CN104852153A

CN104852153A - Broadband reduction RCS composite material based on crossed bow-tie-shaped AMC

Info

Publication number: CN104852153A
Application number: CN201510178058.XA
Authority: CN
Inventors: 马剑南; 洪韬; 陈益龙
Original assignee: Beihang University
Current assignee: Beihang University
Priority date: 2015-04-15
Filing date: 2015-04-15
Publication date: 2015-08-19
Anticipated expiration: 2035-04-15
Also published as: CN104852153B

Abstract

The invention provides a broadband reduction RCS composite material based on crossed bow-tie-shaped AMC (artificial magnetic conductors). The material is characterized in that the composite material is in a three-layer structure, and comprises an AMC patch array, a medium substrate, and a metal floor in sequence from top to bottom, wherein the AMC patch array is arrays respectively formed by two kinds of crossed bow-tie-shaped AMC patches. The shapes of the two kinds of crossed bow-tie-shaped AMC patches are that the center is square, four edges of the square are respectively connected with four trapezoids, the short bottom edges of the trapezoids are connected with the square, the long bottom edges of the four trapezoids are connected with rectangles in sequence, and each patch is a whole integrated structure. The composite material is good in broadband performance. Compared with a metal sheet in the same size, the composite material has RCS reduction of more than -10 dB in the frequency range of 16.2-27.2 GHz, covering the whole K-band. The composite material is small in thickness, and can be conformal easily. The composite material is suitable to manufacture ultralight and ultrathin wave absorbers or radar absorbing materials. The composite material is simple in structure and materials, and is low in processing and manufacturing difficulty.

Description

A kind of broadband reduction RCS composite material based on intersection bowtie-shaped AMC

Technical field

The application relates to stealth technology field, especially relates to a kind of composite material.

Background technology

Stealth technology, be on modern military hidden oneself in order to avoid enemy finds, so as to strengthening assault ability or protecting self important means.The Stealth Fighter of weapon or flying body, depends mainly on the size in their radar scattering cross section (Radar Cross Section, referred to as RCS).The RCS value reducing target could more difficultly be found by enemy.The method of common reduction RCS is configuration design and radar absorbing.Configuration design is by reasonable design objective profile, energy is reflected and departs from arrival bearing, namely the large echo of forward direction is moved on to side direction.But configuration design, by the restriction of structure, size etc., has certain bottleneck.Radar absorbing (Radar Absorbing Material, referred to as RAM) generally has two kinds, and one is absorption-type, and one is interfere type.Absorption-type material electromagnetic energy is converted to heat energy or other forms of energy dissipation is fallen, but it exists aerodynamic performance difference, and thickness is large, and the shortcoming such as easily come off.Interfere type material to disappear mutually principle based on the interference of reflected wave, under specific thicknesses, interferes weaken between twice reflected wave because of anti-phase.The content of the application is exactly a kind of interfere type radar absorbing.

Along with the development of stealth technology, low RCS stealth material receives increasing concern.

Meta Materials is the new academic vocabulary that 21 century physics field occurs, is a kind of artificial composite structure or composite material with extraordinary physical property not available for natural material." Meta Materials " that develop so far comprising: left-handed materials, photonic crystal, super magnetic material etc.Wherein, photonic crystal invents at light-wave band, introduces microwave band afterwards, has occurred electromagnetic bandgap structure (Electromagnetic Band-Gap, referred to as EBG), this material can make the electromagnetic wave in a certain frequency range can not propagate in this periodic structure.Thinner, lighter, that frequency band the is wider stealth material of development that appears as of electromagnetic bandgap structure provides new technological means.

Artificial magnetic conductor (Artificial Magnetic Conductors, referred to as AMC) be a kind of typical electromagnetic bandgap structure, plane electromagnetic wave under a certain frequency perpendicular to its surface incidence is had to the effect of same-phase reflection, that is in its surface, the phase place of reflected wave equals incident wave, because this zero reflected phase will property class is similar to perfect magnetic conductor, so by its called after artificial magnetic conductor.In recent years, people to AMC reduction target RCS in should be used as large quantifier elimination.Based on AMC and perfect electric conductor (Perfect Electrical Conductors, referred to as PEC) plane checkerboard configuration, RCS reduction can be realized in arrowband, compared to traditional Salisbury radiation shield, eliminate quarter-wave thickness interval, there is low section, easily conformal advantage.

