CN104577324B - Method for designing large-power-resisting broadband radar antenna cover - Google Patents

Abstract

The invention discloses a method for designing a large-power-resisting broadband radar antenna cover, which belongs to the technical field of large-size ground radar antenna covers, and aims to solve the problems that a method for designing an antenna cover starting with material study is not applicable to large-size ground antenna covers. The method comprises the following steps: under the condition of broadband, acquiring maximum power density of radiation of an antenna according to an array antenna aperture field; selecting the material and structural parameters of the wall of the antenna cover; furthermore acquiring electromagnetic radiation energy absorption coefficients; furthermore, with the combination of energy conservation of heat conduction of the antenna cover, acquiring the temperature of the antenna cover under large-power radiation; judging whether the temperature resisting value of the material of the wall of the antenna cover at present is greater than the acquired temperature or not, if the temperature resisting value of the material of the wall of the antenna cover at present is greater than the acquired temperature, taking the antenna cover as a finally designed antenna cover, otherwise, reselecting an antenna cover structure material and redesigning the antenna cover. The method can be used for designing large-size ground radar antenna covers.

Description

A kind of resistance to large-power broadband radome method for designing

Technical field

The invention belongs to the technical field of heavy ground-based radar antenna house.

Background technology

Large-scale ground antenna house is the protective equipment of radar antenna, and it can prevent interference and shadow of the environment to radar equipment Ring, antenna house is made by fiberglass and foaming structure composite more.It is various large-scale as electronic information technology constantly develops Warning, information, early warning radar present that working band is more and more wider, the spy that transmission power is increasing under electronic countermeasure background Point.Under HIGH-POWERED MICROWAVES irradiation, composite is intermolecular to produce high frequency oscillation to antenna house, cause local pyrexia, work as temperature When increasing to over materials'use temperature, antenna house has ablation or even the danger burnt.

The method for solving the resistance to high-power problem of antenna house at present, is started with from investigation of materials mostly, by being damaged from low dielectric Consumption, high-temperature resistant material carry out solve problem.This method is substantially that one kind puts into practice method, lacks theoretical direction, and experimental result is also only A certain detailed programs are can apply to, if design condition changes, can only be tested again.In addition, this analysis method is only suitable for In the small size antenna cover of homogenous material molding, for large-scale antenna dome, different materials complex form, this analysis side are typically adopted Method is not just applied to.In a word, method for designing of the neither one for the resistance to high-power property of large-scale all channel antenna cover is gone back in the industry at present.

The content of the invention

The invention aims to solve at present from investigation of materials start with designing antenna cover method be not suitable for it is large-scale The problem of the design of ground radome, the present invention provides a kind of resistance to large-power broadband radome method for designing.

A kind of resistance to large-power broadband radome method for designing of the present invention, methods described comprises the steps：

Step one：Under the conditions of broadband, according to array antenna aperture field, aerial radiation Ferned Area field intensity value E is calculated, And then the maximum power density P of acquisition aerial radiation_m；

Step 2：Under the requirement for meeting all channel antenna cover, antenna house cover is selected in antenna cover structure list of materials The material and structural parameters of wall；

Step 3：The structural parameters of the antenna house cover wall determined according to step 2, are calculated with four-pole network theory, The power transmission coefficient and reflection coefficient of power of antenna house cover wall are obtained, and then obtains electromagnetic radiation energy absorptance L；

Step 4：According to the maximum power density P that step one is obtained_mSystem is absorbed with the electromagnetic radiation energy that step 3 is obtained Number L, with reference to the preservation of energy of antenna house heat transfer, obtains temperature of the antenna house under high-power irradiation；

Step 5：Table look-up and obtain the resistance to temperature value of current antenna cover cover wall material, judge the resistance to temperature value whether more than step Temperature of four antenna houses for obtaining under high-power irradiation, if so, then the antenna house is the antenna house of final design, if it is not, Then current antenna is covered on into corresponding material structure in antenna cover structure list of materials to delete, proceed to step 2, reselect material Material.

