CN103745060B - Large-scale antenna dome electrical performance compensation method based on reflecting surface figuration - Google Patents

Abstract

The invention discloses a kind of large-scale antenna dome electrical performance compensation method based on reflecting surface figuration, mainly solve the problem that antenna house is excessive on antenna electric performance impact.Its technical scheme is: calculate Antenna Far Field according to aperture field, draws far-field pattern and extracts electrical performance indexes；Calculate the aperture field through antenna house；Calculate the coordinate of point on Shaped reflector；The aperture field of antenna house is passed through after calculating reflecting surface figuration；Calculate the far field of reflecting surface figuration front and back belt cover antenna, draw far-field pattern and extract electrical performance indexes；Contrast is without cover antenna, the far-field pattern of reflecting surface figuration front and back belt cover antenna and electrical performance indexes, and as met the requirement on electric performance of antenna, then output is without cover antenna, the far-field pattern of reflecting surface figuration front and back belt cover antenna and electrical performance indexes；Otherwise, Shaped reflector is finely adjusted, and repeats said process, until electrical property meets requirement.The present invention can be effectively improved the electrical property of band cover antenna system, can be used for analysis and the design of antenna house.

Description

Large-scale antenna dome electrical performance compensation method based on reflecting surface figuration

Technical field

The invention belongs to Radar Antenna System field, specifically a kind of radome electrical property energy compensation method, can be used for band The electrical property having the reflector antenna system of dielectric interlayer formula antenna house compensates.

Technical background

Antenna house is the wave transparent shell protecting an antenna from natural environment influence, is made up of natural or artificial dielectric's material Covering, or the bright window of electromagnetism of the special shape being made up of the dielectric housing of truss support.The antenna house of excellent in design, In addition to there is protectiveness, conductivity, reliability, the function such as disguised and ornamental, it is also possible to extend whole system each several part Service life, reduce Life Cost and running cost, simplification design, reduce maintenance cost, ensure antenna surface and position Degree of accuracy, create good working environment to antenna operation personnel.But the electromagnetic radiation of ideal antenna also can be produced by antenna house Raw impact, makes preferable antenna electric performance decrease.

Along with progress and the development of military situation of China's aviation, meteorology and military technology, carry out long-range precision tracking survey The research of the High Accuracy Radars such as amount radar and high-gain aerial and manufacture have become urgent task.And Special geographical position from So environment is relatively big on the impact of equipment, and being equipped with antenna house becomes these radars, the requisite requirement of antenna, dielectric interlayer formula sky Irdome is widely used with its good structural behaviour and electrical property.

Du Yaowei analyzes dielectric interlayer in classical works " antenna house telecommunications design method " book of publication in 1993 The impact on Antenna Far Field of the formula antenna house, first the method obtains the transmission coefficient of antenna house, then according to the aperture field of antenna Obtaining the aperture field after covering with the transmission coefficient of antenna house, integration obtains the far field of covering aft antenna.The deficiency of the method is: Do not account for being improved the electrical property of band cover antenna system by reflecting surface figuration.

Ren Yahong uses physical optical method to analyze method in the paper " research of single reflection surface antenna figuration " of 2012, will Reflector shape represents with one group of orthogonal polynomial, carrys out Shaped-beam reflector antenna, to realize antenna by optimizing multinomial coefficient Required electrical property, but reflecting surface figuration is not applied in the compensation to covering aft antenna electrical property by the method.

Summary of the invention

Present invention aims to above-mentioned the deficiencies in the prior art, it is provided that a kind of large-scale sky based on reflecting surface figuration Irdome electrical performance compensation method, to improve the electrical property of band cover antenna system.

