Electromagnetic shielding performance testing system and method

Abstract

The present invention relates to the field of electromagnetic field and microwave technology, and specifically to an electromagnetic shielding performance testing system and method, the system comprising: a device to be tested, a comparison device and a calculation device, the calculation device respectively collects the electromagnetic conduction power of the device to be tested and the comparison device under the application of electromagnetic energy of the same frequency, and calculates the electromagnetic shielding performance of the components to be tested inside the device to be tested based on the collected electromagnetic conduction power, so as to realize the electromagnetic shielding performance test of the small cavity such as the components to be tested inside the device to be tested. It can be understood that the technical solution provided by the present invention can accurately test the electromagnetic shielding performance of a small cavity.

Description

Technical Field

[0001] The invention relates to the field of electromagnetic field and microwave technology, and in particular to an electromagnetic shielding performance testing method based on a resonant cavity. Background Art

[0002] As the electromagnetic environment becomes increasingly complex, the integration of electrical and electronic equipment becomes higher and higher, and the demand for electromagnetic protection becomes increasingly urgent. Small test pieces, such as conductive rubber, can effectively solve the electromagnetic shielding sealing problem that traditional methods cannot solve. The conductive rubber dispensing process achieves the electromagnetic shielding requirements by applying fluid conductive rubber on the surface of the casing and forming a sealing gasket after curing.

[0003] However, the existing testing methods for electromagnetic shielding performance are only for the shielding performance of large shielding rooms, cables, shielding gaskets, sheet materials, etc. There is a lack of testing methods for the shielding performance of small cavities such as conductive rubber and other test pieces, and it is impossible to accurately test the electromagnetic shielding performance of small cavities. Summary of the invention

[0004] In view of this, an object of the present invention is to provide an electromagnetic shielding performance testing system and method to solve the problem in the prior art that the electromagnetic shielding performance of a small cavity cannot be accurately tested.

[0005] According to a first aspect of an embodiment of the present invention, there is provided an electromagnetic shielding performance testing system, comprising:

[0006] Device under test, comparison device, calculation device and network analyzer;

[0007] The device under test is composed of a top cover, a first probe, a second probe, an external chamber, an internal shielding chamber and a device under test, wherein the first probe and the second probe penetrate the top cover and are connected to the computing device through a network analyzer, the top cover is located above the external chamber to form a closed cavity, the internal shielding chamber is placed inside the closed cavity, the device under test is covered on the upper part of the internal shielding chamber, so that the internal shielding chamber is sealed, and the upper part of the device under test is in contact with the top cover;

[0008] The comparison device at least comprises a device without a DUT, wherein the device without a DUT is based on the device to be tested, but the DUT is removed, and the rest of the structure is the same as that of the device to be tested;

[0009] The calculation device at least includes a result calculation module, which is used to apply electromagnetic energy to the first probe in the device under test and the device without the device under test according to a preset frequency, and use a network analyzer to respectively measure the electromagnetic conduction power of the device under test and the electromagnetic conduction power of the device without the device under test obtained from the second probe; and is also used to calculate the electromagnetic shielding performance of the device under test based on the electromagnetic conduction power of the device under test and the electromagnetic conduction power of the device without the device under test.

[0010] Preferably, the system further comprises:

[0011] A device without a shielding chamber, wherein the device without a shielding chamber is based on the device under test, but the internal shielding chamber and the device under test are removed, and the remaining structure is the same as that of the device under test;

[0012] The result calculation module of the computing device is also used to apply electromagnetic energy to the first probe in the non-shielding chamber device at a preset frequency, and use a network analyzer to measure the electromagnetic conduction power of the device without the device under test from the second probe in the device without the device under test; and is also used to calculate the electromagnetic shielding performance of the device under test based on the electromagnetic conduction power of the device under test and the electromagnetic conduction power of the device without the device under test.