The beneficial effects of the present invention is, method for designing integrated use electromagnetism, thermal conduction study, the materialogy phase of the present invention Knowledge is closed, the design that the existing single method for designing started with from material is not suitable for the antenna house of resistance to large-power broadband is solved Problem.Design process has taken into full account the various premise bars such as antenna electromagnetic property, antenna cover structure characteristic and material parameter Part, is analyzed whole electromagnetic process and diabatic process, the antenna house of design, is irradiated in actual high powered radar long-time Under, resistance to power sexual satisfaction is required.The design method is applied in certain large-scale ground radome design, test result with Design is consistent.

Description of the drawings

Fig. 1 is that the principle of a kind of resistance to large-power broadband radome method for designing described in specific embodiment one is shown It is intended to.

Fig. 2 is the schematic diagram of the antenna house plate using the method for designing design of the present invention.

Fig. 3 is the generalized section of C interlayer cover wall constructions in embodiment.

Fig. 4 is the curve synoptic diagram of the power transmission coefficient obtained using the method for designing of the present invention, and abscissa represents frequency Rate, vertical coordinate is power transmission coefficient.

Fig. 5 is the curve synoptic diagram of the reflection coefficient of power obtained using the method for designing of the present invention, and abscissa represents frequency Rate, vertical coordinate is reflection coefficient of power.

Specific embodiment

Specific embodiment one：Present embodiment, a kind of resistance to high-power broadband described in present embodiment are illustrated with reference to Fig. 1 Band radome method for designing, methods described comprises the steps：

Step one：Under the conditions of broadband, according to array antenna aperture field, aerial radiation Ferned Area field intensity value E is calculated, And then the maximum power density P of acquisition aerial radiation_m；

Step 2：Under the requirement for meeting all channel antenna cover, antenna house cover is selected in antenna cover structure list of materials The material and structural parameters of wall；

Step 3：The structural parameters of the antenna house cover wall determined according to step 2, are calculated with four-pole network theory, The power transmission coefficient and reflection coefficient of power of antenna house cover wall are obtained, and then obtains electromagnetic radiation energy absorptance L；

Step 4：According to the maximum power density P that step one is obtained_mSystem is absorbed with the electromagnetic radiation energy that step 3 is obtained Number L, with reference to the preservation of energy of antenna house heat transfer, obtains temperature of the antenna house under high-power irradiation；

Step 5：Table look-up and obtain the resistance to temperature value of current antenna cover cover wall material, judge the resistance to temperature value whether more than step Temperature of four antenna houses for obtaining under high-power irradiation, if so, then the antenna house is the antenna house of final design, if it is not, Then current antenna is covered on into corresponding material structure in antenna cover structure list of materials to delete, proceed to step 2, reselect material Material.

In step 5, the selected radome material performance indications of contrast, if temperature is in the range of material is allowed after irradiation, Then export design result；Otherwise, there are two kinds of solutions：A readjusts electrical property design, repeat step two, step 3 and step Rapid four, until design temperature rise meets material requirements；The selected material of b adjustment, uses the higher material of operating temperature instead, and determines new The unit for electrical property parameters of material, then repeat step two, step 3 and step 4.

Specific embodiment two：Present embodiment is to a kind of thunder of resistance to large-power broadband described in specific embodiment one Up to the further restriction of radome design method,

In step one, under the conditions of broadband, according to array antenna aperture field, aerial radiation Ferned Area field intensity value is calculated E, and then obtain maximum power density P_mMethod be：

With Antenna aperture center as origin O, in Antenna aperture to set up rectangular coordinate system O-XYZ in the plane of XY, G (x, y) is distributed according to Antenna aperture, antenna is calculated in Ferned Area field intensity value E_P:

In above formula：θ is azimuth plane viewing angle,For pitching face viewing angle, r=R, R are antenna house radius, and k is freely empty Between propagation constant, Integral domain (s) is Antenna aperture, and j is plural number Imaginary part；

When θ=0,When, the axis direction radiation field of Antenna aperture is most strong, Ferned Area field intensity value maximum E_Pmax, Power density now is maximum, maximum power densityη be free space natural impedance, η=120 π；

Ferned Area field intensity value maximum E_PmaxAcquisition methods：

First according to bandwidth, frequency band low side frequency f1, frequency band middle-end frequency f2 and the high-end frequency f3 of frequency band are determined；

