A method for designing a reflectionless structure for perfect transmission through a complex medium

Abstract

The application discloses a reflection-free structure design method for perfect transmission through complex media, and belongs to the electromagnetic wave propagation field. The reflection-free structure design method is obtained from the formula of the internal multi-port method, the internal excitation source load state is preset, and the preset load state is optimized by using a genetic algorithm, so that the highest average energy transmission coefficient from a transmitting antenna to a receiving antenna under different complex media is successfully realized. The application starts from port information, converts field information into port information, discloses a design method of the reflection-free structure for transmitting through complex media, and realizes significant reduction of scattering loss caused by wave propagation in different complex media. The method enriches the theoretical system of wave propagation in complex media, provides an important thought and direction for realizing reduction of scattering loss caused by wave propagation in complex media, and has important research significance.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of electromagnetic wave propagation, and particularly relates to a design method of a reflection-free structure for perfect transmission through complex media. BACKGROUND

[0002] At present, the scattering loss caused by the propagation of electromagnetic waves in complex media is an important limitation in a series of applications in the field of electromagnetics, including radar, satellite communication technology, electromagnetic wave propagation, etc. How to reduce the scattering loss caused by the propagation of electromagnetic waves and make the information carried by the electromagnetic waves be collected more is a hot issue in the current research. The method of wavefront shaping can reduce the influence of scattering, and through a specific mode, the electromagnetic waves can be converged in the complex medium without causing any reflection. However, such a specific mode transmission channel is very rare, and a lot of time is needed to design such a mode, and it is not suitable for any complex medium. The present application provides a design method of a reflection-free structure for perfect transmission through complex media, so that the field energy can be completely transmitted in the complex medium as much as possible, and the operation is simple, only related data needs to be collected, and the structure matched with the complex medium can be obtained by optimizing the data in the related software, and the designed structure and the complex medium jointly form a reflection-free structure.

[0003] Through the above analysis, the problems and defects of the prior art are as follows:

[0004] (1) The existing wavefront shaping technology still faces a challenge in how to achieve the required control level of the "open channel" transmission state in the complex medium, and the operation is complex.

[0005] (2) In the existing method, the design of the reflection-free structure is mostly borrowed from topology optimization, which requires a large amount of data and a long time, and requires a high-performance computer. SUMMARY

[0006] In view of the problems existing in the prior art, the present application provides a design method of a reflection-free structure for perfect transmission through complex media.

[0007] The present application is implemented as follows: a design method of a reflection-free structure for perfect transmission through complex media is obtained by sequentially exciting the internal excitation source arranged in the design area in front of the complex medium and the transmitting antenna and the receiving antenna placed behind the complex medium to obtain complete S parameter information, the data is imported into MATLAB, and the load state of the internal excitation source is optimized by MATLAB to match the complex medium, so that a reflection-free structure is obtained.

[0008] Specifically, it includes:

[0009] Step one, determine the number and spacing of internal excitation sources, and place the determined internal excitation sources in the determined optimal design area;

[0010] Further, sequentially excite the internal excitation sources and the transmitting antennas arranged in the design area in front of the complex medium and the receiving antennas placed behind the complex medium to obtain complete S parameter information.

[0011] Step two, convert the obtained S parameter information into a scattering matrix at each frequency point, and convert it into an impedance matrix, as follows:

[0012]

[0013] Further, link the actual port impedance with the required optimized internal excitation source load state, and write it as follows:

[0014]

[0015] wherein, is the port characteristic impedance of the i-th port, w is the number of external ports, which is also the actual port, n is the number of internal excitation sources, also known as internal port, z in is the actual port impedance after optimization, is the load state of the internal port, which has only two states, short circuit and open circuit, i.e. only 0 or ∞ can be taken, z i,i is the collected data.

[0016] Step three, select a genetic algorithm, and set the internal port load state as the optimization variable;

[0017] Further, calculate the S parameter scattering matrix from the input impedance expression. The formula for calculating the S parameter is as follows:

[0018]

[0019]

[0020] wherein, S A is the actual port scattering matrix after optimization, T is the defined average energy transmission coefficient, S b,a is the transmission coefficient from the transmitting antenna to the receiving antenna, and M is the number of receiving antennas.