[0013] Preferably, the computing device further comprises:

[0014] An information acquisition module, used to acquire the size information of the device to be tested and the device without the device to be tested;

[0015] The test result judgment module is used to calculate the minimum operating frequency according to the size information, and calculate the mode number according to the preset frequency; if the minimum operating frequency is less than or equal to the preset frequency and the mode number is greater than the preset value, the electromagnetic shielding performance test result of the output device under test is credible.

[0016] According to a second aspect of an embodiment of the present invention, there is provided an electromagnetic shielding performance testing method, which is applied to a computing device in the above system, comprising:

[0017] Applying electromagnetic energy to a first probe in the device under test at a preset frequency, and obtaining electromagnetic conduction power of the device under test from a second probe in the device under test;

[0018] Applying electromagnetic energy to a first probe in the device without the device under test at a preset frequency, and obtaining electromagnetic conduction power of the device without the device under test from a second probe in the device without the device under test;

[0019] The electromagnetic shielding performance of the device under test is calculated based on the electromagnetic conduction power of the device under test and the electromagnetic conduction power of the device without the device under test.

[0020] Preferably, the electromagnetic shielding performance of the internal shielding chamber is calculated based on the electromagnetic conduction power of the device to be tested and the electromagnetic conduction power of the device without the device to be tested, including:

[0021] According to the electromagnetic conduction power of the device under test, the energy transmission efficiency of the device under test is obtained by using a network analyzer or HFSS electromagnetic simulation software;

[0022] According to the electromagnetic conduction power of the device without the device under test, the energy transmission efficiency of the device without the device under test is obtained by using a network analyzer or HFSS electromagnetic simulation software;

[0023] The electromagnetic shielding performance of the device under test is calculated based on the energy transmission efficiency of the device under test and the energy transmission efficiency of the device without the device under test.

[0024] Preferably, the method further comprises:

[0025] Acquiring dimension information of the device under test and the device without the device under test;

[0026] Calculating the lowest usage frequency based on the size information;

[0027] According to the preset frequency, the mode number is calculated;

[0028] If the minimum operating frequency is less than or equal to the preset frequency and the mode number is greater than a preset value, the output electromagnetic shielding performance test result of the device under test is credible.

[0029] Preferably, the calculating the electromagnetic shielding performance of the device under test according to the energy transmission efficiency of the device under test and the energy transmission efficiency of the device without the device under test comprises:

[0030] According to the formula SE 被测件 (dB) = S 21-无被测件 (dB)-S' 21 (dB) is used to calculate the electromagnetic shielding performance of the device under test, where S' 21 (dB) is the energy transmission efficiency of the device under test, S 21-无被测件 (dB) is the energy transmission efficiency of the device without the DUT, SE 被测件 (dB) is the electromagnetic shielding performance of the device under test.

[0031] Preferably, calculating the minimum usage frequency according to the size information includes:

[0032] According to the formula Calculate the frequency f 110 , where l and w represent the length and width of the closed cavity respectively, μ represents the magnetic permeability of the medium in the closed cavity, and ε represents the dielectric constant;

[0033] According to the formula f r =6×f 110 The minimum frequency of use is calculated.

[0034] The technical solution provided by the embodiments of the present invention may have the following beneficial effects:

[0035] It is understandable that the technical solution provided by the present invention relates to an electromagnetic shielding performance test system and method, the system includes: a device to be tested, a comparison device and a calculation device, the calculation device respectively collects the electromagnetic conduction power of the device to be tested and the comparison device under the application of electromagnetic energy of the same frequency, and calculates the electromagnetic shielding performance of the component to be tested inside the device to be tested based on the collected electromagnetic conduction power, so as to realize the electromagnetic shielding performance test of the small cavity such as the component to be tested inside the device to be tested. It is understandable that the technical solution provided by the present invention can accurately test the electromagnetic shielding performance of a small cavity.

[0036] It is to be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the invention and, together with the description, serve to explain the principles of the invention.

