Low-level sweep field test method and device, computer equipment, readable storage medium and program product

Abstract

The invention relates to a low-level sweep field test method and device, computer equipment, a computer readable storage medium and a computer program product. The method comprises the following steps: acquiring a plurality of preset polarization modes and a plurality of preset irradiation angles of a transmitting antenna, and reference electric field intensity corresponding to each preset polarization mode; for a preset combination formed by different preset polarization modes and different preset irradiation angles, under the condition that the transmitting antenna transmits electromagnetic waves with preset intensity based on the preset combination, acquiring the receiving electric field intensity of an electric field in the first electromagnetic waves received by the receiving antenna; and determining a target shielding coefficient of the tested system based on the receiving electric field intensity corresponding to the preset combination of the preset polarization mode and the reference electric field intensity corresponding to the preset polarization mode. According to the method provided by the invention, the determined shielding coefficient can be more accurate.

Description

Technical Field

[0001] This application relates to the technical field of aircraft system-level HIRF testing, and particularly to a low-level swept field test method, device, computer device, computer-readable storage medium, and computer program product. Background Art

[0002] To determine the anti-interference ability of an aircraft against external electric fields and ensure that the aircraft can still operate normally after being irradiated by external high-intensity electromagnetic fields, it is necessary to determine the anti-interference ability of the aircraft against external electric fields based on High Intensity Radiated Fields (HIRF) testing.

[0003] The prior art proposes a low-level sweep method to obtain the transfer function of the aircraft's full-aircraft-level HIRF environment. Among them, low-level swept field testing is used in the frequency band of 100 MHz to 18 GHz, aiming to obtain the shielding coefficient of the aircraft, so as to calculate the magnitude of the internal electric field strength when the aircraft is exposed to the external HIRF environment. Finally, the HIRF test is carried out on the aircraft's internal equipment with the attenuated electric field strength, thus replacing the full-aircraft-level HIRF test. However, this method does not describe in detail the requirements of the test system and the test method, and there are many problems in actual engineering applications, which may lead to inaccurate shielding coefficients of the tested aircraft. Summary of the Invention

[0004] Based on this, it is necessary to provide a low-level swept field test method, device, computer device, computer-readable storage medium, and computer program product that can accurately determine the shielding coefficient of an aircraft system for the above technical problems.

[0005] In a first aspect, this application provides a low-level swept field test method, the method comprising:

[0006] When the positional relationship between the transmitting antenna located outside the system under test and the receiving antenna located inside the system under test satisfies a preset positional relationship, obtain various preset polarization modes, various preset irradiation angles of the transmitting antenna, and the reference electric field strength corresponding to each preset polarization mode; wherein, the polarization mode is used to determine the vector direction of the electric field in the electromagnetic wave emitted by the transmitting antenna, and the irradiation angle is used to determine the propagation direction of the electromagnetic wave emitted by the transmitting antenna;

[0007] For each preset combination formed by different preset polarization modes and different preset irradiation angles, when the transmitting antenna emits electromagnetic waves of a preset intensity based on the preset combination, obtain the received electric field strength of the electric field in the first electromagnetic wave received by the receiving antenna, and determine the received electric field strength as the received electric field strength corresponding to the preset combination;

[0008] Determine the target shielding coefficient of the system under test based on the received electric field strength corresponding to the preset combination of the preset polarization modes and the reference electric field strength corresponding to the preset polarization modes; wherein, the shielding coefficient characterizes the shielding ability of the system under test against external electric fields.

[0009] In one embodiment, the preset positional relationship is that the height of the first preset point on the transmitting antenna relative to the ground is the first preset height, the height of the second preset point on the receiving antenna relative to the ground is the second preset height, the distance between the first preset point and the second preset point is the preset distance, and both the transmitting antenna and the receiving antenna are within the preset test range.

[0010] In one embodiment, obtaining the reference electric field strength corresponding to each preset polarization mode includes:

[0011] When the height of the first preset point relative to the ground is the first preset height, the height of the second preset point relative to the ground is the second preset height, the distance between the first preset point and the second preset point is the preset distance, both the transmitting antenna and the receiving antenna are outside the system under test and within the preset test range, obtain the reference irradiation angle of the transmitting antenna.

[0012] For the reference combination formed by the preset polarization mode and the reference irradiation angle, when the transmitting antenna emits electromagnetic waves of a preset intensity based on the reference combination, obtain the initial frequency-domain signal of the second electromagnetic wave received by the receiving antenna, and perform an inverse transform on the initial frequency-domain signal to obtain multiple frames of continuous initial time-domain signals.

[0013] Obtain a preset time period, and determine the signals within the preset time period among the multiple frames of continuous initial time-domain signals as the target time-domain signals.

[0014] Perform a forward transform on the target time-domain signals to obtain target frequency-domain signals, and determine the electric field strength corresponding to the target frequency-domain signals as the reference electric field strength corresponding to the preset polarization modes.

[0015] In one embodiment, the second electromagnetic wave includes a direct wave and a reflected wave; wherein, the direct wave is the electromagnetic wave directly received by the receiving antenna and emitted by the transmitting antenna, and the reflected wave is the electromagnetic wave reflected outward by the reflecting object based on the electromagnetic wave received from the transmitting antenna; obtaining the preset time period includes:

[0016] Obtain the first reception moment when the receiving antenna receives the direct wave and the second reception moment when it receives the reflected wave.

[0017] Obtain the time interval between the first reception moment and the second reception moment, and determine the time period centered on the first reception moment and with the time interval as the duration as the preset time period.

[0018] In one embodiment, determining the target shielding coefficient of the system under test based on the received electric field intensity corresponding to a preset combination of a preset polarization mode and the reference electric field intensity corresponding to the preset polarization mode includes:

[0019] For all received electric field intensities corresponding to a preset combination of each preset polarization mode, based on the ratio between the maximum electric field intensity among all received electric field intensities and the reference electric field intensity, obtain the initial shielding coefficient of the system under test in the preset polarization mode;

[0020] For all initial shielding coefficients of the system under test in multiple preset polarization modes, determine the minimum shielding coefficient among all initial shielding coefficients as the target shielding coefficient.

