A simulation method and system for a seven-element antenna array

Abstract

The present invention provides a simulation method and system for a seven-element antenna array, belonging to the technical field of radio direction finding. The method includes: establishing a seven-element antenna array and sorting the array elements in the antenna array; designing a path difference according to the sorted seven-element antenna array elements; designing the length of a radio frequency cable according to the designed path difference, and using the radio frequency cable to simulate the path difference of the incoming wave direction; introducing a wave-shrinking coefficient to match the path difference simulated by the radio frequency cable with the actual receiving direction, and finely adjusting the path difference to complete the antenna array simulation. The present invention solves the problems of strong dependence on the test environment, complex test setup and high cost, difficulty in controlling external environmental interference, instability of the incoming wave direction, poor flexibility of the delay line technology, and difficulty in reducing the cost and time of repeated tests in the existing antenna array simulation methods.

Description

Technical Field

[0001] The present invention belongs to the technical field of radio direction finding, and particularly relates to a simulation method and system for a seven-element antenna array. Background Technique

[0002] With the rapid development of technologies such as wireless communication, radar, and electronic reconnaissance, direction finding technology has important application values in fields such as signal positioning, target tracking, and interference suppression. A direction finding antenna array is an important device for achieving accurate direction finding. Its principle is to calculate the direction of the incoming wave by receiving the path difference of the signal at each antenna element and combining corresponding algorithms. However, in the development and testing of actual direction finding systems, traditional methods require erecting transmitting antennas and receiving antennas and completing direction finding verification through the actual path difference of the incoming wave signal.

[0003] The traditional methods have the following disadvantages:

[0004] Strong environmental dependence. The test environment usually requires a large space to ensure signal propagation between the transmitting antenna and the receiving antenna, and it is impossible to complete the test in a limited indoor environment; complex to build and high in cost. Actual testing requires arranging a large number of devices, such as transmitting antennas, receiving antennas, and related support facilities, increasing the complexity and economic cost of the test; difficult to fix the simulated azimuth. When using real antennas for testing, the direction of the incoming wave signal is usually difficult to stably fix, which brings many inconveniences to the system debugging and software verification.

[0005] The existing technology uses the antenna array delay line calibration technology: to simplify the test process, delay lines and power dividers are used to simulate the phase difference and time difference of signals in the experimental environment; the delay line can accurately simulate the path difference of signals and is suitable for the calibration and verification of some small-scale systems; it reduces the dependence on the real environment to a certain extent and is suitable for small-scale array testing and calibration work under some laboratory conditions. However, the combination scheme of power dividers and delay lines is usually for a single scenario, with poor flexibility, lack of optimized design for large-scale antenna arrays, difficult to handle complex signals, the system construction is still complex, and the signal stability and accuracy are limited. Summary of the Invention

[0006] Aiming at the above deficiencies in the prior art, a simulation method for a seven-element antenna array provided by the present invention solves the problems of strong test environment dependence, complex and costly test setup, difficulty in controlling external environmental interference, difficulty in stably fixing the incoming wave direction, poor flexibility of the delay line technology, and difficulty in reducing the cost and time of repeated tests in the existing antenna array simulation methods.

[0007] To achieve the above objectives, the technical solution adopted by the present invention is: on the one hand, the present invention provides a simulation method for a seven-element antenna array, including the following steps:

[0008] S1. Establish a seven - element antenna array and sort the array elements within the antenna array;

[0009] S2. Design the path difference according to the sorted seven - element antenna array elements;

[0010] S3. Design the length of the RF cable according to the designed path difference, and use the RF cable to simulate the path difference of the incoming wave direction;

[0011] S4. Introduce a wave - contraction coefficient, match the path difference simulated by the RF cable with the actual receiving direction, and adjust the path difference to complete the antenna array simulation.

[0012] The beneficial effects of the present invention are as follows: By combining the delay characteristics of the RF cable and the array layout, the present invention improves the accuracy, reliability and applicability of the incoming wave direction simulation; and uses an accurate path difference to reduce the dependence of the antenna array simulation on the test environment, as well as the complexity and cost of test setup; through the key technologies of antenna array layout, path difference calculation, RF delay design and direction - finding accuracy control, high - precision incoming wave direction simulation is achieved, with the remarkable advantages of small phase error, high amplitude consistency and strong adaptability; and it improves the control ability of external environmental interference, realizes the stable fixation of the incoming wave direction, improves the flexibility of the delay line technology, and reduces the repeated test cost and time.