Then formula is passed throughThe corresponding wavelength of f1, f2 and f3 is calculated respectively, and c is the light velocity, and f is frequency；

According to the wavelength for calculating, then the corresponding Ferned Area field intensity value of f1, f2 and f3 is calculated respectively；

Take maximum absolute value in the corresponding Ferned Area field intensity value of f1, f2 and f3 for Ferned Area field intensity value maximum E_Pmax。

In present embodiment, antenna outfield is typically divided into three places by antenna house field by distance：Near field, take alunite That area, far-field region；So-called near field refers to that near the region of Antenna aperture be commonly defined as d≤8 λ, d is point of observation and antenna The distance in mouth face, λ is wavelength；Ferned Area is also referred to as near-field field, and Ferned Area lower bound is d=8 λ, and the upper bound is d=2D²/ λ, D are the dimension of Antenna aperture；A long way off, outside Ferned Area, far-field region is just belonged to.Radome is located at the Fei Nieer of antenna Area.

For array antenna, the axis direction radiation field of Antenna aperture is most strong, so the region that antenna house burns at first is The axial positive irradiation area crossed with antenna house of Antenna aperture, this region corresponds to viewing angle and is：θ=0,Can be with this For input condition, Ferned Area field intensity value maximum E is calculated_Pmax。

Specific embodiment three：Present embodiment is to a kind of resistance to high-power broadband described in specific embodiment one or two Further restriction with radome method for designing,

In step 2, the antenna house cover wall construction is C interlayer cover wall constructions, and the C interlayers cover wall construction includes five layers Dielectric-slab, five layers of dielectric-slab be respectively ground floor eyelid covering, third layer eyelid covering, layer 5 eyelid covering, second layer intermediate core layer and 4th layer of intermediate core layer；

The material of ground floor eyelid covering, third layer eyelid covering and layer 5 eyelid covering chooses E glass fibre composite polyester resin glass The material of glass steel, second layer intermediate core layer and the 4th layer of intermediate core layer chooses polyurethane foam, layers of material performance such as following table：

The material property of each layer of table C interlayer cover walls

	Ground floor	The second layer	Third layer	4th layer	Layer 5
						DIELECTRIC CONSTANT εn	4.2	1.08	4.2	1.08	4.2
Loss angle tangent tg δ	0.02	0.002	0.02	0.002	0.02
						Density (kg/m3)	1750	60	1750	60	1750
Heat conductivity (W/m.k)	0.4	0.07	0.4	0.07	0.4
						Specific heat capacity	1100	1000	1100	1000	1100

A interlayer cover wall constructions are adopted current large-scale ground antenna house more.So-called A interlayers, refer to inside and outside thin skin and Middle one layer of sandwich of layers version.From in terms of electric angle, this is a kind of arrowband structure, is not suitable for bandwidth requirement；

For all channel antenna cover, C sandwich forms are adopted in present embodiment.This structure is covered by inside and outside two-layer Skin, a middle eyelid covering and two intermediate core layer compositions.This structure fabrication process is more complicated than A interlayers, but has broader work Make bandwidth.For superwide frequency band (2.0-18G) is required, Chebyshev's multilayer acoustical panel can be adopted.This fabric bandwidths performance is excellent It is different, but manufacturing process has high demands.Consider electrical property and manufacturability, the C interlayer cover wall constructions that present embodiment is chosen, this Structure is planted on the premise of requirement on electric performance is met, with reasonable manufacturability.

Specific embodiment four：Present embodiment is to a kind of thunder of resistance to large-power broadband described in specific embodiment three Up to the further restriction of radome design method, in step 3, the structural parameters of the antenna house cover wall determined according to step 2, fortune Calculated with four-pole network theory, obtained the power transmission coefficient and reflection coefficient of power of antenna house cover wall, and then obtained electricity Magnetic radiation energy absorption coefficient L；

The structural parameters and four-pole network of the antenna house cover wall determined according to step 2 are theoretical, the shape of C interlayer cover wall constructions State transfer matrix is：

In five matrix multiplications in equation the right, one layer of dielectric-slab of each matrix representative C interlayer cover wall constructions, A, B, C It is equal intermediate variable with D, the computation formula of matrix element is：v_nAnd Z_CnIt is intermediate variable；

