CN113092884A - Antenna far field prediction method based on bounce ray method, storage medium and device - Google Patents

Antenna far field prediction method based on bounce ray method, storage medium and device Download PDF

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CN113092884A
CN113092884A CN202110424734.2A CN202110424734A CN113092884A CN 113092884 A CN113092884 A CN 113092884A CN 202110424734 A CN202110424734 A CN 202110424734A CN 113092884 A CN113092884 A CN 113092884A
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ray
reflection
field
point
far
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李尧尧
蔡少雄
胡蓉
曹成
苏东林
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Beihang University
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Abstract

The invention discloses an antenna far field prediction method, a storage medium and a device based on a bounce ray method, wherein the method comprises the following steps: loading a CAD grid model, and initializing a ray and a transmitting antenna; obtaining effective emission rays, obtaining a grid number intersected by each effective emission ray, and establishing a mapping relation between the effective emission rays and the grid number by utilizing a hash table mapRayCell; circulating the rays reflected at most maxbnc times, and recording all ray paths; calculating the amplitude and the phase of each ray at each intersection point to obtain the reflection field intensity of each ray at the reflection point after the last reflection; collecting field intensity contributions of all rays at each target observation angle, and performing complex vector summation to obtain far field amplitude at each target observation angle; an antenna prediction is obtained. Compared with the traditional moment method/full-wave methods such as multilayer fast multipole and the like, the method improves the simulation calculation efficiency and reduces the use of computer resources such as internal memory and the like.

Description

Antenna far field prediction method based on bounce ray method, storage medium and device
Technical Field
The invention relates to the field of computational electromagnetism, in particular to an antenna far-field prediction method based on a bounce ray method, a storage medium and a device.
Background
The bounce ray (SBR) method is a universal and efficient estimation method for calculating the radar scattering cross section of an electrically large and complex target, and a geometric optical method and a physical optical method are mixed; the SBR method is particularly suitable for the problem of calculating such multiple reflection fields, since it takes into account the multiple reflection situation between the target geometries.
However, the existing SBR has the following disadvantages: the traditional SBR method is used for solving the problems of electromagnetic scattering of uniform plane wave excitation and cannot be directly applied to the problems of electromagnetic radiation of spherical wave excitation.
Disclosure of Invention
The invention aims to overcome the defects of the prior art and provides an antenna far-field prediction method, a storage medium and a device based on a bounce ray method.
The purpose of the invention is realized by the following technical scheme:
the invention provides an antenna far-field prediction method based on a bounce ray method, which comprises the following steps:
loading a CAD grid model, and initializing a ray and a transmitting antenna;
obtaining effective emission rays, obtaining a grid number intersected by each effective emission ray, and establishing a mapping relation between the effective emission rays and the grid number by utilizing a hash table mapRayCell;
circulating the ray reflected at most maxbnc times, and recording the starting point coordinate start _ i, the intersection point coordinate end _ i and the path length trip _ i of all ray paths, wherein i is the reflection times;
calculating the amplitude and the phase of each ray at each intersection point to obtain the reflection field intensity of each ray at the reflection point after the last reflection;
collecting field intensity contributions of all rays at each target observation angle, and performing complex vector summation to obtain far field amplitude at each target observation angle;
and performing power integration on the electric fields of all the target observation angles to obtain a directivity coefficient, and normalizing the directivity coefficient for the electric fields to obtain antenna prediction.
Further, the loading the CAD grid model comprises:
and loading the CAD grid model, and extracting a point list and a point connection list of the CAD grid model from the platform surface element file in the nastran format.
Further, the initializing ray includes:
initializing rays, and initializing a ray tracing tree structure by utilizing a CAD grid so as to accelerate the ray tracing process;
emitting rays around the emission point TX as the center to form an incident angle list
Figure BDA0003028900520000021
Where I and j are both traversed from 1 to n, n being determined by the ray density and the wavenumber at the calculated frequency, I representing the incidence; collecting emission ray data intersected with the CAD grid, wherein the emission ray intersected with the CAD grid is an effective emission ray, and the emission ray intersected with the CAD grid is an ineffective emission ray; each ray emerging from the tube; initializing the angle of the observed target to form a target angle list
Figure BDA0003028900520000022
Where i traverses from 1 to mSJ goes from 1 to nSS denotes the target viewing angle, mSAnd nSDetermined by the user, defining a density of far-field viewing angle grids, wherein
Figure BDA0003028900520000023
The direction of the azimuth is represented by,
Figure BDA0003028900520000024
indicating the tilt angle.
