CN117835260B - Multi-frequency multi-polarization wide-beam scanning base station system and optimal design method - Google Patents
Multi-frequency multi-polarization wide-beam scanning base station system and optimal design method Download PDFInfo
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Abstract
The invention discloses a multi-frequency multi-polarization wide-beam scanning base station system and an optimal design method, which relate to the field of mobile high-speed wireless communication and comprise the following steps: according to the theory of the expansion of the oral-plane field and the mode coupling, designing a conical horn feed source antenna capable of radiating Gaussian-mode beams, and providing stable beam width and phase center; designing a beam splitting device based on a periodic structure, wherein the beam splitting device comprises a band-pass frequency selection surface and a linear polarization grating; synthesizing front-end quasi-optical links of the multi-frequency multi-polarization channels to expand the bandwidth and communication rate of the base station antenna; the invention combines the genetic optimization algorithm and the reflector shaping to effectively reduce the contradiction between the shielding effect of the double reflector antenna and the scanning angle, and realize the multiplication of the beam scanning angle.
Description
Technical Field
The invention relates to the field of mobile high-speed wireless communication, in particular to a multi-frequency multi-polarization wide-beam scanning base station system and an optimal design method.
Background
At the end of the 80 s of the 20 th century, mobile communication technology has gradually begun to spread with the development of digital communication technology. Currently, the fifth generation mobile communication system (5G) has begun to be commercially used. Advantages of 5G technology include higher speed, lower latency, greater bandwidth, better network reliability and security, and better energy efficiency. The high-speed mobile communication base station antenna technology plays a significant role in the popularization of 5G and even 6G. The quasi-optical technology is a technology for wireless communication by utilizing millimeter waves, combines the characteristics of optical communication and microwave communication, and is used for directional propagation of wave beams, wave beam forming and spatial filtering in engineering. Quasi-optical technology is based on optical principles, and utilizes electromagnetic waves in the microwave and millimeter wave frequency ranges to carry out beam forming and form a beam directional system. Quasi-optical systems are currently used in the fields of radar systems, satellite communications, wireless communications networks, and the like.
The current mobile communication base station antenna technology has the following difficulties: the transmission rate is low, and large bandwidth cannot be realized in the millimeter wave frequency band; the loss is large in the millimeter wave frequency band; the beam scanning limit angle is small and the ability to track moving objects is poor.
In view of this, it is necessary to provide a multi-frequency multi-polarization wide beam scanning base station system and an optimal design method.
Disclosure of Invention
In order to solve the technical problems, the invention provides a multi-frequency multi-polarization wide beam scanning base station system and an optimal design method, which are used for expanding the bandwidth of the existing base station, reducing the transmission loss and improving the beam scanning function. The invention uses conical corrugated horns of 45GHz, 100GHz and 220GHz as beam generating devices, radiates Gaussian beams of fundamental mode and is used as a feed source of initial signals. The conical corrugated horn is used as an improvement of a smooth inner wall conical horn, so that the diffraction effect of the metal edge of the horn can be remarkably reduced, the axisymmetry of the directional diagram can be optimized, and the cross polarization in the horn can be reduced. In general, the electromagnetic wave fed by the circular waveguide is a TE 11 main mode, and is converted into an HE 11 mode after passing through a mode conversion section, which is an electromagnetic balance mode, and the good radiation performance of the conical corrugated horn is positively caused.
The linear polarization grating and the 45GHz and 220GHz band-pass frequency selective surfaces are used as beam separation devices to provide multi-channel beam separation and synthesis. The linear polarization grating can separate or synthesize the vertical polarization beam and the horizontal polarization beam, thereby realizing the design requirement of multiple polarizations. The linear polarization grating has a simple structure and is formed by closely arranging metal wires on a vertical plane. A frequency selective surface is a surface structure that provides a controlling effect on electromagnetic waves, typically having a two-dimensional periodic structure, consisting of a plurality of periodic metallic conductors or dielectric arrays. The frequency response characteristic of the frequency selective surface can be rapidly and accurately calculated by a finite time domain difference method (FDTD) algorithm by using the Floque (Floque) periodic boundary theory.