Z₀Represent personal space wave number；ε₀Represent dielectric constant of air； Represent the plural form dielectric constant of n-th layer, θ₀Represent angle of incidence；

Parameter

Wherein, n represents the number of plies of dielectric-slab, n=1,2 ... 5, d_nRepresent the thickness of n-th layer dielectric-slab, Z₀Represent freely empty Between natural impedance, tg δ_nThe loss angle tangent of n-th layer dielectric-slab is represented, λ represents wavelength, ε_nRepresent that the dielectric of n-th layer dielectric-slab is normal Number；

The structural parameters of five layers of dielectric-slab of antenna house cover wall are：

ε₁=4.2, tg δ₁=0.02, d₁；ε₂=1.08, tg δ₂=0.002, d₂；ε₃=4.2, tg δ₃=0.02, d₃；ε₄= 1.08, tg δ₄=0.002, d₄；ε₅=4.2, tg δ₅=0.02, d₅；

Formula is brought into according to said structure parameter, state-transition matrix is obtained；

According to the state-transition matrix for obtaining, the power transmission coefficient F and reflection coefficient of power R of antenna house cover wall are obtained：

According to the power transmission coefficient F and reflection coefficient of power R of the antenna house cover wall for obtaining, obtain electromagnetic radiation energy and inhale Receive coefficient L：

L=1-L=1- | R |²-|F|²

|F|²、|R|²The respectively modulus value square of plural number F and R.

In present embodiment, the thickness d of dielectric-slab_nIt is adjustable variable according to demand.

Specific embodiment five：Present embodiment is to a kind of resistance to high-power broadband described in specific embodiment one or four Further restriction with radome method for designing, in step 4, according to the maximum power density P that step one is obtained_mAnd step The rapid three electromagnetic radiation energy absorptance L for obtaining, with reference to the preservation of energy of antenna house heat transfer, obtain antenna house in high-power photograph The method of the temperature under penetrating is：

Step 4 one：The microwave energy of spillage of material for obtaining antenna house cover wall is：

ω₁=qS △ t,

Wherein, q absorbs and is converted into the microwave energy of heat energy, q=P for antenna house cover wall_mL, S are microwave irradiation surface Product, △ t are irradiation time；

Step 4 two：Obtain antenna house cover wall and radiate gross energy to surrounding air：

According to this Pan that makes a mistake-Boltzmann law radiant heat flux φ=μ S δ_bT⁴,

In formula：

T for black matrix thermodynamic temperature, δ_bFor the radiation constant of black matrix, and for natural constant, μ for object emissivity；

From 0 to moment t₀Radiant heat flux calorimetric φ is integrated, antenna house cover wall is obtained and is radiated total energy to surrounding air Amount ω₂For:

T_rFor t₀The temperature of moment object；T is the antenna Continuous irradiation time；

Step 4 three：Obtain cross-ventilation radiating total amount of the antenna house cover wall to inner side：

According to Newtonian Cooling formula, from 0 moment to moment t₀Heat loss through convection total amount is：

T₀For ambient temperature；

L is characteristic dimension, takes 0.04；

The span of C is 0.4-0.7；

Step 4 four：Antenna house cover wall is obtained from 0 moment to moment t₀The total amount of heat that the temperature rise of material is absorbed：

ω₄=C₀·ρ·S·h·(T_r-T₀)

C₀For the specific heat capacity of material, ρ is the density of material, and h is the thickness of material；

Step 4 five：According to the preservation of energy ω of antenna house heat transfer₁=ω₂+ω₃+ω₄, antenna house is obtained in high-power photograph Temperature T under penetrating_r。

In present embodiment, the microwave energy that antenna house inside panel absorbs is converted into heat energy, and this energy equivalence is in a warm Source.The portion of energy of thermal source raises material temperature, and another part energy is transmitted to surrounding by heat radiation and thermal convection current mode In environment, whole process preservation of energy.Heat transfer has three kinds of modes, i.e. conduction of heat, heat radiation and thermal convection current.

For antenna house inwall, side is air, and opposite side is foamed sandwich structure.Due to foam heat conductivity very It is little, so conduction of heat is extremely faint can not to consider.

