CN117706211A - Method and system for testing shielding effectiveness of radio frequency cable in automobile environment - Google Patents
Method and system for testing shielding effectiveness of radio frequency cable in automobile environment Download PDFInfo
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- CN117706211A CN117706211A CN202311706521.4A CN202311706521A CN117706211A CN 117706211 A CN117706211 A CN 117706211A CN 202311706521 A CN202311706521 A CN 202311706521A CN 117706211 A CN117706211 A CN 117706211A
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- 238000012360 testing method Methods 0.000 title claims abstract description 133
- 238000000034 method Methods 0.000 title claims abstract description 79
- 230000005540 biological transmission Effects 0.000 claims abstract description 61
- 238000012545 processing Methods 0.000 claims description 99
- 239000002184 metal Substances 0.000 claims description 12
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R29/00—Arrangements for measuring or indicating electric quantities not covered by groups G01R19/00 - G01R27/00
- G01R29/08—Measuring electromagnetic field characteristics
- G01R29/0807—Measuring electromagnetic field characteristics characterised by the application
- G01R29/0814—Field measurements related to measuring influence on or from apparatus, components or humans, e.g. in ESD, EMI, EMC, EMP testing, measuring radiation leakage; detecting presence of micro- or radiowave emitters; dosimetry; testing shielding; measurements related to lightning
- G01R29/0835—Testing shielding, e.g. for efficiency
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R1/00—Details of instruments or arrangements of the types included in groups G01R5/00 - G01R13/00 and G01R31/00
- G01R1/02—General constructional details
- G01R1/04—Housings; Supporting members; Arrangements of terminals
- G01R1/0408—Test fixtures or contact fields; Connectors or connecting adaptors; Test clips; Test sockets
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R1/00—Details of instruments or arrangements of the types included in groups G01R5/00 - G01R13/00 and G01R31/00
- G01R1/02—General constructional details
- G01R1/04—Housings; Supporting members; Arrangements of terminals
- G01R1/0408—Test fixtures or contact fields; Connectors or connecting adaptors; Test clips; Test sockets
- G01R1/0425—Test clips, e.g. for IC's
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R29/00—Arrangements for measuring or indicating electric quantities not covered by groups G01R19/00 - G01R27/00
- G01R29/08—Measuring electromagnetic field characteristics
- G01R29/0864—Measuring electromagnetic field characteristics characterised by constructional or functional features
- G01R29/0871—Complete apparatus or systems; circuits, e.g. receivers or amplifiers
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R29/00—Arrangements for measuring or indicating electric quantities not covered by groups G01R19/00 - G01R27/00
- G01R29/08—Measuring electromagnetic field characteristics
- G01R29/0864—Measuring electromagnetic field characteristics characterised by constructional or functional features
- G01R29/0878—Sensors; antennas; probes; detectors
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Abstract
The invention discloses a method and a system for testing shielding effectiveness of a radio frequency cable in an automobile environment, wherein the testing method comprises the following steps: determining a transmission attenuation reference value SE of a radio frequency signal with a preset frequency in a current test environment 0 The method comprises the steps of carrying out a first treatment on the surface of the Determining a first transmission power P of the radio frequency signal transmitted by the radio frequency cable to be tested placed on a first test table ref The method comprises the steps of carrying out a first treatment on the surface of the Determining a second transmission power P of the radio frequency signal transmitted by the radio frequency cable to be tested placed on a second test table dut The method comprises the steps of carrying out a first treatment on the surface of the Using the formula: se=se 0 ‑(P ref ‑P dut ) Calculating to obtain shielding effectiveness SE of the radio frequency cable to be tested in an actual assembly environment of the automobile; the shielding effectiveness SE is used as the shielding effectiveness of the radio frequency cable in the automobile environment. The invention can rapidly and accurately obtain the shielding effect of the radio frequency cable in the automobile environment, and saves the cost.
Description
Technical Field
The invention belongs to the field of electromagnetic shielding test, and particularly relates to a method and a system for testing shielding effectiveness of a radio frequency cable in an automobile environment.
Background
The shielding effectiveness refers to the ability of the shielding structure or material of the radio frequency cable to suppress external electromagnetic interference. Under the complex electromagnetic environment inside and outside the automobile, when electromagnetic noise signals exist, if the shielding effectiveness of the radio frequency cable is higher, the radio frequency cable can effectively inhibit the transmission of external electromagnetic noise, avoid entering a sensitive circuit and improve the electromagnetic interference resistance of an automobile electrical system.
The conventional method for testing the shielding effectiveness of the radio frequency cable can only evaluate the shielding effectiveness of the cable of the radio frequency cable under the standard test environment (such as the device and the method for testing the shielding effectiveness of the high-voltage cable of the new energy automobile disclosed in CN109375020 a). When the automobile real environment is applied, the obtained cable parameters and the automobile metal structure are subjected to joint simulation evaluation by combining a simulation tool, so that time is consumed, and the simulation result may be inaccurate.