For achieving the above object, technical scheme comprises the steps:

(1) according to known antenna aperture field E, (x y), calculates the far field F (θ, φ) of antenna, draws far-field pattern T₁, And from far-field pattern, extract electrical performance indexes, i.e. maximum field strength G₁, the first secondary lobe L₁And beam angle R₁；

(2) transmission coefficient at each point is calculated on antenna house by transmission line theoryAnd calculate through the mouth after antenna house Field, footpath: $E^{\′}(x,y)=E(x,y)\·\stackrel{\·}{T_M};$

(3) according to through the aperture field E ' after antenna house, (x, y), calculates the far field F ' (θ, φ) of band cover antenna, draws remote Field pattern T₂, and from this far-field pattern, extract maximum field strength G₂, the first secondary lobe and beam angle R₂These electrical properties refer to Mark；

(4) with (x, y, z) represent the coordinate in ideally-reflecting face, and the z coordinate changing ideally-reflecting face is z ', obtains figuration anti- The coordinate penetrating face is (x, y, z ')；

(5) according to the coordinate of point on gained Shaped-beam reflector antenna, the aperture field phase contrast that reflecting surface figuration causes is calculated Through the aperture field E of antenna house after Δ ψ, and then calculating reflecting surface figuration " (x, y)；

(6) according to the aperture field E passing through antenna house after reflecting surface figuration, " (x y), calculates band cover antenna after reflecting surface figuration Far field F " (θ, φ) draws this far-field pattern T₃, and from far-field pattern, extract maximum field strength G₃, the first secondary lobe L₃And Beam angle R₃These electrical performance indexes；

(7) according to the far-field pattern obtained in step (1), (3), (6) and corresponding electrical performance indexes, after calculating covering The knots modification of the electrical performance indexes of band cover antenna system after the knots modification of antenna electric performance index, and calculating reflecting surface figuration；

(8) according to the requirement on electric performance of Antenna Design, it is judged that the electrical performance indexes of system after covering and reflecting surface figuration Whether knots modification meets preset requirement, if it is satisfied, then the far-field pattern obtained in output step (1), (3), (6) is with corresponding Electrical performance indexes；Otherwise, Shaped reflector is finely adjusted, and repeats step (5) to step (8), until meeting electrical property Requirement.

Due to the fact that employing reflecting surface figuration to compensate the phase distortion of covering aft antenna aperture field, thus with existing skill Art is compared, and improves the electrical property of band cover antenna system.

Simulation result shows, uses after this method compensates, the maximum field strength of band cover antenna system, minor level and Beam angle all has clear improvement, and the adverse effect of antenna electric performance is diminished by antenna house.

Accompanying drawing explanation

Fig. 1 be the present invention realize general flow chart；

Fig. 2 is to calculate the sub-process figure through the aperture field after antenna house in the present invention；

Fig. 3 is the structure chart of dielectric interlayer formula antenna house；

Fig. 4 is the cross section structure schematic diagram of the antenna house in Fig. 3;

Fig. 5 is the far-field pattern of antenna;

Fig. 6 is the far-field pattern of band cover antenna;

Fig. 7 is the far-field pattern of band cover antenna after reflecting surface figuration.

Detailed description of the invention

Referring to the drawings the present invention is described in further detail.

With reference to Fig. 1, the present invention specifically comprises the following steps that

Step one, calculates Antenna Far Field according to the known aperture field of antenna.

(1a) with antenna opening diametric plane center for initial point O, the plane that bore face is xy is set up rectangular coordinate system O- Xyz, according to known antenna aperture field distribution E (x, y), calculate antenna far field value F (θ, φ):

$F(\mathrm{\θ},\mathrm{\φ})=\underset{S}{\∫\∫}E(x,y)e^{{\mathrm{jk}}_0\sin \mathrm{\θ}(x\cos \mathrm{\φ}+y\sin \mathrm{\φ})}\mathrm{dxdy},$

Wherein, θ, φ are point of observation spherical coordinates angles in rectangular coordinate system O-xyz, k₀For free-space propagation constant, By formulaCalculate, λ is the wavelength of antenna, according to operating frequency of antenna f and light velocity c, passes through formulaCalculate Arriving, s is the area of integral unit；

(1b) far-field pattern T is drawn according to gained Antenna Far Field F (θ, φ)₁, and from this far-field pattern, extract electricity Performance indications, i.e. maximum field strength G₁, the first secondary lobe L₁With beam angle R₁。

Step 2, calculates through the aperture field after antenna house.

