阅读说明：本技术 去法布里-珀罗伪谐振逆推复合材料电磁参数的方法 (The method for removing Fabry-Perot puppet resonance backstepping composite material electromagnetic parameter ) 是由 李红梅 蒋哲 祁嘉然 于 2019-08-30 设计创作，主要内容包括：一种去法布里-珀罗伪谐振逆推复合材料电磁参数的方法,属于复合材料电磁参数获取技术领域。本发明针对现有复合材料电磁参数获取过程中,忽略了Fabry-Pérot伪谐振所带来的电磁参数的畸变,使电磁参数的结果不准确的问题。包括对待测复合材料进行模拟；在模拟板层结构方向的两端分别接入波导端口,垂直照射模拟板,根据照射结果分别计算获得两种模拟板的散射参数模拟值；再计算获得相应模拟板的阻抗计算值；再计算获得模拟板厚度校正项；根据模拟板厚度校正项再计算获得待测复合材料的校正阻抗,进而确定待测复合材料的折射率,由待测复合材料的校正阻抗和折射率计算获得待测复合材料的电磁参数。本发明用于逆推复合材料的电磁参数。(A method of Fabry-Perot puppet resonance backstepping composite material electromagnetic parameter is removed, composite material electromagnetic parameter acquiring technology field is belonged to.The present invention has ignored the distortion of electromagnetic parameter brought by Fabry-P é rot puppet resonance, makes the problem of the result inaccuracy of electromagnetic parameter in existing composite material electromagnetic parameter acquisition process.Including being simulated to composite material to be measured；It is respectively connected to waveguide port at the both ends of analog board layer structure direction, vertical irradiation analog board calculates separately the scattering parameter analogue value for obtaining two kinds of analog boards according to irradiation result；The impedance computation value for obtaining corresponding analog board is calculated again；It calculates again and obtains analog board thickness correction item；It calculates the correction impedance for obtaining composite material to be measured again according to analog board thickness correction item, and then determines the refractive index of composite material to be measured, the electromagnetic parameter for obtaining composite material to be measured is calculated by the correction impedance of composite material to be measured and refractive index.The present invention is used for the electromagnetic parameter of backstepping composite material.)

1. a kind of method for removing Fabry-Perot puppet resonance backstepping composite material electromagnetic parameter, which is characterized in that including following step It is rapid:

Composite material to be measured is simulated, M layers of structural simulation plate and N layers of structural simulation plate are obtained；In two kinds of analog board layer knots The both ends in structure direction are respectively connected to waveguide port, are respectively perpendicular irradiation analog board by simulation plate surface with incident plane wave, according to Irradiation result calculates separately the scattering parameter analogue value for obtaining two kinds of analog boards；

The impedance computation value for obtaining corresponding analog board is calculated according to the scattering parameter analogue value of two kinds of analog boards；

It is identical according to the impedance computation of two kinds of analog boards value, it calculates and obtains the corresponding simulation plate thickness of different frequency incident plane wave Correction term；

It calculates the correction impedance for obtaining composite material to be measured again according to analog board thickness correction item, and then determines composite material to be measured Refractive index, the electromagnetic parameter for obtaining composite material to be measured is calculated by the correction impedance of composite material to be measured and refractive index.

2. the method according to claim 1 for removing Fabry-Perot puppet resonance backstepping composite material electromagnetic parameter, feature It is, described to simulate to composite material to be measured, the method for obtaining M layers of structural simulation plate and N layers of structural simulation plate includes:

It is modeled using fullwave simulator, obtains composite material model to be measured, include the freedom of i layers of structure and preset length in model Space, i=M or N；Wherein every layer of structure includes the analogue unit of array arrangement, and each analogue unit includes one or more The composite construction that dielectric material is constituted；The free space of preset length is supplemented respectively at the both ends of analog board layer structure direction, is obtained M layers of structural simulation plate and N layers of structural simulation plate, analog board with a thickness of d, d=Mh+2d_ADOr d=Nh+2d_AD, h is in formula The thickness of single layer structure, d_ADFor the length of the free space.