[0021] Step four, set the expected average energy transmission coefficient change (the average energy transmission coefficient at the target frequency point is the maximum) or the number of algorithm iterations and time in the genetic algorithm script program;

[0022] Step five, the average energy transmission coefficient from the transmitting antenna to the receiving antenna is calculated through the procedures in steps two, three and four, and the genetic algorithm optimizes the variables to make the average energy transmission coefficient the highest;

[0023] Step six, if the average energy transmission coefficient is not the highest, steps three to five are repeated;

[0024] Step seven, if the average energy transmission coefficient is the highest, the internal port load state achieving the highest energy transmission coefficient from the transmitting antenna to the receiving antenna is obtained.

[0025] Another object of the present application is to provide a system for implementing the method for designing a reflectionless structure for perfect transmission through complex media.

[0026] Another object of the present application is to provide a computer device comprising a memory and a processor, wherein the memory stores a computer program, and the computer program is executed by the processor to make the processor execute the method for designing a reflectionless structure for perfect transmission through complex media.

[0027] Another object of the present application is to provide a computer readable storage medium storing a computer program, and the computer program is executed by a processor to make the processor execute the method for designing a reflectionless structure for perfect transmission through complex media.

[0028] Another object of the present application is to provide an information data processing terminal for implementing the method for designing a reflectionless structure for perfect transmission through complex media.

[0029] In combination with the above technical solutions and the technical problems solved, the advantages and positive effects of the technical solution to be protected by the present application are analyzed from the following aspects:

[0030] The present application starts from the formula of the internal multi-port method, presets the internal excitation source load state, and optimizes the preset load state using a genetic algorithm, thereby successfully achieving the highest average energy transmission coefficient from the transmitting antenna to the receiving antenna in different complex media. The present application starts from the port information, converts the field information into the port information, and discloses a method for designing a reflectionless structure for perfect transmission through complex media, which significantly reduces the scattering loss caused by wave propagation in different complex media, simplifies the operation of finding an "open transmission channel" in complex media by previous researchers, and reduces the design difficulty and the consumption of computing resources.

[0031] Secondly, the present application uses genetic algorithm to find the load state combination of the internal multi-port, so that the average energy transmission coefficient is significantly higher than that of the non-optimized matching structure; the present application enriches the theoretical system of wave propagation in complex media, and provides an important idea and direction for reducing the scattering loss caused by wave propagation in complex media.

[0032] Thirdly, the creativity of the present application as the evidence of the claim is also reflected in the following important aspects:

[0033] (1) At present, for the wave propagation in complex media, since the complex media is not a single medium, there may be multiple scatterers. In order to achieve less scattering or no scattering propagation of the wave in the complex media, the wave front shaping method is used to find the "open channel" in the complex media. However, such "open channel" is rare in the complex media, and requires high computing resources, so the design is difficult and the calculation cost is high. The method provided by the present application for reducing the scattering loss of the wave in the complex media can be used to achieve complete transmission or close to complete transmission of the energy of the wave in the complex media, and the operation is simple and the required computing resources are low, so the cost of designing the matching complex media structure can be greatly reduced.

[0034] (2) In recent years, the method for realizing no scattering loss of the wave in the complex media is usually based on the wave front shaping technology, which needs to find the "open channel" in the complex media, and the design is difficult and requires large computing resources. The present application starts from the internal multi-port method, designs the structure matching the complex media through the internal multi-port method, and realizes the low or no scattering loss propagation of the wave in the complex media.

[0035] (3) The scattering loss caused by the electromagnetic wave propagation in the complex media is an important limitation in the field of electromagnetics. How to construct a non-reflective structure matching the complex media to make the energy reach complete transmission is a problem to be solved at present. The present application successfully solves this problem based on the internal multi-port method, and the operation is simple and easy to use. After adding the structure matching the complex media, the average energy transmission coefficient is significantly higher than that without the matching structure.

[0036] (4) Because the scholars in the field of electromagnetic wave propagation consider the amplitude and phase feeding of the incident wave, and do not change the transmission medium, how to change the amplitude or phase of the incident wave to achieve focusing or imaging of the outgoing wave, so it is generally believed that the amplitude and phase of the wave front are adjusted before the incident to offset the distortion effect of the complex medium on the wave front, and the distortion effect of the wave in one complex medium can offset the distortion effect of the wave in another complex medium. However, the present application uses the internal multi-port method to break the traditional technical prejudice, successfully designs the matching structure of the complex medium, and significantly reduces the scattering loss caused by the wave propagation in the complex medium. BRIEF DESCRIPTION OF DRAWINGS

[0037] Figure 1 is a flow chart of a method for designing a reflectionless structure for perfect transmission through a complex medium according to an embodiment of the present application.