Reference Fig. 2, being implemented as follows of this step:

(2a) in Mercantile Models analyzes software, the several of dielectric interlayer formula antenna house are set up according to the version of antenna house What model, arranges a length of λ of Grid Edge, model is carried out stress and strain model；

(2b) according to structural parameters and the material parameter of antenna house, with transmission line theory calculate on antenna house at each point saturating Penetrate coefficient $\stackrel{\·}{T_M:}$

(2b1) according to geometry and the incident aperture field of antenna house, the incidence angle θ at each point on antenna house is obtained_M With polarizing angle φ_M, incidence angle θ will be designated as by the normal angle at electromagnetic wave incident line and incidence point_M, by polarization of electromagnetic wave side It is designated as polarizing angle φ to the angle with plane of incidence_M, wherein plane of incidence is by the normal structure of electromagnetic wave incident line Yu incidence point Become；

(2b2) according to thickness d, the relative dielectric constant ε of antenna house_r, losstangenttanδ, calculate each point on antenna house The horizontal polarized components transmission coefficient at placeWith perpendicular polarisation components transmission coefficient

$\stackrel{\·}{T_H}=\frac{2}{\stackrel{\·}{A}+\stackrel{\·}{B_H}+\stackrel{\·}{C_H}+\stackrel{\·}{D}}=T_H{e}^{{-\mathrm{j\η}}_H}$

$\stackrel{\·}{T_V}=\frac{2}{\stackrel{\·}{A}+\stackrel{\·}{B_V}+\stackrel{\·}{C_V}+\stackrel{\·}{D}}=T_V{e}^{{-\mathrm{j\η}}_V}$

Wherein, $\stackrel{\·}{A}=\mathrm{ch}\left(j\stackrel{\·}{V}d\right),\stackrel{\·}{B_H}=\frac{\stackrel{\·}{Z_{1H}}\mathrm{sh}\left(j\stackrel{\·}{V}d\right)}{Z_H},\stackrel{\·}{B_V}=\frac{\stackrel{\·}{Z_{1V}}\mathrm{sh}\left(j\stackrel{\·}{\mathrm{Vd}}\right)}{Z_V},\stackrel{\·}{C_H}=\frac{Z_H\mathrm{sh}\left(j\stackrel{\·}{\mathrm{Vd}}\right)}{\stackrel{\·}{Z_{1H}}},$

$\stackrel{\·}{C_V}=\frac{Z_V\mathrm{sh}\left(j\stackrel{\·}{\mathrm{Vd}}\right)}{\stackrel{\·}{Z_{1V}}},\stackrel{\·}{D}=\mathrm{ch}\left(j\stackrel{\·}{\mathrm{Vd}}\right),\stackrel{\·}{V}=\frac{2\mathrm{\π}}{\mathrm{\λ}}\sqrt{\stackrel{\·}{{\mathrm{\ϵ}}_r}-{\sin }^2{\mathrm{\θ}}_M},\stackrel{\·}{Z_{1H}}=\sqrt{\stackrel{\·}{{\mathrm{\ϵ}}_r}-\frac{{\sin }^2{\mathrm{\θ}}_M}{{\stackrel{\·}{\mathrm{\ϵ}}}_r}},\stackrel{\·}{Z_{1V}}=\frac{1}{\sqrt{\stackrel{\·}{{\mathrm{\ϵ}}_r}-{\sin }^2{\mathrm{\θ}}_M}},$

$\stackrel{\·}{{\mathrm{\ϵ}}_r}={\mathrm{\ϵ}}_r(1-j\tan \mathrm{\δ}),$ Z_H=cos θ_M, $Z_V=\frac{1}{\cos {\mathrm{\θ}}_M},$ These parameters are intermediate variable；T_H、T_VIt is respectivelyModulus value, η_H、η_VIt is respectivelyPhase place；

(2b3) according to horizontal polarized components transmission coefficientWith perpendicular polarisation components transmission coefficientObtain main polarization point The transmission coefficient of amount:

$\stackrel{\·}{T_M}=\sqrt{T_H^2{\cos }^4{\mathrm{\φ}}_M+T_V^2{\sin }^4{\mathrm{\φ}}_M+{2T}_H{T}_V\cos ({\mathrm{\η}}_H-{\mathrm{\η}}_V){\cos }^2{\mathrm{\φ}}_M{\sin }^2{\mathrm{\φ}}_M}\·e^{-j({\mathrm{\η}}_H-\mathrm{\α})},$