Further, initializing the transmit antenna comprises:
calculating the direction of each effective emission ray
Figure BDA0003028900520000025
Initial electric field vertical polarization component E⊥And a horizontally polarized component E||Calling a vector formula to obtain an initial electric field complex vector
Figure BDA0003028900520000026
The vector formula is:
Figure BDA0003028900520000027
further, the acquiring effective emission rays comprises:
effective emission rays are found by sequentially intersecting and judging the tree structure and the leaves in the tracking tree structure.
Further, the calculating the amplitude and the phase of each ray at each intersection point to obtain the reflection field strength of each ray at the reflection point after the last reflection includes:
ray amplitude tracking, including first reflection calculation and ith reflection calculation; wherein the formula of the incident wave before the first reflection is as follows:
Figure BDA0003028900520000028
wherein the content of the first and second substances,
Figure BDA0003028900520000029
is an initial electric field complex vector;
Figure BDA00030289005200000210
is the incident electric field on the first reflection point; t is t0Is the distance from the transmitting antenna to the first reflection point; j represents an imaginary unit, k represents a free space wavenumber;
tracking the phase of the ray from the ith reflection point to the i +1 incidence point, wherein the iterative formula of the phase is as follows:
Figure BDA00030289005200000211
wherein, tripΔThe distance from the ith reflection point to the i +1 incidence point;
the decomposition of the horizontal polarization wave TM and the vertical polarization wave TE of the i-th incident wave is as follows:
Figure BDA00030289005200000212
Figure BDA00030289005200000213
Figure BDA00030289005200000214
wherein the content of the first and second substances,
Figure BDA00030289005200000215
is the incident electric field at the ith reflection point,
Figure BDA00030289005200000216
is the normal vector of the bin at the ith reflection,
Figure BDA00030289005200000217
is the vector of the direction of the incident wave,
Figure BDA00030289005200000218
as the angle of incidence,
Figure BDA00030289005200000219
is a unit length vector of the horizontal polarized wave direction of an incident wave,
Figure BDA00030289005200000220
unit length vector of vertical polarized wave direction of incident wave:
aiming at the ith reflection of the horizontal polarized wave and the vertical polarized wave respectively, a geometric optical formula is applied to obtain a field iteration formula as follows:
Figure BDA0003028900520000031
Figure BDA0003028900520000032
Figure BDA0003028900520000033
Figure BDA0003028900520000034
Figure BDA0003028900520000035
wherein the content of the first and second substances,
Figure BDA0003028900520000036
is the reflected electric field at the ith reflection point,
Figure BDA0003028900520000037
represents a unit length vector of a horizontal polarized wave direction of the reflected wave,
Figure BDA0003028900520000038
is the angle of reflection; t is tiThe distance from the ith reflection point to the (i + 1) th reflection point; k is the free space wavenumber.
Further, the collecting the field intensity contributions of all the rays at each target observation angle and performing complex vector summation to obtain the far-field amplitude at each target observation angle includes: calculating target observation angles obtained by all rays
Figure BDA0003028900520000039
The electric field intensity of far-field radiation in the direction specifically includes:
firstly, the electric field at the last reflection point (x, y, z) of each ray is obtained according to the calculation steps of the amplitude and the phase of the intersection point
Figure BDA00030289005200000310
Wherein
Figure BDA00030289005200000311
And
Figure BDA00030289005200000312
x, y and z components representing the electric field of the last reflection point,
Figure BDA00030289005200000313
Respectively representing unit direction vectors of x, y and z axes of global coordinates; then obtaining the size du-dv- Δ λ of the ray tube according to an initialization step, wherein λ is a ray wavelength, and u and v respectively represent two orthogonal axes on a wavefront curved surface of the ray tube; then, the ray path is used to obtain the total optical path (total ∑ trip) of the ith effective emission rayiAnd calling the integral formula of the tube at the reflection escape position to obtain
Figure BDA00030289005200000314
A far field radiant electric field strength in a direction, the tube integral at reflection escape formula comprising:
Figure BDA00030289005200000315
Figure BDA00030289005200000316
Figure BDA00030289005200000317
I＝S(u，v)/S(0，0)
Figure BDA00030289005200000318
S(0，0)＝(du*tall)*(dv*tall)
Figure BDA00030289005200000319
Figure BDA00030289005200000320
wherein E isSTo represent
Figure BDA0003028900520000041
Far field radiation electric field in the direction, r
Figure BDA0003028900520000042
Radial distance in direction, θiAnd
Figure BDA0003028900520000043
the angle coordinate corresponding to the reflection direction at the last reflection point; sxAnd syThe x and y coordinate values of the viewing direction vector.