[0038] Figure 1 is a schematic block diagram of an electromagnetic shielding performance testing system according to an exemplary embodiment;

[0039] Figure 2 is a schematic diagram of the structure of a device to be tested according to an exemplary embodiment;

[0040] Figure 3 is a schematic structural diagram of a non-shielding chamber device according to an exemplary embodiment;

[0041] Figure 4 is a schematic structural diagram of a device without a device under test according to an exemplary embodiment;

[0042] Figure 5 It is a schematic diagram of the steps of a method for testing electromagnetic shielding performance according to an exemplary embodiment. DETAILED DESCRIPTION

[0043] Exemplary embodiments will be described in detail herein, examples of which are shown in the accompanying drawings. When the following description refers to the drawings, the same numbers in different drawings represent the same or similar elements unless otherwise indicated. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present invention. Instead, they are merely examples of devices and methods consistent with some aspects of the present invention as detailed in the appended claims.

[0044] Embodiment 1

[0045] Figure 1 is a schematic block diagram of an electromagnetic shielding performance testing system according to an exemplary embodiment. Figure 1 , providing an electromagnetic shielding performance test system, comprising:

[0046] The device under test 200, the comparison device 300 / 400, the calculation device 100 and the network analyzer 500;

[0047] Figure 2 is a schematic diagram of the structure of the device to be tested according to an exemplary embodiment, see Figure 2 The device under test 200 is composed of a top cover 201, a first probe 202, a second probe 203, an external chamber 204, an internal shielding chamber 205 and a device under test 206, wherein the first probe 202 and the second probe 203 penetrate the top cover 201 and are connected to the computing device 100 through a network analyzer, the top cover 201 is located above the external chamber 204 to form a closed cavity, the internal shielding chamber 205 is placed inside the closed cavity, the device under test 206 is coated on the upper part of the internal shielding chamber 205 to make the internal shielding chamber 205 sealed, and the upper part of the device under test 206 is attached to the top cover 201;

[0048] Preferably, the tested object may be conductive rubber.

[0049] Figure 4 is a schematic diagram of a structure without a device under test according to an exemplary embodiment, see Figure 4 The comparison device 300 / 400 at least includes a device without a DUT 400. The device without a DUT 400 is based on the device under test 200, but the DUT is removed. The rest of the structure is the same as that of the device under test.

[0050] The specific structure of the device without a test piece is composed of a top cover 401, a first probe 402, a second probe 403, an external chamber 404 and an internal shielding chamber 405. The first probe 402 and the second probe 403 penetrate the top cover 401 and are connected to the computing device 100 through a network analyzer. The top cover 401 is located above the external chamber 404 to form a closed cavity, and the internal shielding chamber 405 is placed inside the closed cavity.

[0051] The computing device 100 at least includes a result computing module, which is used to apply electromagnetic energy to the first probes in the device under test 200 and the device without the device under test 400 at a preset frequency, and to measure the electromagnetic conduction power of the device under test and the electromagnetic conduction power of the device without the device under test obtained from the second probe using a network analyzer; and is also used to calculate the electromagnetic shielding performance of the device under test based on the electromagnetic conduction power of the device under test and the electromagnetic conduction power of the device without the device under test.

[0052] Preferably, the calculation method in the calculation device may also be a manual calculation method.