Various ellipsoidal mirror curved surfaces with different long and short axes are used as beam converging devices, and each beam channel is folded and converged by utilizing the ellipsoidal beam converging function, so that the whole link volume is controlled. According to the parameters of the incident beam and the ABCD beam transfer matrix of the ellipsoid, various parameters of the emergent beam can be rapidly calculated. Meanwhile, the ellipsoid is a metal surface, and the large bandwidth characteristic of the system is supported. The radiation fields before and after beam transformation can be simulated rapidly by using a physical optical algorithm (PO).
The large-aperture reflector antenna is used as a beam scanning device, and high gain is provided. The reflector antenna is the last quasi-optical device of the overall link, focusing all beam channels and providing them with highly directional radiation into free space. The beam scanning with a large angle is realized by optimizing the forming of the reflecting surface and the small focus deflection movement of the equivalent feed source, and the contradiction between the shielding effect of the secondary reflecting surface and the beam scanning angle is relieved.
In order to achieve the above purpose, the invention adopts the following technical scheme:
A multi-frequency multi-polarization wide beam scanning base station system comprises a beam generating device, a beam converging device, a beam separating device and a beam scanning device;
The beam generating device is used for radiating an approximate Gaussian beam by a broadband conical horn feed source;
the beam converging device is used for folding and converging the multi-beam channels by utilizing the beam converging characteristics of the ellipsoidal mirror;
the beam separation device separates the multichannel beams by the beam separation characteristics of the frequency selective surface and the linear polarization grating;
The beam scanning device realizes wide-angle beam scanning through the shaped and optimized large-caliber reflecting surface antenna.
Further, the beam generating device includes: 45GHz, 100GHz and 220GHz conical corrugated horns, and the mode conversion band wave groove depth is gradually changed from lambda/2 to lambda/4, wherein lambda is the central wavelength of a feed source; and the beam waist of the radiation Gaussian beam is omega 0, the near-field energy distribution and Gaussian fundamental mode coupling degree reaches 98% when the radius of a horn mouth surface is omega 0/a=0.644, and the radiation Gaussian beam can provide stable phase center and beam width for subsequent quasi-optical link design and high-speed communication.
Further, the beam converging device includes: an ellipsoidal reflector with a high-precision surface is used for converging and folding beams of all channels and keeping small distortion by utilizing an ABCD beam transfer matrix of the ellipsoidal reflector and a beam matching condition R 1＝Rin, wherein R 1 is the distance from an incident focus to a reflection point, and R in is the curvature radius of the incident beam, so that the controllability of the system volume is realized.
Further, the beam splitting device includes: 45GHz, 220GHz band-pass frequency selective surfaces and linear polarization gratings; the separation and synthesis of the multi-frequency beams are realized through the band-pass frequency selective periodic surface according to the Floque (Floque) theorem, and the separation and synthesis of the dual-polarized beams are realized through the linear polarization grating, so that the beam channels are multiplied.
Further, the beam scanning device includes: and a large-aperture plane reflecting surface antenna taking a Cassegrain antenna structure as a prototype realizes a beam scanning angle of more than or equal to 20deg by using a defocusing movement combined with a physical optical simulation method of which the equivalent feed source is less than 4 cm.
The invention also provides an optimal design method of the multi-frequency multi-polarization wide beam scanning base station system, which comprises the following steps:
S1, measuring the beam waist width and the equivalent beam waist position of an output beam of a front-end quasi-optical link, and taking the beam waist width and the equivalent beam waist position as an equivalent Gaussian feed source of a reflecting surface antenna;
s2, carrying out finite term expansion on the main reflection surface bus by utilizing Fourier series, and taking the first 11 expansion coefficients to satisfy simulation precision;
S3, modeling simulation is realized in electromagnetic simulation software by using a programming language, so that the simulation optimization efficiency of the system is greatly improved;
S4, setting an fitness function according to the target scanning angle, the equivalent feed source position and the equivalent beam waist width, wherein the fitness function mainly depends on the energy duty ratio of the target scanning angle interval of the E-plane directional diagram obtained through simulation analysis;
S5, continuously adjusting Fourier expansion coefficients by utilizing a genetic algorithm and electromagnetic simulation analysis, wherein the genetic algorithm is a heuristic algorithm, and the optimization problem is solved by simulating a biological evolution process. Based on the basic principles of natural selection and genetics, the method gradually screens out excellent genes in the population by simulating the evolution process of the natural world so as to achieve the aim of optimization;
and S6, optimizing and stopping when the fitness function obtains the minimum value, and reserving the optimized expansion coefficient, wherein the shaping optimization is finished at the moment, and all steps of optimizing the design are completed.
