Patch antenna-based planar near-field shielding detection device and detection method thereof

Abstract

The invention discloses a planar near-field shielding detection device based on a patch antenna and a detection method thereof. The detection device comprises the patch antenna, a metal shielding frame is arranged above the patch antenna, one end of the patch antenna is connected with a vector network analyzer, and the other end of the patch antenna is connected with load impedance; the vector network analyzer is also connected with a waveguide probe; the waveguide probe is arranged in a near-field area of the patch antenna; a shielding film for shielding radiation waves of the patch antenna in the vertical direction can be placed on the metal shielding frame. The near-field shielding test of the shielding film material can be accurately and quickly completed, the shielding effectiveness of different frequency wavebands is tested by using simple equipment, the patch antenna is taken as a radiation source to be closer to the radiation wave condition generated during high-speed signal transmission in a chip, and the shielding effectiveness of the near field at different heights is analyzed by depending on a simple frame. The test efficiency is improved; the device is simple and convenient, the near-field shielding effect of the thin-film material is rapidly determined through the height change of the frame, and operability is high.

Description

Technical Field

[0001] The invention relates to a shielding detection device and a detection method thereof, and in particular to a planar near-field shielding detection device and a detection method thereof based on a patch antenna. Background Art

[0002] With the improvement of performance computing speed, the development of new technologies such as 5G / 6G communications and artificial intelligence, high-speed electronic devices have been widely used in our lives. The operating frequency of circuits continues to increase, and their high-order harmonics have reached hundreds of GHz. The electromagnetic interference problem of high-speed circuits is becoming increasingly serious. In order to achieve bonding with ultra-thin electronic products, new composite film shielding methods have been intensively emerging in recent years.

[0003] The near-field scanning test method is a new method for testing shielding effects. It can directly test the electromagnetic radiation intensity at a certain point in a vacuum through a probe, and obtain the shielding characteristics of the material by comparing the radiation intensity before and after the shielding material is placed. At present, the widely used near-field test methods mainly include: (1) double-loop test method; (2) microstrip line and probe test method. The test results of the two methods have poor high-frequency characteristics, the equipment requires precision, the test process is complicated, and it takes a long time. Summary of the invention

[0004] Purpose of the invention: In order to overcome the shortcomings of the prior art, the purpose of the present invention is to provide a planar near-field shielding detection device based on a patch antenna with high test efficiency. Another purpose of the present invention is to provide an accurate and fast planar near-field shielding detection method based on a patch antenna.

[0005] Technical solution: The present invention describes a planar near-field shielding detection device based on a patch antenna, including a patch antenna. A metal shielding frame is arranged above the patch antenna. One end of the patch antenna is connected to a vector network analyzer, and the other end is connected to a load impedance. The vector network analyzer is also connected to a waveguide probe, and the waveguide probe is arranged in the near-field area of ​​the patch antenna. A shielding film for shielding the radiated waves of the patch antenna in the vertical direction can be placed on the metal shielding frame.

[0006] Furthermore, the feed radiation field frequency of the patch antenna is 1.42 to 9.5 GHz.

[0007] Further, the shielding film is made of a silver nanowire shielding film, a graphene absorption shielding film or a MXene shielding film. Preferably, the shielding film is a silver wire shielding film, a copper foil shielding film or a white copper shielding film.

[0008] Furthermore, the impedance of the load impedance matches the line impedance of the patch antenna. The impedance of the load impedance is 45 to 55Ω.

[0009] Furthermore, the height of the metal shielding frame is less than λ is the wavelength of electromagnetic waves. When it is lower than 1.42GHz, the patch antenna cannot provide a suitable radiation source to the outside; when it is higher than 9.5GHz, due to the limitation of near field range, The height of the metal shielding frame is less than 5 mm, which makes the design difficult.

[0010] The present invention provides a planar near-field shielding detection method based on a patch antenna, comprising the following steps:

[0011] Step 1: The feed source of the patch antenna provides a radiation field to the near-field test area;

[0012] Step 2: After the metal shielding frame with a hollow top is placed in the near field area and fixed to the patch antenna, a waveguide probe is used to perform multiple near field tests on the area to be tested to obtain stable pre-shielding parameters;

[0013] Step 3: Add the shielding film to be tested on the top of the metal shielding frame, fit and fix it, and use the waveguide probe to test the area to be tested again to obtain the parameters after shielding;

[0014] Step 4: Based on the corresponding measurement data before and after the shielding film is placed, the near-field shielding effectiveness of the shielding film to be tested at the shielding height is obtained.