Wherein, $\mathrm{\α}=\arctan \frac{T_V{\sin }^2{\mathrm{\φ}}_M\sin ({\mathrm{\η}}_H-{\mathrm{\η}}_V)}{T_H{\cos }^2{\mathrm{\φ}}_M+T_V\cos ({\mathrm{\η}}_H-{\mathrm{\η}}_V){\sin }^2{\mathrm{\φ}}_M}$ For intermediate variable；

(2c) aperture field incided on cover body is multiplied by the transmission coefficient of its corresponding point position, calculates through after antenna house Aperture field: $E^{\′}(x,y)=E(x,y)\·\stackrel{\·}{T_M}.$

Step 3, calculates the far field of band cover antenna.

(3a) according to through after antenna house aperture field E ' (x, y), calculate band cover antenna far field F ' (θ, φ):

$F^{\′}(\mathrm{\θ},\mathrm{\φ})=\underset{S}{\∫\∫}{E}^{\′}(x,y)e^{{\mathrm{jk}}_0\sin \mathrm{\θ}(x\cos \mathrm{\φ}+y\sin \mathrm{\φ})}\mathrm{dxdy},$

(3b) far-field pattern T is drawn according to gained far field F ' (θ, φ)₂, and from this far-field pattern, extract maximum field Strong G₂, the first secondary lobe L₂With beam angle R₂These electrical performance indexes.

Step 4, calculates the coordinate of each point on Shaped reflector.

With (x, y, z) represent the coordinate in ideally-reflecting face, and the z coordinate changing ideally-reflecting face is z ', obtains figuration anti- The coordinate penetrating face is (x, y, z '),

_z' computing formula be:

$z^{\′}=\frac{x^2+y^2-{2\mathrm{Qf}}_l-Q^2}{{4f}_l+2Q},$

Wherein f_lFor the focal length of antenna,For intermediate variable, (x y) is point (x, y) phase of place's transmission coefficient to γ Position and the phase difference value of point (0,0) place transmission coefficient, k₀For free-space propagation constant, by formulaCalculating, λ is antenna Wavelength, according to operating frequency of antenna f and light velocity c, pass through formulaIt is calculated.

Step 5, passes through the aperture field of antenna house after calculating reflecting surface figuration.

(5a) aperture field phase difference ψ that reflecting surface figuration causes is calculated:

$\mathrm{\Δ\ψ}=e^{{-\mathrm{jk}}_0(z-z^{\′})},$

Wherein z is the coordinate in ideally-reflecting face, the coordinate that z ' is Shaped reflector, k₀For free-space propagation constant, press FormulaCalculating, λ is the wavelength of antenna；

(5b) the aperture field E of antenna house is passed through after calculating reflecting surface figuration " (x, y):

E " (x, y)=E ' (x, y) Δ ψ,

Wherein (x, is y) through the aperture field after antenna house to E ', and Δ ψ is the aperture field phase contrast that reflecting surface figuration causes.

Step 6, the far field of band cover antenna after calculating reflecting surface figuration.

(6a) according to the rear aperture field passing through antenna house after reflecting surface figurationCalculate band cover after reflecting surface figuration The far field F of antenna " (θ, φ):

$F^{\′\′}(\mathrm{\θ},\mathrm{\φ})=\underset{S}{\∫\∫}{E}^{\′\′}(x,y)e^{{\mathrm{jk}}_0\sin \mathrm{\θ}(x\cos \mathrm{\φ}+y\sin \mathrm{\φ})}\mathrm{dxdy},$

(6b) according to gained far field F, " (θ, φ) draws far-field pattern T₃, and from this far-field pattern, extract maximum field Strong G₃, the first secondary lobe L₃With beam angle R₃These electrical performance indexes.

Step 7, according to without cover antenna and the electrical performance indexes of band cover antenna, calculates covering aft antenna electrical performance indexes Knots modification.