Disclosure of Invention
The invention aims to provide a method and a system for testing shielding effectiveness of a radio frequency cable in an automobile environment, so as to quickly and accurately obtain the shielding effectiveness of the radio frequency cable in the automobile environment.
The invention relates to a method for testing the shielding effectiveness of a radio frequency cable in an automobile environment, which comprises the following steps:
determining a transmission attenuation reference value SE of a radio frequency signal with a preset frequency in a current test environment 0 The method comprises the steps of carrying out a first treatment on the surface of the The preset frequency is the frequency which is actually applied to the automobile and needs to be tested.
Determining a first transmission power P of the radio frequency signal transmitted by the radio frequency cable to be tested placed on a first test table ref The method comprises the steps of carrying out a first treatment on the surface of the Wherein, first test mesa is the insulation board.
Determining a second transmission power P of the radio frequency signal transmitted by the radio frequency cable to be tested placed on a second test table dut The method comprises the steps of carrying out a first treatment on the surface of the The second test table top is a metal plate simulating the actual assembly environment of the radio frequency cable on the automobile.
Using the formula: se=se 0 -(P ref -P dut ) Calculating to obtain that the radio frequency cable to be tested is in an automobileShielding effectiveness SE in the actual assembly environment.
And taking the shielding effectiveness SE as the shielding effectiveness of the radio frequency cable in the automobile environment.
Preferably, the transmission attenuation reference value SE of the radio frequency signal with the preset frequency in the current test environment is determined 0 The method of (1) comprises:
and a radio frequency transmitting antenna, a radio frequency receiving antenna and a balun (used for suppressing common mode interference brought by the antenna) are arranged on the first test table surface, the radio frequency transmitting antenna is connected with a transmitting end of the radio frequency signal receiving and transmitting processing device, and the radio frequency receiving antenna is connected with an input end of the balun.
And the output end of the balun is connected with the receiving end of the radio frequency signal receiving and transmitting processing device. The transmitting end of the radio frequency signal receiving and transmitting processing device transmits radio frequency signals with preset frequency through the radio frequency transmitting antenna, the radio frequency receiving antenna receives the radio frequency signals with preset frequency, the radio frequency signals are converted by the balun and transmitted to the receiving end of the radio frequency signal receiving and transmitting processing device, and the radio frequency signal receiving and transmitting processing device processes the received radio frequency signals with preset frequency to obtain first calibration power P mt 。
And placing the first calibration cable on a first test table board, connecting one end of the first calibration cable with the output end of the balun, and connecting the other end of the first calibration cable with the receiving end of the radio frequency signal receiving and transmitting processing device. The transmitting end of the radio frequency signal receiving and transmitting processing device transmits radio frequency signals with preset frequency through the radio frequency transmitting antenna, the radio frequency receiving antenna receives the radio frequency signals with the preset frequency, the radio frequency signals are transmitted to the receiving end of the radio frequency signal receiving and transmitting processing device through the first calibration cable after being subjected to balun conversion, and the radio frequency signal receiving and transmitting processing device processes the received radio frequency signals with the preset frequency to obtain second calibration power P cal The method comprises the steps of carrying out a first treatment on the surface of the The first calibration cable is a copper core wire formed by removing a shielding layer of the radio frequency cable.
Using the formula: SE (SE) 0 =P mt -P cal Calculating the transmission attenuation reference value SE 0 。
Preferably, the radio frequency signal is determined to be transmitted through the radio frequency cable to be tested placed on the first test table topFirst transmission power P of transmission ref The method of (1) comprises:
the method comprises the steps that a radio frequency transmitting antenna, a radio frequency receiving antenna, a balun and a radio frequency cable to be tested are placed on a first test table surface, the radio frequency transmitting antenna is connected with a transmitting end of a radio frequency signal receiving and transmitting processing device, the radio frequency receiving antenna is connected with an input end of the balun, one end of the radio frequency cable to be tested is connected with an output end of the balun, and the other end of the radio frequency cable to be tested is connected with a receiving end of the radio frequency signal receiving and transmitting processing device.
The transmitting end of the radio frequency signal receiving and transmitting processing device transmits a radio frequency signal with preset frequency through the radio frequency transmitting antenna, the radio frequency receiving antenna receives the radio frequency signal with preset frequency, the radio frequency signal is converted by the balun and is transmitted to the receiving end of the radio frequency signal receiving and transmitting processing device through the radio frequency cable to be tested, and the radio frequency signal receiving and transmitting processing device processes the received radio frequency signal with preset frequency to obtain the first transmission power P ref 。
Preferably, a second transmission power P of the radio frequency signal transmitted through the radio frequency cable to be tested placed on the second test table top is determined dut The method of (1) comprises:
the radio frequency transmitting antenna, the radio frequency receiving antenna, the balun and the radio frequency cable to be tested are placed on a second test table surface, the radio frequency transmitting antenna is connected with the transmitting end of the radio frequency signal receiving and transmitting processing device, the radio frequency receiving antenna is connected with the input end of the balun, one end of the radio frequency cable to be tested is connected with the output end of the balun, and the other end of the radio frequency cable to be tested is connected with the receiving end of the radio frequency signal receiving and transmitting processing device.