Further, the performing power integration on the electric fields of all the target observation angles to obtain a directivity coefficient, and normalizing the directivity coefficient for the electric fields to obtain the antenna prediction includes:
Figure BDA0003028900520000044
Figure BDA0003028900520000045
Dθ＝20log10|Eθ|+Dnorm
Figure BDA0003028900520000047
D＝20log10|E|+Dnorm
wherein, P represents far-field radiation power, eta-120 pi represents free space wave impedance, DnormRepresents a directivity coefficient, DθWhich indicates the directionality of the vertical polarization,
Figure BDA0003028900520000048
indicating horizontal polarization directivity, D indicating total directivity, Eθ＝θi·ES；
Figure BDA0003028900520000049
E＝|ES|。
In a second aspect of the present invention, a storage medium is provided, on which computer instructions are stored, and when the computer instructions are executed, the steps of the antenna far-field prediction method based on the bounce ray method are executed.
In a third aspect of the present invention, there is provided an apparatus comprising a memory and a processor, wherein the memory stores computer instructions executable on the processor, and the processor executes the computer instructions to perform the steps of the antenna far-field prediction method based on the bounce ray method.
The invention has the beneficial effects that:
in an exemplary embodiment of the invention, a concrete method of an antenna far-field prediction method based on a bounce ray method is disclosed, compared with a traditional moment method/full-wave methods such as a multilayer fast multipole method and the like, the method improves the simulation calculation efficiency, reduces the use of computer resources such as a memory and the like, and can be directly suitable for the electromagnetic radiation problem excited by spherical waves. The storage medium is the same as the terminal.
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FIG. 1 is a flowchart of a method disclosed in an exemplary embodiment of the invention;
FIG. 2 is a schematic illustration of a ray generation system disclosed in an exemplary embodiment of the present invention;
FIG. 3 is a schematic illustration of a ray judgment disclosed in an exemplary embodiment of the present invention;
fig. 4 is a schematic view of a disclosed tube according to an exemplary embodiment of the present invention;
FIG. 5 is a schematic illustration of a ray path tracing system as disclosed in an exemplary embodiment of the present invention;
FIG. 6 is a TM reflection diagram disclosed in an exemplary embodiment of the present invention;
FIG. 7 is a TE reflection diagram disclosed in accordance with an exemplary embodiment of the present invention;
FIG. 8 is a schematic illustration of a computational model disclosed in an exemplary embodiment of the invention;
fig. 9 is a diagram of a Tx antenna pattern disclosed in an exemplary embodiment of the present invention;
FIG. 10 is a schematic diagram illustrating a ray tracing path according to an exemplary embodiment of the present disclosure;
fig. 11 is a far field gain three-dimensional pattern disclosed in an exemplary embodiment of the invention.
Detailed Description
The technical solutions of the present invention will be described clearly and completely with reference to the accompanying drawings, and it should be understood that the described embodiments are some, but not all embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. As used in this application and the appended claims, the singular forms "a", "an", and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It should also be understood that the term "and/or" as used herein refers to and encompasses any and all possible combinations of one or more of the associated listed items.
It is to be understood that although the terms first, second, third, etc. may be used herein to describe various information, such information should not be limited to these terms. These terms are only used to distinguish one type of information from another. For example, first information may also be referred to as second information, and similarly, second information may also be referred to as first information, without departing from the scope of the present application. The word "if," as used herein, may be interpreted as "when or" responsive to a determination, "depending on the context.
Referring to fig. 1, fig. 1 illustrates an antenna far-field prediction method based on a bounce ray method according to an exemplary embodiment of the present invention, including the following steps:
s01: loading the CAD grid model, and initializing the ray and the transmitting antenna.
In particular, this step is an initialization step for processing before data processing.
More preferably, in an exemplary embodiment, this step may be divided into three sub-steps:
s011: for loading of a CAD grid model, extracting a point list and a point connection list of the CAD grid model from a platform surface element file in a nastran format;
s012: initializing the ray, specifically including: initializing rays, and initializing a ray tracing tree structure (such as a BSP tree, a KD tree and the like) by utilizing a CAD grid so as to accelerate the ray tracing process;
s0121: emitting rays around the emission point TX as the center to form an incident angle list
Figure BDA0003028900520000051
Where I and j are both traversed from 1 to n, n is determined by the ray density and the wavenumber at the calculated frequency, and I represents the incidence (as shown in FIG. 2, the specific equation is described below);
Figure BDA0003028900520000052
Figure BDA0003028900520000053
s0122: collecting emission ray data intersected with the CAD grid, wherein the emission ray intersected with the CAD grid is an effective emission ray, and the emission ray intersected with the CAD grid is an ineffective emission ray (shown in figure 3);
s0123: each rayThe wire exits the tube (as shown in figure 4); initializing the angle of the observed target to form a target angle list
Figure BDA0003028900520000061
Where i traverses from 1 to mSJ goes from 1 to nSS represents the target observation angle (the specific formula is as follows), mSAnd nSDetermined by the user, defining a density of far-field viewing angle grid, where θSThe direction of the azimuth is represented by,
Figure BDA0003028900520000062
indicating the tilt angle.
