阅读说明：本技术 一种基于龙伯透镜的紧缩场分布式平面波生成器 (Compact field distributed plane wave generator based on luneberg lens ) 是由 侯建强 陈政宏 史啸天 秦翱翔 聂禾阳 赵延河 满明远 郑宏振 芦永超 尚春辉 于 2021-08-13 设计创作，主要内容包括：本发明提供了一种基于龙伯透镜的紧缩场分布式平面波生成器,包括设于暗室内的馈源阵列单元、馈电网络单元、分布式龙伯透镜阵列单元、矢量网络分析仪及阵列天线支架,所述馈源阵列单元固定安装于阵列天线支架,所述分布式龙伯透镜阵列单元包括X个龙伯透镜,所述X个龙伯透镜与X个天线单元一一对应,所述馈电网络单元采用幅相模拟器。本发明利用龙伯透镜来产生平面波,相比传统的远场测试节约了空间,适合于宽频带的测试,有利于扩展生成平面波的面积,组建阵列灵活性高。龙伯透镜使用发泡工艺制作,重量更轻,且多个龙伯透镜可分别操作,更加灵活便捷。采用幅相模拟器,方便快捷的实现了馈电调节,有利于产生更稳定的辐射源,进行平面波变换。(The invention provides a compact range distributed plane wave generator based on a luneberg lens, which comprises a feed source array unit, a feed network unit, a distributed luneberg lens array unit, a vector network analyzer and an array antenna support, wherein the feed source array unit, the feed network unit, the distributed luneberg lens array unit, the vector network analyzer and the array antenna support are arranged in a darkroom, the feed source array unit is fixedly arranged on the array antenna support, the distributed luneberg lens array unit comprises X luneberg lenses, the X luneberg lenses correspond to the X antenna units one by one, and the feed network unit adopts an amplitude phase simulator. The invention utilizes the Luneberg lens to generate the plane wave, saves space compared with the traditional far field test, is suitable for the test of a wide frequency band, is beneficial to expanding the area of the generated plane wave and has high flexibility in constructing an array. The luneberg lens is manufactured by a foaming process, so that the luneberg lens is lighter in weight, and the plurality of luneberg lenses can be operated respectively, so that the luneberg lens is more flexible and convenient. By adopting the amplitude-phase simulator, the feed regulation is conveniently and quickly realized, and the generation of a more stable radiation source is facilitated, so that the plane wave transformation is carried out.)

1. A compact field distributed plane wave generator based on a Luneberg lens is characterized by comprising a feed source array unit, a feed network unit, a distributed Luneberg lens array unit, a vector network analyzer and an array antenna support which are arranged in a darkroom, wherein the feed source array unit is fixedly arranged on the array antenna support and comprises X antenna units, the distributed Luneberg lens array unit comprises X Luneberg lenses, the X Luneberg lenses correspond to the X antenna units one by one, the vector network analyzer inputs radio frequency signals to the feed network unit, the feed network outputs X-path electromagnetic wave signals to be respectively transmitted to each antenna unit of the feed source array unit, each antenna unit generates spherical electromagnetic waves according to the electromagnetic wave signals and transmits the spherical electromagnetic waves to the corresponding Luneberg lens, and converging the spherical electromagnetic waves into plane waves by using the luneberg lens, wherein X is an integer greater than zero.

2. The luneberg lens-based compact field distributed plane wave generator according to claim 1, wherein said feed network element employs an amplitude-phase simulator, said amplitude-phase simulator includes a power divider, X attenuators, X phase shifters, and X output ports, said radio frequency signal is divided into X electromagnetic wave signals by said power divider, each electromagnetic wave signal is outputted to the corresponding antenna element sequentially through one attenuator and one phase shifter.

3. The luneberg lens based compact range distributed plane wave generator as claimed in claim 2, wherein the electromagnetic wave signals output from each output port of said amplitude and phase simulator are identical in amplitude and phase.

4. The luneberg lens based compact range distributed plane wave generator according to claim 3, wherein said feed array unit is a corrugated horn feed array comprising X corrugated horns, wherein X is an integer greater than zero.

5. The luneberg lens-based compact range distributed plane wave generator as claimed in claim 4, wherein the inner wall surface of said corrugated horn is formed with a longitudinal or oblique groove perpendicular to the inner wall.

6. A compact range distributed plane wave generator according to any of claims 1 to 5, further comprising a power amplifier, the input of said power amplifier being connected to said vector network analyzer and the output of said power amplifier being connected to a feed network element.