3. the method according to claim 2 for removing Fabry-Perot puppet resonance backstepping composite material electromagnetic parameter, feature It is, TMxy polarization plane wave is selected vertically to be shone as incident plane wave M layers of structural simulation plate and N layers of structural simulation plate It penetrates.

4. the method according to claim 3 for removing Fabry-Perot puppet resonance backstepping composite material electromagnetic parameter, feature It is, the impedance computation value that the scattering parameter analogue value according to two kinds of analog boards calculates the corresponding analog board of acquisition includes:

Impedance computation value z_i(δ, ω) are as follows:

δ is analog board thickness correction item in formula, and ω is plane of incidence wave frequency rate；S_11,iFor the input reflection coefficient of analog board, S_21,i For the output reflection coefficient of analog board；

Wherein:

In formulaFor the input reflection coefficient analogue value of analog board,For the output reflection coefficient analogue value of analog board, k₀For certainly By space wave vector, d_ADFor the length of the free space.

5. the method according to claim 4 for removing Fabry-Perot puppet resonance backstepping composite material electromagnetic parameter, feature It is, it is identical according to the impedance computation of two kinds of analog boards value, it calculates and obtains the corresponding simulation plate thickness of different frequency incident plane wave Degree correction term method include:

Analog board thickness correction item δ (ω) are as follows:

δ (ω)=solve [z_M(δ,ω)-z_N(δ, ω)=0].

6. the method according to claim 5 for removing Fabry-Perot puppet resonance backstepping composite material electromagnetic parameter, feature It is, the calculation formula of analog board thickness correction item δ (ω) and impedance further according to acquisition calculate the correction of composite material to be measured Impedance z.

7. the method according to claim 6 for removing Fabry-Perot puppet resonance backstepping composite material electromagnetic parameter, feature It is, the refractive index n of the composite material to be measured are as follows:

k₀Dn=jln { S₂₁/[1-S₁₁(z-1)/(z+1)]}+2mπ。

8. the method according to claim 7 for removing Fabry-Perot puppet resonance backstepping composite material electromagnetic parameter, feature It is, the electromagnetic parameter for obtaining composite material to be measured is calculated by the correction impedance of composite material to be measured and refractive index:

ε_eff=n/z, μ_eff=nz,

ε in formula_effFor the effective dielectric constant of composite material to be measured, μ_effFor the equivalent permeability of composite material to be measured.

9. the Fabry-Perot puppet resonance backstepping composite material electromagnetic parameter according to any one of claim 1 to 9 of going Method, which is characterized in that the composite material to be measured includes two-dimentional mixture or three-dimensional cylinder type medium or super surface.

Technical field

The present invention relates to the methods for removing Fabry-Perot puppet resonance backstepping composite material electromagnetic parameter, belong to composite material Electromagnetic parameter acquiring technology field.

Background technique

Early in the 1970s, Nicolson (NICOLSON) and Ross (ROSS) describe a kind of Transient Technique, use In the complex permeability and dielectric constant of linear material of the analysis scattering parameter within the scope of 0.4 to 10GHZ.Based on scattering parameter, Weir (WEIR) proposes similar inversion formula.Therefore, Buddhist nun is also referred to as using scattering parameter (S parameter) inverting electromagnetic parameter Section's Ademilson-Ross-Weir (NRW) method.Nearly ten years, NRW method has become characterization new structure and material (such as Meta Materials) is macro See one of most common method of electromagnetic response.In homogenization process, it is commonly encountered two critical issues related with NRW method: one A is branch's ambiguity of refractive index, and refractive index is an intermediate parameters in retrieving, is not solved uniquely；The other is Fabry-Perot (Fabry-P é rot) puppet resonance can serious shadow when sample panel is with a thickness of the integral multiple of effective wavelength in plate Ring frequency dependence parameter.