Figure BDA0003028900520000063
rad＝π/180
n＝k/Δ
Where Δ is the ray density (the subdivision length of the ray on the unit length sphere), and k is the free space wavenumber of about 376.99.
S013: initializing the transmitting antenna includes:
calculating the direction of each effective emission ray
Figure BDA0003028900520000064
Initial electric field vertical polarization component E⊥And a horizontally polarized component E||Calling a vector formula to obtain an initial electric field complex vector
Figure BDA0003028900520000065
The vector formula is:
Figure BDA0003028900520000066
s02: and obtaining effective emission rays, obtaining the grid number intersected by each effective emission ray, and establishing a mapping relation between the effective emission rays and the grid number by utilizing a hash table mapRayCell.
In one exemplary embodiment, mapraycell (iray) obtains the grid number (the grid number corresponding to the shortest path) where the ray of the first ray intersects; a mapraycell (iray) of-1 indicates that some iray has no intersection with all the grids of the CAD.
In yet another exemplary embodiment, the acquiring the effective emission rays includes:
effective emission rays are found by sequentially intersecting and judging the tree structure and the leaves in the tracking tree structure.
S03: and circulating the rays reflected by maxbnc times at most, and recording the starting point coordinate start _ i, the intersection point coordinate end _ i and the path length trip _ i of all ray paths, wherein i is the reflection times. Recording all origin coordinates start with a listiThe coordinates of the intersection endiAnd path length tripi(as shown in fig. 5).
In one exemplary embodiment, the method further comprises an optional step of: invoking the ray to visually display the ray through the interface via the path of the multiple reflections.
S04: calculating the amplitude and phase of each ray at each intersection point to obtain the reflection field intensity at the reflection point of each ray after the last reflection
Figure BDA0003028900520000067
Namely, the ray can escape from the scatterer and enter a free space after undergoing the Nth reflection, wherein N is less than or equal to maxbnc.
In an exemplary embodiment, the calculating the amplitude and the phase of each ray at each intersection point to obtain the reflection field strength at the reflection point after the last reflection of each ray includes:
ray amplitude tracking, including first reflection calculation and ith reflection calculation; wherein the formula of the incident wave before the first reflection is as follows:
Figure BDA0003028900520000071
wherein the content of the first and second substances,
Figure BDA0003028900520000072
is an initial electric field complex vector;
Figure BDA0003028900520000073
is the incident electric field on the first reflection point; t is t0Is the distance from the transmitting antenna to the first reflection point; j represents an imaginary unit, k represents a free space wavenumber;
the decomposition of the horizontal polarization wave TM and the vertical polarization wave TE of the i-th incident wave is as follows:
Figure BDA0003028900520000074
Figure BDA0003028900520000075
Figure BDA0003028900520000076
wherein the content of the first and second substances,
Figure BDA0003028900520000077
is the incident electric field at the ith reflection point,
Figure BDA0003028900520000078
is the normal vector of the bin at the ith reflection,
Figure BDA0003028900520000079
is the vector of the direction of the incident wave,
Figure BDA00030289005200000710
as the angle of incidence,
Figure BDA00030289005200000711
is a unit length vector of the horizontal polarized wave direction of an incident wave,
Figure BDA00030289005200000712
unit length vector of vertical polarized wave direction of incident wave:
for the ith reflection of the horizontally polarized wave and the vertically polarized wave, respectively, geometric optics (as shown in fig. 6 and fig. 7, respectively, where fig. 6 is a TM reflection diagram and fig. 7 is a TE reflection diagram) is applied to obtain a field iteration formula as follows:
Figure BDA00030289005200000713
Figure BDA00030289005200000714
Figure BDA00030289005200000715
Figure BDA00030289005200000716
Figure BDA00030289005200000717
wherein the content of the first and second substances,
Figure BDA00030289005200000718
is the reflected electric field at the ith reflection point,
Figure BDA00030289005200000719
represents a unit length vector of a horizontal polarized wave direction of the reflected wave,
Figure BDA00030289005200000720
is the angle of reflection; t is tiThe distance from the ith reflection point to the (i + 1) th reflection point; k is the free space wavenumber.
S05: and collecting the field intensity contributions of all rays at each target observation angle, and performing complex vector summation to obtain the far field amplitude at each target observation angle.
