CN217739340U - Electromagnetic interference test system - Google Patents
Electromagnetic interference test system Download PDFInfo
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- CN217739340U CN217739340U CN202221142399.3U CN202221142399U CN217739340U CN 217739340 U CN217739340 U CN 217739340U CN 202221142399 U CN202221142399 U CN 202221142399U CN 217739340 U CN217739340 U CN 217739340U
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Abstract
The embodiment of the utility model discloses electromagnetic interference test system, include: the device comprises a measurement receiving device, a shielding device, a power supply device and a receiving antenna; the power supply equipment is used for connecting equipment to be tested arranged in the shielding device to supply power to the equipment to be tested; the receiving antenna is arranged in the shielding device, connected with the measuring and receiving equipment, and used for receiving an electromagnetic interference signal generated when the equipment to be measured operates and transmitting the electromagnetic interference signal to the measuring and receiving equipment; the measurement receiving equipment is arranged outside the shielding device and used for calculating and measuring the electromagnetic interference signals. Compared with the existing electromagnetic interference test system, the electromagnetic interference test system has the advantages of simpler structure, cheaper components, easiness in assembly and reduction in the cost required by the test.
Description
Technical Field
The utility model relates to a test field especially relates to an electromagnetic interference test system.
Background
With the continuous development of electronic products, the signal processing speed of electronic products such as vehicle-mounted electronics, communication information and the like is higher and higher. The electromagnetic interference generated by the circuit is more and more serious. Thus interfering the normal communication of the radio, GNSS and 2G \\\\ 3G \\\ 4G \5G signals of the product circuit. Therefore, when designing electronic products, the problem of EMC field emission is considered, and regulations impose that the electronic products need to pass EMC certification before being sold in the market. EMC touchdown testing needs to be performed on the electronic product in the design stage. When the electromagnetic field radiation emission is tested, a shielded anechoic chamber electromagnetic interference test system is needed for experiment and debugging. The laboratory construction of a complete radiation emission anechoic chamber is less than one or two million, and more than two million of the laboratory is required. For small and medium-sized enterprises, the cost of the laboratory is hard to bear, and the detection cost of the third-party laboratory is hundreds of hours or thousands of hours.
SUMMERY OF THE UTILITY MODEL
In view of the above, the present application provides an electromagnetic interference testing system, which includes: the device comprises a measurement receiving device, a shielding device, a power supply device and a receiving antenna;
the power supply equipment is used for connecting equipment to be tested arranged in the shielding device to supply power to the equipment to be tested;
the receiving antenna is arranged in the shielding device, connected with the measuring and receiving equipment, and used for receiving an electromagnetic interference signal generated when the equipment to be measured operates and transmitting the electromagnetic interference signal to the measuring and receiving equipment;
the measurement receiving equipment is arranged outside the shielding device and used for calculating and measuring the electromagnetic interference signals.
Furthermore, the receiving antenna is a double-sided PCB antenna, one side of the receiving antenna is a spiral coil antenna, and the other side of the receiving antenna is a half-wave dipole antenna.
Furthermore, the length of each side of the half-wave dipole antenna is one quarter of the wavelength of the electromagnetic wave.
Further, the material of the shielding device comprises one of aluminum alloy or iron sheet.
Further, the outer surface of the shielding device is also coated with shielding paint, and the shielding paint is one or a combination of graphite and carbon black.
Further, the measurement receiving device is one of a receiver or a spectrometer.
Furthermore, the receiving antenna is connected to the measuring and receiving device through a signal receiving cable, and the signal receiving cable is a coaxial shielding cable with an SMA interface.
Further, the distance between the receiving antenna and the device to be tested is not less than one meter.
Furthermore, the power supply equipment comprises a power supply and a filter, and the power supply is connected with the equipment to be tested through an external interface of the shielding device.
The filter is connected between the power supply and the equipment to be tested and used for removing noise waves from the power supply.
Furthermore, the insertion loss of the filter is larger than 40db.
The embodiment of the utility model discloses electromagnetic interference test system, include: the device comprises a measurement receiving device, a shielding device, a power supply device and a receiving antenna. The power supply equipment is used for connecting equipment to be tested arranged in the shielding device to supply power to the equipment to be tested; the receiving antenna is arranged in the shielding device, connected with the measuring and receiving equipment, and used for receiving an electromagnetic interference signal generated when the equipment to be measured operates and transmitting the electromagnetic interference signal to the measuring and receiving equipment; the measurement receiving equipment is arranged outside the shielding device and used for calculating and measuring the electromagnetic interference signals. Compared with the existing electromagnetic interference test system, the electromagnetic interference test system has the advantages that the structure is simpler, each part is cheaper and is easy to assemble, the cost required by the test is reduced, meanwhile, the system adopts a printed small antenna adopting a spiral coil and a half-wave symmetrical oscillator, the distance from the test antenna to the measuring equipment can be adjusted at any time in use, and the electromagnetic interference strength of a PCB circuit can be detected in a short distance. The interference source of the circuit board can be quickly positioned in the positioning and debugging process, and the electromagnetic interference problem of the system is further quickly solved. The time spent by engineers in finding electromagnetic interference problems can be greatly reduced.