But the working band of this absorbing material is narrower, can not support that the defect of broadband operation greatly reduces its practical value.

Summary of the invention

In order to obtain wider suction ripple frequency band, present applicant proposes a kind of composite material based on intersection bowtie-shaped AMC unit, adopt two kinds of AMC arrays to form, this design overcomes the arrowband feature of AMC as resonance structure, utilizes effective phase difference concept to substantially increase bandwidth of operation.

Present applicant proposes a kind of broadband reduction RCS composite material based on intersection bowtie-shaped AMC, it is characterized in that, this material is three-decker, be followed successively by AMC patch array from top to bottom, dielectric substrate and metal floor, wherein said AMC patch array is the array that two kinds of intersection bowtie-shaped AMC pasters form respectively, the shape of described two kinds of intersection bowtie-shaped AMC pasters is: central authorities are squares, foursquare four limits connect respectively four trapezoidal, connecting foursquare is trapezoidal short base, four trapezoidal long bases connect rectangle successively, each paster is a complete integrative-structure.

Further, wherein the first intersection bowtie-shaped AMC paster AMC1, intermediate square length of side 0.22mm, trapezoidal short base 0.22mm, long base 1.06mm, trapezoidal high 0.76mm, cycle 4mm; The second intersection bowtie-shaped AMC paster AMC2, intermediate square length of side 0.12mm, trapezoidal short base 0.12mm, long base 0.57mm, trapezoidal high 0.405mm, cycle 4mm.

Further, described AMC patch array is checkerboard pattern, and formed to the unlimited continuation of four direction by multiple chessboard unit, described chessboard unit by AMC1 block and AMC2 block with 2 × 2 number cross arrangement form, described AMC1 block by AMC1 unit with 6 × 6 number form, described AMC2 block by AMC2 unit with 6 × 6 number form.

Further, the material of described paster is metal.

Further, described dielectric substrate adopts ROGERS 3010 dielectric material, and dielectric material thickness is 1.05mm.

The intersection bowtie-shaped AMC composite material that the application proposes, (1) its broadband performance is excellent, relatively has the RCS of more than-10dB to reduce with size metallic plate, cover whole K-band in the frequency range of 16.2-27.2GHz; (2) thickness is little, easily conformal, is applicable to manufacturing ultralight, ultra-thin absorbing material; (3) simply, processing and manufacturing difficulty is little for structure, materials.

Accompanying drawing explanation

Fig. 1 the first intersect the shape of bowtie-shaped AMC1 paster and the size that uses in broadband reduction target RCS composite material;

Fig. 2 the second intersects the shape of bowtie-shaped AMC2 paster and the size that uses in broadband reduction target RCS composite material;

The vertical view of the broadband reduction target RCS composite material that Fig. 3 the application proposes;

The end view of the broadband reduction target RCS composite material that Fig. 4 the application proposes;

The normalization mono-static RCS curve of Fig. 5 composite material.

Embodiment

Below in conjunction with accompanying drawing, the present invention is described in further detail.

Because Bow―tie antenna has good broadband character relative to other paster antennas, characteristic impedance can keep in wider frequency range, so intersection bowtie-shaped paster has broadband character as AMC unit, two kinds have the reflected wave of opposite phase can interfere the phenomenon disappeared mutually simultaneously, thus backward energy is reduced, phase difference is more close to 180 °, and backward energy is lower.According to the theory of array antenna, the phase difference frequency band of two kinds of AMC arrays and the RCS of this composite material reduce frequency band corresponding relation, with same size metallic plate for comparison other, if choose-10dB for reduction target, then the reflected phase will difference scope of two kinds of AMC arrays is 180 ° ± 37 °.For the purpose of simple, usually get 180 ° ± 30 °, corresponding frequency is called effective phase difference frequency range.