[0015] Furthermore, in step 2, the feed position of the patch antenna and the height of the waveguide probe are fixed, and the height of the metal shielding frame without the shielding film is adjusted to correspond to the feed signal frequency, so that the shielding height to be tested is within the test range of the waveguide probe and the feed radiation field of the patch antenna; the height of the shielding frame is Based on the shielding frequency of the test shielding film, the size of the patch antenna and the metal shielding frame are designed to make them perfectly combined.

[0016] Furthermore, in step three, the feed position of the patch antenna and the height of the waveguide probe are fixed, and the height of the metal shielding frame after the shielding film is placed is adjusted so that the shielding height to be tested is within the test range of the waveguide probe and the radiation field of the feed patch antenna; the height of the shielding frame is The shielding film is used to shield the radiated waves of the patch antenna in the vertical direction, so that it fits perfectly with the metal shielding frame to avoid leakage.

[0017] Furthermore, in step 4, the shielding effectiveness is calculated as follows:

[0018]

[0019] Among them, SE is shielding effectiveness, S 21,ref is the transmission loss data before shielding, S 21,mat This is the transmission loss data after shielding.

[0020] Furthermore, the height of the shielding frame was changed several times to test the S before and after adding the film. 21 Parameters are used to obtain the actual shielding effectiveness of the shielding film to be tested at different heights in the near field, and the shielding mechanism at different positions in the near field is summarized and analyzed.

[0021] Test principle: Near-field shielding test mainly tests the shielding effect of shielding materials on electric field, magnetic field or electromagnetic field. The key to the test is to evaluate the insertion loss (InsertionLoss) or shielding effectiveness (Shielding Effectiveness, SE) of the shielding material through S parameter measurement of the vector network analyzer. Under the condition of no shielding material, measure the reference transmission signal S 21,ref ; Place the shielding material on top of the shielding frame and measure the transmission signal S 21,mat ; By comparing S 21,ref and S 21,mat Calculate shielding effectiveness.

[0022] Beneficial effects: Compared with the prior art, the present invention has the following significant features:

[0023] 1. It can accurately and quickly complete the near-field shielding test of shielding film materials, use simple equipment to test the shielding effectiveness of different frequency bands, use patch antennas as radiation sources to get closer to the radiation waves generated by high-speed signal transmission in chips, rely on a simple framework to analyze the shielding effectiveness at different heights in the near field, summarize and improve the near-field shielding mechanism, and improve test efficiency;

[0024] 2. The device is simple and convenient, and the near-field shielding effect of the film material can be quickly determined by using the height change of the frame, which has strong operability;

[0025] 3. The film and shielding frame required for the test can be reused, with high economic benefits;

[0026] 4. Using patch antenna as feed source is closer to the principle of electromagnetic interference generated by physical chips, and the film is more provable to achieve conformal shielding;

[0027] 5. The test method has lower cost. The test materials include but are not limited to optically transparent shielding materials. The near-field shielding position can be changed directly by adjusting the height of the metal frame. The combination of the feed source and the shielding film and the test state are closer to the actual working state of the electronic components. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It is a structural schematic diagram of the testing device of the present invention;

[0029] Figure 2 is a physical picture of the silver wire composite film of Example 1 of the present invention;

[0030] Figure 3 is a front view of the patch antenna and the metal frame combined in Embodiment 1 of the present invention;

[0031] Figure 4 is a diagram of near-field shielding test results of Example 1 of the present invention;

[0032] Figure 5 It is a near-field SE variation diagram corresponding to the shielding height variation of the present invention. DETAILED DESCRIPTION