Specifically, this step is mainly for calculating a certain target observation angle obtained in step S012
Figure BDA00030289005200000721
The strength of the electric field radiated by the far field in the direction, in a preferred exemplary embodiment:
first, the electric field at the last reflection point (x, y, z) of each ray is obtained according to step S04
Figure BDA00030289005200000722
Wherein Ex、Ey、EzRespectively representing the x-component, y-component and z-component of the electric field of the last reflection point,
Figure BDA00030289005200000723
respectively representing unit direction vectors of x, y and z axes of global coordinates; then obtaining the size du-dv- Δ λ of the ray tube according to S0123, where λ is a radiation wavelength, where u and v respectively represent two orthogonal axes on a wavefront curved surface of the ray tube; then, using step S03 to obtain the total optical path total of the ith effective emission ray, and calling the integral formula of the tube at the reflection escape to obtain
Figure BDA0003028900520000081
A far field radiant electric field strength in a direction, the tube integral at reflection escape formula comprising:
Figure BDA0003028900520000082
Figure BDA0003028900520000083
Figure BDA0003028900520000084
I＝S(u，v)/S(0，0)
Figure BDA0003028900520000085
S(0，0)＝(du*tall)*(dv*tall)
Figure BDA0003028900520000086
Figure BDA0003028900520000087
wherein E isSTo represent
Figure BDA0003028900520000088
Far field radiation electric field in the direction, r
Figure BDA0003028900520000089
Radial distance in direction, θiAnd
Figure BDA00030289005200000810
the angle coordinate corresponding to the reflection direction at the last reflection point; sxAnd syThe x and y coordinate values of the viewing direction vector.
S06: and performing power integration on the electric fields of all the target observation angles to obtain a directivity coefficient, and normalizing the directivity coefficient for the electric fields to obtain antenna prediction.
Specifically, in this exemplary embodiment, the power integration of the electric fields at all target observation angles to obtain a directivity coefficient, and the normalization of the electric fields by the directivity coefficient to obtain the antenna prediction includes:
Figure BDA00030289005200000811
Figure BDA00030289005200000812
Dθ＝20log10|Eθ|+Dnorm
Figure BDA00030289005200000813
D＝20log10|E|+Dnorm
wherein, P represents far-field radiation power, eta-120 pi represents free space wave impedance, DnormRepresents a directivity coefficient, DθWhich indicates the directionality of the vertical polarization,
Figure BDA00030289005200000814
indicating horizontal polarization directivity, D indicating total directivity, Eθ＝θi·ES；
Figure BDA00030289005200000815
E＝|ES|。
Fig. 8 to 11 respectively show a prediction diagram of exciting a cassgrain antenna by using the 18GHz horn antenna according to the above exemplary embodiment, where fig. 8 is a calculation model diagram, fig. 9 is a directional diagram of the Tx antenna, fig. 10 is a ray tracing path display diagram, and fig. 11 is a far-field gain three-dimensional directional diagram. The following table shows the time-consuming and memory comparison of the present application with the prior art moment method.
Method of moment SBR process (i.e. the present applicant's process)Method) Ratio of resources
Calculating consumed time (min) 120 1.5 80:1
EMS memory (M) 5600 252 22:1
As can be seen from the above table, the method of the present application has the advantages of fast calculation speed and low memory compared to the conventional moment method.
For the three disadvantages described in the background: (1) the traditional full wave methods such as a moment method, a multilayer rapid multipole method and the like need to consume huge computer resources such as memory, calculation time and the like; (2) the traditional moment method/multilayer fast multipole method has the problem that the mesh division has huge efficiency when the problem of large size of electricity is calculated due to the fact that the calculation of the mesh length is limited by 0.2 times of wavelength; (3) the calculation frequency is changed due to the algorithm reason, and the calculation process of the traditional moment method/multilayer fast multipole method needs to be completed once
Aiming at the defects in the step (1), the SBR method adopts high-frequency electromagnetic calculation means such as high-frequency asymptotic physical optics, geometric optics and the like and adopts a ray tracing method, so that a calculation model does not need to be converted into a large system matrix, and the problem that the traditional full-wave methods such as a moment method, a multilayer fast multipole and the like need to consume huge computer resources such as memory, calculation time and the like is greatly reduced.
Aiming at the defect of (2), the SBR adopts a self ray encryption mode, the limitation that the grid length of 0.2 times wavelength is calculated by the traditional moment method/multilayer fast multipole method is eliminated, and the problem that the grid subdivision faces huge efficiency when the large size problem of electricity is calculated is solved.