7. The luneberg lens-based compact range distributed plane wave generator as claimed in claim 6, wherein said luneberg lens is made using a foaming process.

8. The luneberg lens based compact range distributed plane wave generator as claimed in claim 7, wherein the number of layers of said luneberg lens is 2-9.

9. The luneberg lens-based compact range distributed plane wave generator as claimed in claim 8, wherein said luneberg lens is a sphere or an ellipsoid.

10. The luneberg lens based compact range distributed plane wave generator as claimed in claim 9 wherein said feed array elements are a 4X 8 antenna array, X32; or the feed source array unit is a 4 × 4 antenna array, and X is 16; or the feed source array unit is a 4 × 6 antenna array, and X is 24; or the feed source array unit is a 6 × 6 antenna array, and X is 36.

Technical Field

The invention relates to the technical field of microwave darkroom measurement, in particular to a compact range distributed plane wave generator based on a Luneberg lens.

Background

In order to achieve uniformity of electromagnetic energy radiated to the receiving antenna during the antenna system test, the electromagnetic wave reaching the receiving antenna preferably has plane wave characteristics, i.e., satisfies far-field conditions. The distance of the antenna meeting the far field condition is 6-10 lambda, which means that a very large test space is needed for testing the low-frequency antenna. In order to meet the far-field testing condition by using the smallest distance, the far-field testing method needs to be realized by means of a compact range technology, and the far-field testing method has the advantages of all weather, good confidentiality, low background level, wide working frequency band and the like.

Disclosure of Invention

The object of the present invention is to provide a compact field distributed plane wave generator based on luneberg lenses in order to at least partially solve the above technical problem, which object is achieved by the following solution.

The invention provides a compact range distributed plane wave generator based on a luneberg lens, which comprises a feed source array unit, a feed network unit, a distributed luneberg lens array unit, a vector network analyzer and an array antenna bracket, wherein the feed source array unit is arranged in a darkroom and fixedly arranged on the array antenna bracket, the feed source array unit comprises X antenna units, the distributed luneberg lens array unit comprises X luneberg lenses, the X luneberg lenses are in one-to-one correspondence with the X antenna units, the vector network analyzer inputs radio frequency signals to the feed network unit, the feed network outputs X-path electromagnetic wave signals of the feed source to be respectively transmitted to each antenna unit of the feed source array unit, each antenna unit generates spherical electromagnetic waves according to the electromagnetic wave signals and transmits the spherical electromagnetic waves to the corresponding luneberg lens, and converging the spherical electromagnetic waves into plane waves by using the luneberg lens, wherein X is an integer greater than zero.

Preferably, the feed network unit adopts an amplitude-phase simulator, the amplitude-phase simulator comprises a power divider, X attenuators, X phase shifters and X output ports, the radio frequency signal is divided into X paths of electromagnetic wave signals through the power divider, and each path of electromagnetic wave signal is output to the corresponding antenna unit through one attenuator and one phase shifter in sequence.

Preferably, the amplitude and phase of the electromagnetic wave signals output by the output ports of the amplitude-phase simulator are consistent.

Preferably, the feed source array unit is a corrugated horn feed source array, and the corrugated horn feed source array comprises X corrugated horns, wherein X is an integer greater than zero.

Preferably, the inner wall surface of the corrugated horn is provided with a longitudinal groove or an inclined groove perpendicular to the inner wall.

Preferably, the vector network analyzer further comprises a power amplifier, an input end of the power amplifier is connected with the vector network analyzer, and an output end of the power amplifier is connected with the feed network unit.

Preferably, the luneberg lens is prepared by a foaming process.

Preferably, the number of the layers of the luneberg lens is 5-15.

Preferably, the luneberg lens is a sphere or an ellipsoid.

Preferably, the feed array unit is a 4 × 8 antenna array, and X is 32; or the feed source array unit is a 4 × 4 antenna array, and X is 16; or the feed source array unit is a 4 × 6 antenna array, and X is 24; or the feed source array unit is a 6 × 6 antenna array, and X is 36.

One or more technical solutions in the embodiments of the present application have at least one or more of the following technical effects:

according to the compact range distributed plane wave generator based on the Luneberg lens, the amplitude phase simulator is utilized, feed adjustment of the feed source antenna is conveniently and rapidly achieved, a more stable radiation source is generated, and therefore plane wave conversion is conducted.