[0053] In specific practice, the device to be tested, preferably, when the tested piece is conductive rubber, the conductivity of the conductive rubber is 1000 Siemens / meter, and the top cover is an aluminum top cover, two probes are embedded in the aluminum top cover and are distributed in an axisymmetric state, the external bin and the internal shielding bin are both made of copper, when the user constructs the device to be tested, the tested piece is evenly and sufficiently dotted on the edge of the copper internal shielding bin to ensure that there are no bubbles, the metal top cover with two probes inserted is tightly covered on the edge of the external bin, and it is ensured that there is no gap between the glue dots on the internal shielding bin and the top cover, and the internal shielding bin and the top cover are sealed. The device without the tested piece is used as a comparison device for the device to be tested by removing the tested piece. The tested piece is the electromagnetic shielding performance of the tested piece to be measured. When the system is working, the computing device emits the same electromagnetic energy, which is input into the device under test through the first probe of the device under test, and the electromagnetic conduction power of the device under test is obtained from the second probe, and is input into the device without the device under test through the first probe of the device without the device under test, and the electromagnetic conduction power of the device without the device under test is obtained from the second probe of the device without the device under test through the network analyzer. Then, the electromagnetic shielding performance of the device under test is calculated through the two conduction powers.

[0054] It can be understood that the technical solution provided in this embodiment relates to an electromagnetic shielding performance test system and method, which includes: a device to be tested, a comparison device and a calculation device, through which the electromagnetic conduction power of the device to be tested and the comparison device under the same frequency electromagnetic energy is respectively collected by the calculation device, and the electromagnetic shielding performance of the component to be tested inside the device to be tested is calculated based on the collected electromagnetic conduction power, so as to realize the electromagnetic shielding performance test of the small cavity such as the component to be tested inside the device to be tested. It can be understood that the technical solution provided in this embodiment can accurately test the electromagnetic shielding performance of a small cavity.

[0055] It should be noted that the system further includes:

[0056] A device without a shielding chamber, wherein the device without a shielding chamber is based on the device under test, but the internal shielding chamber and the device under test are removed, and the remaining structure is the same as that of the device under test;

[0057] The result calculation module of the calculation device is also used to apply electromagnetic energy to the first probe in the unshielded chamber device at a preset frequency, and use a network analyzer to measure the electromagnetic conduction power of the unshielded chamber device obtained from the second probe in the unshielded chamber device; it is also used to calculate the electromagnetic shielding performance of the shielding chamber based on the electromagnetic conduction power of the device to be tested and the electromagnetic conduction power of the unshielded chamber device.

[0058] In practice, see Figure 3 The specific structure of the non-shielding chamber device is composed of a top cover 301, a first probe 302, a second probe 303, and an external chamber 304. The first probe 302 and the second probe 303 penetrate the top cover 301 and are connected to the computing device 100 through a network analyzer. The top cover 301 is located above the external chamber 304 to form a closed cavity, and the internal shielding chamber 305 is placed inside the closed cavity. After the system includes the non-shielding chamber device, the electromagnetic shielding performance of the internal shielding chamber can be finally calculated through the non-shielding chamber device and the device to be tested.

[0059] It should be noted that the computing device further includes:

[0060] An information acquisition module, used to acquire the size information of the device to be tested and the device without the device to be tested;

[0061] The test result judgment module is used to calculate the minimum operating frequency according to the size information, and calculate the mode number according to the preset frequency; if the minimum operating frequency is less than or equal to the preset frequency and the mode number is greater than the preset value, the electromagnetic shielding performance test result of the output device under test is credible.

[0062] It can be understood that the technical solution provided in this embodiment can test the credibility of the test results obtained by the computing device, thereby determining whether the final computing results are credible.

[0063] Embodiment 2

[0064] Figure 5 is a schematic diagram of the steps of a method for testing electromagnetic shielding performance according to an exemplary embodiment, see Figure 5 , provides an electromagnetic shielding performance testing method, which is applied to a computing device in the above system, comprising:

[0065] Step S11, applying electromagnetic energy to the first probe in the device to be tested according to a preset frequency, and obtaining the electromagnetic conduction power of the device to be tested from the second probe in the device to be tested;

[0066] Step S12, applying electromagnetic energy to the first probe in the device without the device under test according to a preset frequency, and obtaining electromagnetic conduction power of the device without the device under test from the second probe in the device without the device under test;

[0067] Step S13: Calculate the electromagnetic shielding performance of the device under test according to the electromagnetic conduction power of the device under test and the electromagnetic conduction power of the device without the device under test.