Aiming at the defect of (3), the most time-consuming ray tracing process in the SBR of the application only needs to be carried out once, and the calculation of the field and the phase of each frequency can be completed only by acquiring the path information from the memory along with the change of the recorded ray path information (including the reflection point and the path length); the whole calculation process, especially the calculation of the most time consuming part, does not need to be repeated once.
Based on any of the above method exemplary embodiments, a further exemplary embodiment of the present invention provides a storage medium having stored thereon computer instructions which, when executed, perform the steps of the bouncing ray method-based antenna far-field prediction method.
Based on any of the above method exemplary embodiments, a further exemplary embodiment of the present invention provides an apparatus, which includes a memory and a processor, where the memory stores computer instructions executable on the processor, and the processor executes the computer instructions to perform the steps of the antenna far-field prediction method based on the bouncing ray method.
Based on such understanding, the technical solutions of the present embodiments may be essentially implemented or make a contribution to the prior art, or may be implemented in the form of a software product stored in a storage medium and including several instructions for causing an apparatus to execute all or part of the steps of the methods according to the embodiments of the present invention. And the aforementioned storage medium includes: various media capable of storing program codes, such as a usb disk, a removable hard disk, a Read-Only Memory (ROM), a Random Access Memory (RAM), a magnetic disk, or an optical disk.
It is to be understood that the above-described embodiments are illustrative only and not restrictive of the broad invention, and that various other modifications and changes in light thereof will be suggested to persons skilled in the art based upon the above teachings. And are neither required nor exhaustive of all embodiments. And obvious variations or modifications of the invention may be made without departing from the spirit or scope of the invention.

Claims (10)

1. An antenna far field prediction method based on a bounce ray method is characterized in that: the method comprises the following steps:
loading a CAD grid model, and initializing a ray and a transmitting antenna;
obtaining effective emission rays, obtaining a grid number intersected by each effective emission ray, and establishing a mapping relation between the effective emission rays and the grid number by utilizing a hash table mapRayCell;
circulating the ray reflected at most maxbnc times, and recording the starting point coordinate start _ i, the intersection point coordinate end _ i and the path length trip _ i of all ray paths, wherein i is the reflection times;
calculating the amplitude and the phase of each ray at each intersection point to obtain the reflection field intensity of each ray at the reflection point after the last reflection;
collecting field intensity contributions of all rays at each target observation angle, and performing complex vector summation to obtain far field amplitude at each target observation angle;
and performing power integration on the electric fields of all the target observation angles to obtain a directivity coefficient, and normalizing the directivity coefficient for the electric fields to obtain antenna prediction.
2. The antenna far-field prediction method based on the bounce ray method according to claim 1, characterized in that: the loading of the CAD mesh model includes:
and loading the CAD grid model, and extracting a point list and a point connection list of the CAD grid model from the platform surface element file in the nastran format.
3. The antenna far-field prediction method based on the bounce ray method according to claim 1, characterized in that: the initialization ray includes:
initializing rays, and initializing a ray tracing tree structure by utilizing a CAD grid so as to accelerate the ray tracing process;
emitting rays around the emission point TX as the center to form an incident angle list
Figure FDA0003028900510000011
Where I and j are both traversed from 1 to n, n being determined by the ray density and the wavenumber at the calculated frequency, I representing the incidence; collecting emission ray data intersected with the CAD grid, wherein the emission ray intersected with the CAD grid is an effective emission ray, and the emission ray intersected with the CAD grid is an ineffective emission ray; each ray emerging from the tube; initializing the angle of the observed target to form a target angle list
Figure FDA0003028900510000012
Where i traverses from 1 to mSJ goes from 1 to nSS denotes the target viewing angle, mSAnd nSDetermined by the user, defining a density of far-field viewing angle grid, where θSThe direction of the azimuth is represented by,
Figure FDA0003028900510000013
indicating the tilt angle.
4. The bouncing ray method-based antenna far-field prediction method according to claim 3, wherein: initializing the transmitting antenna includes:
calculating the direction of each effective emission ray
Figure FDA0003028900510000014
Initial electric field vertical polarization component E⊥And a horizontally polarized component E||Calling a vector formula to obtain an initial electric field complex vector
Figure FDA0003028900510000015
The vector formula is:
Figure FDA0003028900510000016
5. the bouncing ray method-based antenna far-field prediction method according to claim 3, wherein: the acquiring of the effective emission ray includes:
effective emission rays are found by sequentially intersecting and judging the tree structure and the leaves in the tracking tree structure.
