CN108281790B - Method and device for adjusting secondary surface of shaped double-reflector antenna - Google Patents
Method and device for adjusting secondary surface of shaped double-reflector antenna Download PDFInfo
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Abstract
The embodiment of the invention provides a method and a device for adjusting an auxiliary surface of a shaped double-reflector antenna, wherein the position of the auxiliary surface is adjusted by accurately describing a formula of a main reflector of the shaped double-reflector antenna and based on a main reflector parameter and vector parameter iteration method after accurate formula description, so that the position of the auxiliary surface can be optimized, the structural deformation of the shaped double-reflector antenna is compensated, and the antenna efficiency is effectively improved.
Description
Technical Field
The invention relates to the technical field of shaped double-reflector antennas, in particular to a method and a device for adjusting an auxiliary surface of a shaped double-reflector antenna.
Background
The cassegrain-type antenna has been used in many fields such as radar tracking, satellite communication, and deep space exploration in recent years because of its advantages such as high radiation efficiency and low edge leakage. The main surface and the secondary surface of the double-reflector antenna are both correction curved surfaces, so that the amplitude and the phase of the aperture field of the main reflector are uniformly distributed, and the electric efficiency of the antenna is further improved. However, the dual-reflector antenna structure is subjected to various loads such as self-weight, wind load, rain and snow, and the like, so that the main reflector is deformed, the surface precision is reduced, and the electrical performance of the antenna is further deteriorated.
On the other hand, s.von Hoerner, german scholars, gives the idea of a shape-preserving design that can reduce the deformation of the main surface of the antenna to some extent, but cannot completely eliminate it. For example, although the blocking panel on the main surface of the antenna can be slightly adjusted, and the deviation caused by the deformation of the back frame structure can be improved, the correction degree of the light path collimation error between the reflecting surface and the feed source is limited. For another example, the relative position relationship between the main and sub-planes is changed by moving the sub-planes, so that the phase deviation formed by a part of the main plane deformation on the oral plane can be eliminated, and for this reason, the U.S. GBT 100m and Italy SRT 64m radio telescope antennas also adopt adjustable sub-planes to compensate the influence of the main plane deformation on the electrical performance.
Currently, the most commonly used methods for adjusting the minor plane of the dual reflector antenna at home and abroad include the following methods:
(1) and testing the electrical property of the antenna by selecting the experimental antenna under different elevation working conditions, calculating the axial deviation of the secondary surface, and performing curve fitting on the test data to obtain the approximate relation of the axial deviation of the secondary surface along with the elevation. And calculating the radial deviation of the auxiliary surfaces with different elevation angles by using finite element software, and adjusting the positions of the auxiliary surfaces according to the calculated axial deviation and radial deviation at a certain working elevation angle.
(2) According to the design principle of the shaped antenna, a ray tracing method is applied, the auxiliary surface is axially adjusted by a certain quantity value, so that the aperture surface of the main surface meets the equal optical path condition, and the axial adjustment quantity of the auxiliary surface is calculated by adopting a least square method.
(3) And detecting the deformation of the main surface of the antenna by using test equipment such as a laser tracker and the like, performing standard paraboloid fitting on the deformed main surface to obtain the focus of the optimal fitting surface, and determining the position of the secondary surface according to the matching relationship between the main surface and the secondary surface. The method is suitable for the case that the main reflecting surface of the antenna is a standard paraboloid, but has larger error for the shaping main surface.
However, for the adjustment of the secondary surface of the shaped cassegrain antenna, the above methods for adjusting the secondary surface are mostly considered from the geometric angle of the reflecting surface, so that the geometric error of the paraboloid is minimized, the phase error of the mouth surface caused by the geometric error can seriously affect the electrical performance of the antenna, and the methods need to depend on measurement and simulation, and are relatively complex to operate in actual work. Therefore, for those skilled in the art, it is urgently needed to research a conveniently implemented secondary plane adjustment method from the viewpoint of antenna electrical performance so as to solve the above problems, improve antenna efficiency, and improve antenna electrical performance.
Disclosure of Invention
In view of the above, an object of the embodiments of the present invention is to provide a method and an apparatus for adjusting a secondary surface of a shaped dual reflector antenna, so as to improve the above problem.