The transmitting end of the radio frequency signal receiving and transmitting processing device transmits a radio frequency signal with preset frequency through the radio frequency transmitting antenna, the radio frequency receiving antenna receives the radio frequency signal with preset frequency, the radio frequency signal is converted by the balun and is transmitted to the receiving end of the radio frequency signal receiving and transmitting processing device through the radio frequency cable to be tested, and the radio frequency signal receiving and transmitting processing device processes the received radio frequency signal with preset frequency to obtain the second transmission power P dut 。
The invention discloses a radio frequency cable shielding effectiveness test system in an automobile environment, which is used for realizing a radio frequency cable shielding effectiveness test method in the automobile environment.
Preferably, the transmission attenuation reference value SE of the radio frequency signal with the preset frequency in the current test environment is determined 0 The method of (1) comprises:
the method comprises the steps of placing a first current clamp, a first impedance load, a second current clamp and a second impedance load on a first test table surface, wherein the first current clamp is connected with a transmitting end of a radio frequency signal receiving and transmitting processing device, and the second current clamp is connected with a receiving end of the radio frequency signal receiving and transmitting processing device. The first impedance load and the second impedance load are used for preventing signal reflection and absorbing redundant signal energy.
Placing a second calibration cable on the first test table surface, connecting one end of the second calibration cable with the first impedance load, connecting the other end of the second calibration cable with the second impedance load, clamping one end of the second calibration cable by the first current clamp, and clamping the other end of the second calibration cable by the second current clamp. The transmitting end of the radio frequency signal receiving and transmitting processing device transmits radio frequency signals with preset frequency through the first current clamp, the radio frequency signals are coupled through the second calibration cable and the second current clamp and transmitted to the receiving end of the radio frequency signal receiving and transmitting processing device, and the radio frequency signal receiving and transmitting processing device processes the received radio frequency signals with preset frequency to obtain first calibration power P mt The method comprises the steps of carrying out a first treatment on the surface of the The second calibration cable is a double-layer shielding cable with shielding effectiveness greater than or equal to a preset effectiveness threshold, namely, the shielding effect of the second calibration cable is good.
And placing the first calibration cable on a first test table surface, connecting one end of the first calibration cable with a first impedance load, connecting the other end of the first calibration cable with a second impedance load, and clamping one end of the first calibration cable by a first current clamp and the other end of the first calibration cable by a second current clamp. The transmitting end of the radio frequency signal receiving and transmitting processing device transmits a radio frequency signal with preset frequency through the first current clamp, and is coupled with and transmitted to the radio frequency signal receiving and transmitting processing device through the first calibration cable and the second current clampThe receiving end, the radio frequency signal receiving and transmitting processing device processes the received radio frequency signal with preset frequency to obtain second calibration power P cal The method comprises the steps of carrying out a first treatment on the surface of the The first calibration cable is a copper core wire formed by removing a shielding layer of the radio frequency cable.
Using the formula: SE (SE) 0 =P mt -P cal Calculating the transmission attenuation reference value SE 0 。
Preferably, a first transmission power P of the radio frequency signal transmitted through the radio frequency cable to be tested placed on the first test table top is determined ref The method of (1) comprises:
the method comprises the steps of placing a first current clamp, a first impedance load, a second current clamp, a second impedance load and a radio frequency cable to be tested on a first test table, connecting the first current clamp with a transmitting end of a radio frequency signal receiving and transmitting processing device, connecting the second current clamp with a receiving end of the radio frequency signal receiving and transmitting processing device, connecting one end of the radio frequency cable to be tested with the first impedance load, connecting the other end of the radio frequency cable to be tested with the second impedance load, clamping one end of the radio frequency cable to be tested by the first current clamp, and clamping the other end of the radio frequency cable to be tested by the second current clamp.