6. The bouncing ray method-based antenna far-field prediction method according to claim 4, wherein: the calculating the amplitude and the phase of each ray at each intersection point to obtain the reflection field intensity of each ray at the reflection point after the last reflection comprises the following steps:
ray amplitude tracking, including first reflection calculation and ith reflection calculation; wherein the formula of the incident wave before the first reflection is as follows:
Figure FDA0003028900510000021
wherein the content of the first and second substances,
Figure FDA0003028900510000022
is an initial electric field complex vector;
Figure FDA0003028900510000023
is the incident electric field on the first reflection point; t is t0Is the distance from the transmitting antenna to the first reflection point; j represents an imaginary unit, k represents a free space wavenumber;
tracking the phase of the ray from the ith reflection point to the i +1 incidence point, wherein the iterative formula of the phase is as follows:
Figure FDA0003028900510000024
wherein, tripΔThe distance from the ith reflection point to the i +1 incidence point;
at the ith reflection point, the decomposition of the horizontal polarization wave TM and the vertical polarization wave TE of the incident wave is as follows:
Figure FDA0003028900510000025
Figure FDA0003028900510000026
Figure FDA0003028900510000027
wherein the content of the first and second substances,
Figure FDA0003028900510000028
is the incident electric field at the ith reflection point,
Figure FDA0003028900510000029
is the normal vector of the bin at the ith reflection,
Figure FDA00030289005100000210
is the vector of the direction of the incident wave,
Figure FDA00030289005100000211
as the angle of incidence,
Figure FDA00030289005100000212
is a unit length vector of the horizontal polarized wave direction of an incident wave,
Figure FDA00030289005100000213
unit length vector of vertical polarized wave direction of incident wave:
aiming at the ith reflection of the horizontal polarized wave and the vertical polarized wave respectively, a geometric optical formula is applied to obtain a field iteration formula as follows:
Figure FDA00030289005100000214
Figure FDA00030289005100000215
Figure FDA00030289005100000216
Figure FDA00030289005100000217
Figure FDA00030289005100000218
wherein the content of the first and second substances,
Figure FDA00030289005100000219
is the reflected electric field at the ith reflection point,
Figure FDA00030289005100000220
represents a unit length vector of a horizontal polarized wave direction of the reflected wave,
Figure FDA0003028900510000031
is the angle of reflection; t is tiThe distance from the ith reflection point to the (i + 1) th reflection point; k is the free space wavenumber.
7. The bouncing ray method-based antenna far-field prediction method according to claim 6, wherein: the collecting field intensity contributions of all rays at each target observation angle and performing complex vector summation to obtain far-field amplitude at each target observation angle comprises: calculating target observation angles obtained by all rays
Figure FDA0003028900510000032
The electric field intensity of far-field radiation in the direction specifically includes:
firstly, the electric field at the last reflection point (x, y, z) of each ray is obtained according to the calculation steps of the amplitude and the phase of the intersection point
Figure FDA0003028900510000033
Wherein
Figure FDA0003028900510000034
And
Figure FDA0003028900510000035
x, y and z components representing the electric field of the last reflection point,
Figure FDA0003028900510000036
Respectively representing unit direction vectors of x, y and z axes of global coordinates; then obtaining the size du-dv- Δ λ of the ray tube according to an initialization step, wherein λ is a ray wavelength, and u and v respectively represent two orthogonal axes on a wavefront curved surface of the ray tube; then, the ray path is used to obtain the total optical path (total ∑ trip) of the ith effective emission raytAnd obtaining by calling integral formula of ray tube at reflection escape position
Figure FDA0003028900510000037
A far field radiant electric field strength in a direction, the tube integral at reflection escape formula comprising:
Figure FDA0003028900510000038
Figure FDA0003028900510000039
Figure FDA00030289005100000310
I＝S(u，v)/S(0，0)
Figure FDA00030289005100000311
S(0，0)＝(du*tall)*(dv*tall)
Figure FDA00030289005100000312
Figure FDA00030289005100000313
wherein E isSTo represent
Figure FDA00030289005100000314
Far field radiation electric field in the direction, r
Figure FDA00030289005100000315
Radial distance in direction, θiAnd
Figure FDA00030289005100000316
the angle coordinate corresponding to the reflection direction at the last reflection point; sxAnd syThe x and y coordinate values of the viewing direction vector.
8. The bouncing ray method-based antenna far-field prediction method according to claim 7, wherein: the power integration is performed on the electric fields of all the target observation angles to obtain a directivity coefficient, and the directivity coefficient for the electric fields is normalized to obtain the antenna prediction, and the method comprises the following steps:
Figure FDA00030289005100000317
Figure FDA00030289005100000318
Dθ＝20log10|Eθ|+Dnorm
Figure FDA00030289005100000319
D＝20log10|E|+Dnorm
wherein, P represents far-field radiation power, eta-120 pi represents free space wave impedance, DnormRepresents a directivity coefficient, DθWhich indicates the directionality of the vertical polarization,
Figure FDA0003028900510000041
indicating horizontal polarization directivity, D indicating total directivity, Eθ＝θi·Es；
Figure FDA0003028900510000042
E＝|ES|。
9. A storage medium having stored thereon computer instructions, characterized in that: the computer instructions are executed to execute the steps of the antenna far-field prediction method based on the bounce ray method according to any one of claims 1-8.