(7a) according to the maximum field strength G without cover antenna₁Maximum field strength G with band cover antenna₂, calculate maximum field strength after covering Decreasing value: Δ G₁=G₁-G₂；

(7b) according to the first secondary lobe L without cover antenna₁The first secondary lobe L with band cover antenna₂, calculate the first secondary lobe after covering Lift-off value: Δ L₁=L₂-L₁；

(7c) according to the beam angle R without cover antenna₁Beam angle R with band cover antenna₂, calculate beam angle after covering Changing value: Δ R₁=R₂-R₁。

Step 8, according to the electrical performance indexes of band cover antenna after band cover antenna and reflecting surface figuration, calculates reflecting surface figuration The knots modification of the electrical performance indexes of rear band cover antenna.

(8a) according to the maximum field strength G of band cover antenna₂With the maximum field strength G of band cover antenna after reflecting surface figuration₃, calculate anti- Penetrate maximum field strength decreasing value after the figuration of face: Δ G₂=G₂-G₃；

(8b) according to the first secondary lobe L of band cover antenna₂With the first secondary lobe L of band cover antenna after reflecting surface figuration₃, calculate anti- Penetrate the first secondary lobe lift-off value after the figuration of face: Δ L₂=L₃-L₂；

(8c) according to the beam angle R of band cover antenna₂Beam angle R with reflecting surface figuration offspring's cover antenna₃, calculate anti- Penetrate beam angle changing value after the figuration of face: Δ R₂=R₃-R₂。

Step 9, it is judged that after covering and reflecting surface figuration, whether the electrical property of system meets requirement.

Requirement on electric performance according to Antenna Design, it is judged that after covering and reflecting surface figuration, the electrical performance indexes of system changes Whether amount meets preset requirement, if it is satisfied, then the far-field pattern obtained in output step one, step 3, step 6 and phase The electrical performance indexes answered；Otherwise, Shaped reflector is finely adjusted, and repeats step 5 to step 9, until meeting electrical property Requirement.

Advantages of the present invention can be further illustrated by following emulation experiment:

1. simulation parameter

The 9.14m dielectric interlayer formula antenna house of certain ground satellite communication station, structure as it is shown on figure 3, use A sandwich format, As shown in Figure 4, single-layer skins thickness 0.5mm, single layer core layer thickness 43mm, skin material dielectric constant is 4.2, dielectric loss angle Just being cut to 0.026, core material dielectric constant is 1.15, and dielectric loss angle tangent is 0.0098.Inside antenna is 5.2m bore Single reflection surface antenna, its burnt footpath ratio is 0.4, and operating frequency is 5.6GHz.

2. emulation content and result

Emulation 1, calculates the far field of antenna, draws far-field pattern as it is shown in figure 5, extract the electrical performance indexes such as table 1 of Fig. 5 Shown in.

Emulation 2, calculates the far field of band cover antenna, draws far-field pattern as shown in Figure 6, extracts the electrical performance indexes of Fig. 6 As shown in table 1.

Emulation 3, the far field of band cover antenna after calculating reflecting surface figuration, draw far-field pattern as it is shown in fig. 7, extract Fig. 7 Electrical performance indexes as shown in table 1.

The electrical performance indexes of table 1 system

As seen from Table 1, the maximum field strength of covering aft antenna reduces, and minor level raises, and beam angle increases, and is adopting After compensating with reflecting surface figuration, the maximum field strength of antenna, minor level and beam angle all have clear improvement, antenna house The adverse effect of antenna electric performance is diminished.

Above-mentioned emulation number is it was demonstrated that the present invention can be effectively improved the electrical property of band cover antenna system.

Claims (4)

1. a large-scale antenna dome electrical performance compensation method based on reflecting surface figuration, it is characterised in that comprise the steps:

(1) according to known antenna aperture field E, (x y), calculates the far field F (θ, φ) of antenna, draws far-field pattern T₁, and from Far-field pattern extracts electrical performance indexes, i.e. maximum field strength G₁, the first secondary lobe L₁And beam angle R₁；

(2) transmission coefficient at each point is calculated on antenna house by transmission line theoryAnd calculate through the aperture field after antenna house:

(3) according to through the aperture field E ' after antenna house, (x y), calculates the far field F ' (θ, φ) of band cover antenna, draws far field side To figure T₂, and from this far-field pattern, extract maximum field strength G₂, the first secondary lobe and beam angle R₂These electrical performance indexes；