[0021] In one embodiment, the method further includes:

[0022] For the electromagnetic wave with a preset intensity emitted by the transmitting antenna, obtain the preset transmission frequency of the electromagnetic wave;

[0023] When the preset transmission frequency is within the first frequency range, determine the type of the transmitting antenna as a log-periodic antenna;

[0024] When the preset transmission frequency is within the second frequency range, determine the type of the transmitting antenna as a horn antenna; wherein, the lower limit value of the second frequency range is not less than the upper limit value of the first frequency range.

[0025] In a second aspect, the present application further provides a low-level swept-field test device, and the device includes:

[0026] A first acquisition module, configured to, when the positional relationship between a transmitting antenna located outside the system under test and a receiving antenna located inside the system under test satisfies a preset positional relationship, acquire multiple preset polarization modes, multiple preset irradiation angles of the transmitting antenna, and the reference electric field intensity corresponding to each preset polarization mode; wherein, the polarization mode is used to determine the vector direction of the electric field in the electromagnetic wave emitted by the transmitting antenna, and the irradiation angle is used to determine the propagation direction of the electromagnetic wave emitted by the transmitting antenna;

[0027] A second acquisition module, configured to, for a preset combination formed by different preset polarization modes and different preset irradiation angles, when the transmitting antenna emits an electromagnetic wave with a preset intensity based on the preset combination, acquire the received electric field intensity of the electric field in the first electromagnetic wave received by the receiving antenna, and determine the received electric field intensity as the received electric field intensity corresponding to the preset combination;

[0028] A determination module is configured to determine a target shielding coefficient of a system under test based on the received electric field strength corresponding to a preset combination of preset polarization modes and the reference electric field strength corresponding to the preset polarization modes; wherein the shielding coefficient characterizes the shielding ability of the system under test against an external electric field.

[0029] In a third aspect, the present application further provides a computer device. The computer device includes a memory and a processor. The memory stores a computer program, and when the processor executes the computer program, the steps of the method in any one of the above embodiments are implemented.

[0030] In a fourth aspect, the present application further provides a computer-readable storage medium. The computer-readable storage medium stores a computer program thereon, and when the computer program is executed by a processor, the steps of the method in any one of the above embodiments are implemented.

[0031] In a fifth aspect, the present application further provides a computer program product. The computer program product includes a computer program, and when the computer program is executed by a processor, the steps of the method in any one of the above embodiments are implemented.

[0032] In the above low-level sweep field test method, device, computer device, computer-readable storage medium, and computer program product, when the positional relationship between the transmitting antenna located outside the system under test and the receiving antenna located inside the system under test satisfies a preset positional relationship, a plurality of preset polarization modes, a plurality of preset irradiation angles of the transmitting antenna, and the reference electric field strength corresponding to each preset polarization mode are obtained; wherein, the polarization mode is used to determine the vector direction of the electric field in the electromagnetic wave transmitted by the transmitting antenna, and the irradiation angle is used to determine the propagation direction of the electromagnetic wave transmitted by the transmitting antenna; for each preset combination formed by different preset polarization modes and different preset irradiation angles, when the transmitting antenna transmits an electromagnetic wave with a preset intensity based on the preset combination, the received electric field strength of the electric field in the first electromagnetic wave received by the receiving antenna is obtained, and the received electric field strength is determined as the received electric field strength corresponding to the preset combination; based on the received electric field strength corresponding to the preset combination in which the preset polarization mode is located and the reference electric field strength corresponding to the preset polarization mode, the target shielding coefficient of the system under test is determined; wherein, the shielding coefficient characterizes the shielding ability of the system under test against an external electric field. The method provided by the present application can directly determine the shielding coefficient of the entire system, and the determined shielding coefficient is more matched with the actual shielding ability of the system. Moreover, the shielding coefficient is comprehensively determined based on different preset polarization modes and different preset irradiation angles, making the determined shielding coefficient more accurate. Description of the Drawings

[0033] To more clearly illustrate the technical solutions in the embodiments of the present application or the related art, the following will briefly introduce the drawings required for use in the description of the embodiments of the present application or the related art. Obviously, the drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other related drawings can also be obtained based on these drawings.

[0034] Figure 1 It is a schematic flowchart of the low-level sweep field test method in an embodiment;

[0035] Figure 2 It is a structural block diagram of a test system in an embodiment;

[0036] Figure 3 It is a schematic flowchart of the reference electric field intensity determination method in an embodiment;

[0037] Figure 4 It is a structural block diagram of another test system in an embodiment;

[0038] Figure 5 It is a schematic diagram of the electromagnetic wave received by the receiving antenna in an embodiment;

[0039] Figure 6 It is a schematic diagram of the direct wave and the reflected wave in an embodiment;

[0040] Figure 7 It is a schematic diagram of the electromagnetic wave received by another receiving antenna in an embodiment;

[0041] Figure 8 It is a schematic flowchart of the low-level sweep field test method in another embodiment;

[0042] Figure 9 It is a structural block diagram of the low-level sweep field test device in an embodiment;

[0043] Figure 10 It is the internal structure diagram of a computer device in an embodiment. Detailed implementation manners

[0044] In order to make the purpose, technical solutions and advantages of the present application clearer, the following further details the present application in combination with the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0045] In the prior art, the reverberation chamber method is often used for high-intensity radiation field tests. However, since the reverberation chamber method needs to be carried out in a reverberation chamber with a small space, this method can only test the equipment in the aircraft and cannot test the entire aircraft system.

[0046] The method provided in this embodiment can directly determine the shielding coefficient of the entire aircraft system. The determined shielding coefficient is more matched with the actual shielding ability of the aircraft system. Moreover, the shielding coefficient is comprehensively determined based on different preset polarization modes and different preset irradiation angles, making the determined shielding coefficient more accurate.