The transmitting end of the radio frequency signal receiving and transmitting processing device transmits a radio frequency signal with preset frequency through the first current clamp, the radio frequency signal receiving and transmitting processing device receives the radio frequency signal with preset frequency through the radio frequency cable to be tested and the second current clamp, and the radio frequency signal receiving and transmitting processing device processes the received radio frequency signal with preset frequency to obtain the first transmission power P ref 。
Preferably, a second transmission power P of the radio frequency signal transmitted through the radio frequency cable to be tested placed on the second test table top is determined dut The method of (1) comprises:
the method comprises the steps that a first current clamp, a first impedance load, a second current clamp, a second impedance load and a radio frequency cable to be tested are placed on a second test table surface, the first current clamp is connected with a transmitting end of a radio frequency signal receiving and transmitting processing device, the second current clamp is connected with a receiving end of the radio frequency signal receiving and transmitting processing device, one end of the radio frequency cable to be tested is connected with the first impedance load, the other end of the radio frequency cable to be tested is connected with the second impedance load, the first current clamp clamps one end of the radio frequency cable to be tested, and the second current clamp clamps the other end of the radio frequency cable to be tested.
The transmitting end of the radio frequency signal receiving and transmitting processing device transmits a radio frequency signal with preset frequency through the first current clamp, the radio frequency signal receiving and transmitting processing device receives the radio frequency signal with preset frequency through the radio frequency cable to be tested and the second current clamp, and the radio frequency signal receiving and transmitting processing device processes the received radio frequency signal with preset frequency to obtain the second transmission power P dut 。
The invention relates to a radio frequency cable shielding effectiveness test system in an automobile environment, which is used for realizing the radio frequency cable shielding effectiveness test method in the automobile environment.
Preferably, the radio frequency signal receiving and transmitting processing device comprises a radio frequency signal source, a radio frequency power amplifier, a preamplifier and a receiving processor. The output end of the radio frequency signal source is connected with the input end of the radio frequency power amplifier, and the output end of the radio frequency power amplifier is used as the transmitting end of the radio frequency signal receiving and transmitting processing device. The input end of the pre-amplifier is used as the receiving end of the radio frequency signal receiving and transmitting processing device, and the output end of the pre-amplifier is connected with the receiving processor. The radio frequency signal source is a radio frequency signal generator and provides radio frequency signals with frequencies required by the test (namely, frequencies which are actually applied to the automobile and need to be tested). The radio frequency power amplifier is used for amplifying a radio frequency signal output by the radio frequency signal source so as to excite the radio frequency transmitting antenna or the first current clamp. The preamplifier is used for amplifying the received radio frequency signal and transmitting to the receiving processor. The receiving processor is used for processing the received radio frequency signals in the testing process to obtain the absolute power of the radio frequency signals.
Preferably, the radio frequency signal receiving and transmitting processing device comprises a vector network analyzer, a radio frequency power amplifier and a preamplifier, wherein the radio frequency signal output end of the vector network analyzer is connected with the input end of the radio frequency power amplifier, the output end of the radio frequency power amplifier is used as the transmitting end of the radio frequency signal receiving and transmitting processing device, the input end of the preamplifier is used as the receiving end of the radio frequency signal receiving and transmitting processing device, and the output end of the preamplifier is connected with the radio frequency signal input end of the vector network analyzer. The vector network analyzer replaces a radio frequency signal source and a receiving processor, and uses a single device to output and receive signals, so that the vector network analyzer is more convenient and quick.
The invention has the following effects:
(1) The radio frequency cable shielding effectiveness under the automobile environment can be directly calculated through the test data without simulation evaluation, so that the radio frequency cable shielding effectiveness is rapidly and accurately tested, and meanwhile, the cost is saved.
(2) By changing the placement positions of the radio frequency transmitting antenna and the radio frequency receiving antenna, the radio frequency signal injection with different polarization directions can be performed, and the method has higher flexibility compared with the traditional method.
(3) By changing the types of the radio frequency transmitting antenna and the radio frequency receiving antenna, the radio frequency signal injection of a wide frequency band or a narrow band can be realized, and the test of the radio frequency cable in any frequency band can be realized.
(4) The first current clamp and the second current clamp are utilized to realize coupling transmission of radio frequency signals, and the shielding effectiveness of the low-frequency radio frequency cable can be evaluated.
Drawings
Fig. 1 is a flowchart of a method for testing shielding effectiveness of a radio frequency cable in an automotive environment according to an embodiment of the present invention.
FIG. 2 is a diagram showing the determination of the transmission attenuation reference value SE in embodiment 1 0 And one of the structural schematic diagrams of the test system is built.
FIG. 3 is a diagram showing the determination of the transmission attenuation reference value SE in embodiment 1 0 And a second structural diagram of the test system is constructed.
Fig. 4 is a diagram showing the determination of the first transmission power P in embodiment 1 ref And a structural schematic diagram of the test system is built.
Fig. 5 is a diagram showing the determination of the second transmission power P in embodiment 1 dut And a structural schematic diagram of the test system is built.
Fig. 6 is a schematic structural diagram of the rf signal transceiver processing apparatus in embodiment 2 and embodiment 4.
FIG. 7 is a diagram showing the determination of the transmission attenuation reference value SE in embodiment 3 0 And one of the structural schematic diagrams of the test system is built.