[0068] Preferably, the electromagnetic shielding performance of the internal shielding chamber can also be calculated through the above steps.

[0069] It can be understood that the technical solution provided by this embodiment applies electromagnetic energy to the first probe in the device to be tested according to a preset frequency, and obtains the electromagnetic conduction power of the device to be tested from the second probe in the device to be tested; applies electromagnetic energy to the first probe in the device without the device to be tested according to a preset frequency, and obtains the electromagnetic conduction power of the device without the device to be tested from the second probe in the device without the device to be tested; and calculates the electromagnetic shielding performance of the device to be tested based on the electromagnetic conduction power of the device to be tested and the electromagnetic conduction power of the device without the device to be tested. It can be understood that the technical solution provided by this embodiment can accurately test the electromagnetic shielding performance of a small cavity.

[0070] It should be noted that the electromagnetic shielding performance of the internal shielding chamber is calculated based on the electromagnetic conduction power of the device under test and the electromagnetic conduction power of the device without the device under test, including:

[0071] According to the electromagnetic conduction power of the device under test, the energy transmission efficiency of the device under test is obtained by using a network analyzer or HFSS electromagnetic simulation software;

[0072] According to the electromagnetic conduction power of the device without the device under test, the energy transmission efficiency of the device without the device under test is obtained by using a network analyzer or HFSS electromagnetic simulation software;

[0073] The electromagnetic shielding performance of the device under test is calculated based on the energy transmission efficiency of the device under test and the energy transmission efficiency of the device without the device under test.

[0074] In practice, the electromagnetic shielding efficiency SE (dB) is usually defined as follows:

[0075] Considering the electric field, the electromagnetic shielding efficiency SE (dB) is expressed as follows:

[0076] Considering the magnetic field, the electromagnetic shielding efficiency SE (dB) is expressed as follows:

[0077] Considering the energy, the electromagnetic shielding efficiency SE (dB) is expressed as follows:

[0078] After converting the energy unit into power, the electromagnetic shielding efficiency SE (dB) of the shielding chamber or the device under test is determined by comparing the electromagnetic transmission power before and after adding the shielding chamber or the device under test with electromagnetic shielding function and the corresponding structure. The electromagnetic shielding efficiency calculation formula becomes:

[0079] In the above formula, E2, H2, W2, and P2 are corresponding parameters in the device under test, and E1, H1, W1, and P1 are corresponding parameters in the comparison device, which is the above-mentioned device without a shielding chamber or a device without a device under test.

[0080] In actual application, the HFSS software simulation method is used. Compared with the output power P1 and P2, the parameter S 21 It is easier to obtain and more accurate in simulation results. According to the parameter S 21 The definition formula is:

[0081]

[0082] When the input electromagnetic energy is the same, the S 21 (dB) parameter and S' of the device under test 21 (dB) parameter formula is as follows:

[0083]

[0084] From the above formula, it can be deduced that:

[0085]

[0086] It can be seen that under the condition of ensuring the same input electromagnetic energy, the S 21 The electromagnetic shielding efficiency SE (dB) of the shielding chamber and the tested object (taking conductive rubber as an example) can also be obtained. The specific formula is as follows:

[0087] SE(dB)=S 21 (dB)-S' 21 (dB)

[0088] Substitute the test cases of the shielding chamber and the conductive rubber into the test cases and obtain the following formula:

[0089] SE 屏蔽仓 (dB) = S 21-无屏蔽仓 (dB)-S' 21 (dB)

[0090] SE 橡胶(dB) = S 21-无橡胶 (dB)-S' 21 (dB)

[0091] Therefore, preferably, the electromagnetic shielding performance of the internal shielding chamber is calculated based on the energy transmission efficiency of the device under test and the energy transmission efficiency of the device without the shielding chamber, including:

[0092] According to the formula SE 屏蔽仓 (dB) = S 21-无屏蔽仓 (dB)-S' 21 (dB) is used to calculate the electromagnetic shielding performance of the internal shielding chamber, where S' 21 (dB) is the energy transmission efficiency of the device under test, S 21-无屏蔽仓 (dB) is the energy transmission efficiency of the unshielded chamber device, SE 屏蔽仓 (dB) is the electromagnetic shielding performance of the internal shielding chamber.