[0047] In one embodiment, as Figure 1 shown, a low-level swept-field test method is provided. In this embodiment, an example is given where this method is applied to a terminal. It can be understood that this method can also be applied to a server, and can also be applied to a system including a terminal and a server, and is implemented through the interaction between the terminal and the server. In this embodiment, the method includes the following steps:

[0048] S102. When the positional relationship between the transmitting antenna located outside the system under test and the receiving antenna located inside the system under test satisfies a preset positional relationship, obtain various preset polarization modes, various preset irradiation angles of the transmitting antenna, and the reference electric field strength corresponding to each preset polarization mode; wherein, the polarization mode is used to determine the vector direction of the electric field in the electromagnetic wave emitted by the transmitting antenna, and the irradiation angle is used to determine the propagation direction of the electromagnetic wave emitted by the transmitting antenna.

[0049] Among them, the transmitting antenna is a device that converts an electrical signal into an electromagnetic wave and radiates it into free space, and the receiving antenna is a device that converts the electromagnetic wave in space into an electrical signal; the polarization mode can be represented by the angle between the transmitting antenna and the ground. The angle between the vector direction of the electric field and the ground is the same as the angle between the transmitting antenna and the ground. The polarization mode can include, but is not limited to, horizontal polarization, vertical polarization, and linear polarization. Among them, horizontal polarization means that the vector direction of the electric field is parallel to the ground (the angle with the ground is 0°), vertical polarization means that the vector direction of the electric field is perpendicular to the ground (the angle with the ground is 90°), and linear polarization means that the angle between the vector direction of the electric field and the ground is any angle between 0° and 90°; the irradiation angle represents the main direction or the width of the main lobe of the electromagnetic wave emitted by the transmitting antenna, and is used to describe the concentration degree of the radiation energy of the transmitting antenna in space.

[0050] Optionally, when the system under test is an aircraft, the connection block diagram of the test system can be as Figure 2 shown, where the frequency coverage range of the test system can include, but is not limited to, 100 MHz to 18 GHz. Figure 2Among them, the signal analyzer has the functions of radio frequency signal transmission and reception, is used to output and receive sine wave signals, can realize the radio frequency signal sweep output stage reception, and at the same time has signal analysis windowing, time domain mode measurement and time domain gating functions. For example, the signal analyzer can be a vector network analyzer; the power amplifier is used to amplify the signal output by the signal analyzer, with the input end connected to the signal analyzer and the output end connected to the transmitting antenna, and is used to drive the transmitting antenna to generate an electric field. During the HIRF test, a power amplifier with multiple frequency bands is usually required; the stirrer is located in the cabin and near the receiving antenna. During the test, the stirrer rotates the electric field inside the mixer cabin to make the electric field in the cabin uniform; the optical fiber transmission system includes a transmitting module and a receiving module. Among them, the input end of the transmitting module is a radio frequency signal, connected to the receiving antenna, and the output end is an optical signal, connected to the input end of the receiving module through an optical fiber. The receiving module converts the optical signal into an electrical signal and outputs the electrical signal to the input end of the signal analyzer. The optical fiber transmission system is built-in with an attenuator and an amplifier, and can attenuate or amplify the input signal; the control computer controls the signal analyzer and the optical fiber transmission system through the installed test software. Specifically, the test software can control the point frequency, frequency selection, sweep output and reception process of the signal analyzer, can automatically adjust the attenuation or gain of the optical fiber transmission system according to the test signal strength, can automatically compensate the attenuation according to the transmission link loss, can calculate the test time per frequency point according to the stirrer speed, and can also perform data processing and analysis according to the test results to generate a transfer function.

[0051] S104. For different preset polarization modes and preset combinations formed by different preset irradiation angles, when the transmitting antenna transmits electromagnetic waves with a preset intensity based on the preset combination, obtain the received electric field intensity of the electric field in the first electromagnetic wave received by the receiving antenna, and determine the received electric field intensity as the received electric field intensity corresponding to the preset combination.

[0052] Optionally, since the electric field has directivity, the received electric field intensity can be the combined electric field intensity of the electric field in the first electromagnetic wave in the three directions of X, Y, and Z. Among them, the plane formed by the X direction and the Y direction is parallel to the ground, and the X direction and the Y direction are perpendicular to each other, and the Z direction is perpendicular to the ground; the received electric field intensity can be shown as follows:

[0053]

[0054] In the formula, is the received electric field intensity, is the electric field intensity in the X direction, is the electric field intensity in the Y direction, is the electric field intensity in the Z direction.

[0055] Optionally, due to the reflections inside the system under test and the presence of the stirrer, after the electromagnetic wave irradiates inside the system under test, it will be reflected multiple times. The measured electric field after multiple reflections is a reverberant environment electric field. Therefore, the received electric field strength of the electric field received by the receiving antenna is theoretically a statistically uniform value, that is, the electric field strengths of the electric fields in the X, Y, and Z directions are the same. For example, in the case where the preset polarization mode is horizontal polarization or vertical polarization, the received electric field strengths can be respectively shown as follows:

[0056]

[0057]

[0058] In the formula, and are respectively the received electric field strengths corresponding to horizontal polarization and the received electric field strengths corresponding to vertical polarization, is the electric field strength of the electric field in any one of the X, Y, and Z directions under horizontal polarization, is the electric field strength of the electric field in any one of the X, Y, and Z directions under vertical polarization.

[0059] S106. Determine the target shielding coefficient of the system under test based on the received electric field strength corresponding to the preset combination where the preset polarization mode is located and the reference electric field strength corresponding to the preset polarization mode; wherein, the shielding coefficient characterizes the shielding ability of the system under test against external electric fields.

[0060] Among them, the larger the shielding coefficient, the stronger the shielding ability of the system under test against external electric fields.

[0061] Optionally, the initial shielding coefficient corresponding to the system under test in each preset polarization mode can be determined first, and then a shielding coefficient can be selected from all the initial shielding coefficients as the target shielding coefficient according to the preset selection rule, or all the initial shielding coefficients can be input into a preset function, and the target shielding coefficient can be determined based on the function output result. The embodiments of the present application do not make specific limitations on this.