Drawings
In order to illustrate the technical solution of the present invention more clearly, the drawings that are needed in the embodiments will be briefly described below, and it should be understood that the following drawings only illustrate some embodiments of the present invention, and therefore should not be considered as limiting the scope of the present invention. Like components are numbered similarly in the various figures.
FIG. 1 is a schematic diagram of an EMI testing system according to the present application;
fig. 2 is a schematic diagram illustrating a structure of a receiving antenna according to the present application;
fig. 3 shows another schematic structure of a receiving antenna according to the present application.
Detailed Description
The technical solutions in the embodiments of the present invention will be described clearly and completely below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only some embodiments of the present invention, not all embodiments.
The components of embodiments of the present invention, as generally described and illustrated in the figures herein, may be arranged and designed in a wide variety of different configurations. Thus, the following detailed description of the embodiments of the present invention, presented in the accompanying drawings, is not intended to limit the scope of the invention, as claimed, but is merely representative of selected embodiments of the invention. Based on the embodiment of the present invention, all other embodiments obtained by the person skilled in the art without creative work belong to the protection scope of the present invention.
Hereinafter, the terms "including", "having", and their derivatives, which may be used in various embodiments of the present invention, are only intended to indicate specific features, numbers, steps, operations, elements, components, or combinations of the foregoing, and should not be construed as first excluding the existence of, or adding to, one or more other features, numbers, steps, operations, elements, components, or combinations of the foregoing.
Furthermore, the terms "first," "second," "third," and the like are used solely to distinguish one from another and are not to be construed as indicating or implying relative importance.
Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the various embodiments of the present invention belong. The terms (such as those defined in commonly used dictionaries) should be interpreted as having a meaning that is consistent with their contextual meaning in the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein in various embodiments of the present invention.
The technical solution of the present application is explained with specific examples.
Example 1
As shown in fig. 1, a schematic structural diagram of an electromagnetic interference testing system according to the present application is shown, and the electromagnetic interference testing system includes: the device under test comprises a shielding device 100, a power supply device 300, a receiving antenna 400 and a measuring and receiving device 500, wherein the device under test 200 is arranged in the shielding device 100.
In the embodiment, the shielding apparatus 100 may be a shielding room, a shielding cover, a shielding box, or the like, and in order to ensure effective detection of electromagnetic interference, a distance of at least 1 meter is required between the receiving antenna 400 and the device under test 200, so that an internal space of the shielding apparatus 100 needs to be at least 1.2 meters to meet the above requirement. Meanwhile, the housing of the shielding apparatus 100 needs to be grounded to achieve its shielding effect and shield the external electromagnetic interference, and specifically, the shielding apparatus 100 needs a shielding function of at least 70 db.
The device to be tested can be various electronic devices which need debugging in development, such as vehicle-mounted computers, routers and various terminal-only devices.
The shielding device 100 of the present embodiment can be made of iron sheet or aluminum alloy, and has the advantages of cheap material, simple assembly, and lower cost compared to those of ferrite shielding chambers.
The power supply device 300 is configured to be connected to the device under test 200 disposed inside the shielding apparatus 100, so as to supply power to the device under test 200. Specifically, the outer wall of the shielding device 100 may be provided with a plurality of plugs for power supply access, the inner wall of the shielding device 100 may be provided with corresponding interfaces or power supply plugs corresponding to the plugs, and the device 200 to be tested, which is disposed inside the shielding device 100, may obtain a required operating voltage from the power supply device 300 by connecting the interfaces or the power supply plugs.
The power supply device 300 is disposed outside the shielding apparatus 100 to ensure that only the device under test 200 in the shielding box releases the electromagnetic interference signal and the test is not affected by the power supply device 300. In one embodiment, the power supply device 300 is composed of a power supply and a filter, and the external interface and the filter passing through the shielding device 100 are used for filtering noise waves from the power supply device to the device to be tested, so as to ensure the purity of power supply of the testing device, reduce the influence brought by the outside, and ensure the accuracy of the testing result, specifically, the insertion loss of the filter is greater than 40db, and the filter is arranged between the power supply and the shielding device 100 to achieve the filtering effect.