FIG. 8 is a diagram showing the determination of the transmission attenuation reference value SE in embodiment 3 0 And a second structural diagram of the test system is constructed.
Fig. 9 is a diagram showing the determination of the first transmission power P in embodiment 3 ref And a structural schematic diagram of the test system is built.
Fig. 10 is a diagram showing the determination of the second transmission power P in embodiment 3 dut And a structural schematic diagram of the test system is built.
In the figure, a 1-radio frequency cable to be tested, a 2-first calibration cable, a 3-first test table top, a 4-second test table top, a 5-radio frequency transmitting antenna, a 6-radio frequency receiving antenna, a 7-balun, an 8-first current clamp, a 9-second current clamp, a 10-first impedance load, a 11-second impedance load, a 12-second calibration cable, a 13-radio frequency power amplifier, a 14-preamplifier, a 15-receiving processor, a 16-radio frequency signal source and a 17-vector network analyzer.
Detailed Description
For a more complete understanding of the nature and the technical content of the embodiments of the present invention, reference should be made to the following detailed description of embodiments of the invention, taken in conjunction with the accompanying drawings, which are meant to be illustrative only and not limiting of the embodiments of the invention.
Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used herein is for the purpose of describing embodiments of the invention only and is not intended to be limiting of the invention.
It should also be noted that the term "first\second" in relation to embodiments of the present invention is used merely to distinguish between similar objects and does not represent a particular ordering for the objects.
Example 1: as shown in fig. 2 to 5, the system for testing shielding effectiveness of a radio frequency cable in an automotive environment in this embodiment includes a radio frequency cable 1 to be tested, a first calibration cable 2, a first test table board 3, a second test table board 4, a radio frequency transmitting antenna 5, a radio frequency receiving antenna 6, a balun 7 and a radio frequency signal receiving and transmitting processing device.
The first calibration cable 2 is a copper core wire formed by removing a shielding layer of a radio frequency cable. The lengths of the radio frequency cable 1 to be tested and the first calibration cable 2 are equal.
The first test table 3 is an insulating board, and the second test table 4 is a metal plate simulating the actual assembly environment of the radio frequency cable on the automobile. The first test table top 3 is used for realizing the test of the radio frequency cable 1 to be tested and the first calibration cable 2 in an environment far away from metal. As an example, the first test bench 3 may be a wood board.
The radio frequency transmitting antenna 5, the radio frequency receiving antenna 6 and the balun 7 are selected according to the test requirement, and a broadband antenna or a narrowband antenna can be used to meet the requirements of different test frequencies. In addition, the radio frequency signal injection with different polarization directions can also be performed by changing the placement positions of the radio frequency transmitting antenna 5 and the radio frequency receiving antenna 6. It should be noted that, in the whole testing process of the embodiment, the placement positions of the radio frequency transmitting antenna 5 and the radio frequency receiving antenna 6 on the first test table surface 3 and the placement position of the radio frequency receiving antenna 6 on the second test table surface 4 are kept unchanged all the time, so that the influence on the testing result caused by the change of the positions of the radio frequency transmitting antenna 5 and the radio frequency receiving antenna 6 is avoided.
The radio frequency signal transceiving processing means comprises a radio frequency signal source 16, a radio frequency power amplifier 13, a preamplifier 14 and a receiving processor 15. The output end of the radio frequency signal source 16 is connected with the input end of the radio frequency power amplifier 13, and the output end of the radio frequency power amplifier 13 is used as the transmitting end of the radio frequency signal receiving and transmitting processing device. The input end of the preamplifier 14 is used as the receiving end of the radio frequency signal receiving and transmitting processing device, and the output end of the preamplifier 14 is connected with the receiving processor 15. It should be noted that, the rf signal source 16 can generate an rf signal with a preset frequency, where the preset frequency is a frequency that needs to be tested and is actually applied to the automobile; the tester adjusts the rf signal source 16 to change the frequency of the rf signal. The receiving processor 15 can process the received rf signal to obtain a corresponding absolute power (in dBm, milliwatt db) which can be read directly by a tester from the display screen of the receiving processor 15.
As shown in fig. 1, the method for testing the shielding effectiveness of the radio frequency cable in the automotive environment in this embodiment adopts the system for testing the shielding effectiveness of the radio frequency cable, and specifically includes the following steps:
step one, determining a transmission attenuation reference value SE of a radio frequency signal with preset frequency in a current test environment 0 . The specific determination method comprises the following steps:
s11, a radio frequency transmitting antenna 5, a radio frequency receiving antenna 6 and a balun 7 are placed on the first test table board 3, the radio frequency transmitting antenna 5 is connected with the output end of a radio frequency power amplifier 13, and the radio frequency receiving antenna 6 is connected with the input end of the balun 7 (see fig. 2 and 3).