[0013] Further, the specific content of S1 is as follows:

[0014] Use seven elements to establish an antenna array, arrange the seven elements in the antenna array in sequence, obtain the geometric distribution between the elements and the incident wave direction, and set a preset aperture.

[0015] The beneficial effects of the above - mentioned further solution are as follows: By establishing a seven - element antenna array, the present invention obtains the geometric distribution between the elements and the incident wave direction, providing a solid foundation for the subsequent construction of the path difference; using fewer elements and a simple geometric distribution reduces the complexity and cost of the antenna array simulation setup.

[0016] Still further, S2 includes the following steps:

[0017] S201. According to the sorted seven - element antenna array elements, define the path of all elements except the first element relative to the first element as the path difference;

[0018] S202. According to the geometric distribution between the elements, the incident wave direction and the complete phase period, use the trigonometric function formula and phase idea of the incoming wave to design the path difference.

[0019] The beneficial effects of the above further solution are as follows: By using the precise path difference to replace the functions of the real transmitting and receiving antennas, the present invention improves the universality of the application scenarios of antenna array simulation, gets rid of the dependence on large-scale sites, and improves the accuracy of the phase difference and the precision of beam direction simulation; precisely simulates the fixed incoming wave azimuth, reduces the test repeatability caused by the uncertainty of the incoming wave direction, thus significantly reducing the test cost and improving the test efficiency.

[0020] Furthermore, S3 includes the following steps:

[0021] S301. Design the RF cable lengths of different array elements according to the designed path difference;

[0022] S302. Use the transmission delay of the RF cable to simulate the path difference of the incoming wave direction.

[0023] The beneficial effects of the above further solution are as follows: The present invention realizes the simulation of the incoming wave direction through the RF cable delay, combines with the direction-finding antenna array to simulate the radio wave state of a specific incident angle; and uses the transmission delay of the RF cable to precisely simulate the path difference of the incoming wave direction, stably fixing the direction of the simulated incoming wave, making the test conditions stable and improving the simulation accuracy of the antenna array.

[0024] Furthermore, S4 includes the following steps:

[0025] S401. Introduce a wave-shrinking coefficient to the path difference according to the inconsistency between the dielectric constant of air and the medium dielectric constant of the cable, match the path difference simulated by the RF cable with the actual receiving direction, and design the path difference with the introduced wave-shrinking coefficient;

[0026] S402. Adjust the path difference according to the specified threshold of the simulation phase error to complete the antenna array simulation.

[0027] Furthermore, the expression of the path difference with the introduced wave-shrinking coefficient is as follows:

[0028] ;

[0029] Wherein, represents the path difference of the i th array element, represents the wave-shrinking coefficient, represents the aperture, represents the complete phase period, represents the incident wave direction, represents the total number of antenna array elements.

[0030] The beneficial effects of the above further solution are as follows: By introducing the wave-shrinking coefficient, the present invention corrects the amplitude error in the simulation process, improving the authenticity of the simulation; and optimizes the amplitude consistency by finely adjusting the path difference and correcting the amplitude error with the wave-shrinking coefficient; by strictly calculating the path difference and adjusting the cable delay, the phase error of each array element signal is strictly controlled, realizing the simulation of the incoming wave direction at the sub-angle level.

[0031] To achieve the above object, according to the second aspect of the present invention, a seven-element antenna array simulation system is provided for performing the seven-element antenna array simulation method as described above, which is characterized in that it includes: a radio frequency signal source subsystem, a radio frequency cable network subsystem, an antenna element subsystem, and a control subsystem;

[0032] The radio frequency signal source subsystem is used to provide a standardized radio frequency signal;

[0033] The radio frequency cable network subsystem is used to achieve signal delay according to the path difference design;

[0034] The antenna element subsystem is used to receive the standardized radio frequency signal and simulate the incoming wave in the target direction;

[0035] The control subsystem is used to adjust the cable delay in real time to match the incident angle.