10. An apparatus comprising a memory and a processor, the memory having stored thereon computer instructions executable on the processor, wherein the processor when executing the computer instructions performs the steps of the method for antenna far-field prediction based on bouncing ray method of any of claims 1-8.
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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN114076854A (en) * 2021-11-17 2022-02-22 北京航空航天大学 Antenna directional diagram visualization method suitable for moment method post-processing

Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101344564A (en) * 2008-08-14 2009-01-14 西安电子科技大学 Active phase array antenna electrical property prediction method based on mechanical, electric and thermal three-field coupling
CN103888205A (en) * 2014-03-24 2014-06-25 上海华为技术有限公司 Electromagnetic wave transmission forecast method and device
CN104992001A (en) * 2015-06-19 2015-10-21 中国人民解放军信息工程大学 Rapid and accurate computation method for large-scale MIMO array antenna far-field radiation field
CN105227249A (en) * 2015-10-23 2016-01-06 中国人民解放军海军工程大学 A kind of short wavelength emissions antenna radiation efficiency automatic monitoring method and monitoring system
CN106886656A (en) * 2017-03-15 2017-06-23 南京航空航天大学 A kind of cubical array antenna radiation pattern side lobe suppression method based on improvement MOPSO and convex optimized algorithm
CN109581340A (en) * 2018-10-11 2019-04-05 上海无线电设备研究所 A kind of plasma electromagnetic scattering modeling method based on time domain Shooting and bouncing rays
CN110274920A (en) * 2018-03-14 2019-09-24 南京理工大学 The method of honorable subdivision Shooting and bouncing rays analysis metal medium target transient response
CN110703000A (en) * 2019-08-26 2020-01-17 中汽研汽车检验中心（天津）有限公司 Eccentricity correction method applied to automobile antenna performance test
CN112380643A (en) * 2020-11-02 2021-02-19 上海无线电设备研究所 Near-field electromagnetic scattering modeling method for plasma coated target

Patent Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101344564A (en) * 2008-08-14 2009-01-14 西安电子科技大学 Active phase array antenna electrical property prediction method based on mechanical, electric and thermal three-field coupling
CN103888205A (en) * 2014-03-24 2014-06-25 上海华为技术有限公司 Electromagnetic wave transmission forecast method and device
CN104992001A (en) * 2015-06-19 2015-10-21 中国人民解放军信息工程大学 Rapid and accurate computation method for large-scale MIMO array antenna far-field radiation field
CN105227249A (en) * 2015-10-23 2016-01-06 中国人民解放军海军工程大学 A kind of short wavelength emissions antenna radiation efficiency automatic monitoring method and monitoring system
CN106886656A (en) * 2017-03-15 2017-06-23 南京航空航天大学 A kind of cubical array antenna radiation pattern side lobe suppression method based on improvement MOPSO and convex optimized algorithm
CN110274920A (en) * 2018-03-14 2019-09-24 南京理工大学 The method of honorable subdivision Shooting and bouncing rays analysis metal medium target transient response
CN109581340A (en) * 2018-10-11 2019-04-05 上海无线电设备研究所 A kind of plasma electromagnetic scattering modeling method based on time domain Shooting and bouncing rays
CN110703000A (en) * 2019-08-26 2020-01-17 中汽研汽车检验中心（天津）有限公司 Eccentricity correction method applied to automobile antenna performance test
CN112380643A (en) * 2020-11-02 2021-02-19 上海无线电设备研究所 Near-field electromagnetic scattering modeling method for plasma coated target

Non-Patent Citations (2)

* Cited by examiner, † Cited by third party
Title
李厚喜: "舰船目标电磁散射的SBR算法研究", 《中国优秀博硕士学位论文全文数据库(硕士)工程科技Ⅱ辑》 *
李腾飞: "复杂环境下目标的电磁特性研究", 《中国优秀博硕士学位论文全文数据库(硕士)基础科学辑》 *

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN114076854A (en) * 2021-11-17 2022-02-22 北京航空航天大学 Antenna directional diagram visualization method suitable for moment method post-processing
CN114076854B (en) * 2021-11-17 2022-04-22 北京航空航天大学 Antenna directional diagram visualization method suitable for moment method post-processing

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