In step 4 one, when microwave is propagated in media as well, the periodic vibration of electromagnetic wave makes the polarization of molecule convergent, molecule Synchronous concussion produces heat, and the microwave energy for obtaining the spillage of material of antenna house cover wall is：ω₁=qA △ t；

It is simultaneously foam layer for antenna house inwall in step 4 three, air therein does not circulate, its Heat loss through convection is negligible, so antenna house inwall only radiates with the cross-ventilation of inner side.According to Newtonian Cooling formula, from 0 then Carving t0 heat loss through convection total amounts is：

C is coefficient, for vertically arranged antenna house, C=0.59；

In step 4 five, material temperature is raised and started soon, and after temperature is raised, the heat dissipation capacity of heat radiation and thermal convection current adds Greatly.So, after a period of time, it is finally reached thermal balance.Using alternative manner, final thermal equilibrium temperature can be calculated T_r。

C interlayer antenna house technological designs in the present invention：

After the completion of electrical property and power capacity design, each structure of output antenna house cover wall, and the material and thickness of each layer.On Output is stated, as the input of technological design.For C sandwiches, antenna house adopts female mould forming technique, cover wall work from outside to inside Skill is separately designed as 5 layers, respectively I exterior skin, II outside laminboard layer, eyelid covering, IV inner side laminboard layer, V inside panel in III, tool Body formed work step is as follows：

One：Spray hydrophobic ageing-resistant gel coating resin in the female mold surfaces for coating releasing agent first；

Two：The hydrophobic ageing-resistant lay exterior skin fiber after gel coating resin solidification simultaneously infiltrates resin, solid in exterior skin resin The outside laminboard layer of preforming is placed during change, then auxiliary material is laid on outside laminboard layer surface, isolating membrane, inducing QI is laid successively and is inhaled Glue-line and vacuum bag film, by vacuum bag film and former periphery sealing is carried out, evacuation pressurization, vacuum pressure typically no less than- 0.06MPa.Be so designed that, make the laminating of hydrophobic ageing-resistant gel coating resin, exterior skin and outside laminboard layer closely, bonding it is firm.

Three：After exterior skin resin solidification, auxiliary material is removed；

Four：Eyelid covering fiber and resin is infiltrated in outside laminboard layer surface lays, placed when middle eyelid covering resin is uncured The outside laminboard layer and lay Inner Mongol hide fiber of preforming simultaneously infiltrate resin, then lay auxiliary material on inside panel surface, spread successively Put release cloth, inducing QI and inhale glue-line and vacuum bag film, vacuum bag film and former periphery are carried out into sealing, evacuation pressurization, vacuum pressure Power is typically no less than -0.08MPa.Be so designed that, make outside laminboard layer, middle eyelid covering, inner side laminboard layer, inside panel laminating closely, Bonding is firm.

Five：After exterior skin resin solidification, remove auxiliary material and by the radome plate demoulding, excision burr, Suo Yougong Step completes that product just can be obtained.

The technique of the C interlayer radome plates, has carried out altogether 3 solidifications, respectively：I hydrophobic ageing-resistant gel coating resin Solidification；The solidification bonding with outside laminboard layer of II ageing-resistant gel coating resin, exterior skin；III outside laminboard layer, middle eyelid covering, inner side sandwich The bonding solidification of layer, inside panel.

This technological design, can effectively ensure that the bonding quality between each layer of C interlayer antenna house cover walls, and bubble-free is existing with layering As without fiber dry spot and the exceeded phenomenon of local resin content, the thickness for making each formable layer reaches design requirement, so as to meet electricity The requirement of performance and power capacity design index.

Embodiment：

The supporting antenna house of certain large-scale early warning radar, 20 meters of antenna house diameter, 16 meters of height of intercepting ball, whole antenna house plate with Machine is divided, as shown in Figure 2.The radar bandwidth of operation 18%, antenna is high-power array antenna.During radome design, Using method for designing of the present invention and sample cover is made.Sample cover has carried out the use more than position testing and half a year, measured result It is consistent with design, property indices meet requirement.