The invention has the advantages that:
In the invention, the broadband covers all available mobile communication frequency bands in the range from 24.25GHz to 226GHz, and the bandwidth of the existing base station is greatly enlarged; the loss is low, the front-end feed system adopts a quasi-optical scheme, and electromagnetic waves propagate between the free space and the metal reflecting surface; the beam scanning angle is large, the contradiction between the shielding effect of the secondary reflecting surface and the beam scanning angle is relieved by utilizing a genetic algorithm to carry out shaping optimization on the reflecting surface, and the beam scanning angle which is more than or equal to 20deg is realized by small out-of-focus movement.
Drawings
FIG. 1 is a schematic diagram of a multi-frequency multi-polarization wide beam scanning base station system according to the present invention;
FIG. 2 is a cross-sectional view of a conical corrugated horn;
FIG. 3 is a schematic diagram of a frequency selective surface period unit;
FIG. 4 is a schematic diagram of a linear polarization grating;
FIG. 5 is a flowchart of the steps of designing an ellipsoid;
FIG. 6 is a flow chart for reflector profiling optimization;
Fig. 7 is a schematic diagram of results before and after shape optimization.
The reference numerals in the figures mean: 1 is an H polarization 100GHz feed source, 2 is an H polarization 220GHz feed source, 3 is an H polarization 45GHz feed source, 4 is a V polarization 220GHz feed source, 5 is a V polarization 100GHz feed source, 6 is a V polarization 45GHz feed source, 7 is an H polarization 100GHz feed source converging mirror group, 8 is an H polarization 220GHz feed source converging mirror group, 9 is an H polarization 45GHz feed source converging mirror group, 10 is a V polarization 100GHz feed source converging mirror group, 11 is a V polarization 220GHz feed source converging mirror group, 12 is a V polarization 45GHz feed source converging mirror group, 13 is an H polarization 220GHz band-pass frequency selective surface, 14 is an H polarization 45GHz band-pass frequency selective surface, 15 is a V polarization 220GHz band-pass frequency selective surface, 16 is a V polarization 45GHz band-pass frequency selective surface, 17 is a V polarization multi-beam converging mirror, 18 is an H polarization beam converging mirror, 19 is a linear polarization grating, and 20 is a terminal reflection surface antenna.
Detailed Description
In order to make the objects, technical solutions and advantages of the embodiments of the present application more clear, the technical solutions of the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application. It will be apparent that the described embodiments are only some, but not all, embodiments of the application. All other embodiments, which can be made by those skilled in the art based on the embodiments of the application without making any inventive effort, are intended to be within the scope of the application.
How the system may be designed will be further described in connection with the drawings and the detailed description below.