[0093] Similarly, according to the formula SE 橡胶 (dB) = S 21-无橡胶 (dB)-S' 21 (dB) The electromagnetic shielding performance of the conductive rubber is calculated as follows: According to the formula SE 被测件 (dB) = S 21-无被测件 (dB)-S' 21 (dB) is used to calculate the electromagnetic shielding performance of the device under test, where S' 21 (dB) is the energy transmission efficiency of the device under test, S 21-无被测件 (dB) is the energy transmission efficiency of the device without the DUT, SE 被测件 (dB) is the electromagnetic shielding performance of the device under test.

[0094] It should be noted that the method described above further includes:

[0095] Acquiring dimension information of the device under test and the device without the device under test;

[0096] Calculating the lowest usage frequency based on the size information;

[0097] According to the preset frequency, the mode number is calculated;

[0098] If the minimum operating frequency is less than or equal to the preset frequency and the mode number is greater than a preset value, the electromagnetic shielding performance test result outputted from the internal shielding chamber is credible.

[0099] It should be noted that the calculation of the minimum usage frequency according to the size information includes:

[0100] According to the formula Calculate the frequency f 110 , where l and w represent the length and width of the closed cavity respectively, μ represents the magnetic permeability of the medium in the closed cavity, and ε represents the dielectric constant;

[0101] According to the formula f r =6×f 110 The minimum frequency of use is calculated.

[0102] The calculating the number of modes according to the preset frequency includes:

[0103] Using the formula The frequency is calculated, where m, n, and p are integers representing the three-dimensional position information in space, and at least one of the three integers is not zero. l, w, and h represent the length, width, and height of the cavity, respectively. f mnp represents the frequency of the corresponding positions of m, n, and p, and c0 represents the speed of light in a vacuum, which is: 3×10 8 m / s.

[0104] Furthermore, the relationship between the mode number and the cavity structure size and frequency is expressed by the following calculation formula:

[0105]

[0106] Among them, l, w, h represent the length, width, and height of the cavity, respectively, in m, f represents the frequency, in Hz, and c represents the speed of light. It can be seen that different frequencies correspond to different numbers of modes, and it is obvious that as the frequency increases, the number of modes increases.

[0107] In actual application scenarios, specific data is used for the following explanation:

[0108] First, establish the device to be tested, the device without shielding chamber, and the device without the device to be tested. The device to be tested here is conductive rubber, and the dimensions of its corresponding parts are as follows:

[0109] Copper external compartment: overall dimensions are 120mm×81.8mm×48.2mm, inner tank dimensions are 100mm×61.8mm×38.2mm;

[0110] Aluminum top cover: overall dimensions are 120mm×81.8mm×10mm;

[0111] Two probes: head diameter is 2.8mm, tip diameter is 1.03mm.

[0112] A certain amount of electromagnetic energy is input into the first probe of the unshielded chamber device, and the S of the unshielded chamber device at 20 GHz is obtained using HFSS electromagnetic simulation software. 21-无屏蔽仓 (dB) is: -2.8381dB.

[0113] A certain amount of electromagnetic energy is input into the first probe of the non-conductive rubber device, and the S of the non-conductive rubber device at 20 GHz is obtained using HFSS electromagnetic simulation software. 21-无橡胶 (dB) is: -13.0dB.

[0114] A certain amount of electromagnetic energy is input into the first probe of the device under test, and the S' of the device under test at 20 GHz is obtained using HFSS electromagnetic simulation software. 21 (dB) is: -59.6dB.