The preferred embodiment of the invention provides a method for adjusting the secondary surface of a shaped double-reflector antenna, which comprises the following steps:
accurately formulaically describing a main reflecting surface of the shaped double reflecting surface, and initializing a position adjustment parameter of the auxiliary surface based on the accurately formulaically described parameter of the main reflecting surface;
calculating a phase difference caused by the adjustment of the position of the secondary surface based on the adjustment parameter of the position of the secondary surface, and calculating an additional error beam according to the phase difference;
acquiring a measured far-field beam and an ideal far-field beam, and calculating an objective function value according to the measured far-field beam, the ideal far-field beam and the additional error beam;
and judging whether the objective function value meets a preset value, if so, taking the minor plane position adjustment parameter as an optimal adjustment parameter, and adjusting the minor plane position in the dual-reflector antenna based on the optimal adjustment parameter.
Further, the method further comprises:
if the objective function value does not meet the preset value, adjusting and updating the secondary surface position adjustment parameter according to a preset step value, and calculating the objective function value again based on the updated secondary surface position adjustment parameter until the objective function value corresponding to the updated secondary surface position adjustment parameter meets the preset value;
and taking the updated minor surface position adjustment parameter corresponding to the objective function value meeting the preset value as an optimal adjustment parameter, and adjusting the minor surface position in the dual-reflector antenna based on the optimal adjustment parameter. Further, the step of calculating the phase difference caused by the adjustment of the sub-surface position based on the sub-surface position adjustment parameter includes:
acquiring a translation error and a rotation angle error when the shaped secondary surface generates rigid body displacement;
calculating an optical path difference caused by the position error of the shaping auxiliary surface according to the translation error and the rotation angle error;
and calculating the phase difference caused by the position deviation of the secondary surface according to the optical path difference.
Further, the phase difference
Calculated by the following formula:
wherein, [ Delta x [ ]s,Δys,Δzs]For translational error, [ Delta Gamma ]x,Δγy]For corner error, k is the slope of the tangent of the parabola, θiIs the half opening angle of the corresponding point of the minor face,
half opening angle of a point corresponding to a principal planeiIs the angle of the aperture face in the circumferential direction of the corresponding point, MiThe double reflecting surfaces correspond to equivalent magnification.
Further, the additional error beam caused by the change of the position of the secondary surface
Calculated by the following formula:
wherein F (r, phi) is an aperture field distribution function,
is a bore surface phase error distribution function, p (theta ', phi') is a far zone observation point,
is a unit vector from the origin of coordinates to the far field viewpoint P,
is a polar coordinate on the aperture surface, dS' is an aperture surface area element, k is a free space wave constant, and A represents the aperture surface area.
Further, the objective function value VlCalculated by the following formula:
The preferred embodiment of the present invention further provides a device for adjusting the secondary surface of a shaped dual reflector antenna, comprising:
the initialization module is used for accurately describing the formulaic double-reflector main reflector and initializing the auxiliary surface position adjustment parameter based on the accurately described main reflector parameter;
the error calculation module is used for calculating a phase difference caused by the adjustment of the position of the secondary surface based on the adjustment parameter of the position of the secondary surface and calculating an additional error beam according to the phase difference;
the objective function calculation module is used for acquiring an actual measurement far-field beam and an ideal far-field beam and calculating an objective function value according to the actual measurement far-field beam, the ideal far-field beam and the additional error beam;
and the judging module is used for judging whether the objective function value meets a preset value or not, if so, taking an adjusting parameter corresponding to the objective function value as an optimal adjusting parameter, and adjusting the position of the secondary surface in the dual-reflector antenna based on the optimal adjusting parameter.
Further, the judging module is further configured to update the secondary surface position adjustment parameter according to a preset step value when the objective function value does not meet a preset value, and calculate the objective function value again based on the updated secondary surface position adjustment parameter until the objective function value corresponding to the updated secondary surface position adjustment parameter meets the preset value; and
and taking the updated minor surface position adjustment parameter corresponding to the objective function value meeting the preset value as an optimal adjustment parameter, and adjusting the minor surface position in the dual-reflector antenna based on the optimal adjustment parameter.
Further, the error calculation module includes:
the parameter acquisition unit is used for acquiring a translation error and a corner error when the rigid body displacement is generated on the forming secondary surface;
the optical path difference calculating unit is used for calculating the optical path difference caused by the position error of the shaping auxiliary surface according to the translation error and the rotation angle error;
and the phase difference calculating unit is used for calculating the phase difference caused by the position deviation of the secondary surface according to the optical path difference.
Further, the phase difference
Calculated by the following formula:
wherein, [ Delta x [ ]s,Δys,Δzs]For translational error, [ Delta Gamma ]x,Δγy]For corner error, k is the slope of the tangent of the parabola, θiIs the half opening angle of the corresponding point of the minor face,
half opening angle of a point corresponding to a principal planeiIs the angle of the aperture face in the circumferential direction of the corresponding point, MiThe double reflecting surfaces correspond to equivalent magnification. Compared with the prior art, the method and the device for adjusting the secondary surface of the shaped double-reflector antenna have the advantages that the secondary surface of the shaped double-reflector antenna is adjusted by accurately describing the main reflector of the shaped double-reflector antenna through a formula and selecting the optimal adjustment parameters in a parameter iteration mode, so that the structural deformation of the shaped double-reflector antenna can be compensated, the antenna efficiency is effectively improved, and the electrical property is improved.