[0036] The beneficial effects of the above solution are as follows: The seven-element antenna array simulation system provided by the present invention uses a radio frequency signal source to provide a standardized radio frequency signal and designs a radio frequency cable network, realizing the support for combinations of various numbers of array elements and antenna apertures, being applicable to different direction-finding requirements; and based on the technical solution of standard radio frequency cables, it has a low implementation cost; it can simulate the incoming wave direction in an indoor closed environment, avoiding interference from external signals and improving stability and accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 It is a flowchart of the method of the present invention.

[0038] Figure 2 It is a geometric layout diagram of the seven-element antenna array in this embodiment.

[0039] Figure 3 It is a simulation diagram of the path difference of the incoming wave direction using the radio frequency cable length in this embodiment.

[0040] Figure 4 It is a structural diagram of an antenna array simulation system in this embodiment.

[0041] Figure 5 It is a schematic diagram of an antenna simulator in this embodiment.

[0042] Figure 6This is the simulation 3D model diagram of an antenna array simulation device in this embodiment. Detailed implementation manners

[0043] The following describes the detailed implementation manners of the present invention to facilitate those skilled in the art to understand the present invention. However, it should be clear that the present invention is not limited to the scope of the detailed implementation manners. For those of ordinary skill in the art, as long as various changes are within the spirit and scope of the present invention defined and determined by the appended claims, these changes are obvious, and all inventions made using the concept of the present invention are within the scope of protection.

[0044] Before explaining this embodiment, the following terms are first explained:

[0045] FPGA: Field Programmable Gate Array;

[0046] MEMS controller: Micro-Electro-Mechanical System controller.

[0047] Embodiment 1

[0048] As Figure 1 shown, the present invention provides a seven-element antenna array simulation method, and its implementation method is as follows:

[0049] S1. Establish a seven-element antenna array and sort the array elements in the antenna array. Specifically:

[0050] Use seven array elements to establish an antenna array, arrange the seven array elements in the antenna array in sequence, obtain the geometric distribution between the array elements and the incident wave direction, and set a preset aperture.

[0051] In this embodiment, as Figure 2 shown, establish an antenna array, including 7 array elements, sort each array element in sequence, and set a preset aperture. Assume that the incoming wave is incident at an angle , then the paths of the incoming wave received by each array element are different; in the figure, N represents the due north direction, A represents that the incoming wave is perpendicular to the plane of N, represents the angle formed by the incoming wave and the plane formed by antenna 1, antenna 2, and antenna 3.

[0052] S2. Design the path difference according to the sorted seven-element antenna array elements. The specific steps are as follows:

[0053] S201. According to the sorted seven-element antenna array elements, define the path of all array elements except the first array element relative to the first array element as the path difference;

[0054] S202. According to the geometric distribution between the array elements, the incident wave direction, and the complete phase period, use the trigonometric function formula and phase idea of the incoming wave to design the path difference.

[0055] In this embodiment, according to the sorted seven-element antenna array elements, the path difference of the current element is defined , which represents the path of the current element relative to the first element except the first element; since the path difference directly affects the phase difference, the incoming wave arrives at an angle , that is, the incident wave direction , which determines the spatial distribution of the path difference. Therefore, by precisely studying the path difference, accurate simulation of the beam direction can be achieved; according to the geometric distribution between the elements, the incident wave direction, and the complete phase period, using the trigonometric function formula and phase idea of the incoming wave, the path difference is designed; the initial expression of the path difference is as follows:

[0056] ;

[0057] where represents the path difference of the i th element, represents the aperture, represents the complete phase period, represents the incident wave direction, represents the total number of antenna array elements, which is a seven-element antenna array in this embodiment. Therefore ; this embodiment uses of the complete phase period, which can make the path difference formula applicable to different incident wave directions and the total number of antenna array elements .

[0058] S3. According to the designed path difference, design the length of the RF cable, and use the RF cable to simulate the path difference of the incoming wave direction. The specific steps are as follows:

[0059] S301. According to the designed path difference, design the RF cable lengths of different elements;

[0060] S302. Use the transmission delay of the RF cable to simulate the path difference of the incoming wave direction.

[0061] In this embodiment, the transmission delay of the RF cable is 4.7 nanoseconds per meter (4.7 ns / m). According to the designed path difference, design the RF cable lengths of different elements to adjust the transmission delay of the RF cable; use the transmission delay of the RF cable to achieve the simulation of the path difference of the incoming wave direction.