Fig. 1 and Fig. 2 respectively illustrates the shape of intersection bowtie-shaped AMC1 and AMC2 paster.The central authorities of intersection bowtie-shaped paster are squares, foursquare four limits connect respectively four trapezoidal, connecting foursquare is trapezoidal short base, four trapezoidal long bases connect rectangle successively, paster is a complete integrative-structure, the shape of description just in order to this paster is described of above-mentioned separation.In use, two kinds of AMC are combined into checkerboard configuration.Also respectively illustrate at Fig. 1 and Fig. 2 and intersect the size that bowtie-shaped AMC1 and AMC2 paster use in the broadband of design reduction RCS composite material, be exactly specifically the intermediate square length of side 0.22mm of AMC1, trapezoidal short base 0.22mm, long base 1.06mm, trapezoidal high 0.76mm, the cycle is 4mm; The intermediate square length of side 0.12mm of AMC2, trapezoidal short base 0.12mm, long base 0.57mm, trapezoidal high 0.405mm, the cycle is 4mm.The material of this paster is metal in the composite.

The vertical view of the broadband reduction RCS composite material that the application proposes is given in Fig. 3.Wherein, as can be seen from figure (a), AMC patch array 1 is checkerboard pattern, and is formed to the unlimited continuation of four direction by multiple chessboard unit 2; As can be seen from figure (b), each chessboard unit 2 by AMC1 block 3 and AMC2 block 4 with 2 × 2 number cross arrangement form, often kind of AMC unit with 6 × 6 number composition AMC block (the AMC1 unit of such as 6 × 6 forms AMC1 blocks 3).It is pointed out that this absorbing material is infinitely great periodic structure in the design phase, as far as possible many chessboard unit can be selected to make material object according to cost during making, service behaviour can not have obvious reduction than infinitely great structure.

Fig. 4 is the end view of the broadband reduction RCS composite material that the application proposes.Composite material is three-decker, is followed successively by AMC patch array, dielectric substrate and metal floor from top to bottom.In an embodiment, orlop is metal floor, and intermediate layer is ROGERS 3010 dielectric substrate, and dielectric substrate thickness is 1.05mm, and the superiors are AMC patch array.

Fig. 5 is the mono-static RCS simulation curve of broadband reduction RCS composite material, and has carried out normalized with the metallic plate of size.Emulation tool is ANSYS HFSS, and simulation result shows: adopt intersection bowtie-shaped paster as the elementary cell of composite material ,-10dB mono-static RCS reduction frequency band is 16.2-27.2GH, bandwidth reaches 50.7%, maximum reduction amplitude-36dB, broadband performance is good, has good practical value.

Claims

1. the broadband reduction RCS composite material based on intersection bowtie-shaped AMC, it is characterized in that, described composite material is three-decker, be followed successively by AMC patch array from top to bottom, dielectric substrate and metal floor, wherein said AMC patch array is the array that two kinds of intersection bowtie-shaped AMC pasters form respectively, the shape of described two kinds of intersection bowtie-shaped AMC pasters is: central authorities are squares, foursquare four limits connect respectively four trapezoidal, connecting foursquare is trapezoidal short base, four trapezoidal long bases connect rectangle successively, each paster is a complete integrative-structure.

2. the broadband reduction RCS composite material based on intersection bowtie-shaped AMC according to claim 1, wherein the first intersection bowtie-shaped AMC paster AMC1, its intermediate square length of side 0.22mm, trapezoidal short base 0.22mm, long base 1.06mm, trapezoidal high 0.76mm, the cycle is 4mm; The second intersection bowtie-shaped AMC paster AMC2, its intermediate square length of side 0.12mm, trapezoidal short base 0.12mm, long base 0.57mm, trapezoidal high 0.405mm, the cycle is 4mm.

3. the broadband reduction RCS composite material based on intersection bowtie-shaped AMC according to claim 2, wherein said AMC patch array is checkerboard pattern, and formed to the unlimited continuation of four direction by multiple chessboard unit, described chessboard unit by AMC1 block and AMC2 block with 2 × 2 number cross arrangement form, AMC1 block by AMC1 unit with 6 × 6 number form, AMC2 block by AMC2 unit with 6 × 6 number form.

4. the broadband reduction RCS composite material based on intersection bowtie-shaped AMC according to claim 1, the material of described paster is metal.

5. the broadband reduction RCS composite material based on intersection bowtie-shaped AMC according to claim 1, described dielectric substrate adopts ROGERS 3010 dielectric material, and dielectric material thickness is 1.05mm.