[0033] like Figure 1 A metal shielding frame 2 is provided above the patch antenna 1 of the planar near-field shielding detection device. One end of the patch antenna 1 is connected to the vector network analyzer 3, and the other end is connected to the load impedance 4. The vector network analyzer 3 is connected to the waveguide probe 5, and the waveguide probe 5 is arranged in the near field area of ​​the patch antenna 1. When it is necessary to test the transmission loss data after shielding, a shielding film 6 for shielding the radiated waves of the patch antenna 1 in the vertical direction can be placed on the metal shielding frame 2. The feed radiation field frequency of the patch antenna 1 is 1.42 to 9.5 GHz. The shielding film 6 is made of a silver nanowire shielding film, a graphene absorption shielding film or a MXene shielding film. The impedance of the load impedance 4 matches the line impedance of the patch antenna 1. The height of the metal shielding frame 2 is less than λ is the wavelength of electromagnetic wave. The metal shielding frame 2 is a nickel silver frame.

[0034] The test method of the planar near-field shielding detection device of the present embodiment is applicable to the frequency band above 1.42 GHz and below 9.5 GHz, and can help the tester to quickly determine the near-field shielding effectiveness of the shielding material.

[0035] Example 1

[0036] A planar near-field shielding detection method based on a patch antenna 1 comprises the following steps:

[0037] Step 1, connect one end of the patch antenna 1 to the No. 1 port of the vector network analyzer 3, input a radio frequency signal with a frequency of 2 to 3 GHz to the patch antenna 1, and connect the other end to a 50Ω load impedance 4, and then connect the waveguide probe 5 of the corresponding frequency band to the No. 2 port of the vector network analyzer 3 so that it can receive the radiation signal of the patch antenna 1. After the entire test device is connected, fix the position of the patch antenna 1, and adjust the waveguide probe 5 to be 40 mm above the patch antenna 1.

[0038] Step 2: Place a 5mm high metal shield frame 2 directly above the patch antenna 1, that is, fix the lower surface of the metal shield frame 2 and the lower surface of the patch antenna 1 on the same horizontal plane. The height of the metal shield frame 2 minus the height of the patch antenna 1 is the actual shielding height. Record the S value of the vector network analyzer 3. 21,ref Keep the metal shielding frame 2 in place, place a silver wire shielding film 6 (which can be replaced with a shielding film of any material) with a surface resistance of 6Ω on the top of the metal shielding frame 2, and record the S 21,mat The parameter is used as masked data.

[0039] Step 3: Shield the pre-S obtained in step 2 21,ref And after shielding S 21,mat The data are subtracted to obtain the near field SE of the silver wire shielding film 6 to be tested with a surface resistance of 6Ω when the shielding height is 5mm.

[0040] like Figures 2-3 , the metal shielding frame 2 is perfectly combined with the patch antenna 1. The PCB size of the patch antenna 1 is 90×90mm, the size of the metal shielding frame 2 is 100×100mm, and the thickness is 0.3mm. The size of the shielding film 6 is the same as that of the metal shielding frame 2, which is 100×100mm. The shielding film 6 can be perfectly integrated with the metal shielding frame 2 and the patch antenna 1 to prevent electromagnetic wave leakage. d is the distance from the plane to be measured to the radiation source. The dielectric constant of the epoxy resin in the patch antenna 1 is ε=4.3, and the height h is 1.6mm. The feed line width of the patch antenna 1 is W1=2.8mm, and the copper layer thickness is t=0.035mm.

[0041] Figure 4 This is a data comparison chart obtained from the vector network analysis test. The surface resistance of the silver wire shielding film 6 is 6Ω. By calculating the data difference, the near-field SE of the film at a shielding height of 5mm can be successfully obtained.

[0042] Example 2

[0043] A planar near-field shielding detection method based on a patch antenna 1 comprises the following steps:

[0044] Step 1, connect one end of the patch antenna 1 to the No. 1 port of the vector network analyzer 3, input a radio frequency signal with a frequency of 2 to 3 GHz to the patch antenna 1, and connect the other end to a 50Ω load impedance 4, and then connect the waveguide probe 5 of the corresponding frequency band to the No. 2 port of the vector network analyzer 3 so that it can receive the radiation signal of the patch antenna 1. After the entire test device is connected, fix the position of the patch antenna 1, and adjust the waveguide probe 5 to be 40 mm above the patch antenna 1.