Compared with Fabry-P é rot puppet resonance, branch's ambiguity of refractive index is receive more and more attention, especially In Meta Materials field.When being related to Fabry-P é rot puppet resonance, people usually have ignored Fabry-P é rot puppet resonance and are brought Electromagnetic parameter distortion and eliminate these distortion respective compensation methods.Reason includes following two points: first according to inverting Formula, as input reflection coefficient S₁₁When being close to 1, equation (1) below can become unstable, while output reflection coefficient S₂₁ It goes to zero, so as to cause the distortion of Fabry-P é rot puppet resonance.When the reflection of the first and second plate interfaces is cancelled out each other When, i.e., when slab-thickness is the integral multiple of internal effective wavelength half, the distortion of Fabry-P é rot puppet resonance will be generated.However, Most of Meta Materials are all lossy in interested frequency band.In the case where loss, part electromagnetic energy in the material by It dissipates, therefore the unstable condition of the equation (1) will not meet simultaneously.Therefore, Fabry-P é rot puppet resonance distortion can lead to The loss for crossing electromagnetic energy is eased.Secondly, the Lorentz that the electromagnetic parameter of Meta Materials often shows wide frequency ranges is total Vibration.This shows the value of backstepping parameter, such as the real and imaginary parts of dielectric constant, may change in sizable dynamic range. Although this variation is easy ignored in Meta Materials characterization, for low-loss dielectric composite material, with NRW inversion method electricity When magnetic parameter, the distortion that result is homogenized caused by Fabry-P é rot puppet resonance is more significant.

Nicolson-Ross-Weir (NRW) method specifically:

k₀Dn=jln { S₂₁/[1-S₁₁(z-1)/(z+1)] }+2m π, (2)

ε_eff=n/z, μ_eff=nz, (3)

Wherein, z is impedance, k₀For free space wave vector, d is thickness of composite material, and n is refractive index, and m is integer, m For logarithmic function ln { S₂₁/[1-S₁₁(z-1)/(z+1)] } Branch Index, m difference is corresponding different branch's ambiguity；ε_eff For effective dielectric constant, μ_effFor equivalent permeability.

In order to eliminate Fabry-P é rot puppet resonance, a kind of compensation method based on non magnetic hypothesis is proposed, especially pair In the dielectric composite material with periodic arrangement unit.Unfortunately, compensation method introduces in corresponding EFFECTIVE MEDIUM Error.Under the irradiation of normal incidence plane wave, it can not gradually reproduce scattering parameter identical with true composite material.

Therefore, against the above deficiency, it is desirable to provide a kind of acquisition methods of composite material electromagnetic parameter can remove The distortion of electromagnetic parameter brought by Fabry-P é rot puppet resonance.

Summary of the invention

For in existing composite material electromagnetic parameter acquisition process, having ignored electricity brought by Fabry-P é rot puppet resonance The distortion of magnetic parameter, makes the problem of the result inaccuracy of electromagnetic parameter, and the present invention provides one kind and goes Fabry-Perot puppet resonance inverse The method for pushing away composite material electromagnetic parameter.

A kind of method for removing Fabry-Perot puppet resonance backstepping composite material electromagnetic parameter of the invention, including following step It is rapid:

Composite material to be measured is simulated, M layers of structural simulation plate and N layers of structural simulation plate are obtained；In two kinds of analog boards The both ends of layer structure direction are respectively connected to waveguide port, are respectively perpendicular irradiation analog board by simulation plate surface with incident plane wave, The scattering parameter analogue value for obtaining two kinds of analog boards is calculated separately according to irradiation result；

The impedance computation value for obtaining corresponding analog board is calculated according to the scattering parameter analogue value of two kinds of analog boards；

It is identical according to the impedance computation of two kinds of analog boards value, it calculates and obtains the corresponding analog board of different frequency incident plane wave Thickness correction item；

Calculate the correction impedance for obtaining composite material to be measured again according to analog board thickness correction item, and then determination is to be measured compound The refractive index of material is calculated the electromagnetic parameter for obtaining composite material to be measured by the correction impedance of composite material to be measured and refractive index.

