin to make a microstrip array antenna. 2. the weaving method of the microstrip array antenna based on woven spacer fabric as claimed in claim 1, is characterized in that, the volume content of textile fiber in the step 1) of described first step accounts for textile fiber and epoxy resin 40% to 50% of the total volume. 3. the weaving method of the microstrip array antenna based on woven spacer fabric as claimed in claim 1, is characterized in that, in the step a) of described second step, high-strength high-modulus yarn is glass fiber or aramid fiber or basalt fiber. 4. the weaving method of the microstrip array antenna based on woven spacer fabric as claimed in claim 1, is characterized in that, described feed network feeds the antenna array of weaving by the method for coaxial feed or edge feed , for a multi-element array, use the coaxial connector probe to weld the final 50ohm impedance transmission line, and the base of the coaxial connector to weld the bottom conductive yarn; for a multi-element square array, use a coaxial connector probe to pass through the fabric and The center of the feed network is welded, and the base of the coaxial connector is welded to the bottom layer of conductive yarn.