The invention utilizes the Luneberg lens to generate plane waves, saves space compared with the traditional far field test, enables the test to be carried out indoors, has wider working bandwidth and is suitable for testing wide frequency bands. The luneberg lens array is beneficial to expanding the area of generated plane waves, the area of the generated plane waves can be infinite through calculation theoretically, the array can be built according to requirements in the test process, and the flexibility is high. The luneberg lens is manufactured by a foaming process, so that the luneberg lens is lighter in weight, and the plurality of luneberg lenses can be operated respectively, so that the luneberg lens is more flexible and convenient.

Compared with the traditional standard horn, the spherical electromagnetic wave generated by the invention has the advantages of high phase center stability, axisymmetric radiation pattern, low cross polarization ratio and the like, and the generated plane wave is more stable.

The foregoing description is only an overview of the technical solutions of the present invention, and the embodiments of the present invention are described below in order to make the technical means of the present invention more clearly understood and to make the above and other objects, features, and advantages of the present invention more clearly understandable.

Drawings

FIG. 1 is a schematic diagram of a compact range antenna measurement system of the prior art;

FIG. 2 is a schematic diagram of a compact range antenna measurement according to an embodiment of the present invention;

FIG. 3 is a schematic diagram of an electromagnetic wave transmission structure between a corrugated horn antenna unit and a Luneberg lens unit according to an embodiment of the present invention;

FIG. 4 is a schematic diagram of the overall structure of a compact field distributed plane wave generator based on a luneberg lens according to an embodiment of the present invention;

fig. 5 is a vector diagram of a rectangular planar feed array.

Description of reference numerals: the device comprises a darkroom 1, a feed source array unit 2, a Luneberg lens array unit 3, a feed network unit 4, an array antenna support 5, a to-be-detected piece 6, a to-be-detected piece rotary table 7, a Luneberg lens 8, a corrugated horn 9 and a plane wave 10.

Detailed Description

The embodiment of the invention provides a compact range distributed plane wave generator based on a luneberg lens, which is used for solving the problems that a compact range test system consisting of single feed sources in the prior art forms a small plane wave area, a reflecting surface has high precision requirement, large manufacturing difficulty and high manufacturing cost; narrow working bandwidth of the compact range of the reflecting surface and the like.

The technical scheme provided by the invention has the following general idea:

a compact field distributed plane wave generator based on a Luneberg lens comprises a feed source array unit, a feed network unit, a distributed Luneberg lens array unit, a vector network analyzer and an array antenna bracket which are arranged in a darkroom, the feed source array unit is fixedly arranged on the array antenna bracket and comprises X antenna units, the distributed luneberg lens array unit comprises X luneberg lenses, the X luneberg lenses correspond to the X antenna units one by one, the vector network analyzer inputs radio frequency signals to the feed network unit, the feed network outputs X-path electromagnetic wave signals to be respectively transmitted to each antenna unit of the feed array unit, each antenna unit generates spherical electromagnetic waves according to electromagnetic wave signals and transmits the spherical electromagnetic waves to the corresponding luneberg lens, and the luneberg lenses are utilized to converge the spherical electromagnetic waves into plane waves. The luneberg lens is used for generating plane waves, and compared with the traditional far-field test, the space is saved, so that the test can be carried out indoors, and meanwhile, the luneberg lens is wide in working bandwidth and suitable for testing of a wide frequency band. The luneberg lens array is beneficial to expanding the area of generated plane waves, the area of the generated plane waves can be infinite through calculation theoretically, the array can be built according to requirements in the test process, and the flexibility is high.

The feed network unit adopts an amplitude-phase simulator, the amplitude-phase simulator comprises a power divider, X attenuators, X phase shifters and X output ports, the radio-frequency signals are divided into X paths of electromagnetic wave signals through the power divider, each path of electromagnetic wave signal sequentially passes through one attenuator and one phase shifter and is output to the corresponding antenna unit, and X is an integer larger than zero. By using the amplitude-phase simulator, the feed adjustment of the feed source antenna is conveniently and quickly realized, and a more stable radiation source is favorably generated, so that the plane wave transformation is carried out.

The feed source array unit is a corrugated horn feed source array, the generated spherical electromagnetic wave has the advantages of high phase center stability, axial symmetry of a radiation directional diagram, low cross polarization ratio and the like, and the generated plane wave is more stable.

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, 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 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.