In order to make the aforementioned and other objects, features and advantages of the present invention comprehensible, preferred embodiments accompanied with figures are described in detail below.
Drawings
In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings needed to be used in the embodiments will be briefly described below, it should be understood that the following drawings only illustrate some embodiments of the present invention and therefore should not be considered as limiting the scope, and for those skilled in the art, other related drawings can be obtained according to the drawings without inventive efforts.
Fig. 1 is a schematic block structure diagram of a terminal device according to an embodiment of the present invention.
Fig. 2 is a schematic flow chart of a method for adjusting a secondary surface of a shaped dual reflector antenna according to an embodiment of the present invention.
Fig. 3 is a schematic diagram of a shaped cassegrain antenna bus according to an embodiment of the present invention.
Fig. 4 is a schematic diagram of the standardization of the shaped paraboloid provided by the embodiment of the invention.
Fig. 5 is a sub-flowchart of step S120 shown in fig. 2.
Fig. 6 is a schematic diagram of a geometric relationship of a shaped dual reflector antenna according to an embodiment of the present invention.
Fig. 7 is a schematic block structure diagram of a secondary surface adjusting device of a shaped dual-reflector antenna according to an embodiment of the present invention.
Fig. 8 is a block diagram of the error calculation module shown in fig. 7.
Icon: 10-a terminal device; 100-adjusting device for secondary surface of shaped double-reflector antenna; 110-an initialization module; 120-an error calculation module; 121-a parameter acquisition unit; 122-optical path difference calculating unit; 123-phase difference calculation unit; 130-an objective function calculation module; 140-a judgment module; 200-a memory; 300-a memory controller; 400-processor.
Detailed Description
The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. The components of embodiments of the present invention generally described and illustrated in the figures herein may be arranged and designed in a wide variety of different configurations. Thus, the following detailed description of the embodiments of the present invention, presented in the figures, is not intended to limit the scope of the invention, as claimed, but is merely representative of selected embodiments of the invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments of the present invention without making any creative effort, shall fall within the protection scope of the present invention.
It should be noted that: like reference numbers and letters refer to like items in the following figures, and thus, once an item is defined in one figure, it need not be further defined and explained in subsequent figures.
Fig. 1 is a schematic block structure diagram of a terminal device 10 according to an embodiment of the present invention. The terminal device 10 includes a shaping dual-reflector antenna minor plane adjusting apparatus 100, a memory 200, a storage controller 300, and a processor 400. The terminal device 10 may be, but is not limited to, an electronic device with a processing function, such as a computer, a Mobile Internet Device (MID), and the like, and may also be a server and the like.
Specifically, the elements of the memory 200, the memory controller 300 and the processor 400 are directly or indirectly electrically connected to each other to realize data transmission or interaction. For example, the components are electrically connected to each other through one or more communication buses or signal lines. The adjusting apparatus 100 for secondary surface of shaped dual-reflector antenna comprises at least one software functional module which can be stored in the memory 200 in the form of software or firmware or solidified in the operating system of the terminal device 10. The processor 400 accesses the memory 200 under the control of the memory controller 300, so as to execute executable modules stored in the memory 200, for example, software functional modules and computer programs included in the shaping dual reflector antenna minor surface adjusting apparatus 100.
It will be appreciated that the configuration shown in fig. 1 is merely illustrative and that the terminal device 10 may include more or fewer components than shown in fig. 1 or may have a different configuration than shown in fig. 1. The components shown in fig. 1 may be implemented in hardware, software, or a combination thereof.
Further, as shown in fig. 2, a schematic flow chart of a method for adjusting a secondary surface of a shaped dual reflector antenna according to an embodiment of the present invention is provided, where the method for adjusting a secondary surface of a shaped dual reflector antenna is applied to the terminal device 10, and a detailed description will be given below on a specific flow chart and steps of the method for adjusting a secondary surface of a shaped dual reflector antenna with reference to fig. 2. It should be noted that the adjusting method for the secondary surface of the shaped dual reflector antenna provided in the embodiment of the present invention is not limited by the specific sequence shown in fig. 2 and described below.
Step S110, the main reflecting surface of the shaped double reflecting surface is accurately formulaically described, and the position adjusting parameters of the auxiliary surface are initialized based on the main reflecting surface parameters after the accurate formulaic description.