(4) with (x, y, z) represent the coordinate in ideally-reflecting face, and the z coordinate changing ideally-reflecting face is z ', i.e.The coordinate obtaining Shaped reflector is (x, y, z '), wherein f_lFor the focal length of antenna,For intermediate variable, (x y) is point (x, y) phase place of place's transmission coefficient and the phase place of point (0,0) place transmission coefficient to γ Difference, k₀For free-space propagation constant, by formulaCalculating, λ is the wavelength of antenna, according to operating frequency of antenna f and Light velocity c, passes through formulaIt is calculated；

(5) according to the coordinate of point on gained Shaped-beam reflector antenna, aperture field phase difference ψ that reflecting surface figuration causes is calculated, I.e.And then calculate after reflecting surface figuration that " (x, y), wherein z is ideally-reflecting through the aperture field E of antenna house The coordinate in face, the coordinate that z ' is Shaped reflector,λ is the wavelength of antenna, according to operating frequency of antenna f and light velocity c, Pass through formulaIt is calculated；

(6) according to the aperture field E passing through antenna house after reflecting surface figuration, " (x, y), after calculating reflecting surface figuration, band cover antenna is remote " (θ, φ) draws this far-field pattern T to field F₃, and from far-field pattern, extract maximum field strength G₃, the first secondary lobe L₃And wave beam Width R₃These electrical performance indexes；

(7) according to the far-field pattern obtained in step (1), (3), (6) and corresponding electrical performance indexes, covering aft antenna is calculated The knots modification of the electrical performance indexes of band cover antenna system after the knots modification of electrical performance indexes, and calculating reflecting surface figuration；

(8) according to the requirement on electric performance of Antenna Design, it is judged that after covering and reflecting surface figuration, the electrical performance indexes of system changes Whether amount meets preset requirement, if it is satisfied, then the far-field pattern obtained in output step (1), (3), (6) and corresponding electricity Performance indications；Otherwise, Shaped reflector is finely adjusted, and repeats step (5) to step (8), until meeting requirement on electric performance.

Large-scale antenna dome electrical performance compensation method based on reflecting surface figuration the most according to claim 1, it is characterised in that The aperture field E of antenna house is passed through after described step (5) calculates reflecting surface figuration " (x, y), is calculated by equation below:

E " (x, y)=E ' (x, y) Δ ψ,

Wherein (x, is y) through the aperture field after antenna house to E ', and Δ ψ is the aperture field phase contrast that reflecting surface figuration causes.

Large-scale antenna dome electrical performance compensation method based on reflecting surface figuration the most according to claim 1, it is characterised in that Described step (7) calculates the knots modification of covering aft antenna electrical performance indexes, including:

Maximum field strength decreasing value after covering: Δ G₁=G₁-G₂,

First secondary lobe lift-off value after covering: Δ L₁=L₂-L₁,

Beam angle changing value after covering: Δ R₁=R₂-R₁,

Wherein G₁、L₁、R₁It is respectively the far-field pattern T from antenna₁The maximum field strength of middle extraction, the first secondary lobe and beam angle, G₂、L₂、R₂It is respectively the far-field pattern T from band cover antenna₂The maximum field strength of middle extraction, the first secondary lobe and beam angle.

Large-scale antenna dome electrical performance compensation method based on reflecting surface figuration the most according to claim 1, it is characterised in that The knots modification of the electrical performance indexes of band cover antenna system after calculating reflecting surface figuration in described step (7), including:

Maximum field strength decreasing value after reflecting surface figuration: Δ G₂=G₂-G₃,

First secondary lobe lift-off value after reflecting surface figuration: Δ L₂=L₃-L₂,

Beam angle changing value after reflecting surface figuration: Δ R₂=R₃-R₂,

Wherein G₂、L₂、R₂It is respectively the far-field pattern T from band cover antenna₂The maximum field strength of middle extraction, the first secondary lobe and wave beam width Degree, G₃、L₃、R₃It is respectively the far-field pattern T of band cover antenna after reflecting surface figuration₃The maximum field strength of middle extraction, the first secondary lobe And beam angle.