The basic principle structure of the invention is shown in figure 1. The feeds employ 45GHz, 100GHz and 220GHz conical corrugated horns to provide an initial gaussian beam. The feeds comprise an H polarization 100GHz feed 1, an H polarization 220GHz feed 2, an H polarization 45GHz feed 3, a V polarization 220GHz feed 4, a V polarization 100GHz feed 5 and a V polarization 45GHz feed 6. The beam waist sizes and positions of the gaussian beams of the three 45GHz, 100GHz and 220GHz conical corrugated horns will be given below. Only the beam waist size and the position of the Gaussian beam of the feed source are defined, and the Gaussian beam parameters such as the beam radius, the curvature radius and the like of each position of the quasi-optical link system can be accurately calculated. After Gaussian beams are sent out by an H-polarized 100GHz feed source1, an H-polarized 220GHz feed source2, an H-polarized 45GHz feed source 3, a V-polarized 220GHz feed source 4, a V-polarized 100GHz feed source 5 and a V-polarized 45GHz feed source 6, the Gaussian beams enter a group of reflector systems, and the reflector systems comprise an H-polarized 100GHz feed source converging reflector group 7,H polarized 220GHz feed source converging reflector group 8,H polarized 45GHz feed source converging reflector group 9,V polarized 100GHz feed source converging reflector group 10, a V-polarized 220GHz feed source converging reflector group 11 and a V-polarized 45GHz feed source converging reflector group 12. The mirror system folds, converges and transforms the incident gaussian beam so that the parameters of the outgoing gaussian beam meet the subsequent design criteria. The design method and steps of the mirror will be given below. The 100GHz and 220GHz wave beams enter a 220GHz band-pass frequency selection surface after passing through an H polarization 100GHz feed source converging mirror group 7,H polarization 220GHz feed source converging mirror group 8,V polarization 100GHz feed source converging mirror group 10 and a V polarization 220GHz feed source converging mirror group 11, and the two transmission paths are synthesized through the 220GHz band-pass frequency selection surface. And then the path beam and the 45GHz beam polarized by the H-polarized 45GHz feed source converging reflector group 9,V and the 45GHz beam polarized by the 45GHz feed source converging reflector group 12 enter a 45GHz band-pass frequency selection surface, and the beam transmission paths with three frequencies are synthesized through the 45GHz band-pass frequency selection surface. And then the beam enters a linear polarization grating to synthesize the beam paths of H polarization and V polarization, so that the number of channels is doubled. Finally, the wave beam synthesis of all frequency channels and all polarization channels is uniformly fed into the reflecting surface antenna at the same position and in the same direction. Finally, the reflecting surface antenna realizes the beam scanning function of high gain.
The following describes in detail the transmission process of the 6-channel signal: the H polarization 100GHz signal is transmitted by the H polarization 100GHz feed source 1, then enters the H polarization 100GHz feed source converging reflector group 7, then sequentially passes through the H polarization 220GHz band-pass frequency selection surface 13 and the H polarization 45GHz band-pass frequency selection surface 14, then passes through the H polarization multi-beam converging mirror 18, and finally is fed into the terminal reflecting surface antenna 20 through the linear polarization grating 19. The H-polarized 220GHz signal is transmitted by the H-polarized 220GHz feed source 2, then enters the H-polarized 220GHz feed source converging reflector group 8, then sequentially passes through the H-polarized 220GHz band-pass frequency selection surface 13 and the H-polarized 45GHz band-pass frequency selection surface 14, then passes through the H-polarized multi-beam converging mirror 18, and finally is fed into the terminal reflecting surface antenna 20 through the linear polarization grating 19. The H polarization 45GHz signal is transmitted by the H polarization 45GHz feed source 3, then enters the H polarization 45GHz feed source converging reflector group 9, then passes through the H polarization 45GHz band-pass frequency selection surface 14, then passes through the H polarization multi-beam converging mirror 18, and finally is fed into the terminal reflecting surface antenna 20 through the linear polarization grating 19. The V-polarized 100GHz signal is transmitted by the V-polarized 100GHz feed source 5, then enters the V-polarized 100GHz feed source converging reflector group 10, then sequentially passes through the V-polarized 220GHz band-pass frequency selection surface 15 and the V-polarized 45GHz band-pass frequency selection surface 16, then passes through the V-polarized multi-beam converging mirror 17, and finally is fed into the terminal reflecting surface antenna 20 through the linear polarization grating 19. The V-polarized 220GHz signal is transmitted by the V-polarized 220GHz feed source 4, then enters the V-polarized 220GHz feed source converging reflector group 11, then sequentially passes through the V-polarized 220GHz band-pass frequency selection surface 15 and the V-polarized 45GHz band-pass frequency selection surface 16, then passes through the V-polarized multi-beam converging mirror 17, and finally is fed into the terminal reflecting surface antenna 20 through the linear polarization grating 19. The V-polarized 45GHz signal is transmitted through the V-polarized 45GHz feed 6, then enters the V-polarized 45GHz feed converging mirror group 12, then passes through the V-polarized 45GHz band-pass frequency selective surface 16, then passes through the V-polarized multi-beam converging mirror 17, and finally is fed into the terminal reflecting surface antenna 20 through the linear polarization grating 19. The overall size of the front-end quasi-optical link panel is 30cm by 40cm.