[0062] In the above low-level sweep field test method, when the positional relationship between the transmitting antenna located outside the system under test and the receiving antenna located inside the system under test meets the preset positional relationship, various preset polarization modes, various preset irradiation angles of the transmitting antenna, and the corresponding reference electric field strength for each preset polarization mode are obtained; wherein, the polarization mode is used to determine the vector direction of the electric field in the electromagnetic wave emitted by the transmitting antenna, and the irradiation angle is used to determine the propagation direction of the electromagnetic wave emitted by the transmitting antenna; for different preset combinations formed by different preset polarization modes and different preset irradiation angles, when the transmitting antenna emits electromagnetic waves of a preset intensity based on the preset combination, the received electric field strength of the electric field in the first electromagnetic wave received by the receiving antenna is obtained, and the received electric field strength is determined as the received electric field strength corresponding to the preset combination; based on the received electric field strength corresponding to the preset combination in which the preset polarization mode is located and the reference electric field strength corresponding to the preset polarization mode, the target shielding coefficient of the system under test is determined; wherein, the shielding coefficient characterizes the shielding ability of the system under test against external electric fields. The method provided by this application can directly determine the shielding coefficient of the entire system, and the determined shielding coefficient is more matched with the actual shielding ability of the system. Moreover, the shielding coefficient is comprehensively determined based on different preset polarization modes and different preset irradiation angles, making the determined shielding coefficient more accurate.

[0063] In some embodiments, the preset positional relationship is that the height of the first preset point on the transmitting antenna relative to the ground is the first preset height, the height of the second preset point on the receiving antenna relative to the ground is the second preset height, the distance between the first preset point and the second preset point is the preset distance, and both the transmitting antenna and the receiving antenna are within the preset test range.

[0064] In some embodiments, as Figure 3 shown, obtaining the reference electric field strength corresponding to each preset polarization mode includes:

[0065] S302. When the height of the first preset point relative to the ground is the first preset height, the height of the second preset point relative to the ground is the second preset height, the distance between the first preset point and the second preset point is the preset distance, both the transmitting antenna and the receiving antenna are outside the system under test and within the preset test range, obtain the reference irradiation angle of the transmitting antenna.

[0066] S304. For the reference combination formed by the preset polarization mode and the reference irradiation angle, when the transmitting antenna emits electromagnetic waves of a preset intensity based on the reference combination, obtain the initial frequency domain signal of the second electromagnetic wave received by the receiving antenna, and perform inverse transformation on the initial frequency domain signal to obtain multiple frames of continuous initial time domain signals.

[0067] S306. Obtain a preset time period, and determine the signals within the preset time period among multiple consecutive initial time-domain signals as target time-domain signals.

[0068] S308. Perform a forward transform on the target time-domain signal to obtain a target frequency-domain signal, and determine the corresponding electric field strength of the target frequency-domain signal as the reference electric field strength corresponding to the preset polarization mode.

[0069] Optionally, the inverse transform of the initial frequency-domain signal can be performed based on, but not limited to, the inverse fast Fourier transform (IFFT) or the inverse chirp Z-transform (ICZT), and the forward transform of the target time-domain signal can be performed based on, but not limited to, the fast Fourier transform (FFT) or the chirp Z-transform (CZT).

[0070] Optionally, the preset time period can be regarded as a time-domain gate for filtering multiple consecutive initial time-domain signals, retaining the initial time-domain signals within the time-domain gate, and eliminating the initial time-domain signals outside the time-domain gate.

[0071] Optionally, the connection block diagram of the test system for determining the reference electric field strength can be as Figure 4 shown Figure 4 In which, both the receiving antenna and the transmitting antenna are located outside the system under test.

[0072] In this embodiment, the signals within the preset time period among multiple consecutive initial time-domain signals are determined as target time-domain signals, so that only the time-domain signals related to determining the reference electric field strength are retained, and the irrelevant time-domain signals are eliminated, making the determined reference electric field strength more accurate.

[0073] In some embodiments, the second electromagnetic wave includes a direct wave and a reflected wave; wherein, the direct wave is the electromagnetic wave directly received by the receiving antenna and transmitted by the transmitting antenna, and the reflected wave is the electromagnetic wave reflected outward by the reflecting object based on the electromagnetic wave transmitted by the transmitting antenna received; obtaining the preset time period includes: obtaining the first receiving moment when the receiving antenna receives the direct wave and the second receiving moment when it receives the reflected wave; obtaining the time interval between the first receiving moment and the second receiving moment, and determining the time period centered on the first receiving moment and with the time interval as the duration as the preset time period.

[0074] Optionally, when electromagnetic waves propagate and encounter buildings, trees, or other objects, reflections will occur, forming reflected waves. When the reflected waves and the direct waves act together at a location point, the direct waves and reflected waves with different phases are superimposed, which will affect the electric field strength at that location point and cause multipath effects. Therefore, during the process of determining the reference electric field strength, it is necessary to filter out the electric field strength corresponding to the reflected waves in the electric field strength received by the receiving antenna. The target time-domain signal within the preset time period is the remaining time-domain signal after the filtering process, that is, the time-domain signal corresponding to the direct wave. The reference electric field strength determined based on the target time-domain signal is the electric field strength of the direct wave received by the receiving antenna.

[0075] Optionally, during the process of determining the reference electric field strength, if there are no reflecting objects, the electric field strength received by the receiving antenna is only related to the gains of the transmitting antenna and the receiving antenna and the spatial attenuation. When the preset test range is covered with absorbing materials, it can be considered that there are no reflecting objects in the preset test range. As Figure 5 shown, Figure 5 the more tortuous curve in the figure is the change of the electromagnetic waves received by the receiving antenna when the absorbing materials are not laid in the preset test range, and the smoother curve is the change of the electromagnetic waves received by the receiving antenna when the preset test range is covered with absorbing materials. It can be seen from the figure that when there are reflecting objects, the impact on the electromagnetic waves received by the receiving antenna is greater.