[0038] Figure 2 is a schematic diagram of a substrate integrated waveguide front structure according to an embodiment of the present application.

[0039] Figure 3 is a schematic diagram of a metal scatterer scattering region structure for simulating a complex medium according to an embodiment of the present application (taking 10 metal scatterers as an example).

[0040] Figure 4 is a schematic diagram of a complex medium matching structure design region according to an embodiment of the present application.

[0041] Figure 5 is a simulation result diagram of an average energy transmission coefficient in different complex media without a complex medium matching structure according to an embodiment of the present application.

[0042] Figure 6 is a simulation result diagram of an average energy transmission coefficient in different complex media with a complex medium matching structure according to an embodiment of the present application.

[0043] In the above drawings: 1, dielectric substrate; 2, metal scatterer; 3, internal excitation source; 4, transmitting port; 5, receiving port. DETAILED DESCRIPTION

[0044] In order to make the objectives, technical solutions, and advantages of the present application clearer, the following further describes the present application in conjunction with embodiments. It should be understood that the specific embodiments described herein are merely intended to explain the present application and are not intended to limit the present application.

[0045] I. Explanation of Embodiments In order for those skilled in the art to fully understand how the present application is specifically implemented, this part is an explanation of the embodiments of the technical solution of the claims.

[0046] As shown in FIG. 1, the method for designing a reflectionless structure for perfect transmission through a complex medium according to an embodiment of the present application includes the following steps. Figure 1

[0047] Step one, determine the number and spacing of internal excitation sources, and place the determined internal excitation sources in a determined optimal design region;

[0048] Further, sequentially excite the internal excitation sources and transmitting antennas arranged in the design region in front of the complex medium and the receiving antenna placed behind the complex medium to obtain complete S parameter information.

[0049] ​Step two, the obtained S parameter information is converted into scattering matrix at each frequency point, and is converted into impedance matrix, the formula is as follows:

[0050]

[0051] Further, the actual port impedance is connected with the required optimized internal excitation source load state, and is written as formula:

[0052]

[0053] Wherein, The port characteristic impedance of the i-th port is w, the number of external ports, also the actual port, n is the number of internal excitation sources, also called internal port, z in The optimized actual port impedance is z The load state of the internal port is only two states, short circuit and open circuit, that is, only 0 or ∞ can be taken, z i,i The collected data is z

[0054] Step three, the genetic algorithm is selected, and the load state of the internal port is Set as optimization variable;

[0055] Further, the S parameter scattering matrix is calculated from the input impedance expression. The formula for calculating the S parameter is as follows:

[0056]

[0057]

[0058] Wherein, S A The optimized actual port scattering matrix is T, the defined average energy transmission coefficient, S b,a The transmission coefficient from the transmitting antenna to the receiving antenna is M, the number of receiving antennas.

[0059] Step four, set the expected transmission coefficient change (the transmission coefficient is maximum at the target frequency point) or the number of iterations and time of the algorithm in the genetic algorithm script program;

[0060] Step five, the average energy transmission coefficient from the transmitting antenna to the receiving antenna is calculated through the programs in steps two, three and four, and the genetic algorithm will optimize the variable to make the average energy transmission coefficient highest;

[0061] Step six, if the average energy transmission coefficient is not the highest, repeat steps three to five;

[0062] Step seven, if the average energy transmission coefficient is the highest, the internal port load state realizing the highest energy transmission coefficient from the transmitting antenna to the receiving antenna is obtained.

[0063] II. Application Examples. In order to prove the creativity and technical value of the technical solutions of the present application, this part is the application examples of the technical solutions of the claims on specific products or related technologies.