Fig. 1 is a schematic structural diagram of a compact range antenna measurement system in the prior art, the compact range antenna measurement system includes a microwave dark room 11, a feed source 13 disposed in the microwave dark room 11, an antenna test turntable 17, and a plane wave generation unit 15, where the plane wave generation unit 15 is made of metamaterial, and after an electromagnetic wave generated by the feed source 13 is refracted by the plane generation unit 15, a quasi-plane wave test area with excellent performance is provided on the antenna test turntable 17 for testing a device to be tested 19. The plane wave generating unit 15 is formed by stacking a plurality of metamaterial layers. The compact range test system composed of a single feed source in the patent forms a small plane wave area; the planar wave generating unit made of the metamaterial needs to design the geometric shape or the filling structure of the surface of the multilayer metamaterial, and the process is complex.

FIG. 2 is a schematic structural diagram of a compact range antenna measurement according to an embodiment of the present invention. The embodiment of the invention provides a compact range distributed plane wave generator based on a luneberg lens, please refer to fig. 3, which comprises a feed source array unit 2, a feed network unit 4, a distributed luneberg lens array unit 3, a vector network analyzer and an array antenna bracket 5 arranged in a darkroom 1, the feed source array unit 2 is fixedly arranged on an array antenna bracket 5, the feed source array unit 2 comprises X antenna units, the distributed luneberg lens array unit 3 comprises X luneberg lenses 8, the X luneberg lenses 8 correspond to the X antenna units one by one, and each luneberg lens 8 is arranged at the axial front end of the corresponding antenna unit, the vector network analyzer inputs radio frequency signals to the feed network unit 4, the feed network unit 4 outputs X paths of electromagnetic wave signals to be respectively transmitted to each antenna unit of the feed array unit 2. Each antenna unit of the antenna unit generates spherical electromagnetic waves according to electromagnetic wave signals and transmits the spherical electromagnetic waves to the corresponding luneberg lens, the luneberg lens is utilized to converge the spherical electromagnetic waves into plane waves 10, and the plane waves are used for testing a far field. The distributed luneberg lens array is beneficial to expanding the area of generated plane waves, the area of the generated plane waves can be infinite theoretically through calculation, the array can be built according to requirements in the test process, and the flexibility is high.

Further, the feed source array unit 2 is a corrugated horn feed source array, and the corrugated horn feed source array includes X corrugated horns, where X is an integer greater than zero. Referring to fig. 3, the corrugated horns 9 are in a cone-like shape with a symmetrical central axis, and each corrugated horn 9 corresponds to one luneberg lens 8, and the central axes of the two corrugated horns are consistent. The inner wall surface of the corrugated horn 9 is provided with a longitudinal groove or a skewed slot which is vertical to the inner wall, so that the electromagnetism and the magnetic field have the same boundary condition, an axially symmetric amplitude and phase direction diagram is obtained, and the corrugated horn has the advantages of high gain, low side lobe, low cross polarization, high phase center stability and the like. The advantage of high stability of the phase center of the corrugated horn makes it very suitable as a feed source for the system due to the special requirement of the lens as a plane wave former.

The luneberg lens 8 is an electromagnetic wave refracting device having a multilayer structure, and spherical electromagnetic wave signals radiated by the corrugated horn 9 can be converged into a shape of a plane wave after passing through the luneberg lens 8. The luneberg lens antenna is an onion-shaped structure made of multiple layers of materials with different dielectric constants, the variation curve of the dielectric constant is discrete, the larger the number of layers is, the closer the dielectric constant variation curve is to an ideal curve, however, the larger the number of layers is, the air between the layers is increased, the performance of the lens is affected, the manufacturing difficulty and the manufacturing cost are increased, and generally, the number of layers of a sphere is controlled to be about 10. According to practical requirements, the luneberg lens 8 in the embodiment of the present application can adopt a 5-15 layer structure. The luneberg lens 8 is made by a foaming process, and consists of a plurality of layers of spherical shells with different dielectric constants and a spherical core, and polystyrene or polytetrafluoroethylene is usually adopted. The printing ink can also be prepared by adopting a fused deposition type 3D printing process, has the advantages of simple operation, safety, environmental protection and low cost, and is usually prepared by adopting a BaTiO3/PLA composite material.

Fig. 4 is a schematic diagram of the overall structure of the luneberg lens-based compact field distributed plane wave generator according to the embodiment of the present invention. As can be seen from fig. 4, the plane wave generator described in the present application uses an amplitude-phase simulator as the feeding network unit 4, where the amplitude-phase simulator includes a power divider, X attenuators, X phase shifters, and X output ports, the radio frequency signal is divided into X paths of electromagnetic wave signals by the power divider, and each path of electromagnetic wave signal sequentially passes through one attenuator and one phase shifter and is output to a corresponding antenna unit, where X is an integer greater than zero. The amplitude-phase simulator inputs signals through the vector network analyzer, divides the signals into X paths of electromagnetic wave signals at an output end and respectively feeds the electromagnetic wave signals to the feed source, and controls the phase and the amplitude of an X path of output port through self-contained software. By using the amplitude-phase simulator, the feed adjustment of the feed source antenna is conveniently and quickly realized, and a more stable radiation source is favorably generated, so that the plane wave transformation is carried out.