[0045] Step 2: Place a 10mm high metal shielding frame 2 directly above the patch antenna 1, that is, fix the lower surface of the metal shielding frame 2 and the lower surface of the patch antenna 1 on the same horizontal plane. The height of the metal shielding frame 2 minus the height of the patch antenna 1 itself is the actual shielding height. Record the S value of the vector network analyzer 3. 21,ref The parameters are taken as the data before shielding. Keep the metal shielding frame 2 in place, place the silver wire shielding film 6 with a surface resistance of 6Ω on the top of the metal shielding frame 2, and record the S 21,mat The parameter is used as masked data.

[0046] Step 3: Shield the pre-S obtained in step 2 21,ref And after shielding S 21,mat The data are subtracted to obtain the near field SE of the silver wire shielding film 6 to be tested with a surface resistance of 6Ω when the shielding height is 10 mm.

[0047] Example 3

[0048] A planar near-field shielding detection method based on a patch antenna 1 comprises the following steps:

[0049] Step 1, connect one end of the patch antenna 1 to the No. 1 port of the vector network analyzer 3, input a radio frequency signal with a frequency of 2 to 3 GHz to the patch antenna 1, and connect the other end to a 50Ω load impedance 4, and then connect the waveguide probe 5 of the corresponding frequency band to the No. 2 port of the vector network analyzer 3 so that it can receive the radiation signal of the patch antenna 1. After the entire test device is connected, fix the position of the patch antenna 1, and adjust the waveguide probe 5 to be 40 mm above the patch antenna 1.

[0050] Step 2: Place a 15mm high metal shielding frame 2 directly above the patch antenna 1, that is, fix the lower surface of the metal shielding frame 2 and the lower surface of the patch antenna 1 on the same horizontal plane. The height of the metal shielding frame 2 minus the height of the patch antenna 1 is the actual shielding height. Record the S value of the vector network analyzer 3. 21,ref The parameters are taken as the data before shielding. Keep the metal shielding frame 2 in place, place the silver wire shielding film 6 with a surface resistance of 6Ω on the top of the metal shielding frame 2, and record the S 21,mat The parameter is used as masked data.

[0051] Step 3: Shield the pre-S obtained in step 2 21,ref And after shielding S 21,mat The data are subtracted to obtain the near field SE of the silver wire shielding film 6 to be tested with a surface resistance of 6Ω when the shielding height is 15 mm.

[0052] Example 4

[0053] A planar near-field shielding detection method based on a patch antenna 1 comprises the following steps:

[0054] Step 1, connect one end of the patch antenna 1 to the No. 1 port of the vector network analyzer 3, input a radio frequency signal with a frequency of 2 to 3 GHz to the patch antenna 1, and connect the other end to a 50Ω load impedance 4, and then connect the waveguide probe 5 of the corresponding frequency band to the No. 2 port of the vector network analyzer 3 so that it can receive the radiation signal of the patch antenna 1. After the entire test device is connected, fix the position of the patch antenna 1, and adjust the waveguide probe 5 to be 40 mm above the patch antenna 1.

[0055] Step 2: Place a 20mm high metal shielding frame 2 directly above the patch antenna 1, that is, fix the lower surface of the metal shielding frame 2 and the lower surface of the patch antenna 1 on the same horizontal plane. The height of the metal shielding frame 2 minus the height of the patch antenna 1 is the actual shielding height. Record the S value of the vector network analyzer 3. 21,ref The parameters are taken as the data before shielding. Keep the metal shielding frame 2 in place, place the silver wire shielding film 6 with a surface resistance of 6Ω on the top of the metal shielding frame 2, and record the S 21,mat The parameter is used as masked data.

[0056] Step 3: Shield the pre-S obtained in step 2 21,ref And after shielding S 21,mat The data are subtracted to obtain the near field SE of the silver wire shielding film 6 to be tested with a surface resistance of 6Ω when the shielding height is 20 mm.

[0057] Example 5

[0058] A planar near-field shielding detection method based on a patch antenna 1 comprises the following steps:

[0059] Step 1, connect one end of the patch antenna 1 to the No. 1 port of the vector network analyzer 3, input a radio frequency signal with a frequency of 2 to 3 GHz to the patch antenna 1, and connect the other end to a 50Ω load impedance 4, and then connect the waveguide probe 5 of the corresponding frequency band to the No. 2 port of the vector network analyzer 3 so that it can receive the radiation signal of the patch antenna 1. After the entire test device is connected, fix the position of the patch antenna 1, and adjust the waveguide probe 5 to be 40 mm above the patch antenna 1.