[0115] According to the formula SE 屏蔽仓 (dB) = S 21-无屏蔽仓 (dB)-S' 21 (dB) The calculation shows that the electromagnetic shielding efficiency of the internal shielding chamber is SE (dB) = 57.2169dB.

[0116] According to the formula SE 橡胶 (dB) = S 21-无橡胶 (dB)-S' 21 (dB) The calculation shows that the electromagnetic shielding efficiency of the conductive rubber is SE (dB) = 46.6dB.

[0117] Calculate f 110 The minimum operating frequency is 2.853 GHz, and the minimum operating frequency is 17.118 GHz. When 20 GHz is selected in this embodiment, the cavity size is 100 mm × 61.8 mm × 38.2 mm. The mode number formula shows that N = 321. The mode number is large enough, the energy transfer is uniform enough, and the test result is credible.

[0118] It can be understood that the same or similar parts of the above embodiments can be referenced to each other, and the contents not described in detail in some embodiments can refer to the same or similar contents in other embodiments.

[0119] It should be noted that, in the description of the present invention, the terms "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance. In addition, in the description of the present invention, unless otherwise specified, the meaning of "plurality" refers to at least two.

[0120] Any process or method description in a flowchart or otherwise described herein may be understood to represent a module, segment or portion of code that includes one or more executable instructions for implementing the steps of a specific logical function or process, and the scope of the preferred embodiments of the present invention includes alternative implementations in which functions may not be performed in the order shown or discussed, including performing functions in a substantially simultaneous manner or in the reverse order depending on the functions involved, which should be understood by those skilled in the art to which the embodiments of the present invention belong.

[0121] It should be understood that the various parts of the present invention can be implemented by hardware, software, firmware or a combination thereof. In the above-mentioned embodiments, a plurality of steps or methods can be implemented by software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented by hardware, as in another embodiment, it can be implemented by any one of the following technologies known in the art or their combination: a discrete logic circuit having a logic gate circuit for implementing a logic function for a data signal, a dedicated integrated circuit having a suitable combination of logic gate circuits, a programmable gate array (PGA), a field programmable gate array (FPGA), etc.

[0122] A person skilled in the art may understand that all or part of the steps in the method for implementing the above-mentioned embodiment may be completed by instructing related hardware through a program, and the program may be stored in a computer-readable storage medium, which, when executed, includes one or a combination of the steps of the method embodiment.

[0123] In addition, each functional unit in each embodiment of the present invention may be integrated into a processing module, or each unit may exist physically separately, or two or more units may be integrated into one module. The above-mentioned integrated module may be implemented in the form of hardware or in the form of a software functional module. If the integrated module is implemented in the form of a software functional module and sold or used as an independent product, it may also be stored in a computer-readable storage medium.

[0124] The storage medium mentioned above can be a read-only memory, a magnetic disk or an optical disk, etc.

[0125] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0126] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations of the present invention. A person skilled in the art may change, modify, replace and vary the above embodiments within the scope of the present invention.

Claims

1. An electromagnetic shielding performance testing system, characterized in that: include: Device under test, comparison device, calculation device and network analyzer; The device under test is composed of a top cover, a first probe, a second probe, an external chamber, an internal shielding chamber and a device under test, wherein the first probe and the second probe penetrate the top cover and are connected to the computing device through a network analyzer, the top cover is located above the external chamber to form a closed cavity, the internal shielding chamber is placed inside the closed cavity, the device under test is covered on the upper part of the internal shielding chamber, so that the internal shielding chamber is sealed, and the upper part of the device under test is in contact with the top cover; The comparison device at least comprises a device without a DUT, wherein the device without a DUT is based on the device to be tested, but the DUT is removed, and the rest of the structure is the same as that of the device to be tested; The calculation device at least includes a result calculation module, which is used to apply electromagnetic energy to the first probe in the device under test and the device without the device under test according to a preset frequency, and use a network analyzer to respectively measure the electromagnetic conduction power of the device under test and the electromagnetic conduction power of the device without the device under test obtained from the second probe; and is also used to calculate the electromagnetic shielding performance of the device under test based on the electromagnetic conduction power of the device under test and the electromagnetic conduction power of the device without the device under test.