The basic structure of the conical corrugated horn is shown in fig. 2. Conical corrugated horn antennas can provide axisymmetric orofacial field distribution, which is the basis for coupling with gaussian transmission modes. In quasi-optical systems, conical corrugated horns are often used as feeds, which radiate approximately gaussian beams. The wave groove depth of the mode conversion section is gradually changed from lambda/2 to lambda/4, and then lambda/4 is kept unchanged, wherein lambda is the center wavelength of the feed source. In fig. 2, L 1 is the length of the mode conversion section, L 2 is the length of the mode maintaining section, L 3 is the length of the gaussian profile section, L is the length of the conical corrugated horn, r is the feed circular waveguide radius, d is the corrugated groove depth, w is the wave groove width, t is the tooth width, a is the horn mouth face radius, and α is the mouth face opening angle. The solution of the paraxial wave equation consists of a series of gaussian modes that are orthogonal to each other and thus can be used as the basis for orthonormal of the orofacial field expansion. Therefore, the paraxial beam electric field perpendicular to the optical axis can always be extended to the superposition of these modes. In general, the original electric field can be well developed with fewer gaussian modes, and in some cases, a high coupling coefficient can be provided with only a gaussian fundamental mode. In a conical corrugated horn, the near-field energy distribution is coupled with a gaussian fundamental mode to a degree of 98% when ω 0/a=0.644, and stable phase center and beam width can be provided, wherein the beam waist of the radiation gaussian beam is ω 0, and the radius of the horn mouth surface is a. The parameters of each frequency horn are shown in Table 1. In table 1, f is the center frequency of the conical horn.
TABLE 1
The far-field E-plane H-plane far-field patterns of 45GHz,100GHz and 220GHz conical corrugated horns are approximately the same, and the energy concentration degree in the main lobe is very high. The E-plane beam is wider, and the side lobe is low; the H-plane beam is narrower while the side lobes are high. The highest gain of the E-plane far-field directional diagram of the 45GHz conical corrugated horn is 20.2dBi, and the 3dB beam width is 19.7deg; the highest gain of the H-plane far-field pattern is 20.2dBi and the 3dB beam width is 18.2deg. The highest gain of the E-plane far-field directional diagram of the 100GHz conical corrugated horn is 20.2dBi, and the 3dB beam width is 19.7deg; the highest gain of the H-plane far-field pattern is 20.2dBi and the 3dB beam width is 18.2deg. The highest gain of the E-plane far-field directional diagram of the 220GHz conical corrugated horn is 20.2dBi, and the 3dB beam width is 19.7deg; the highest gain of the H-plane far-field pattern is 20.2dBi and the 3dB beam width is 18.4deg. The horn phase center and beam waist width are shown in table 2.
TABLE 2
The phase center and beam waist widths of 45GHz, 100GHz and 200GHz feed horns are listed in table 2. The visible phase center is basically coincident with the horn mouth surface, and the Gaussian feed horn designed in this way greatly facilitates the system-level design of the quasi-optical link. The reason why the phase center and the flare plane are not completely coincident is that the energy coupling coefficient of the Gaussian fundamental mode and the conical corrugated horn is not 100%.
The periodicity of the frequency selective surface is shown in fig. 3. The frequency response characteristic of the frequency selective surface can be rapidly and accurately calculated by a finite time domain difference method (FDTD) algorithm by using the Floque (Floque) periodic boundary theory. The floret theorem in electromagnetics can be generalized as: in a stable transmission mode, the field of a certain section is only one complex constant worse than the field of another section at a certain spatial period. The detailed parameters of the Frequency Selective Surface (FSS) are listed in table 3. Ts is the periodic unit side length, H 1 is the short side length, H 2 is the long side length, R is the center disk radius, and Hs is the frequency selective surface interlayer distance.
TABLE 3 Table 3
In a quasi-optical link system, a general beam is not normally incident on a frequency selective surface in consideration of an optical path layout and a placement position of components. TE waves are set to be excitation signals and are incident on the 45GHz and 220GHz frequency selective surfaces, incidence angles of 0deg, 15deg, 30deg and 45deg are set in sequence in a simulation program, and reflection coefficients and transmission coefficients of the TE waves are calculated. The frequency selective surface structure of the double layer provides two resonance points which are close in distance, and the bandwidth is effectively increased. The 45GHz frequency selective surface-10 dB bandwidth is approximately 5GHz, and the 220GHz frequency selective surface-10 dB bandwidth is approximately 30GHz. As the angle of incidence increases, the center reflection coefficient of the passband increases slightly, but still below-10 dB, exhibiting good high angle of incidence performance.