[0060] Step 2: Place a 25mm high metal shielding frame 2 directly above the patch antenna 1, that is, fix the lower surface of the metal shielding frame 2 and the lower surface of the patch antenna 1 on the same horizontal plane. The height of the metal shielding frame 2 minus the height of the patch antenna 1 is the actual shielding height. Record the S value of the vector network analyzer 3. 21,refThe parameters are taken as the data before shielding. Keep the metal shielding frame 2 in place, place the silver wire shielding film 6 with a surface resistance of 6Ω on the top of the metal shielding frame 2, and record the S 21,mat The parameter is used as masked data.

[0061] Step 3: Shield the pre-S obtained in step 2 21,ref And after shielding S 21,mat The data are subtracted to obtain the near field SE of the silver wire shielding film 6 to be tested with a surface resistance of 6Ω when the shielding height is 25 mm.

[0062] After testing Examples 1 to 5, the change of shielding height SE in the near field region was analyzed with the same film. The results are as follows: Figure 5 As shown, when the shielding height of the tested silver wire shielding film 6 is 15mm, SE reaches a maximum value, and the surface resistance of the silver wire shielding film 6 is 6Ω, indicating that in the near-field shielding, the change of wave impedance at different positions will form a standing wave, causing the final near-field shielding effectiveness to reach an extreme value with the change of shielding height. The figure shows the SE of the film at a frequency of 2.4GHz.

[0063] Example 6

[0064] A planar near-field shielding detection method based on a patch antenna 1 comprises the following steps:

[0065] Step 1, connect one end of the patch antenna 1 to the No. 1 port of the vector network analyzer 3, input a radio frequency signal with a frequency of 2 to 3 GHz to the patch antenna 1, and connect the other end to a 50Ω load impedance 4, and then connect the waveguide probe 5 of the corresponding frequency band to the No. 2 port of the vector network analyzer 3 so that it can receive the radiation signal of the patch antenna 1. After the entire test device is connected, fix the position of the patch antenna 1, and adjust the waveguide probe 5 to be 40 mm above the patch antenna 1.

[0066] Step 2: Place a 5mm high metal shielding frame 2 directly above the patch antenna 1, that is, fix the lower surface of the metal shielding frame 2 and the lower surface of the patch antenna 1 on the same horizontal plane. The height of the metal shielding frame 2 minus the height of the patch antenna 1 is the actual shielding height. Record the S value of the vector network analyzer 3. 21,ref The parameters are taken as the data before shielding. Keep the metal shielding frame 2 in place, place the silver wire shielding film 6 to be tested with a surface resistance of 25Ω on the top of the metal shielding frame 2, and record the S 21,mat The parameter is used as masked data.

[0067] Step 3: Shield the pre-S obtained in step 2 21,ref And after shielding S 21,matThe data are subtracted to obtain the near field SE of the silver wire shielding film 6 to be tested with a surface resistance of 25Ω when the shielding height is 5mm.

[0068] Example 7

[0069] A planar near-field shielding detection method based on a patch antenna 1 comprises the following steps:

[0070] Step 1, connect one end of the patch antenna 1 to the No. 1 port of the vector network analyzer 3, input a radio frequency signal with a frequency of 2 to 3 GHz to the patch antenna 1, and connect the other end to a 50Ω load impedance 4, and then connect the waveguide probe 5 of the corresponding frequency band to the No. 2 port of the vector network analyzer 3 so that it can receive the radiation signal of the patch antenna 1. After the entire test device is connected, fix the position of the patch antenna 1, and adjust the waveguide probe 5 to be 40 mm above the patch antenna 1.

[0071] Step 2: Place a 5mm high metal shielding frame 2 directly above the patch antenna 1, that is, fix the lower surface of the metal shielding frame 2 and the lower surface of the patch antenna 1 on the same horizontal plane. The height of the metal shielding frame 2 minus the height of the patch antenna 1 is the actual shielding height. Record the S value of the vector network analyzer 3. 21,ref The parameters are taken as the data before shielding. Keep the metal shielding frame 2 in place, place the silver wire shielding film 6 to be tested with a surface resistance of 40Ω on the top of the metal shielding frame 2, and record the S 21,mat The parameter is used as masked data.