The method according to the present invention for removing Fabry-Perot puppet resonance backstepping composite material electromagnetic parameter, it is described to be measured Composite material is simulated, and the method for obtaining M layers of structural simulation plate and N layers of structural simulation plate includes:

It is modeled using fullwave simulator, obtains composite material model to be measured, include i layers of structure and preset length in model Free space, i=M or N；Wherein every layer of structure includes the analogue unit of array arrangement, each analogue unit include it is a kind of or The composite construction that a variety of dielectric materials are constituted；The freely empty of preset length is supplemented respectively at the both ends of analog board layer structure direction Between, obtain M layers of structural simulation plate and N layers of structural simulation plate, analog board with a thickness of d, d=Mh+2d_ADOr d=Nh+2d_AD, formula Middle h is the thickness of single layer structure, d_ADFor the length of the free space.

The method according to the present invention for removing Fabry-Perot puppet resonance backstepping composite material electromagnetic parameter selects the pole TMxy Change plane wave as incident plane wave and vertical irradiation is carried out to M layers of structural simulation plate and N layers of structural simulation plate.

The method according to the present invention for removing Fabry-Perot puppet resonance backstepping composite material electromagnetic parameter, it is described according to two The scattering parameter analogue value of kind of analog board, which calculates, to be obtained the impedance computation value of corresponding analog board and includes:

Impedance computation value z_i(δ, ω) are as follows:

δ is analog board thickness correction item in formula, and ω is plane of incidence wave frequency rate；S_11,iFor the input reflection system of analog board Number, S_21,iFor the output reflection coefficient of analog board；

Wherein:

In formulaFor the input reflection coefficient analogue value of analog board,For the output reflection coefficient analogue value of analog board, k₀ For free space wave vector, d_ADFor the length of the free space.

The method according to the present invention for removing Fabry-Perot puppet resonance backstepping composite material electromagnetic parameter, according to two kinds of moulds The impedance computation value of quasi- plate is identical, calculates the method packet for obtaining the corresponding analog board thickness correction item of different frequency incident plane wave It includes:

Analog board thickness correction item δ (ω) are as follows:

δ (ω)=solve [z_M(δ,ω)-z_N(δ, ω)=0].

The method according to the present invention for removing Fabry-Perot puppet resonance backstepping composite material electromagnetic parameter, further according to acquisition Analog board thickness correction item δ (ω) and the calculation formula of impedance calculate the correction impedance z of composite material to be measured.

The method according to the present invention for removing Fabry-Perot puppet resonance backstepping composite material electromagnetic parameter, it is described to be measured multiple The refractive index n of condensation material are as follows:

k₀Dn=jln { S₂₁/[1-S₁₁(z-1)/(z+1)]}+2mπ。

The method according to the present invention for removing Fabry-Perot puppet resonance backstepping composite material electromagnetic parameter, by be measured compound The correction impedance of material and refractive index calculate the electromagnetic parameter for obtaining composite material to be measured:

ε_eff=n/z, μ_eff=nz,

ε in formula_effFor the effective dielectric constant of composite material to be measured, μ_effFor the equivalent permeability of composite material to be measured.

The method according to the present invention for removing Fabry-Perot puppet resonance backstepping composite material electromagnetic parameter, it is described to be measured multiple Condensation material includes two-dimentional mixture or three-dimensional cylinder type medium or super surface.