The receiving antenna 400 is disposed in the shielding device 100 and connected to the measurement receiving device 500, and the receiving antenna 400 is configured to receive an electromagnetic interference signal generated by the device under test 200 during operation and transmit the received electromagnetic interference signal to the measurement receiving device 500. As shown in fig. 2 and fig. 3, which are structural diagrams of the receiving antenna 400 of the present application, the receiving antenna 400 of the present application is a PCB double-sided antenna, wherein one side is a half-wave dipole antenna 410, and the other side is a spiral coil antenna 430. Wherein both the half-wave dipole antenna 410 and the helical coil antenna 430 are connected to the SMA interface 420 for transmitting the received electromagnetic interference signal to the measurement receiving device 500 connected thereto.
For example, the half-wave dipole antenna 410 may be disposed on the front surface of the PCB printed board, and the helical coil antenna 430 may be disposed on the back surface of the PCB printed board, or vice versa. The two antennas cannot interfere with each other and are connected to the same SMA interface, so that different interference signals are received.
The receiving antenna 400 is connected to the measurement receiving apparatus 500 by a coaxial cable with SMA interface, whose shielding layer needs to achieve a braiding density of 95% or more, while ensuring 50 ohm impedance control of the coaxial cable.
The spiral coil antenna 430 is mainly used for receiving magnetic fields, and mainly receives magnetic field interference in a low frequency band. The half-wave dipole antenna 410 is an electric field receiving antenna for receiving a high frequency interference signal. The detection and inspection of the electric field and the magnetic field are realized simultaneously through the combination of the two antennas on the PCB, and the antenna is manufactured by the PCB, is simple to realize, has low cost and is easy to install and maintain.
Wherein, the single-side length of the half-wave dipole antenna 410 adopts a quarter wavelength of the electromagnetic wave, when the lengths of the two oscillators of the half-wave dipole antenna 410 are equal to a half wavelength of the received electromagnetic wave signal, the gain of the antenna reaches the maximum, and the receiving sensitivity of the antenna also reaches the best effect. Meanwhile, since the receiving bandwidth of the antenna is limited, one antenna may be manufactured every 100M bandwidth from at least 30MHz, so as to manufacture a plurality of receiving antennas 400 with different central receiving frequencies. For each device under test 200, the multiple receiving antennas 400 can be used for testing, and then the antenna can be tested and analyzed most accurately according to the test result to debug the circuit of the device under test 200, so that the electromagnetic interference of the device under test 200 conforms to the EMC certification regulations.
The measurement receiving device 500 is disposed outside the shielding apparatus 100, and is configured to measure the electromagnetic interference signal, specifically, may calculate an interference value of the electromagnetic interference signal.
For example, the measurement receiving device 500 may be a receiver or a spectrometer, and may be a specific device with a relatively high price of DSA815-TG, which is a common source, in view of positioning for development and debugging. It is mainly used for measuring the magnetic field or electric field intensity received by the receiving antenna 400, and the testing frequency band can be preferably 100Khz to more than 1 GHz. The receiving frequency of the measuring and receiving device can be used specifically according to the test standard of the product.
Next, a specific test procedure is taken as an example to describe how the emi test system of the present application operates.
The receive antenna 400 is first calibrated to obtain an antenna factor v3, which reflects the ability of an antenna to convert the electric field in air to a receive terminal voltage. Then, the line loss data v2 of the coaxial cable for connecting the receiving antenna 400 and the measurement receiving device 500 is tested.
After the device under test 200 is powered on, the set test code starts to run, automatic testing starts, and the shielding device 100 needs to be closed in the period to ensure that the test environment is not interfered by the outside world, the device under test 200 runs according to the test code and simultaneously releases an electromagnetic interference signal, the electromagnetic interference signal is received by the receiving antenna 400 and is transmitted to the measurement receiving device 500, and because the receiving antenna 400 is the combination of the half-wave dipole antenna 410 and the spiral coil antenna 430, the information of the magnetic field and the electric field can be received simultaneously.
After the test is started, the measurement receiving apparatus 500 can directly measure a received measurement data v1 through the receiving antenna 400, but in the operation of the whole system, the receiving antenna 400 has a loss during signal reception and the coaxial cable has a loss during transmission, so the final real measurement data calculation formula is as follows:
measured final data V = measured receiving device measurement V1+ line loss V2+ antenna factor V3.
By adjusting the settings of the measurement receiving device 500, the strength of the magnetic field and the strength of the electric field can be measured respectively, and a tester can determine whether the current receiving antenna 400 is suitable for testing the device under test 200 according to the finally obtained data. After one round of test is finished, the antennas with different central frequencies are replaced to carry out the next round of test, so that the accuracy of the test result is guaranteed.