[0072] Step 3: Shield the pre-S obtained in step 2 21,ref And after shielding S 21,mat The data are subtracted to obtain the near field SE of the silver wire shielding film 6 to be tested with a surface resistance of 40Ω when the shielding height is 5 mm.

[0073] Example 8

[0074] A planar near-field shielding detection method based on a patch antenna 1 comprises the following steps:

[0075] Step 1, connect one end of the patch antenna 1 to the No. 1 port of the vector network analyzer 3, input a radio frequency signal with a frequency of 2 to 3 GHz to the patch antenna 1, and connect the other end to a 50Ω load impedance 4, and then connect the waveguide probe 5 of the corresponding frequency band to the No. 2 port of the vector network analyzer 3 so that it can receive the radiation signal of the patch antenna 1. After the entire test device is connected, fix the position of the patch antenna 1, and adjust the waveguide probe 5 to be 40 mm above the patch antenna 1.

[0076] Step 2: Place a 5mm high metal shielding frame 2 directly above the patch antenna 1, that is, fix the lower surface of the metal shielding frame 2 and the lower surface of the patch antenna 1 on the same horizontal plane. The height of the metal shielding frame 2 minus the height of the patch antenna 1 is the actual shielding height. Record the S value of the vector network analyzer 3. 21,ref The parameters are taken as the data before shielding. Keep the metal shielding frame 2 in place, place the silver wire shielding film 6 to be tested with a surface resistance of 105Ω on the top of the metal shielding frame 2, and record the S 21,mat The parameter is used as masked data.

[0077] Step 3: Shield the pre-S obtained in step 2 21,ref And after shielding S 21,mat The data are subtracted to obtain the near field SE of the silver wire shielding film 6 to be tested with a surface resistance of 105Ω when the shielding height is 5mm.

[0078] Example 9

[0079] A planar near-field shielding detection method based on a patch antenna 1 comprises the following steps:

[0080] Step 1, connect one end of the patch antenna 1 to the No. 1 port of the vector network analyzer 3, input a radio frequency signal with a frequency of 2 to 3 GHz to the patch antenna 1, and connect the other end to a 50Ω load impedance 4, and then connect the waveguide probe 5 of the corresponding frequency band to the No. 2 port of the vector network analyzer 3 so that it can receive the radiation signal of the patch antenna 1. After the entire test device is connected, fix the position of the patch antenna 1, and adjust the waveguide probe 5 to be 40 mm above the patch antenna 1.

[0081] Step 2: Place a 15mm high metal shielding frame 2 directly above the patch antenna 1, that is, fix the lower surface of the metal shielding frame 2 and the lower surface of the patch antenna 1 on the same horizontal plane. The height of the metal shielding frame 2 minus the height of the patch antenna 1 is the actual shielding height. Record the S value of the vector network analyzer 3. 21,ref The parameters are taken as the data before shielding. Keep the metal shielding frame 2 in place, place the copper foil shielding film 6 with a thickness of 0.3 mm on the top of the metal shielding frame 2, and record the S 21,mat The parameter is used as masked data.

[0082] Step 3: Shield the pre-S obtained in step 2 21,ref And after shielding S 21,mat The data are subtracted to obtain the near field SE of the copper foil shielding film 6 to be tested when the shielding height is 15 mm.

[0083] Example 10

[0084] A planar near-field shielding detection method based on a patch antenna 1 comprises the following steps:

[0085] Step 1, connect one end of the patch antenna 1 to the No. 1 port of the vector network analyzer 3, input a radio frequency signal with a frequency of 2 to 3 GHz to the patch antenna 1, and connect the other end to a 50Ω load impedance 4, and then connect the waveguide probe 5 of the corresponding frequency band to the No. 2 port of the vector network analyzer 3 so that it can receive the radiation signal of the patch antenna 1. After the entire test device is connected, fix the position of the patch antenna 1, and adjust the waveguide probe 5 to be 40 mm above the patch antenna 1.