S12, the output of balun 7 is connected to the input of preamplifier 14 (see fig. 2). The rf signal source 16 generates and outputs an rf signal with a preset frequency, the rf signal is amplified by the rf power amplifier 13, the rf signal with the preset frequency is transmitted by the rf transmitting antenna 5, the rf receiving antenna 6 receives the rf signal with the preset frequency, the rf signal is converted by the balun 7 (to suppress the common mode interference of the antenna) and transmitted to the preamplifier 14 for amplification, and then received and processed by the receiving processor 15 to obtain the first calibration power P mt (unit: dBm).
S13, the first calibration cable 2 is placed on the first test bench 3, one end of the first calibration cable 2 is connected to the output end of the balun 7, and the other end of the first calibration cable 2 is connected to the input end of the preamplifier 14 (see fig. 3). The rf signal source 16 generates and outputs an rf signal with a preset frequency, the rf signal is amplified by the rf power amplifier 13, the rf signal with the preset frequency is transmitted by the rf transmitting antenna 5, the rf receiving antenna 6 receives the rf signal with the preset frequency, the rf signal is converted by the balun 7 (to suppress the common mode interference of the antenna) and is transmitted to the preamplifier 14 for amplification by the first calibration cable 2, and then is received and processed by the receiving processor 15 to obtain a second calibration power P cal (unit: dBm).
S14, benefitUsing the formula: SE (SE) 0 =P mt -P cal Calculating to obtain a transmission attenuation reference value SE of a radio frequency signal with preset frequency in the current test environment 0 (unit: dB).
P is the same as mt The transmission power (i.e., the first calibration power) of the rf signal output by the rf signal source 16 directly after passing through each device in an environment far away from the metal; the gain of the radio frequency power amplifier 13 and the gain of the pre-amplifier 14 and the loss of the radio frequency transmitting antenna 5, the radio frequency receiving antenna 6 and the balun 7 are included; it should be noted that, at this time, the cable is not connected, and the obtained power data represents that a cable with infinite shielding effectiveness is connected. P (P) cal Is the transmission power (i.e., the second calibration power) obtained after adding the unshielded first calibration cable 2 in an environment far from the metal. Thus, P mt -P cal The absolute power difference between a cable with infinite shielding effectiveness and a cable without shielding effectiveness under the current test environment (away from the metal) is characterized. Under the same test conditions, this absolute power difference is a fixed value.
Step two, determining a first transmission power P of the radio frequency signal transmitted by the radio frequency cable 1 to be tested placed on the first test table board 3 ref . The specific determination method comprises the following steps:
firstly, a radio frequency transmitting antenna 5, a radio frequency receiving antenna 6, a balun 7 and a radio frequency cable 1 to be tested are placed on a first test table board 3, the radio frequency transmitting antenna 5 is connected with an output end of a radio frequency power amplifier 13, the radio frequency receiving antenna 6 is connected with an input end of the balun 7, one end of the radio frequency cable 1 to be tested is connected with an output end of the balun 7, and the other end of the radio frequency cable 1 to be tested is connected with an input end of a preamplifier 14 (see fig. 4).
Then, the RF signal source 16 generates and outputs an RF signal with a preset frequency, the RF signal is amplified by the RF power amplifier 13, the RF signal with the preset frequency is transmitted by the RF transmitting antenna 5, the RF signal with the preset frequency is received by the RF receiving antenna 6, converted by the balun 7 (suppressing the common mode interference of the antenna) and transmitted to the preamplifier 14 for amplification by the RF cable 1 to be tested, and then received by the RF receiving antennaThe processor 15 receives and processes the first transmission power P ref . The first transmission power P ref (unit: dBm).
Step three, determining a second transmission power P of the radio frequency signal transmitted by the radio frequency cable 1 to be tested placed on the second test table top 4 dut . The specific determination method comprises the following steps:
firstly, a radio frequency transmitting antenna 5, a radio frequency receiving antenna 6, a balun 7 and a radio frequency cable 1 to be tested are placed on a second test table top 4, the radio frequency transmitting antenna 5 is connected with the output end of a radio frequency power amplifier 13, the radio frequency receiving antenna 6 is connected with the input end of the balun 7, one end of the radio frequency cable 1 to be tested is connected with the output end of the balun 7, and the other end of the radio frequency cable 1 to be tested is connected with the input end of a preamplifier 14 (see fig. 5).
Then, the rf signal source 16 generates and outputs an rf signal with a preset frequency, the rf signal is amplified by the rf power amplifier 13, the rf signal with the preset frequency is transmitted by the rf transmitting antenna 5, the rf receiving antenna 6 receives the rf signal with the preset frequency, the rf signal is converted by the balun 7 (to suppress the common mode interference of the antenna) and is transmitted to the preamplifier 14 for amplification by the rf cable 1 to be tested, and then the rf signal is received and processed by the receiving processor 15 to obtain the second transmission power P dut (unit: dBm).