The linear polarization grating schematic is shown in fig. 4. The linear polarization grating can separate or synthesize the vertical polarization beam and the horizontal polarization beam, thereby realizing the design requirement of multiple polarizations. Generally, the incident beam is a vertically polarized beam and a horizontally polarized beam, the transmitted beam is a vertically polarized beam, and the reflected beam is a horizontally polarized beam. In general, the linear polarization grid metal wire without the substrate with g less than lambda/4 and c less than lambda/10 can meet the standard of quasi-optical links. Where c is the metal line width and g is the metal line spacing.
The design steps of the ellipsoidal metal reflective surface are shown in fig. 5. First, the outgoing beam parameters are determined from the incoming beam parameters. When designing a reflecting surface in a quasi-optical link system, it is generally determined that the angle θ i between the incident beam and the outgoing beam is a constant value. Meanwhile, the operating wavelength λ (i.e., the feed center wavelength) of the incident beam, the confocal distance z c, the beam waist ω 0in, and the distance d in of the beam waist from the ellipsoidal mirror are all known. If the beam waist of the outgoing beam to be solved is ω 0out, then according to:
The equivalent focal length f e of the ellipsoidal mirror can be obtained, and then according to the following formula:
The distance d out between the beam waist of the outgoing beam and the ellipsoidal mirror is determined.
And secondly, determining ellipsoid specific parameters according to the incident beam and the emergent beam. When the incident beam and the outgoing beam are matched with the ellipsoidal mirror, r1=r in, where R 1 is the distance from the incident focal point to the reflection point, and R in is the radius of curvature of the incident beam. Finally, the ellipsoidal mirror is intercepted according to the 2 omega criterion, and the design of the reflecting surface can be completed. Where ω is the beam radius at the reflecting surface, when the truncated mirror radius is greater than twice the beam radius, 99.99% of the beam energy can be contained.
Three channel beams are not diverged after passing through the quasi-optical link system, the beam waists are converged to the same position, and the phase is kept good, so that great convenience is provided for the subsequent design of the reflecting surface antenna.
How the present system may be optimized is further described below in conjunction with the drawings and detailed description.
S1, measuring the beam waist width and the equivalent beam waist position of the output beam of the front-end quasi-optical link, see table 4 (output beam parameter table).
TABLE 4 Table 4
S2, performing finite term expansion on the main reflection surface bus by using a Fourier series, wherein a 0 to a 10 are Fourier expansion coefficients, and refer to a table 5 (Fourier expansion coefficient table).
TABLE 5
S3, electromagnetic modeling is realized in electromagnetic simulation software by using a programming language;
s4, setting a fitness function according to the target scanning angle, the equivalent feed source position and the equivalent beam waist width;
S5, continuously adjusting Fourier expansion coefficients by utilizing a genetic algorithm and electromagnetic simulation analysis, as shown in FIG. 6, comprising the following steps: calculating a far-field pattern by using special program control electromagnetic simulation software; calculating an fitness function value according to the far-field pattern; returning the fitness function value into a genetic algorithm; adjusting the expansion coefficient according to a genetic algorithm; and calculating a far-field pattern again by using a special program according to the expansion coefficient, and continuously circularly optimizing.
And S6, optimizing and stopping when the fitness function obtains the minimum value, and reserving the optimized expansion coefficient. The optimized expansion coefficient is simulated again, so that the beam scanning angle can be effectively multiplied, as shown in fig. 7.
Claims (5)
1. A multi-frequency multi-polarization wide beam scanning base station system, which is characterized by comprising a beam generating device, a beam converging device, a beam separating device and a beam scanning device;
the beam generating device is used for radiating an approximate Gaussian beam by a broadband conical horn feed source comprising a mode maintaining section;
the beam converging device is used for folding and converging the multi-beam channels by utilizing the beam converging characteristics of the ellipsoidal mirror;
the beam separation device separates the multichannel beams by the beam separation characteristics of the frequency selective surface and the linear polarization grating;
The beam scanning device realizes wide-angle beam scanning through the shaped and optimized large-caliber reflecting surface antenna;
The beam scanning device comprises a large-aperture plane reflecting surface antenna taking a Cassegrain antenna structure as a prototype, and the multiplication of the beam scanning angle is realized by using the defocusing movement of which the equivalent feed source is smaller than 4cm and a physical optical reflecting surface shaping simulation method, so that the beam scanning angle is larger than or equal to 20 deg.