[0086] Step 2: Place a 15mm high metal shielding frame 2 directly above the patch antenna 1, that is, fix the lower surface of the metal shielding frame 2 and the lower surface of the patch antenna 1 on the same horizontal plane. The height of the metal shielding frame 2 minus the height of the patch antenna 1 is the actual shielding height. Record the S value of the vector network analyzer 3. 21,ref The parameters are taken as the data before shielding. Keep the metal shielding frame 2 in place, place the copper-nickel shielding film 6 with a thickness of 0.3 mm on the top of the metal shielding frame 2, and record the S 21,mat The parameter is used as masked data.

[0087] Step 3: Shield the pre-S obtained in step 2 21,ref And after shielding S 21,mat The data are subtracted to obtain the near field SE of the tested cupronickel shielding film 6 when the shielding height is 15 mm.

Claims

1. A planar near-field shielding detection device based on a patch antenna, characterized in that: The invention comprises a patch antenna (1), a metal shielding frame (2) is arranged above the patch antenna (1), one end of the patch antenna (1) is connected to a vector network analyzer (3), and the other end is connected to a load impedance (4); the vector network analyzer (3) is also connected to a waveguide probe (5), and the waveguide probe (5) is arranged in the near field area of ​​the patch antenna (1); a shielding film (6) for shielding the radiated waves of the patch antenna (1) in the vertical direction can be placed on the metal shielding frame (2).

2. A planar near-field shielding detection device based on a patch antenna according to claim 1, characterized in that: The feed radiation field frequency of the patch antenna (1) is 1.42-9.5 GHz.

3. A planar near-field shielding detection device based on a patch antenna according to claim 1, characterized in that: The shielding film (6) is made of a silver nanowire shielding film, a graphene absorption shielding film or a MXene shielding film.

4. A planar near-field shielding detection device based on a patch antenna according to claim 1, characterized in that: The impedance of the load impedance (4) matches the line impedance of the patch antenna (1).

5. A planar near-field shielding detection device based on a patch antenna according to claim 4, characterized in that: The impedance of the load impedance (4) is 45-55Ω.

6. A planar near-field shielding detection device based on a patch antenna according to claim 1, characterized in that: The height of the metal shielding frame (2) is less than λ is the wavelength of electromagnetic wave.

7. A planar near-field shielding detection method based on a patch antenna, characterized in that: The following steps are involved: Step 1: The feed source of the patch antenna provides a radiation field to the near-field area to be measured; Step 2: After a metal shielding frame (2) with a hollow top is placed in the near field region and fixed to the patch antenna (1), a waveguide probe (5) is used to perform multiple near field tests on the region to be tested to obtain stable pre-shielding parameters; Step 3, adding the shielding film (6) to be tested on the top of the metal shielding frame (2), fitting and fixing it, and using the waveguide probe (5) again to test the area to be tested to obtain the parameters after shielding; Step 4: Based on the corresponding measurement data before and after the shielding film (6) is placed, the near-field shielding effectiveness of the shielding film (6) to be tested at the shielding height is obtained.

8. A planar near-field shielding detection method based on a patch antenna according to claim 7, characterized in that: In the second step, the feed position of the patch antenna (1) and the height of the waveguide probe (5) are fixed, and the height of the metal shielding frame (2) without the shielding film (6) is adjusted to correspond to the feed signal frequency, so that the shielding height to be tested is located within the test range of the waveguide probe (5) and the feed radiation field of the patch antenna (1); the height of the shielding frame is Select within the near field range of the feed source.

9. The planar near-field shielding detection method based on patch antenna according to claim 7, characterized in that: In the step three, the feed position of the patch antenna (1) and the height of the waveguide probe (5) are fixed, and the height of the metal shielding frame (2) after the shielding film (6) is placed is adjusted so that the shielding height to be tested is located within the test range of the waveguide probe (5) and in the radiation field of the feed patch antenna (1); the height of the shielding frame is Select within the near field range of the feed source.

10. A planar near-field shielding detection method based on a patch antenna according to claim 7, characterized in that: In step 4, the calculation formula of shielding effectiveness is: Among them, SE is shielding effectiveness, S 21,ref is the transmission loss data before shielding, S 21,mat This is the transmission loss data after shielding.

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