[0062] S4. Introduce a wave reduction coefficient to match the path difference simulated by the RF cable with the actual receiving direction, and adjust the path difference to complete the antenna array simulation. The specific steps are as follows:

[0063] S401. Introduce a wave-shrinking coefficient to the path difference according to the inconsistency between the dielectric constant of air and the medium dielectric constant of the cable, match the path difference simulated by the RF cable with the actual receiving direction, and design a path difference with the wave-shrinking coefficient introduced.

[0064] S402. Adjust the path difference according to the simulated phase error of the specified threshold to complete the antenna array simulation.

[0065] In this embodiment, according to the inconsistency between the medium in space and the medium of the physical object, the dielectric constant of air is 1, the medium dielectric constant of the cable is 2, a wave-shrinking coefficient of 0.7 is introduced to the path difference, the path difference simulated by the RF cable is matched with the actual receiving direction, and a path difference with the wave-shrinking coefficient introduced is designed; the expression of the path difference with the wave-shrinking coefficient introduced is as follows:

[0066] ;

[0067] Among them, represents the wave-shrinking coefficient; introducing the wave-shrinking coefficient , correct the amplitude error during the simulation process; perform phase error control, through strict and precise path difference calculation, achieve a simulated phase error less than the specified threshold, ensure that the phase of the signal received by each array element is consistent with the simulation target, finely adjust the path difference, optimize the amplitude consistency, and complete the antenna array simulation.

[0068] In this embodiment, as Figure 3 shown, where 1#:0 means the cable length from the first array element to the first array element is 0mm, 2#:6.65 means the cable length from the second array element to the first array element is 6.65mm, 3#:62.78 means the cable length from the third array element to the first array element is 62.78mm, 4#:126.12 means the cable length from the fourth array element to the first array element is 126.12mm, 5#:148.97 means the cable length from the fifth array element to the first array element is 148.97mm, 6#:114.13 means the cable length from the sixth array element to the first array element is 114.13mm, 7#:47.83 means the cable length from the first array element to the first array element is 47.83mm. According to a seven-element antenna array simulation method, a seven-element antenna array is established, and the results shown in Table 1 are obtained.

[0069] Table 1

[0070]

[0071] In this embodiment, as Figure 4 shown, a seven-element antenna array simulation system, used to execute a seven-element antenna array simulation method as described above, includes a RF signal source subsystem, a RF cable network subsystem, an antenna element subsystem, and a control subsystem;

[0072] The radio frequency signal source subsystem, through the installed radio frequency signal source, is used to provide standardized radio frequency signals;

[0073] The radio frequency cable network subsystem is used to design the length of the radio frequency cable according to the designed path difference, and complete the construction of the radio frequency cable network by using the radio frequency cable to achieve signal delay;

[0074] The antenna element subsystem, through the elements installed in the seven-element antenna array, is used to receive standardized radio frequency signals and simulate the incoming waves in the target direction;

[0075] The control subsystem is used to adjust the cable delay in real time, change the length of the radio frequency cable, match the incident angle, and achieve precise antenna array simulation.

[0076] Embodiment 2

[0077] In this embodiment, as Figure 5 shown, the present invention can build an antenna array simulation device. Based on the antenna simulator one-to-nine 0-degree power divider, the chassis model is selected as a custom-designed chassis. The custom chassis is 280 mm deep, 240 mm wide, and has a 2U panel height. The custom-designed chassis needs to have modular expansion capabilities (such as the ETT 280 type); By using the custom-designed chassis, the internal structure can be flexibly adjusted according to different antenna simulator types, improving compatibility and heat dissipation performance. Among them, L1~L9 represent simulation extension lines, LK represents the calculated line length of the simulated incoming wave, IN represents the input end of the antenna simulation, and OUT1~OUT9 represent the output ends of the antenna simulation;

[0078] And use a digitally tunable power divider (such as a MEMS controller) to replace the traditional passive power divider, and the precise distribution of the phase can be achieved through software control, further reducing the influence of the physical delay line length on the simulation accuracy; Use a solid-state delay line (such as a PIN diode switch type delay line) or a microwave waveguide delay device to replace the physical cable, which can improve the accuracy of the simulator and reduce the loss;