Specific design process is as follows：

Maximum power density is calculated using step one methods described.Choose f1 (low side frequency), f2 (middle-end frequency), f3 (high-end frequency) three frequencies carry out respectively power density computation, and result of calculation is P_m1=1.6W/cm², P_m2=1.2W/cm², P_m3 =1.7W/cm².The maximum of three result of calculation is taken, and considers certain safety coefficient, final maximum power density is P_m= 2W/cm²,

Through electrical property and the comprehensive demonstration of the aspect of product structure intensity two, antenna house adopts C sandwiches, and cross-section structure is such as Shown in Fig. 3, structural material parameter is shown in Table 1.

Cross-section structure optimization design is carried out using step 3 computational methods, design result is d1=0.6mm, d2=21mm, D3=0.8mm, d4=21mm, d5=0.6mm.Power transmission coefficient | L |²And reflection coefficient of power | R |²Result of calculation, such as scheme Shown in 4 and Fig. 5.See from Fig. 4, in whole frequency band range, do not consider that side rib affects, the transmission coefficient of antenna house is more than 93%, this index meets electrical property design requirement.In whole frequency band, electromagnetic radiation energy absorptance L is less than 4.5%, Final L takes 5%.

Using the method for step 4, using the result of electrical property design as input, Calculation of Heat Transfer is carried out.In ambient temperature 30 Under the conditions of DEG C, antenna house is irradiated by high powered antenna, and through 3800 seconds thermal equilibrium state was reached.When thermal balance, in antenna house Surface balance temperature is 52.4 DEG C, and center skin temperature is 49.3 DEG C, and exterior skin temperature is 46.7 DEG C, foam core material maximum temperature For 48.9 DEG C.Each layer temperature can meet resistance to power input requirements in material tolerance band.

After the completion of design, technological design is carried out using step 6 methods described, finally complete sample cover and manufacture.

After sample cover completes, position is carried out and has set up and electric performance test.Test result shows that antenna house is every electrically Energy index meets design requirement.Resistance to high-power aspect of performance, antenna house is raised by high-power irradiation temperature, and temperature rise numerical value receives bar Part is limited and not measured, but by observation, antenna house surface does not find to burn yellow, the black or burn observations of burning, with reference to Material property parameter comprehensive analysis, antenna house temperature rise is in the range of design temperature.

Claims (5)

1. a kind of resistance to large-power broadband radome method for designing, it is characterised in that methods described comprises the steps：

Step one：Under the conditions of broadband, according to array antenna aperture field, aerial radiation Ferned Area field value E is calculated, and then obtained Obtain the maximum power density P of aerial radiation_m；

Step 2：Under the requirement for meeting all channel antenna cover, antenna house cover wall is selected in antenna cover structure list of materials Material and structural parameters；

Step 3：The structural parameters of the antenna house cover wall determined according to step 2, are calculated with four-pole network theory, are obtained The power transmission coefficient and reflection coefficient of power of antenna house cover wall, and then obtain electromagnetic radiation energy absorptance L；

Step 4：According to the maximum power density P that step one is obtained_mThe electromagnetic radiation energy absorptance L obtained with step 3, With reference to the preservation of energy of antenna house heat transfer, temperature of the antenna house under high-power irradiation is obtained；

Step 5：Table look-up and obtain the resistance to temperature value of current antenna cover cover wall material, judge whether the resistance to temperature value obtains more than step 4 Temperature of the antenna house for obtaining under high-power irradiation, if so, then the antenna house is the antenna house of final design, if it is not, then will Current antenna covers on corresponding material structure in antenna cover structure list of materials and deletes, and proceeds to step 2, reselects material.

2. a kind of resistance to large-power broadband radome method for designing according to claim 1, it is characterised in that

In step one, under the conditions of broadband, according to array antenna aperture field, aerial radiation Ferned Area field value E is calculated, and then Obtain maximum power density P_mMethod be：

With Antenna aperture center as origin O, in Antenna aperture to set up rectangular coordinate system O-XYZ in the plane of XY, according to Antenna aperture is distributed, and calculates antenna in Ferned Area field value E_P:

$E_P=\frac{j(1+cos\mathrm{\θ})}{2\mathrm{\λ}}\frac{e^{-jkr}}{r}\underset{\left(s\right)}{\∫\∫}g(\mathrm{\ξ},\mathrm{\η})\exp \[jk(\mathrm{\α}\mathrm{\ξ}+\mathrm{\β}\mathrm{\η})-\frac{({\mathrm{\ξ}}^2+{\mathrm{\η}}^2)-{(\mathrm{\α}\mathrm{\ξ}+\mathrm{\β}\mathrm{\η})}^2}{2}\]d\mathrm{\ξ}d\mathrm{\η}$

In above formula：θ is azimuth plane viewing angle,For pitching face viewing angle, r=R, R is antenna house radius, and k is free-space propagation Constant,Integral domain (s) is Antenna aperture, and j is imaginary part；

When θ=0,When, the axis direction radiation field of Antenna aperture is most strong, Ferned Area field value maximum E_Pmax, now Power density is maximum, maximum power densityη be free space natural impedance, η=120 π；

When θ=0,When, the Ferned Area field is worth maximum E_PmaxAcquisition methods：

First according to bandwidth, frequency band low side frequency f1, frequency band middle-end frequency f2 and the high-end frequency f3 of frequency band are determined；

Then formula is passed throughThe corresponding wavelength of f1, f2 and f3 is calculated respectively, and the c is the light velocity, and f is frequency；

According to the wavelength for calculating, then the corresponding Ferned Area field value of f1, f2 and f3 is calculated respectively；

Take maximum absolute value in the corresponding Ferned Area field value of f1, f2 and f3 for Ferned Area field value maximum E_Pmax。

3. a kind of resistance to large-power broadband radome method for designing according to claim 1 and 2, it is characterised in that

In step 2, the antenna house cover wall construction is C interlayer cover wall constructions, and the C interlayers cover wall construction includes five layers of medium Plate, five layers of dielectric-slab is respectively ground floor eyelid covering, second layer eyelid covering, third layer eyelid covering, the 4th layer of intermediate core layer and the 5th Layer intermediate core layer；

The material of ground floor eyelid covering, second layer eyelid covering and third layer eyelid covering chooses E glass fibre composite polyester resin fiberglass, The material of four layers of intermediate core layer and layer 5 intermediate core layer chooses polyurethane foam, layers of material performance such as following table：

The material property of each layer of table C interlayer cover walls

4. a kind of resistance to large-power broadband radome method for designing according to claim 3, it is characterised in that step In three, the structural parameters of the antenna house cover wall determined according to step 2 are calculated with four-pole network theory, obtain antenna house The power transmission coefficient of cover wall and reflection coefficient of power, and then obtain electromagnetic radiation energy absorptance L；

The structural parameters and four-pole network of the antenna house cover wall determined according to step 2 are theoretical, and the state of C interlayer cover wall constructions turns Moving matrix is：

$\left[\begin{array}{cc}A& B\\ C& D\end{array}\right]=\left[\begin{array}{cc}{A}_1& B_1\\ C_1& D_1\end{array}\right]\left[\begin{array}{cc}{A}_2& B_2\\ C_2& D_2\end{array}\right]\left[\begin{array}{cc}{A}_3& B_3\\ C_3& D_3\end{array}\right]\left[\begin{array}{cc}{A}_4& B_4\\ C_4& D_4\end{array}\right]\left[\begin{array}{cc}{A}_5& B_5\\ C_5& D_5\end{array}\right]$

In five matrix multiplications in equation the right, one layer of dielectric-slab of each matrix representative C interlayer cover wall constructions, A, B, C and D are Equal intermediate variable, the computation formula of matrix element is：v_nAnd Z_CnIt is intermediate variable；

Z₀Represent free space wave number；ε₀Represent dielectric constant of air；Represent the The plural form dielectric constant of n-layer, θ₀Represent angle of incidence；

Parameter

$v_n{d}_n=\frac{2{\mathrm{\πd}}_n}{\mathrm{\λ}}\sqrt{\frac{{\stackrel{\·}{\mathrm{\ϵ}}}_n}{{\mathrm{\ϵ}}_0}-{\sin }^2{\mathrm{\θ}}_0},$