2. The system according to claim 1, characterized in that Also includes: A device without a shielding chamber, wherein the device without a shielding chamber is based on the device under test, but the internal shielding chamber and the device under test are removed, and the remaining structure is the same as that of the device under test; The result calculation module of the computing device is also used to apply electromagnetic energy to the first probe in the non-shielding chamber device at a preset frequency, and use a network analyzer to measure the electromagnetic conduction power of the device without the device under test from the second probe in the device without the device under test; and is also used to calculate the electromagnetic shielding performance of the device under test based on the electromagnetic conduction power of the device under test and the electromagnetic conduction power of the device without the device under test.

3. The system according to claim 1, characterized in that The computing device further includes: An information acquisition module, used to acquire the size information of the device to be tested and the device without the device to be tested; The test result judgment module is used to calculate the minimum operating frequency according to the size information, and calculate the mode number according to the preset frequency; if the minimum operating frequency is less than or equal to the preset frequency and the mode number is greater than the preset value, the electromagnetic shielding performance test result of the output device under test is credible.

4. A method for testing electromagnetic shielding performance, applied to a computing device in a system as claimed in claim 1, characterized in that: include: Applying electromagnetic energy to a first probe in the device under test at a preset frequency, and obtaining electromagnetic conduction power of the device under test from a second probe in the device under test; Applying electromagnetic energy to a first probe in the device without the device under test at a preset frequency, and obtaining electromagnetic conduction power of the device without the device under test from a second probe in the device without the device under test; The electromagnetic shielding performance of the device under test is calculated based on the electromagnetic conduction power of the device under test and the electromagnetic conduction power of the device without the device under test.

5. The method according to claim 4, characterized in that The calculating the electromagnetic shielding performance of the device under test according to the electromagnetic conduction power of the device under test and the electromagnetic conduction power of the device without the device under test comprises: According to the electromagnetic conduction power of the device under test, the energy transmission efficiency of the device under test is obtained by using a network analyzer or HFSS electromagnetic simulation software; According to the electromagnetic conduction power of the device without the device under test, the energy transmission efficiency of the device without the device under test is obtained by using a network analyzer or HFSS electromagnetic simulation software; The electromagnetic shielding performance of the device under test is calculated based on the energy transmission efficiency of the device under test and the energy transmission efficiency of the device without the device under test.

6. The method according to claim 5, characterized in that Also includes: Acquire the size information of the device under test and the device without the device under test; Calculating the lowest usage frequency based on the size information; According to the preset frequency, the mode number is calculated; If the minimum operating frequency is less than or equal to the preset frequency and the mode number is greater than a preset value, the output electromagnetic shielding performance test result of the device under test is credible.

7. The method according to claim 5, characterized in that The calculating the electromagnetic shielding performance of the device under test according to the energy transmission efficiency of the device under test and the energy transmission efficiency of the device without the device under test comprises: According to the formula SE 被测件 (dB) = S 21-无被测件 (dB)-S' 21 (dB) is used to calculate the electromagnetic shielding performance of the device under test, where S2'1 (dB) is the energy transmission efficiency of the device under test, S 21-无被测件 (dB) is the energy transmission efficiency of the device without the DUT, SE 被测件 (dB) is the electromagnetic shielding performance of the device under test.

8. The method according to claim 6, characterized in that The calculating the minimum usage frequency according to the size information includes: According to the formula Calculate the frequency f 110 , where l and w represent the length and width of the closed cavity respectively, μ represents the magnetic permeability of the medium in the closed cavity, and ε represents the dielectric constant; According to the formula f r =6×f 110 The minimum frequency of use is calculated.

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