The initial value of the secondary surface position adjustment parameter may be flexibly selected according to actual requirements, for example, the initial value of the secondary surface position adjustment parameter may be a set of 0 values, and the like, which is not limited in this embodiment.
In addition, as shown in fig. 3, in order to accurately describe the surface of the main reflecting surface of the shaped dual-reflector antenna, according to the design principle and geometric characteristics of the shaped dual-reflector antenna, the shaped main reflecting surface can be represented by a cluster of points on a standard parabola, and the equation of each parabola is determined by the coordinates of the points on the main surface and the direction angle of the normal vector thereof.
Specifically, as shown in fig. 4, taking the shaped cassegrain antenna as an example, the coordinates and parameters of the corresponding points of the main surface and the secondary surface can be obtained by solving an equation set consisting of energy conservation (such as power conservation), aplanatic condition and reflection law, that is, the coordinates P of the point on the main surface can be obtainedi(xpi,zpi) Coordinates S of corresponding points on the sum minor planei(xsi,zsi) And half opening angle of corresponding point of main surface
Half opening angle theta of point corresponding to minor surfacei. The shaped main reflecting surface is no longer a standard paraboloid, the secondary surface is no longer a standard hyperboloid, and the focal point is no longer a point but is scattered into a defocusing point set along the axis. Therefore, according to the aplanatic condition and the reflection law of the shaped cassegrain antenna, the difference between the optical path calculated from the defocusing point and the optical path calculated from the feed source phase center and the corresponding optical path of the corresponding axial ray is a number only related to the phi angle. For example, the discretized standard parabolic equation can be expressed as xi 2＝4fi(zi-hi) The slope of the tangent line of the discretized standard parabola can be expressed as
The tangent line can be calculated by a discrete point difference method or an adjacent triangle area weighted average method through the known coordinates of the shaped surface point. In this embodiment, the parameters associated with the discretized standard set of parabolic lines according to the classical dual reflector (e.g., cassegrain) system are shown in table 1 below.
TABLE 1
Step S120, calculating the phase difference caused by the adjustment of the position of the secondary surface based on the adjustment parameter of the position of the secondary surface, and calculating the additional error beam according to the phase difference.
As shown in fig. 5, in the present embodiment, the phase difference can be calculated by the following steps.
And step S121, obtaining a translation error and a rotation angle error when the rigid body displacement is generated on the forming secondary surface.
And S122, calculating an optical path difference caused by the position error of the shaping secondary surface according to the translation error and the rotation angle error.
And step S123, calculating the phase difference caused by the position deviation of the secondary surface according to the optical path difference.
Step S121-step S123, assuming that the translation error when the rigid displacement of the shaped secondary surface is generated due to the deformation of the secondary surface supporting structure can be expressed as us＝(Δxs,Δys,Δzs) The rotation angle error can be expressed as gammas＝(Δγx,Δγy) Then, referring to the effect of rigid body displacement of the secondary surface of the standard dual-reflector, the effect of rigid body displacement generated by the shaped secondary surface is equivalent to the effect generated by translating the secondary surface and the feed source together and then moving the feed source back, so that the optical path difference caused by the position error of the shaped secondary surfaces(ri,φi) Can be represented by the following formula (1).
In the formula (1), p ═ Δ xs,Δys,Δzs,Δγx,Δγy]TIs a sub-surface rigid body displacement vector, csiThe optical path difference coefficient vector of the position deviation of the minor surface at the ith point of the aperture surface is shown.
Further, according to the optical path differences(ri,φi) The phase difference caused by the position deviation of the secondary surface can be calculated and obtained
As shown in formula (2).
In the formula (2), [ Delta x [ ]s,Δys,Δzs]For translational error, [ Delta Gamma ]x,Δγy]For corner error, k is the tangent slope of the parabola and can be expressed as
θiIs the half opening angle of the corresponding point of the minor face,
half opening angle of a point corresponding to a principal planeiIs the angle of the aperture face in the circumferential direction of the corresponding point, MiFor the double reflecting surface corresponding to the equivalent magnification, can be expressed as
Further, an additional error beam caused by the position change of the secondary surface can be calculated according to the phase difference and far-field beam synthesis relation
Specifically, the following formula (3) is shown.
In the formula (3), F (r, phi) is the aperture field distribution function,
is a caliber surface phase error distribution function, P is a far zone observation point,
is a unit vector from the origin of coordinates to the far field viewpoint P,
polar coordinates (r, phi) on the caliber surface; dS' is the caliber surface area element and dSRdrd phi, k is the free space wave constant and k 2 pi/lambda, a denotes the aperture face area. It should be noted here that the beamforming relationship is
Wherein the content of the first and second substances,
for a measured far-field beam containing a phase error,
for an ideal far-field beam, E ' (θ ', φ ') is the error beam before adjustment.