Step four, utilizing the formula: se=se 0 -(P ref -P dut ) The shielding effectiveness SE (unit: dB).
P is the same as ref -P dut The signal transmission attenuation caused by the influence of the metal plates simulating the actual assembly environment of the radio frequency cable 1 to be tested on the automobile is represented. The better the shielding effectiveness of the radio frequency cable to be tested is, the smaller the corresponding difference value is. With reference value SE for attenuation of transmission of radio-frequency signals of preset frequency in the current test environment 0 Subtracting the degree P of influence of metal on the power transmission performance of the radio frequency signal ref -P dut To characterize the shielding effectiveness SE, so that the resulting radio-frequency cable 1 to be tested is in the actual assembly environment on the vehicleThe shielding effectiveness is more accurate.
And fifthly, taking the shielding effectiveness SE as the shielding effectiveness of the radio frequency cable in the automobile environment.
Example 2: the method for testing the shielding effectiveness of the radio frequency cable in the automotive environment in this embodiment is the same as that in embodiment 1, and most parts of the test system are the same as that in embodiment 1, except that: in the radio frequency signal receiving and transmitting processing device, a vector network analyzer 17 is used for replacing a radio frequency signal source 16 and a receiving processor 15 (see fig. 6), a radio frequency signal output end of the vector network analyzer 17 is connected with an input end of a radio frequency power amplifier 13, and an output end of a preamplifier 14 is connected with a radio frequency signal input end of the vector network analyzer 17. The vector network analyzer 17 can generate a radio frequency signal with a preset frequency, and can process the received radio frequency signal to obtain corresponding absolute power. The tester adjusts the vector network analyzer 17 to change the frequency of the radio frequency signal, and the tester can directly read the absolute power of the received radio frequency signal from the display screen of the vector network analyzer 17.
Example 3: as shown in fig. 7 to 10, the system for testing shielding effectiveness of a radio frequency cable in an automotive environment in this embodiment includes a radio frequency cable 1 to be tested, a first calibration cable 2, a first test table 3, a second test table 4, a first current clamp 8, a first impedance load 10, a second current clamp 9, a second impedance load 11, a second calibration cable 12, and a radio frequency signal transceiver.
The first calibration cable 2 is a copper core wire formed by removing a shielding layer of a radio frequency cable. The second calibration cable 12 is a double shielded cable having a shielding effectiveness greater than or equal to a preset effectiveness threshold. As an example, the preset efficacy threshold is 90dB. The lengths of the radio frequency cable 1 to be tested, the first calibration cable 2 and the second calibration cable 12 are equal.
The first test table 3 is an insulating board, and the second test table 4 is a metal plate simulating the actual assembly environment of the radio frequency cable on the automobile. The first test table top 3 is used for realizing the test of the radio frequency cable 1 to be tested and the first calibration cable 2 in an environment far away from metal. As an example, the first test bench 3 may be a wood board.
As an example, the impedance values of the first impedance load 10 and the second impedance load 11 are 50Ω. The first impedance load 10 and the second impedance load 11 are used for preventing signal reflection and absorbing redundant signal energy.
The radio frequency signal transceiving processing means comprises a radio frequency signal source 16, a radio frequency power amplifier 13, a preamplifier 14 and a receiving processor 15. The output end of the radio frequency signal source 16 is connected with the input end of the radio frequency power amplifier 13, and the output end of the radio frequency power amplifier 13 is used as the transmitting end of the radio frequency signal receiving and transmitting processing device. The input end of the preamplifier 14 is used as the receiving end of the radio frequency signal receiving and transmitting processing device, and the output end of the preamplifier 14 is connected with the receiving processor 15. It should be noted that, the rf signal source 16 can generate an rf signal with a preset frequency, where the preset frequency is a frequency that needs to be tested and is actually applied to the automobile; the tester adjusts the rf signal source 16 to change the frequency of the rf signal. The receiving processor 15 can process the received rf signal to obtain a corresponding absolute power (in dBm, milliwatt db) which can be read directly by a tester from the display screen of the receiving processor 15.
As shown in fig. 1, the method for testing the shielding effectiveness of the radio frequency cable in the automotive environment in this embodiment adopts the system for testing the shielding effectiveness of the radio frequency cable, and specifically includes the following steps:
step one, determining a transmission attenuation reference value SE of a radio frequency signal with preset frequency in a current test environment 0 . The specific determination method comprises the following steps:
s21, a first current clamp 8, a first impedance load 10, a second current clamp 9, and a second impedance load 11 are placed on the first test bench 3, the first current clamp 8 is connected to the output end of the radio frequency power amplifier 13, and the second current clamp 9 is connected to the input end of the preamplifier 14 (see fig. 7 and 8).