Wherein, n represents the number of plies of dielectric-slab, n=1,2 ... 5, d_nRepresent the thickness of n-th layer dielectric-slab, Z₀Represent free space wave Impedance, tg δ_nRepresent the loss angle tangent of n-th layer dielectric-slab, θ₀Angle of incidence is represented, λ represents wavelength, ε_nRepresent n-th layer dielectric-slab Dielectric constant；

The structural parameters of five layers of dielectric-slab of antenna house cover wall are：

ε₁=4.2, tg δ₁=0.02, d₁；ε₂=1.08, tg δ₂=0.002, d₂；ε₃=4.2, tg δ₃=0.02, d₃；ε₄=1.08, tgδ₄=0.002, d₄；ε₅=4.2, tg δ₅=0.02, d₅；d_nIt is the variable being adjusted according to demand；

Formula is brought into according to said structure parameter, state-transition matrix is obtained；

According to the state-transition matrix for obtaining, the power transmission coefficient F and reflection coefficient of power R of antenna house cover wall are obtained：

$F=\frac{2}{A+B/Z_{C0}+{\mathrm{CZ}}_{C0}+D},$

$R=\frac{A+B/Z_{C0}-{\mathrm{CZ}}_{C0}-D}{A+B/Z_{C0}+{\mathrm{CZ}}_{C0}+D};$

$Z_{C0}=\left\{\begin{array}{c}{Z^{//}}_{C0}=Z_{0}cos{\mathrm{\θ}}_0\\ {Z^{\⊥}}_{C0}=Z_0/{\mathrm{cos\θ}}_0\end{array}\right.;$

According to the power transmission coefficient F and reflection coefficient of power R of the antenna house cover wall for obtaining, obtain electromagnetic radiation energy and absorb system Number L：

L=1- | R |²-|F|²

|F|²、|R|²The respectively modulus value square of plural number F and R.

5. a kind of resistance to large-power broadband radome method for designing according to claim 1 or 4, it is characterised in that In step 4, according to the maximum power density P that step one is obtained_mThe electromagnetic radiation energy absorptance L obtained with step 3, knot The preservation of energy of antenna house heat transfer is closed, the method for obtaining temperature of the antenna house under high-power irradiation is：

Step 4 one：The microwave energy of spillage of material for obtaining antenna house cover wall is：

ω₁=qS △ t,

Wherein, q absorbs and is converted into the microwave energy of heat energy, q=P for antenna house cover wall_mL, S be microwave irradiation surface area, △ T is irradiation time；

Step 4 two：Obtain antenna house cover wall and radiate gross energy to surrounding air：

According to this Pan that makes a mistake-Boltzmann law radiant heat flux φ=μ S δ_bT⁴,

In formula：

T for black matrix thermodynamic temperature, δ_bFor the radiation constant of black matrix, and for natural constant, μ for object emissivity；

From 0 to moment t₀Radiant heat flux calorimetric φ is integrated, antenna house cover wall is obtained and is radiated gross energy ω to surrounding air₂ For:

${\mathrm{\ω}}_2={\∫}_0^{t_0}{\mathrm{\μS\δ}}_b{\left(\frac{t}{t_0}\right(T_r+273\left)\right)}^{4}dt,$

T_rFor t₀The temperature of moment object；T is the antenna Continuous irradiation time；

Step 4 three：Obtain cross-ventilation radiating total amount of the antenna house cover wall to inner side：

According to Newtonian Cooling formula, from 0 moment to moment t₀Heat loss through convection total amount is：

${\mathrm{\ω}}_3={\∫}_0^{t_0}2.5S\·C\·{\left(\frac{t}{t_0}\right(T_r-T_0\left)\right)}^{1.25}/l^{0.25}dt$

T₀For ambient temperature；

L is characteristic dimension, takes 0.04；

The span of C is 0.4-0.7；

Step 4 four：Antenna house cover wall is obtained from 0 moment to moment t₀The total amount of heat that the temperature rise of material is absorbed：

ω₄=C₀·ρ·S·h·(T_r-T₀)

C₀For the specific heat capacity of material, ρ is the density of material, and h is the thickness of material；

Step 4 five：According to the preservation of energy ω of antenna house heat transfer₁=ω₂+ω₃+ω₄, acquisition antenna house is under high-power irradiation Temperature T_r。