Step S130, obtaining the actual measurement far-field beam and the ideal far-field beam, and calculating an objective function value according to the actual measurement far-field beam, the ideal far-field beam, and the additional error beam.
As shown in fig. 6, according to the geometric coordinate information of the shaped dual reflector antenna, the related discrete parameters of the shaped dual reflector can be calculated based on the discrete standard parabola point set description method, and then the ideal far-field beam is calculated according to the aperture field irradiation function of the shaped dual reflector antenna and recorded as the ideal far-field beam
Specifically, the following formula (4) is shown.
It should be noted that the ideal far-field beam can be obtained by integrating the antenna aperture surface by using a surface current method or an aperture field method, specifically, the aperture field distribution of the reflecting surface can be obtained from the feed source radiation field according to the geometric optics law, and then the ideal far-field beam can be obtained from the fourier transform relationship between the aperture field phase distribution and the far field.
Further, as shown in the formula (5), the measured far-field beam containing the phase error before the adjustment of the position of the secondary surface is used
Then, as can be seen from equation (5), the measured far-field beam before the adjustment of the position of the secondary surface
Is an ideal far field beam
And error beam E' (θ, Φ).
Wherein the content of the first and second substances,
and E ' (θ ', φ ') is aperture field phase error
As a function of (c).
Based on the above description, the objective function value V after the ith adjustment parameter iteration can be calculated based on equation (5)lThe value of the objective function VlCan be shown as formula (6).
In the formula (6), the reaction mixture is,
representing an ideal far-field beam of light,
representing the measured far field beam before the secondary position adjustment,
representing the additional error beam, p, caused by the ith parameter iterationlAnd (4) indicating the minor face position adjustment parameter of the parameter iteration of the ith time.
Step S140, determining whether the objective function value meets a preset value, if yes, performing step S150, otherwise, performing step S160 and step S170.
Step S150, using the minor surface position adjustment parameter as an optimal adjustment parameter, and adjusting the minor surface position in the dual reflector antenna based on the optimal adjustment parameter.
And step S160, if the objective function value does not meet the preset value, adjusting and updating the secondary surface position adjusting parameter according to the preset step value, and calculating the objective function value again based on the updated secondary surface position adjusting parameter until the objective function value corresponding to the updated secondary surface position adjusting parameter meets the preset value.
Step S170, using the updated minor-plane position adjustment parameter corresponding to the objective function value satisfying the preset value as an optimal adjustment parameter, and adjusting the minor-plane position in the dual reflector antenna based on the optimal adjustment parameter.
In this embodiment, the preset value may be flexibly selected according to the actual structure of the dual reflector antenna, for example, the preset value may be, but is not limited to, 1 dB. Assuming that the preset value is, then, when V islAnd when the target function value is less than or equal to the target function value, taking the minor surface position adjustment parameter corresponding to the target function value as an optimal adjustment parameter to adjust the minor surface position in the shaped double-reflector antenna. On the contrary, when Vl>Adjusting the secondary surface position adjustment parameter according to a preset step value to adjust and update, calculating an objective function value according to the updated secondary surface position adjustment parameter, judging whether the objective function value meets a preset value, if so, adjusting the secondary surface position in the dual-reflector antenna according to the updated secondary surface position adjustment parameter, if not, repeating the steps S160 and S170 until the objective function value meets the preset value, and taking the secondary surface position adjustment parameter p of the last iteration as the optimal secondary surface adjustment parameter p*. Obtaining the optimal position adjustment parameter of the secondary surface of the shaped double-reflector antenna under the current working condition; the position of the secondary surface movement mechanism is adjusted to realize the optimal adjustment of the position of the secondary surface.
Further, in actual implementation, in addition to the above-mentioned minor plane position deviation, when the deformation error of the main surface of the shaped cassegrain antenna and the feed displacement are known, the influence relational expression of the deformation error of the main surface of the shaped cassegrain antenna and the feed displacement on the optical path difference can be respectively given according to the discretization description method and the geometric optics principle of the shaped double-reflection surface, so as to obtain the comprehensive optical path difference after the components are superposed, and the optical path difference and the phase difference caused by the deformation error of the main surface of the antenna and the feed displacement are respectively introduced below.
(1) Main surface deformation error. Suppose a point P on the main reflecting surfacei(xpi,ypi,zpi) The resulting distortion displacement vector is upi＝(Δxpi,Δypi,Δzpi) Optical path difference caused byp(ri,φi) Which is 2 times the axial component of the normal displacement of the point, as shown in equation (7) below.