[0076] Optionally, since the direct wave and the reflected wave cannot be directly distinguished in the frequency domain, the frequency-domain signal is transformed to the time domain for display through IFFT or ICZT. In the time domain, two relatively prominent signals can be clearly observed. One of them is the direct wave of the transmitting antenna, and the other is the reflected wave of the electromagnetic waves radiated by the transmitting antenna that reach the receiving antenna after being reflected by the reflecting object. Since the propagation path of the direct wave is shorter than that of the reflected wave and takes less time, the first arriving peak is displayed as the direct wave in the time domain, and the subsequent arriving peak is the reflected wave. As shown, M1 and M2 are the signals corresponding to the direct wave and the reflected wave respectively, and the time interval between the two signals is the propagation time of the path difference between the direct wave and the reflected wave. By setting an appropriate preset time period (time domain gate), M1 and M2 can be separated, the M1 signal corresponding to the direct wave can be retained, and the M2 signal corresponding to the reflected wave can be eliminated, thereby eliminating the multipath effect. As Figure 7 shown, Figure 7The most tortuous curve is the waveform diagram of the electromagnetic wave received by the receiving antenna when no absorbing material is laid within the preset test range and no time-domain gating technology is used. Among the two relatively smooth curves, one is the waveform diagram of the electromagnetic wave received by the receiving antenna when absorbing material is laid within the preset test range, and the other is the waveform diagram of the electromagnetic wave received by the receiving antenna when time-domain gating technology is used. It can be seen from the figure that the waveform after time-domain gating processing is basically the same as the waveform obtained by laying absorbing material within the preset test range.

[0077] In this embodiment, by determining the preset time period based on the first reception time when the receiving antenna receives the direct wave and the second reception time when it receives the reflected wave, the reflected wave can be more accurately eliminated from the electromagnetic wave received by the receiving antenna, so that the subsequent determined reference electric field strength is more accurate.

[0078] In some embodiments, based on the received electric field strength corresponding to the preset combination of the preset polarization mode and the reference electric field strength corresponding to the preset polarization mode, determining the target shielding coefficient of the system under test includes: for all received electric field strengths corresponding to the preset combination of each preset polarization mode, based on the ratio between the maximum electric field strength and the reference electric field strength among all received electric field strengths, obtaining the initial shielding coefficient of the system under test in the preset polarization mode; for all initial shielding coefficients of the system under test in multiple preset polarization modes, determining the minimum shielding coefficient among all initial shielding coefficients as the target shielding coefficient.

[0079] Optionally, when the multiple preset polarization modes include horizontal polarization and vertical polarization, the determination formula of the target shielding coefficient is as shown in the following formula:

[0080]

[0081] In the formula, is the target shielding coefficient, are the received electric field strengths corresponding to the preset combinations formed by horizontal polarization and different preset irradiation angles respectively, are the received electric field strengths corresponding to the preset combinations formed by vertical polarization and different preset irradiation angles respectively, is the reference electric field strength corresponding to horizontal polarization, is the reference electric field strength corresponding to vertical polarization, is the initial shielding coefficient corresponding to horizontal polarization, is the initial shielding coefficient corresponding to vertical polarization.

[0082] In this embodiment, the minimum initial shielding coefficient is determined as the target shielding coefficient. In this way, the shielding ability of the system under test determined according to the target shielding coefficient is the lower limit value of the shielding ability of the system under test. According to this lower limit value of the shielding ability, the maximum electric field intensity to which the system under test is allowed to be irradiated is determined, which can maximize the safety of the system under test during the process of being irradiated by electromagnetic waves.

[0083] In some embodiments, the method further includes: for the electromagnetic wave with a preset intensity emitted by the transmitting antenna, obtaining the preset emission frequency of the electromagnetic wave; in the case where the preset emission frequency is within the first frequency range, determining the type of the transmitting antenna as a log-periodic antenna; in the case where the preset emission frequency is within the second frequency range, determining the type of the transmitting antenna as a horn antenna; wherein, the lower limit value of the second frequency range is not less than the upper limit value of the first frequency range.

[0084] Among them, the log-periodic antenna is a broadband antenna, and its design is based on a log-periodic structure, which can maintain good performance within a relatively wide frequency range. This antenna consists of a series of gradually changing dipoles, and the length and spacing of each dipole change according to the log-periodic law; the horn antenna is a waveguide antenna, one end of which gradually expands into a horn shape, used to convert the electromagnetic wave in the waveguide into the electromagnetic wave in free space. The horn antenna is usually used in the microwave band and has high gain and good directivity.

[0085] Optionally, in the case where the first frequency range is 100 MHz to 1 GHz, the type of the transmitting antenna is determined as a log-periodic antenna; in the case where the first frequency range is 1 GHz to 18 GHz, the type of the transmitting antenna is determined as a horn antenna.

[0086] In this embodiment, different types of transmitting antennas are selected for different emission frequencies, which can not only improve the propagation efficiency of electromagnetic waves but also optimize the coverage range of electromagnetic waves.

[0087] In one embodiment, as Figure 8 shown, another low-level swept-field test method is provided, and this method includes the following content:

[0088] (1) Electric field calibration

[0089] a) Select a test location, determine the test area, and connect the test system according to Figure 4 the requirements.

[0090] b) Determine the heights and distances of the transmitting and receiving antennas. The heights of the transmitting and receiving antennas depend on the height of the electric field measurement position inside the aircraft. There is no special requirement for the distance. It is only necessary to ensure that the measurement position can be covered by the main lobe width of the transmitting antenna and an electric field signal can be measured inside the aircraft. Usually, a test distance of 10 m is selected.

[0091] c) First, perform pre-calibration to obtain information on the direct wave and the reflected wave. Set a fixed output power in the signal analyzer, turn on the power amplifier for sweep testing, obtain the spectral curve, switch to the time domain mode, find the direct wave and the reflected wave (in the time domain mode, the earliest arriving peak is the direct wave, and the subsequent arriving peaks are the reflected waves), and mark the arrival time t0 of the direct wave and the arrival time t1 of the first reflected wave.