Beneficial effects of the present invention: the present invention is based on the methods for removing Fabry-P é rot puppet resonance backstepping to obtain composite material Electromagnetic parameter, and Numerical Validation can be carried out, it was demonstrated that the feasibility of the method for the present invention.The present invention passes through plane of incidence wave measurement Method introduces analog board thickness correction item, and the electromagnetic parameter obtained is made to be no longer influenced by the width as caused by Fabry-P é rot puppet resonance Influence with distortion.Meanwhile electromagnetic parameter is also unrelated with the number of plies of composite material, and as frequency converges to quiet close to zero The estimation of state Rayleigh.The method of the present invention can independently find optimal correction thickness in each frequency of incident plane wave, and And any information about front or rear frequency point is not needed.Simulation results show, the method for the present invention is in accuracy better than others The equivalent intrinsic constitutive parameter backstepping method of reciprocity periodical media composite plate, wherein free space wavelength is the unit cell of composite plate At least 20 times of length.

The principle that the present invention realizes is that the amendment of the equivalent thickness progress by frequency point on super surface is integrated to medium substrate, according to The rule that macroscopical electromagnetic property does not change with the thickness change of medium in homogenization theory, it is achievable to equivalent thickness by frequency Point amendment.Firstly, artificially the different medium of the building number of plies integrates super surface period structure；Then, by the auxiliary of full-wave simulation, Optimal correction value can be obtained by Frequency point by working out least square adaptive algorithm, guarantee different layers of period knots Structure equivalent electromagnetic property parameters having the same.Finally, it completes to integrate repairing by frequency point for super surface equivalent thickness to medium substrate Just.

The method of the present invention passes through the equivalent thickness for determining composite panel under each frequency, corrects the resistance of inappropriate definition Anti-, which is an intermediate parameters being introduced into the retrieving of broadband Fabry-P é rot puppet resonance, thus demonstrates invention The validity of method.

Detailed description of the invention:

Fig. 1 is the process schematic using the method for the present invention by frequency point amendment composite panel；A is the list of analog board in figure Layer structure；For M layers of structure, d=Mh+2d_AD；For N layers of structure, d=Nh+2d_AD；

Fig. 2 is the geometry setting schematic diagram simulated to composite material to be measured；

Fig. 3 is the concrete structure schematic diagram of analog board in the embodiment of the present invention；

Fig. 4 is the impedance z of acquisition and the relation curve of frequency by taking 6 layers of structural simulation plate and 17 layers of structural simulation plate as an example； λ in figure₀Indicate free space wavelength；

Fig. 5 is the effective dielectric constant of 6 layers of structural simulation plate and the graph of relation of frequency；

Fig. 6 is using different inversion methods, i.e., traditional NRW inversion method and method proposed by the present invention, to difference The composite panel inverting effective dielectric constant ε of the number of plies_effWith the graph of relation of normalized frequency；

When Fig. 7 is plane wave and 17 layers of true medium composite materials interaction, S₁₁Amplitude schematic diagram；

When Fig. 8 is plane wave and 17 layers of true medium composite materials interaction, S₁₁Phase schematic diagram；This method in figure It indicates to establish model using the effective electromagnetic parameter that the method for the present invention (calibrated altitude changes with frequency) is calculated, after emulation The S parameter curve arrived, penalty method indicate obtained effective electromagnetic parameter when the calibrated altitude of compensation is fixed value, after emulation The S parameter curve arrived, composite plate indicate the S parameter curve that composite plate emulates；

When Fig. 9 is plane wave and 17 layers of true medium composite materials interaction, S₁₁Amplitude schematic diagram；

When Figure 10 is plane wave and 17 layers of true medium composite materials interaction, S₁₁Phase schematic diagram.

Specific embodiment

Following will be combined with the drawings in the embodiments of the present invention, and technical solution in the embodiment of the present invention carries out clear, complete Site preparation description, it is clear that described embodiments are only a part of the embodiments of the present invention, instead of all the embodiments.It is based on Embodiment in the present invention, those of ordinary skill in the art without creative labor it is obtained it is all its His embodiment, shall fall within the protection scope of the present invention.

It should be noted that in the absence of conflict, the feature in embodiment and embodiment in the present invention can phase Mutually combination.

The present invention will be further explained below with reference to the attached drawings and specific examples, but not as the limitation of the invention.