In the formula (7), the reaction mixture is,
i represents the ith Pi point of the shaped main reflecting surface.
(2) And (4) shifting a feed source. The influence of the feed source displacement can be referred to the influence of the feed source displacement of the standard double reflecting surfaces, and the influence is understood as the synthesis of the feed source deviation influences of a plurality of standard surfaces. Wherein, the displacement generated by the feed source is assumed to be uf＝(Δxf,Δyf,Δzf) The optical path length difference caused can be represented by the following formula (8).
Therefore, the optical path difference corresponding to the main surface deformation error, the feed source displacement and the sub-surface position deviation of the shaped double-reflector antenna such as the shaped Cassegrain antenna can be obtained as the comprehensive optical path difference shown in the formula (9)t(ri,φi)。
t(ri,φi)＝p(ri,φi)+f(ri,φi)+s(ri,φi)
＝cpi·upi+cfi·uf+csi·p (9)
It should be understood that, for the comprehensive optical path difference, the phase difference may be calculated by referring to the optical path difference corresponding to the position deviation of the secondary surface, so as to obtain a corresponding objective function value, and adjust the optimal position according to the objective function value, which is not described herein again.
The adjusting method of the secondary surface of the shaped double-reflector antenna can be used for guiding the adjustment of the secondary surface position of the shaped double-reflector antenna, and iteration is carried out on the secondary surface position parameters after an ideal far-field wave beam and an actually-measured far-field wave beam of an ideal surface of the antenna are obtained so as to obtain the optimal secondary surface adjusting parameters. Meanwhile, the invention can also solve the problem that the existing aperture field optical path difference relational expression cannot be applied to the shaped double-reflector antenna, so that the electromechanical coupling model cannot be applied to the structural deformation influence analysis of the shaped double-reflector antenna.
Further, as shown in fig. 7, a schematic block structure diagram of an adjusting apparatus 100 for a shaped dual-reflector antenna according to an embodiment of the present invention is provided, where the adjusting apparatus 100 for a shaped dual-reflector antenna includes an initialization module 110, an error calculation module 120, an objective function calculation module 130, and a determination module 140.
The initialization module 110 is configured to perform precise formulaic description on the main reflecting surface of the shaped dual reflecting surface, and initialize the sub-surface position adjustment parameter based on the main reflecting surface parameter after the precise formulaic description.
In this embodiment, the detailed description of the step S110 may be referred to for the description of the initialization module 110, that is, the step S110 may be executed by the initialization module 110, and therefore, no further description is provided herein.
The error calculating module 120 is configured to calculate a phase difference caused by adjusting the position of the secondary surface based on the secondary surface position adjustment parameter, and calculate an additional error beam according to the phase difference.
In this embodiment, the error calculation module 120 may specifically refer to the detailed description of the step S120, that is, the step S120 may be executed by the error calculation module 120, and therefore, no further description is provided herein. Alternatively, as shown in fig. 8, the error calculation module 120 includes a parameter acquisition unit 121, an optical path difference calculation unit 122, and a phase difference calculation unit 123.
The parameter obtaining unit 121 is configured to obtain a translation error and a rotation angle error when the forming minor surface generates a rigid body displacement.
In this embodiment, the detailed description of the step S121 may be referred to for the description of the parameter obtaining unit 121, that is, the step S121 may be executed by the parameter obtaining unit 121, and thus, no further description is provided herein.
And the optical path difference calculating unit 122 is configured to calculate an optical path difference caused by a position error of the shaped secondary surface according to the translation error and the rotation angle error.
In this embodiment, the description of the optical path difference calculating unit 122 may specifically refer to the detailed description of step S122, that is, the step S122 may be executed by the optical path difference calculating unit 122, and therefore, no further description is provided herein.
The phase difference calculating unit 123 is configured to calculate a phase difference caused by the position deviation of the secondary surface according to the optical path difference.
In this embodiment, the description of the phase difference calculation unit 123 may specifically refer to the detailed description of step S123, that is, step S123 may be executed by the phase difference calculation unit 123, and thus will not be further described here.
The objective function calculating module 130 is configured to obtain a measured far-field beam and an ideal far-field beam, and calculate an objective function value according to the measured far-field beam, the ideal far-field beam, and the additional error beam.
In this embodiment, the description of the objective function calculation module 130 may specifically refer to the detailed description of the step S130, that is, the step S130 may be executed by the objective function calculation module 130, and therefore, no further description is provided herein.