[0092] d) The test software sets the test frequency range of the signal analyzer and a fixed output power P0, and at the same time sets the center time of the time domain gate parameter to t0 and the gate width to t1 - t0. Turn on the time domain gate and perform sweep testing to obtain the spectral curve of the electric field strength after the time domain gate is turned on.

[0093] e) Obtain the calibrated electric field strength E0 - H for horizontal polarization and the calibrated electric field strength E 0-V .

[0094] (2) Measurement of the electric field inside the aircraft

[0095] a) Move the aircraft to the test area and connect the test system according to Figure 2 .

[0096] b) Arrange the receiving antenna at the position to be measured. The polarization mode of the receiving antenna is between horizontal polarization and vertical polarization and is placed at 45° (theoretically, the polarization mode can be not considered in a reverberation environment, but in actual testing, to avoid antenna polarization isolation, the receiving antenna is placed at 45°).

[0097] c) Place the stirrer near the receiving antenna and set the rotation speed to v, in units of revolutions per second (r / s).

[0098] d) The test software sets the test frequency range of the signal analyzer and the fixed output power P0 set during calibration, sets the dwell time per frequency point to seconds, keeps the maximum value in the trace mode, does not need to turn on the time domain gate, and performs sweep testing to obtain the maximum electric field strength value inside.

[0099] e) Switch the polarization of the transmitting antenna while keeping the receiving antenna unchanged, and obtain the electric field strengths E H1 and E V1 inside the aircraft under two polarization test conditions at the current irradiation angle.

[0100] f) Change different irradiation angles and obtain the electric field strengths E Hn and E Vn inside the aircraft under two polarization test conditions at n irradiation angles.

[0101] (3) Data processing

[0102] The electric field has a directionality. The electric field strength at a certain position should be the combined electric field strength in the X, Y, and Z directions at this position. The following formula is used to calculate the combined electric field strength inside the aircraft:

[0103]

[0104] Due to the reflection of the internal cavity of the aircraft and the presence of the stirrer, after the electromagnetic wave irradiates inside the aircraft and undergoes multiple reflections, the measured electric field is an electric field in a reverberation environment. Theoretically, it is a statistically uniform value, and the magnitude of the electric field strength is the same in each direction. During actual testing, only one set of electric field values E H and E V are measured for each polarization mode of the transmitting antenna, which is equivalent to having only the electric field value in one direction. It is necessary to multiply it by , that is and to represent the combined electric field inside the aircraft. Under horizontal polarization and vertical polarization irradiations, the combined electric field strength is expressed as:

[0105]

[0106]

[0107] For each polarization irradiation, there are electric field strength test data at multiple angles. The maximum value is taken at each frequency point to form an envelope curve, which is normalized with the calibrated electric field corresponding to the polarization to obtain the shielding attenuation of the aircraft under a single polarization. Then, by comparing the shielding attenuations under the two polarizations and taking the minimum envelope, which corresponds to the worst-case scenario of the aircraft's shielding effectiveness, a set of shielding attenuation data is finally obtained. The same data processing is performed for each test position, and each position corresponds to a shielding attenuation function. The calculation method of the aircraft's shielding attenuation is as follows:

[0108]

[0109] In the formula is the electric field strength inside the aircraft at n irradiation angles under horizontal polarization, is the electric field strength inside the aircraft at n irradiation angles under vertical polarization, E 0-H and E 0-V are the electric field calibration strengths for horizontal polarization and vertical polarization, respectively.

[0110] It should be understood that although the steps in the flowcharts involved in the above-described embodiments are shown in sequence according to the arrows, these steps are not necessarily executed in the order indicated by the arrows. Unless there is a clear indication in this article, there is no strict order limit for the execution of these steps, and these steps can be executed in other orders. Moreover, at least a part of the steps in the flowcharts involved in the above-described embodiments may include multiple steps or multiple stages. These steps or stages are not necessarily executed at the same moment, but can be executed at different moments. The execution order of these steps or stages is not necessarily sequential, but can be executed alternately or in turn with at least a part of other steps or steps or stages in other steps.

[0111] Based on the same inventive concept, an embodiment of the present application also provides a low-level swept-field test device for implementing the low-level swept-field test method described above. The solution provided by this device to solve the problem is similar to the solution described in the above method. Therefore, the specific limitations in one or more embodiments of the low-level swept-field test device provided below can refer to the limitations on the low-level swept-field test method in the above text, and will not be repeated here.

[0112] In an exemplary embodiment, as Figure 9 shown, a low-level swept-field test device 900 is provided, including: a first acquisition module 901, a second acquisition module 902, and a determination module 903, where:

[0113] The first acquisition module 901 is configured to acquire various preset polarization modes, various preset irradiation angles of the transmitting antenna, and the reference electric field strength corresponding to each preset polarization mode when the positional relationship between the transmitting antenna located outside the system under test and the receiving antenna located inside the system under test satisfies a preset positional relationship; wherein, the polarization mode is used to determine the vector direction of the electric field in the electromagnetic wave emitted by the transmitting antenna, and the irradiation angle is used to determine the propagation direction of the electromagnetic wave emitted by the transmitting antenna.

[0114] The second acquisition module 902 is configured to, for a preset combination formed by different preset polarization modes and different preset irradiation angles, acquire the received electric field strength of the electric field in the first electromagnetic wave received by the receiving antenna when the transmitting antenna emits an electromagnetic wave with a preset intensity based on the preset combination, and determine the received electric field strength as the received electric field strength corresponding to the preset combination.

[0115] The determination module 903 is configured to determine the target shielding coefficient of the system under test based on the received electric field strength corresponding to the preset combination in which the preset polarization mode is located and the reference electric field strength corresponding to the preset polarization mode; wherein, the shielding coefficient characterizes the shielding ability of the system under test for an external electric field.

[0116] In some embodiments, the low-level sweep field test device 900 is specifically configured such that the preset positional relationship is that the height of the first preset point on the transmitting antenna relative to the ground is the first preset height, the height of the second preset point on the receiving antenna relative to the ground is the second preset height, the distance between the first preset point and the second preset point is the preset distance, and both the transmitting antenna and the receiving antenna are within the preset test range.