[0079] And use standard radio frequency interfaces (such as N-type or 3.5 mm connectors) to increase mechanical strength and reduce damage caused by improper operation; Quick plug-and-play interfaces (such as push-button radio frequency interfaces) to improve usability and reduce the possibility of connection errors;

[0080] Use a programmable logic array (such as an FPGA) combined with a digital delay module to replace the physical delay line cable, simulate the signal delay through algorithms, reduce the actual loss of the cable and improve the debugging flexibility of the device;

[0081] Optical fibers are used to replace RF cables to achieve signal delay. Optical fiber delay has lower signal loss and higher anti-interference ability; it is replaced with a microwave absorption load to reduce the interference of reflected signals on system simulation. An automatic switch circuit is added to the unused port to make it dynamically grounded, improving the stability of the system;

[0082] Based on the phase shifter, by changing the phase delay on the signal path through a digital or analog phase shifter, it is possible to achieve without a physical delay cable; and a fixed RF transmission module is used to replace the external cable to avoid cable damage caused by non-standard operations.

[0083] In this embodiment, as Figure 6 shown, based on Figure 5 the antenna emulator one-to-nine 0-degree power divider shown, a simulation 3D model of the antenna array simulation device is built. Among them, the lines of the calculated simulated incoming wave directions are successively simulated to form Figure 6 the antennas in, and each antenna in the figure represents Figure 5 the simulation extension lines L1~L9 in, and then through Figure 6 the antenna array simulation device shown, the antenna array simulation is completed.

Claims

1. A seven-element antenna array simulation method, characterized in that: The following steps are involved: S1. Establish a seven-element antenna array and sort the elements in the antenna array; S2. designing the path difference according to the sorted seven-element antenna array elements; S3. Design the length of the RF cable according to the designed path difference, and use the RF cable to simulate the path difference in the direction of the incoming wave; S4, introduce the wave reduction coefficient, match the simulated path difference of the RF cable with the actual receiving direction, and adjust the path difference to complete the antenna array simulation, specifically: S401, according to the inconsistency between the dielectric constant of air and the dielectric constant of the medium of the cable, the dielectric constant of air is 1, the dielectric constant of the medium of the cable is 2, a wave reduction coefficient of 0.7 is introduced into the path difference, the path difference simulated by the RF cable is matched with the actual receiving direction, and the path difference with the wave reduction coefficient is designed; S402, adjusting the path difference according to the simulated phase error of the specified threshold value to complete the antenna array simulation; The path difference expression for introducing the wave shrinkage coefficient is as follows: in, Indicates i The distance difference between the array elements, represents the wave shrinkage coefficient, Indicates the caliber, represents a complete phase cycle, represents the incident wave direction, Indicates the total number of antenna elements.

2. The seven-element antenna array simulation method according to claim 1, characterized in that: The S1 is specifically: An antenna array is established using seven array elements, the seven array elements in the antenna array are arranged in sequence, the geometric distribution between the array elements and the direction of the incident wave are obtained, and a preset aperture is set.

3. The seven-element antenna array simulation method according to claim 2, characterized in that: The S2 comprises the following steps: S201, according to the sorted seven-element antenna array elements, define the distances of all the elements except the first element relative to the first element as the distance difference; S202. According to the geometric distribution between array elements, the direction of the incident wave and the complete phase cycle, the path difference is designed using the trigonometric function formula of the incoming wave and the phase concept.

4. The seven-element antenna array simulation method according to claim 3, characterized in that: The S3 comprises the following steps: S301. Designing the length of radio frequency cables of different array elements according to the designed path difference; S302: Utilize the transmission delay of the radio frequency cable to simulate the path difference in the direction of the incoming wave.

5. A seven-element antenna array simulation system, used to execute the seven-element antenna array simulation method according to any one of claims 1 to 4, characterized in that: include: RF signal source subsystem, RF cable network subsystem, antenna array element subsystem and control subsystem; The radio frequency signal source subsystem is used to provide a standardized radio frequency signal; The radio frequency cable network subsystem is used to implement signal delay according to the path difference design; The antenna array element subsystem is used to receive the standardized radio frequency signal and simulate the incoming wave in the target direction; The control subsystem is used to adjust the cable delay in real time to match the incident angle.

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