The determining module 140 is configured to determine whether the objective function value meets a preset value, if so, take an adjustment parameter corresponding to the objective function value as an optimal adjustment parameter, and adjust a position of a secondary plane in the dual reflector antenna based on the optimal adjustment parameter.
In this embodiment, the description of the determining module 140 may specifically refer to the detailed description of the step S140, that is, the step S140 may be executed by the determining module 140, and therefore, no further description is provided herein.
In summary, the embodiments of the present invention provide a method and an apparatus for adjusting a secondary surface of a shaped dual reflector antenna, where the method selects an optimal adjustment parameter in a parameter iteration manner to adjust the secondary surface of the shaped dual reflector antenna, so that structural deformation of the shaped dual reflector antenna can be compensated, thereby effectively improving antenna efficiency and electrical performance.
In the embodiments provided in the present invention, it should be understood that the disclosed apparatus and method can be implemented in other ways. The apparatus and method embodiments described above are illustrative only, as the flowcharts and block diagrams in the figures illustrate the architecture, functionality, and operation of possible implementations of apparatus, methods and computer program products according to various embodiments of the present invention. In this regard, each block in the flowchart or block diagrams may represent a module, segment, or portion of code, which comprises one or more executable instructions for implementing the specified logical function(s). It should also be noted that, in some alternative implementations, the functions noted in the block may occur out of the order noted in the figures. For example, two blocks shown in succession may, in fact, be executed substantially concurrently, or the blocks may sometimes be executed in the reverse order, depending upon the functionality involved. It will also be noted that each block of the block diagrams and/or flowchart illustration, and combinations of blocks in the block diagrams and/or flowchart illustration, can be implemented by special purpose hardware-based systems which perform the specified functions or acts, or combinations of special purpose hardware and computer instructions.
In addition, the functional modules in the embodiments of the present invention may be integrated together to form an independent part, or each module may exist separately, or two or more modules may be integrated to form an independent part.
The functions, if implemented in the form of software functional modules and sold or used as a stand-alone product, may be stored in a computer readable storage medium. Based on such understanding, the technical solution of the present invention may be embodied in the form of a software product, which is stored in a storage medium and includes instructions for causing a computer device (which may be a personal computer, an electronic device, or a network device) to perform all or part of the steps of the method according to the embodiments of the present invention. And the aforementioned storage medium includes: a U-disk, a removable hard disk, a Read-Only Memory (ROM), a Random Access Memory (RAM), a magnetic disk or an optical disk, and other various media capable of storing program codes. It should be noted that, in this document, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising an … …" does not exclude the presence of other identical elements in a process, method, article, or apparatus that comprises the element.
The above description is only an alternative embodiment of the present invention and is not intended to limit the present invention, and various modifications and variations of the present invention may occur to those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.
Claims (10)
1. A method for adjusting the secondary surface of a shaped double-reflector antenna is characterized by comprising the following steps:
accurately formulating and describing a main reflecting surface of the shaped double reflecting surface, and initializing a position adjustment parameter of the auxiliary surface based on the accurately formulated and described parameter of the main reflecting surface, wherein the accurately formulated and described parameter of the shaped double reflecting surface comprises the steps of representing the shaped main reflecting surface by using points on a cluster of standard parabolic lines according to the design principle and the geometric characteristics of the shaped double reflecting surface antenna, and determining the equation of each parabolic line by using the coordinates of the points on the main surface and the direction angle of a normal vector of the points;
calculating a phase difference caused by the adjustment of the position of the secondary surface based on the adjustment parameter of the position of the secondary surface, and calculating an additional error beam according to the phase difference;
acquiring a measured far-field beam and an ideal far-field beam, and calculating an objective function value according to the measured far-field beam, the ideal far-field beam and the additional error beam;
and judging whether the objective function value meets a preset value, if so, taking the minor plane position adjustment parameter as an optimal adjustment parameter, and adjusting the minor plane position in the dual-reflector antenna based on the optimal adjustment parameter.
2. The method of adjusting the secondary surface of an shaped dual reflector antenna as recited in claim 1, further comprising:
if the objective function value does not meet the preset value, adjusting and updating the secondary surface position adjustment parameter according to a preset step value, and calculating the objective function value again based on the updated secondary surface position adjustment parameter until the objective function value corresponding to the updated secondary surface position adjustment parameter meets the preset value;
and taking the updated minor surface position adjustment parameter corresponding to the objective function value meeting the preset value as an optimal adjustment parameter, and adjusting the minor surface position in the dual-reflector antenna based on the optimal adjustment parameter.