[0117] In some embodiments, the first acquisition module 901 includes:

[0118] The first acquisition unit is configured to acquire the reference irradiation angle of the transmitting antenna when the height of the first preset point relative to the ground is the first preset height, the height of the second preset point relative to the ground is the second preset height, the distance between the first preset point and the second preset point is the preset distance, both the transmitting antenna and the receiving antenna are outside the system under test, and both are within the preset test range.

[0119] The second acquisition unit is configured to, for the reference combination formed by the preset polarization mode and the reference irradiation angle, acquire the initial frequency domain signal of the second electromagnetic wave received by the receiving antenna when the transmitting antenna transmits electromagnetic waves of a preset intensity based on the reference combination, and perform an inverse transform on the initial frequency domain signal to obtain multiple frames of continuous initial time domain signals.

[0120] The third acquisition unit is configured to acquire a preset time period and determine the signals within the preset time period among the multiple frames of continuous initial time domain signals as the target time domain signals.

[0121] The transformation unit is configured to perform a forward transform on the target time domain signal to obtain a target frequency domain signal, and determine the corresponding electric field intensity of the target frequency domain signal as the reference electric field intensity corresponding to the preset polarization mode.

[0122] In some embodiments, the second electromagnetic wave includes a direct wave and a reflected wave; wherein, the direct wave is the electromagnetic wave directly received by the receiving antenna and transmitted by the transmitting antenna, and the reflected wave is the electromagnetic wave reflected outward by the reflecting object based on the electromagnetic wave received from the transmitting antenna; the third acquisition unit is further configured to acquire the first reception moment when the receiving antenna receives the direct wave and the second reception moment when it receives the reflected wave; acquire the time interval between the first reception moment and the second reception moment, and determine the time period centered on the first reception moment and with the time interval as the duration as the preset time period.

[0123] In some embodiments, the determining module 903 is further configured to, for all received electric field strengths corresponding to each preset polarization mode in a preset combination, obtain an initial shielding coefficient of the system under test in the preset polarization mode based on the ratio between the maximum electric field strength and the reference electric field strength among all the received electric field strengths; for all the initial shielding coefficients of the system under test in multiple preset polarization modes, determine the minimum shielding coefficient among all the initial shielding coefficients as the target shielding coefficient.

[0124] In some embodiments, the low-level swept-field test device 900 is further configured to obtain a preset transmission frequency of the electromagnetic wave for the electromagnetic wave with a preset intensity transmitted by the transmitting antenna; in a case where the preset transmission frequency is within a first frequency range, determine the type of the transmitting antenna as a log-periodic antenna; in a case where the preset transmission frequency is within a second frequency range, determine the type of the transmitting antenna as a horn antenna; wherein, the lower limit value of the second frequency range is not less than the upper limit value of the first frequency range.

[0125] Each module in the above low-level swept-field test device can be implemented in whole or in part by software, hardware, and their combination. The above modules can be embedded in or independent of the processor in the computer device in the form of hardware, or stored in the memory in the computer device in the form of software, so that the processor can call and execute the operations corresponding to the above modules.

[0126] In an exemplary embodiment, a computer device is provided. The computer device can be a terminal, and its internal structure diagram can be as Figure 10 shown. The computer device includes a processor, a memory, an input / output interface, a communication interface, a display unit, and an input device. Among them, the processor, the memory, and the input / output interface are connected through a system bus, and the communication interface, the display unit, and the input device are connected to the system bus through the input / output interface. Among them, the processor of the computer device is used to provide computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system and a computer program. The internal memory provides an environment for the operation of the operating system and the computer program in the non-volatile storage medium. The input / output interface of the computer device is used for exchanging information between the processor and external devices. The communication interface of the computer device is used for communicating with external terminals in a wired or wireless manner, and the wireless manner can be implemented through WIFI, a mobile cellular network, near field communication (NFC), or other technologies. The computer program, when executed by the processor, implements a low-level swept-field test method.

[0127] Those skilled in the art can understand, Figure 10The structure shown is only a block diagram of some structures related to the solution of this application, and does not constitute a limitation on the computer device to which the solution of this application is applied. The specific computer device may include more or fewer components than those shown in the figure, or combine some components, or have different component arrangements.

[0128] In one embodiment, a computer device is further provided, including a memory and a processor. A computer program is stored in the memory, and when the processor executes the computer program, the steps in the above method embodiments are implemented.

[0129] In one embodiment, a computer-readable storage medium is provided, on which a computer program is stored, and when the computer program is executed by a processor, the steps in the above method embodiments are implemented.

[0130] In one embodiment, a computer program product is provided, including a computer program, and when the computer program is executed by a processor, the steps in the above method embodiments are implemented.

[0131] It should be noted that the user information (including but not limited to user device information, user personal information, etc.) and data (including but not limited to data for analysis, stored data, displayed data, etc.) involved in this application are all information and data authorized by the user or fully authorized by all parties, and the collection, use, and processing of relevant data need to comply with relevant regulations.

[0132] Those of ordinary skill in the art can understand that all or part of the processes in the methods of the above embodiments can be completed by instructing relevant hardware through a computer program. The computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the above methods. Among them, any reference to a memory, database, or other medium used in the embodiments provided in this application can include at least one of non-volatile memory and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetoresistive random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. By way of illustration and not limitation, RAM can be in various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM), etc. The databases involved in the embodiments provided in this application can include at least one of relational databases and non-relational databases. Non-relational databases can include distributed databases based on blockchain, etc., without limitation. The processors involved in the embodiments provided in this application can be general-purpose processors, central processing units, graphics processing units, digital signal processors, programmable logic devices, data processing logics based on quantum computing, artificial intelligence (AI) processors, etc., without limitation.

[0133] The technical features of the above embodiments can be combined arbitrarily. For the sake of concise description, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered to be within the scope recorded in this application.