2. The multi-frequency multi-polarization wide beam scanning base station system according to claim 1, wherein said beam generating means comprises: 45GHz, 100GHz and 220GHz conical corrugated horn, and the mode conversion band wave groove depth is defined byGradually change toWhereinIs the central wavelength of the feed source; the beam waist of the radiation Gaussian beam isThe radius of the bell mouth surface is，The coupling degree of the near field energy distribution and the Gaussian fundamental mode reaches 98%, so that stable phase center and beam width can be provided for the subsequent quasi-optical link design, and high-speed communication is provided.
3. The system of claim 1, wherein the beam converging means comprises an ellipsoidal mirror with a high-precision surface, an ABCD beam transfer matrix using the ellipsoidal mirror, and a beam matching conditionWhereinFor the distance of the incident focal point to the reflection point,And for the curvature radius of the incident beam, the beams of all channels are converged and folded, and the small distortion is kept, so that the controllability of the system volume is realized.
4. The multi-frequency multi-polarization wide beam scanning base station system of claim 1, wherein the beam splitting means comprises 45GHz, 220GHz band-pass frequency selective surfaces and linear polarization gratings; the separation and synthesis of the multi-frequency beams are realized through the periodic surface of the band-pass frequency selection according to the Froude theorem, and the separation and synthesis of the dual-polarized beams are realized through the linear polarization grating, so that the beam channels are multiplied.
5. An optimized design method for a multi-frequency multi-polarization wide beam scanning base station system according to one of claims 1-4, comprising the steps of:
s1, measuring the beam waist width and the equivalent beam waist position of an output beam of a front-end quasi-optical link;
S2, carrying out finite term expansion on the main reflection surface bus by utilizing a Fourier series;
S3, realizing modeling simulation in electromagnetic simulation software by using a programming language;
s4, setting a fitness function according to the target scanning angle, the equivalent feed source position and the equivalent beam waist width;
S5, continuously adjusting the Fourier expansion coefficient by utilizing a genetic algorithm and electromagnetic simulation analysis;
and S6, optimizing and stopping when the fitness function obtains the minimum value, and reserving the optimized Fourier expansion coefficient.
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| CN103078162A (en) * | 2013-01-11 | 2013-05-01 | 东南大学 | MMW (millimeter waves) terahertz quasi optical beam power synthesis network |
| CN108987937A (en) * | 2018-06-04 | 2018-12-11 | 中国科学院电子学研究所 | A kind of method and apparatus of bifocus Shaped-beam reflector antenna |
| CN116644546A (en) * | 2023-06-15 | 2023-08-25 | 上海航天测控通信研究所 | Ultra-wideband multichannel quasi-optical feed network design method and system |
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| CN107643522B (en) * | 2017-09-19 | 2020-07-07 | 中国电子科技集团公司第三十八研究所 | Dual-band dual-polarization satellite-borne cloud and rain measurement radar system |
| CN109921197A (en) * | 2019-01-31 | 2019-06-21 | 西南电子技术研究所（中国电子科技集团公司第十研究所） | Wave beam large-angle scanning dual reflector antenna |
| CN114639935A (en) * | 2021-12-27 | 2022-06-17 | 中国航天科工集团八五一一研究所 | Lens antenna for realizing dual-polarized beam scanning |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| CN103078162A (en) * | 2013-01-11 | 2013-05-01 | 东南大学 | MMW (millimeter waves) terahertz quasi optical beam power synthesis network |
| CN108987937A (en) * | 2018-06-04 | 2018-12-11 | 中国科学院电子学研究所 | A kind of method and apparatus of bifocus Shaped-beam reflector antenna |
| CN116644546A (en) * | 2023-06-15 | 2023-08-25 | 上海航天测控通信研究所 | Ultra-wideband multichannel quasi-optical feed network design method and system |
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