3. The adjusting method of the secondary surface of the shaped double reflector antenna as claimed in claim 1, wherein the step of calculating the phase difference caused by the adjustment of the secondary surface position based on the secondary surface position adjustment parameter comprises:
acquiring a translation error and a rotation angle error when the shaped secondary surface generates rigid body displacement;
calculating an optical path difference caused by the position error of the shaping auxiliary surface according to the translation error and the rotation angle error;
and calculating the phase difference caused by the position deviation of the secondary surface according to the optical path difference.
4. The method for adjusting the secondary surface of an shaped dual reflector antenna as claimed in claim 3, wherein the phase difference is measured
Calculated by the following formula:
wherein, [ Delta x [ ]s,Δys,Δzs]For translational error, [ Delta Gamma ]x,Δγy]For corner error, k is the slope of the tangent of the parabola, θiIs the half opening angle of the corresponding point of the minor face,
half opening angle of a point corresponding to a principal planeiIs the angle of the aperture face in the circumferential direction of the corresponding point, MiFor double reflecting surfaces corresponding to equivalent magnification, ciIs a sub-surface half-focal length, aiIs a minor semi-major axis.
5. A method for adjusting the secondary surface of a shaped double reflector antenna as claimed in claim 3, wherein said additional error beam caused by the position change of the secondary surface
Calculated by the following formula:
wherein the content of the first and second substances,
is a function of the aperture field distribution,
is a bore surface phase error distribution function, p (theta ', phi') is a far zone observation point,
is a unit vector from the origin of coordinates to the far field viewpoint P,
is a polar coordinate on the aperture surface, dS is an aperture surface area element, k is a free space wave constant, and A represents the aperture surface area.
6. The method of claim 3, wherein the objective function value V islCalculated by the following formula:
7. A secondary surface adjusting device of a shaped double-reflector antenna is characterized by comprising:
the initialization module is used for accurately formulating and describing the main reflecting surface of the shaped double reflecting surface and initializing the position adjustment parameter of the auxiliary surface on the basis of the accurately formulated and described main reflecting surface parameter, wherein the accurately formulated and described main reflecting surface of the shaped double reflecting surface comprises the steps of representing the shaped main reflecting surface by a cluster of points on a standard parabolic line according to the design principle and the geometric characteristics of the shaped double reflecting surface antenna, and determining the equation of each parabola by the coordinates of the points on the main surface and the direction angle of the normal vector of the points;
the error calculation module is used for calculating a phase difference caused by the adjustment of the position of the secondary surface based on the adjustment parameter of the position of the secondary surface and calculating an additional error beam according to the phase difference;
the objective function calculation module is used for acquiring an actual measurement far-field beam and an ideal far-field beam and calculating an objective function value according to the actual measurement far-field beam, the ideal far-field beam and the additional error beam;
and the judging module is used for judging whether the objective function value meets a preset value or not, if so, taking an adjusting parameter corresponding to the objective function value as an optimal adjusting parameter, and adjusting the position of the secondary surface in the dual-reflector antenna based on the optimal adjusting parameter.
8. The apparatus of claim 7, wherein the determining module is further configured to update the secondary surface position adjustment parameter according to a preset step value when the objective function value does not satisfy a preset value, and to calculate the objective function value again based on the updated secondary surface position adjustment parameter until the objective function value corresponding to the updated secondary surface position adjustment parameter satisfies the preset value; and
and taking the updated minor surface position adjustment parameter corresponding to the objective function value meeting the preset value as an optimal adjustment parameter, and adjusting the minor surface position in the dual-reflector antenna based on the optimal adjustment parameter.
9. The apparatus for adjusting secondary surface of shaped dual reflector antenna as claimed in claim 7, wherein the error calculation module comprises:
the parameter acquisition unit is used for acquiring a translation error and a corner error when the rigid body displacement is generated on the forming secondary surface;
the optical path difference calculating unit is used for calculating the optical path difference caused by the position error of the shaping auxiliary surface according to the translation error and the rotation angle error;
and the phase difference calculating unit is used for calculating the phase difference caused by the position deviation of the secondary surface according to the optical path difference.
10. The apparatus for adjusting secondary surface of shaped double reflector antenna as claimed in claim 9, wherein the phase difference is set
Calculated by the following formula:
wherein, [ Delta x [ ]s,Δys,Δzs]For translational error, [ Delta Gamma ]x,Δγy]For corner error, k is the slope of the tangent of the parabola, θiIs the half opening angle of the corresponding point of the minor face,
half opening angle of a point corresponding to a principal planeiIs the angle of the aperture face in the circumferential direction of the corresponding point, MiFor double reflecting surfaces corresponding to equivalent magnification, ciIs a sub-surface half-focal length, aiIs a minor semi-major axis.
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