[0134] The above-described embodiments merely represent several implementation manners of the present application. The description thereof is relatively specific and detailed, but it should not be construed as a limitation to the patent scope of the present application. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present application, several modifications and improvements can still be made, and these all fall within the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the appended claims.

Claims

1. A low-level sweep field test method, characterized in that, The method includes: When the positional relationship between a transmitting antenna located outside the system under test and a receiving antenna located inside the system under test meets a preset positional relationship, obtaining multiple preset polarization modes, multiple preset irradiation angles of the transmitting antenna, and the reference electric field strength corresponding to each preset polarization mode; wherein, the polarization mode is used to determine the vector direction of the electric field in the electromagnetic wave emitted by the transmitting antenna, and the irradiation angle is used to determine the propagation direction of the electromagnetic wave emitted by the transmitting antenna; For a preset combination formed by different preset polarization modes and different preset irradiation angles, when the transmitting antenna emits an electromagnetic wave with a preset intensity based on the preset combination, obtaining the received electric field strength of the electric field in the first electromagnetic wave received by the receiving antenna, and determining the received electric field strength as the received electric field strength corresponding to the preset combination; Based on the received electric field strength corresponding to the preset combination in which the preset polarization mode is located and the reference electric field strength corresponding to the preset polarization mode, determining the target shielding coefficient of the system under test; wherein, the shielding coefficient characterizes the shielding ability of the system under test for an external electric field.

2. The method according to claim 1, wherein The preset positional relationship is that the height of a first preset point on the transmitting antenna relative to the ground is a first preset height, the height of a second preset point on the receiving antenna relative to the ground is a second preset height, the distance between the first preset point and the second preset point is a preset distance, and both the transmitting antenna and the receiving antenna are within a preset test range.

3. The method according to claim 2, wherein The obtaining of the reference electric field strength corresponding to each preset polarization mode includes: When the height of the first preset point relative to the ground is the first preset height, the height of the second preset point relative to the ground is the second preset height, the distance between the first preset point and the second preset point is the preset distance, and both the transmitting antenna and the receiving antenna are outside the system under test and within the preset test range, obtaining the reference irradiation angle of the transmitting antenna; For a reference combination formed by the preset polarization mode and the reference irradiation angle, when the transmitting antenna emits an electromagnetic wave with the preset intensity based on the reference combination, obtaining the initial frequency-domain signal of the second electromagnetic wave received by the receiving antenna, and performing an inverse transform on the initial frequency-domain signal to obtain multiple frames of continuous initial time-domain signals; Obtaining a preset time period, and determining the signals within the preset time period in the multiple frames of continuous initial time-domain signals as target time-domain signals; Performing a forward transform on the target time-domain signal to obtain a target frequency-domain signal, and determining the electric field strength corresponding to the target frequency-domain signal as the reference electric field strength corresponding to the preset polarization mode.

4. The method according to claim 3, wherein The second electromagnetic wave includes a direct wave and a reflected wave; wherein, the direct wave is the electromagnetic wave directly received by the receiving antenna and emitted by the transmitting antenna, and the reflected wave is the electromagnetic wave reflected outward by a reflecting object based on the electromagnetic wave received and emitted by the transmitting antenna; the obtaining of the preset time period includes: Obtain the first reception moment when the direct wave is received by the receiving antenna and the second reception moment when the reflected wave is received. Obtain the time interval between the first reception moment and the second reception moment, and determine the preset time period with the first reception moment as the central moment and the time interval as the duration.

5. The method according to claim 1, wherein The determining the target shielding coefficient of the system under test based on the received electric field strength corresponding to the preset combination of the preset polarization modes and the reference electric field strength corresponding to the preset polarization mode includes: For all the received electric field strengths corresponding to the preset combination of each preset polarization mode, obtain the initial shielding coefficient of the system under test in the preset polarization mode based on the ratio between the maximum electric field strength among all the received electric field strengths and the reference electric field strength. For all the initial shielding coefficients of the system under test in the multiple preset polarization modes, determine the minimum shielding coefficient among all the initial shielding coefficients as the target shielding coefficient.

6. The method according to claim 1, wherein The method further includes: For the electromagnetic wave with the preset intensity emitted by the transmitting antenna, obtain the preset emission frequency of the electromagnetic wave. When the preset emission frequency is within the first frequency range, determine the type of the transmitting antenna as a log-periodic antenna. When the preset emission frequency is within the second frequency range, determine the type of the transmitting antenna as a horn antenna; wherein, the lower limit value of the second frequency range is not less than the upper limit value of the first frequency range.

7. A low-level sweep field test device, characterized in that, The device includes: A first obtaining module, configured to obtain multiple preset polarization modes, multiple preset irradiation angles of the transmitting antenna, and the reference electric field strength corresponding to each preset polarization mode when the positional relationship between the transmitting antenna located outside the system under test and the receiving antenna located inside the system under test satisfies a preset positional relationship; wherein, the polarization mode is used to determine the vector direction of the electric field in the electromagnetic wave emitted by the transmitting antenna, and the irradiation angle is used to determine the propagation direction of the electromagnetic wave emitted by the transmitting antenna. A second obtaining module, configured to, for a preset combination formed by different preset polarization modes and different preset irradiation angles, when the transmitting antenna emits an electromagnetic wave with a preset intensity based on the preset combination, obtain the received electric field strength of the electric field in the first electromagnetic wave received by the receiving antenna, and determine the received electric field strength as the received electric field strength corresponding to the preset combination. A determining module, configured to determine the target shielding coefficient of the system under test based on the received electric field strength corresponding to the preset combination of the preset polarization mode and the reference electric field strength corresponding to the preset polarization mode; wherein, the shielding coefficient characterizes the shielding ability of the system under test for an external electric field.

8. A computer device, comprising a memory and a processor, the memory storing a computer program, characterized in that, When the processor executes the computer program, it implements the steps of the method according to any one of claims 1 to 6.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by the processor, it implements the steps of the method according to any one of claims 1 to 6.

10. A computer program product, comprising a computer program, characterized in that, When the computer program is executed by the processor, it implements the steps of the method according to any one of claims 1 to 6.

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