Meanwhile, because the receiving antenna 400 used in the application adopts the spiral coil and the half-wave dipole small antenna, under the condition that the test result is not ideal, the distance between the antenna and the equipment to be tested can be adjusted, the electromagnetic interference intensity of the PCB circuit can be detected in a short distance, and an engineer can conveniently search for the electromagnetic interference problem.
The application provides an electromagnetic interference test system, whether the electromagnetic interference signal that this electromagnetic interference test system is used for equipment is up to standard, this electromagnetic interference test system is by shield assembly, power supply unit, receiving antenna and measuring receiving arrangement and constitutes, wherein measure receiving arrangement can be receiver or spectrometer, reduce the cost through selecting the higher equipment of sexual valence, shield assembly uses the iron sheet of skew or aluminum alloy to build, than the shielding room of expensive ferrite (the price is in 80 ten thousand-100 ten thousand), the shielding room (the price is in 5000 yuan-8000 yuan) that aluminum alloy or materials such as iron sheet were made can further reduce the cost, and through the combination of spiral coil and half-wave dipole antenna of PCB printing plate preparation, make the antenna simple and easy to make, easy to maintain, and can satisfy the receipt of electric field and magnetic field signal simultaneously, guaranteed the comprehensive nature of test. Simultaneously because the system of this application adopts the little antenna of spiral coil and half-wave dipole of adoption of printing, in use can adjust the distance of test antenna to measuring equipment at any time, also can survey the electromagnetic interference intensity of PCB board circuit closely. The interference source of the circuit board can be quickly positioned in the positioning and debugging process, and the electromagnetic interference problem of the system is further quickly solved. The time spent by engineers in finding electromagnetic interference problems can be greatly reduced.
In the embodiments provided in the present application, it should be understood that the disclosed apparatus and method can be implemented in other ways. The above-described embodiments of the apparatus are merely illustrative, and in addition, each functional module or unit in the embodiments of the present invention may be integrated together to form an independent part, or each module may exist separately, or two or more modules may be integrated to form an independent part.
The above description is only for the specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto, and any person skilled in the art can easily think of the changes or substitutions within the technical scope of the present invention, and all should be covered within the protection scope of the present invention.
Claims (10)
1. An electromagnetic interference test system, comprising: the device comprises a measurement receiving device, a shielding device, a power supply device and a receiving antenna;
the power supply equipment is used for connecting to-be-tested equipment arranged in the shielding device to supply power to the to-be-tested equipment;
the receiving antenna is arranged in the shielding device, connected with the measuring and receiving equipment, and used for receiving an electromagnetic interference signal generated when the equipment to be measured operates and transmitting the electromagnetic interference signal to the measuring and receiving equipment;
the measurement receiving equipment is arranged outside the shielding device and used for calculating and measuring the electromagnetic interference signals.
2. The EMI testing system of claim 1 wherein the receiving antenna is a dual-sided PCB antenna, one side of which is a helical coil antenna and the other side of which is a half-wave dipole antenna.
3. The EMI testing system of claim 2, wherein each side of said half-wave dipole antenna is one-quarter of a wavelength of an electromagnetic wave.
4. The emi testing system of claim 1, wherein the material of the shielding device comprises one of an aluminum alloy or an iron sheet.
5. The EMI testing system of claim 4, wherein said shielding device further includes a shielding coating on an outer surface thereof, said shielding coating being one or a combination of graphite and carbon black.
6. The EMI testing system of claim 1, wherein the measurement receiving device is one of a receiver or a spectrometer.
7. The EMI testing system of claim 1, wherein said receiving antenna is connected to said measurement receiving device by a signal receiving cable, said signal receiving cable being a coaxial shielded cable with an SMA interface.
8. The emi testing system of claim 1, wherein the distance between the receiving antenna and the device under test is not less than one meter.
9. The EMI testing system of claim 1, wherein said power supply device includes a power supply and a filter, said power supply being connected to said device under test via an external interface of said shielding device,
the filter is connected between the power supply and the equipment to be tested and used for removing noise waves from the power supply.
10. The emi testing system of claim 9, wherein the filter has an insertion loss greater than 40db.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202221142399.3U CN217739340U (en) | 2022-05-11 | 2022-05-11 | Electromagnetic interference test system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202221142399.3U CN217739340U (en) | 2022-05-11 | 2022-05-11 | Electromagnetic interference test system |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN217739340U true CN217739340U (en) | 2022-11-04 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202221142399.3U Active CN217739340U (en) | 2022-05-11 | 2022-05-11 | Electromagnetic interference test system |
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| CN (1) | CN217739340U (en) |
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- 2022-05-11 CN CN202221142399.3U patent/CN217739340U/en active Active
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