The X-path electromagnetic wave signals are converged into a plane wave shape after passing through the distributed Luneberg lens array unit, and the plane waves formed by each small lens are accumulated by using the distributed Luneberg lens array, so that the area of the generated plane waves is greatly increased. After receiving the plane wave, the object to be measured is input into a vector network analyzer through a low noise amplifier for data analysis.

Due to the insertion loss of the amplitude-phase simulator, a power amplifier can be added in front of the input port of the amplitude-phase simulator. Preferably a 32-way amplitude-phase simulator, which has an insertion loss of about 30dB and a gain of the power amplifier of about 25 dB. In the test process, firstly, the amplitude-phase simulator needs to be calibrated so that the output amplitude and the output phase of each port are consistent.

Fig. 5 is a vector diagram of a rectangular planar feed array, in which antenna elements are located in the xoy plane, the number of elements in rows and columns is M, N, and the total number of elements is mxn; the row and column spacing is dx and dy respectively; the serial number of each unit in the array is (M, N) (M is l, 2, …, M; N is l, 2, …, N), and the excitation current on the unit is Imn; the origin of coordinates is located at the cell (1, 1). The array factor is then:

if all columns parallel to the x-axis have the same current profile Ixm and all rows also have the same current profile Iyn, then the currents are separable (i.e., Imn — ixmliyn) and equation (1) separates as:

preferably, the feed array unit may be a 4 × 8 antenna array, or the feed array unit is a 4 × 4 antenna array, or the feed array unit is a 4 × 6 antenna array, or the feed array unit is a 6 × 6 antenna array. The spacing of the antenna elements is related to the specific frequency and horn size and can be given by calculation.

Specifically, the far field test performed by the plane wave generator can be implemented by the following steps:

s1: placing the piece to be tested 6 on a piece to be tested turntable 7;

s2: the vector network analyzer inputs radio frequency signals to the feed network unit 4;

s3: the feed network unit 4 outputs X paths of electromagnetic wave signals 10 to be respectively transmitted to each antenna unit of the feed array unit 2;

s4: the antenna unit generates spherical electromagnetic waves according to the electromagnetic wave signals 10 and transmits the spherical electromagnetic waves to the Luneberg lens;

s5: generating a planar electromagnetic wave by utilizing refraction of a luneberg lens;

s6: and carrying out far field test on the piece to be tested 6 by utilizing the plane electromagnetic wave.

One or more technical solutions in the embodiments of the present application have at least one or more of the following technical effects:

according to the compact range distributed plane wave generator based on the Luneberg lens, the amplitude phase simulator is utilized, feed adjustment of the feed source antenna is conveniently and rapidly achieved, a more stable radiation source is generated, and therefore plane wave conversion is conducted.

The invention utilizes the Luneberg lens to generate plane waves, saves space compared with the traditional far field test, enables the test to be carried out indoors, has wider working bandwidth and is suitable for testing wide frequency bands. The luneberg lens array is beneficial to expanding the area of generated plane waves, the area of the generated plane waves can be infinite through calculation theoretically, the array can be built according to requirements in the test process, and the flexibility is high. The luneberg lens is manufactured by a foaming process, so that the luneberg lens is lighter in weight, and the plurality of luneberg lenses can be operated respectively, so that the luneberg lens is more flexible and convenient.

Compared with the traditional standard horn, the spherical electromagnetic wave generated by the invention has the advantages of high phase center stability, axisymmetric radiation pattern, low cross polarization ratio and the like, and the generated plane wave is more stable.

While preferred embodiments of the present invention have been described, additional variations and modifications in those embodiments may occur to those skilled in the art once they learn of the basic inventive concepts. Therefore, it is intended that the appended claims be interpreted as including preferred embodiments and all such alterations and modifications as fall within the scope of the invention.

It will be apparent to those skilled in the art that various modifications and variations can be made in the embodiments of the present invention without departing from the spirit or scope of the embodiments of the invention. Thus, if such modifications and variations of the embodiments of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to encompass such modifications and variations.