[0064] The present application can be applied to the field of low scattering loss of wave propagation in complex media, including but not limited to mobile communication systems, wireless power transmission. For mobile communication systems, generally through the super surface to reflect or refract the signal emitted by the base station to maximize the signal energy received by the user, the technical solutions provided by the present application will only design an optimized area in the vicinity of the base station, match the scattering environment of the residential area, to maximize the signal energy received by the user, reduce the cost of mobile communication, and improve the communication efficiency. For wireless power transmission, by the present application, the scattering loss through the complex medium can be maximally reduced, so that the energy received by the receiving antenna is maximized, and the wireless power transmission loss is reduced.

[0065] The method for designing a reflection-free structure for perfect transmission through a complex medium provided by the application example is applied to a computer device, the computer device comprising a memory and a processor, the memory storing a computer program, the computer program being executed by the processor to cause the processor to execute the steps of the method for designing a reflection-free structure for perfect transmission through a complex medium.

[0066] The method for designing a reflection-free structure for perfect transmission through a complex medium provided by the application example is applied to an information data processing terminal, the information data processing terminal being used to implement the method for designing a reflection-free structure for perfect transmission through a complex medium.

[0067] III. Evidence of the effects of the embodiments. The embodiments of the present application have achieved some positive effects during research and development or use, and indeed have great advantages compared with the prior art. The following content is described in combination with data, charts, etc. during the test process.

[0068] The present application takes a substrate integrated waveguide complex medium as an example to demonstrate the effects of the method for designing a reflection-free structure for perfect transmission through a complex medium, as shown in Figure 2 , 3 , 4, there are 4 transmitting ports, 4 excitation ports, and 70 internal excitation sources (internal ports), 5, 10, 15, and 20 metal scatterers are respectively added in the non-design area to simulate different complex media together with the surrounding medium, and the simulation results of the average energy transmission coefficient without loading the matching structure are shown in Figure 5 . Under different complex media, taking the 7GHz average energy transmission coefficient as the target, the load state of the internal ports after optimization by the multi-objective genetic algorithm is shown in Table 1, Table 2, Table 3, and Table 4 (where "1" represents open circuit and "0" represents short circuit).

[0069] Table 1 obtains the internal port load state (5 metal scatterers) by using genetic algorithm optimization

[0070] Internal port number 1 2 3 4 5 6 7 8 9 10 Load status 1 1 0 0 1 0 1 0 0 1 Internal port number 11 12 13 14 15 16 17 18 19 20 Load status 1 1 0 0 0 1 0 1 0 1 Internal port number 21 22 23 24 25 26 27 28 29 30 Load status 0 1 0 1 0 0 0 1 1 0 Internal port number 31 32 33 34 35 36 37 38 39 40 Load status 1 0 1 1 1 0 0 1 1 1 Internal port number 41 42 43 44 45 46 47 48 49 50 Load status 1 0 0 0 1 0 0 0 0 1 Internal port number 51 52 53 54 55 56 57 58 59 60 Load status 1 0 1 0 0 0 1 0 1 0 Internal port number 61 62 63 64 65 66 67 68 69 70 Load status 1 1 1 1 0 1 1 1 1 1

[0071] Table 2 obtains the internal port load state (10 metal scatterers) by using genetic algorithm optimization

[0072] Internal port number 1 2 3 4 5 6 7 8 9 10 Load status 0 1 0 1 0 1 0 1 0 1 Internal port number 11 12 13 14 15 16 17 18 19 20 Load status 1 0 1 0 0 0 0 0 1 1 Internal port number 21 22 23 24 25 26 27 28 29 30 Load status 0 1 0 0 0 1 0 0 0 1 Internal port number 31 32 33 34 35 36 37 38 39 40 Load status 1 0 0 0 1 0 0 0 1 0 Internal port number 41 42 43 44 45 46 47 48 49 50 Load status 1 1 1 1 0 0 0 0 0 1 Internal port number 51 52 53 54 55 56 57 58 59 60 Load status 0 0 0 1 1 0 0 0 1 0 Internal port number 61 62 63 64 65 66 67 68 69 70 Load status 1 1 1 0 1 1 1 1 1 1

[0073] Table 3 obtains the internal port load state (15 metal scatterers) by using genetic algorithm optimization

[0074]

[0075]

[0076] Table 4 obtains the internal port load state (20 metal scatterers) by using genetic algorithm optimization

[0077] Internal port number 1 2 3 4 5 6 7 8 9 10 Load status 0 1 0 1 0 1 1 0 1 1 Internal port number 11 12 13 14 15 16 17 18 19 20 Load status 0 1 1 0 0 1 0 1 0 0 Figure 6 21 22 23 24 25 26 27 28 29 30 ​ 0 0 0 0 1 0 1 0 1 1 ​ 31 32 33 34 35 36 37 38 39 40 ​ 1 1 1 0 1 1 1 0 1 1 ​ 41 42 43 44 45 46 47 48 49 50 ​ 1 1 0 0 1 1 1 0 0 1 ​ 51 52 53 54 55 56 57 58 59 60 ​ 0 0 0 1 1 0 1 1 0 0 ​ 61 62 63 64 65 66 67 68 69 70 ​ 1 1 0 1 0 1 0 0 0 1

[0078] The average energy transmission coefficient simulation results obtained according to the above are shown in ​ By comparison, it can be found that the average energy transmission coefficient at 7GHz is significantly increased after using the method, and it can be seen that the present application achieves the target of reducing the scattering loss caused by wave propagation in complex media.

[0079] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited to this, any modification, equivalent replacement and improvement within the technical range disclosed by the present application, which is made by any person skilled in the art within the spirit and principle of the present application, should be covered in the protection scope of the present application.

Claims

1. A method for designing a reflection-free structure for perfect transmission through complex media, characterized in that, The internal multi-port method formula is used to preset the internal excitation source load state, and a genetic algorithm is used to optimize the preset load state, so that the highest average energy transmission coefficient of the transmitting antenna to the receiving antenna in different complex media is successfully realized. The design method of the reflectionless structure for perfect transmission through the complex medium comprises the following steps: Step one, determining the number and interval of the internal excitation sources, placing the determined internal excitation sources in the determined optimization design area, and sequentially exciting the internal excitation sources and the transmitting antenna placed in the design area in front of the complex medium and the receiving antenna placed behind the complex medium to obtain complete S parameter information; Step two, converting the obtained S parameter information into a scattering matrix at each frequency point, and converting the scattering matrix into an impedance matrix, and using a formula to connect the actual port impedance with the internal excitation source load state to be optimized; Step three, selecting a genetic algorithm, and setting the internal port load state as an optimization variable; Step four, setting the expected transmission coefficient change or the number of iterations and time of the algorithm in the genetic algorithm script program; Step five, calculating the average energy transmission coefficient of the transmitting antenna to the receiving antenna through the programs in steps two, three and four, and optimizing the variable by the genetic algorithm to make the average energy transmission coefficient highest; Step six, if the average energy transmission coefficient is not the highest, repeating steps three to five; Step seven, if the average energy transmission coefficient is the highest, obtaining the internal port load state of the transmitting antenna to the receiving antenna with the highest energy transmission coefficient; The expression of the connection between the actual port and the internal excitation source load state is as follows: wherein, , Zi is the port characteristic impedance of the ith port, w is the number of external ports, also the actual ports, n is the number of internal excitation sources, also called internal ports, Zopt is the optimized actual port impedance, Zload is the load state of the internal port, only two states, short circuit and open circuit, that is, only 0 or ∞ can be taken, Zcollected is the collected data; The are set as optimization variables, and the scattering matrix is calculated by the impedance expression, and the average energy transfer coefficient is calculated by the average energy transfer coefficient calculation formula, and the scattering matrix calculation formula and the average energy transfer coefficient calculation formula are as follows: wherein, T is the optimized actual port scattering matrix, T is the defined average energy transfer coefficient, T is the optimized actual port scattering matrix, T is the defined average energy transfer coefficient, 2. A system for implementing the design method of the reflectionless structure for perfect transmission through the complex medium according to claim 1.

3. A computer device, comprising: The computer device comprises a memory and a processor, and the memory stores a computer program, and the computer program is executed by the processor to make the processor execute the design method of the reflectionless structure for perfect transmission through the complex medium according to claim 1.

4. A computer readable storage medium storing a computer program, and the computer program is executed by a processor to make the processor execute the design method of the reflectionless structure for perfect transmission through the complex medium according to claim 1.

5. An information data processing terminal, characterized by The information data processing terminal is used to implement the system of the design method of the reflectionless structure for perfect transmission through the complex medium according to claim 2.

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