S22, placing a second calibration cable 12 on the first test table surface 3, connecting one end of the second calibration cable 12 with the first impedance load 10, connecting the other end of the second calibration cable 12 with the second impedance load 11, clamping one end of the second calibration cable 12 by the first current clamp 8 and clamping one end of the second calibration cable 12 by the second current clamp 9The other end of the second calibration cable 12 (see fig. 7). The RF signal source 16 generates and outputs RF signal with preset frequency, amplified by the RF power amplifier 13, sent by the first current clamp 8, coupled by the second calibration cable 12 and the second current clamp 9 and transmitted to the pre-amplifier 14 for amplification, and then received and processed by the receiving processor 15 to obtain the first calibration power P mt (unit: dBm).
S23, the first calibration cable 2 is placed on the first test bench 3, one end of the first calibration cable 2 is connected to the first impedance load 10, the other end of the first calibration cable 2 is connected to the second impedance load 11, the first current clamp 8 clamps one end of the first calibration cable 2, and the second current clamp 9 clamps the other end of the first calibration cable 2 (see fig. 8). The RF signal source 16 generates and outputs RF signal with preset frequency, amplified by the RF power amplifier 13, sent by the first current clamp 8, coupled by the first calibration cable 2 and the second current clamp 9 and transmitted to the pre-amplifier 14 for amplification, and received and processed by the receiving processor 15 to obtain second calibration power P cal (unit: dBm).
S24, utilizing a formula: SE (SE) 0 =P mt -P cal Calculating to obtain a transmission attenuation reference value SE of a radio frequency signal with preset frequency in the current test environment 0 (unit: dB).
Step two, determining a first transmission power P of the radio frequency signal transmitted by the radio frequency cable 1 to be tested placed on the first test table board 3 ref . The specific determination method comprises the following steps:
first, a first current clamp 8, a first impedance load 10, a second current clamp 9, a second impedance load 11, and a radio frequency cable 1 to be tested are placed on a first test table 3, the first current clamp 8 is connected with an output end of a radio frequency power amplifier 13, the second current clamp 9 is connected with an input end of a preamplifier 14, one end of the radio frequency cable 1 to be tested is connected with the first impedance load 10, the other end of the radio frequency cable 1 to be tested is connected with the second impedance load 11, the first current clamp 8 clamps one end of the radio frequency cable 1 to be tested, and the second current clamp 9 clamps the other end of the radio frequency cable 1 to be tested (see fig. 9).
Then, the RF signal source 16 generates and outputs an RF signal with a preset frequency, the RF signal is amplified by the RF power amplifier 13, then transmitted by the first current clamp 8, coupled by the RF cable 1 to be tested and the second current clamp 9 and transmitted to the pre-amplifier 14 for amplification, and then received and processed by the receiving processor 15 to obtain a first transmission power P ref (unit: dBm).
Step three, determining a second transmission power P of the radio frequency signal transmitted by the radio frequency cable 1 to be tested placed on the second test table top 4 dut . The specific determination method comprises the following steps:
first, a first current clamp 8, a first impedance load 10, a second current clamp 9, a second impedance load 11, and a radio frequency cable 1 to be tested are placed on a second test table 4, the first current clamp 8 is connected with an output end of a radio frequency power amplifier 13, the second current clamp 9 is connected with an input end of a preamplifier 14, one end of the radio frequency cable 1 to be tested is connected with the first impedance load 10, the other end of the radio frequency cable 1 to be tested is connected with the second impedance load 11, the first current clamp 8 clamps one end of the radio frequency cable 1 to be tested, and the second current clamp 9 clamps the other end of the radio frequency cable 1 to be tested (see fig. 10).
Then, the RF signal source 16 generates and outputs an RF signal with a preset frequency, the RF signal is amplified by the RF power amplifier 13, then transmitted by the first current clamp 8, coupled by the RF cable 1 to be tested and the second current clamp 9 and transmitted to the pre-amplifier 14 for amplification, and then received and processed by the receiving processor 15 to obtain a second transmission power P dut (unit: dBm).
Step four, utilizing the formula: se=se 0 -(P ref -P dut ) The shielding effectiveness SE (unit: dB).
And fifthly, taking the shielding effectiveness SE as the shielding effectiveness of the radio frequency cable in the automobile environment.
Example 4: the method for testing the shielding effectiveness of the radio frequency cable in the automotive environment in this embodiment is the same as that in embodiment 3, and most parts of the test system are the same as those in embodiment 3, except that: in the radio frequency signal receiving and transmitting processing device, a vector network analyzer 17 is used for replacing a radio frequency signal source 16 and a receiving processor 15 (see fig. 6), a radio frequency signal output end of the vector network analyzer 17 is connected with an input end of a radio frequency power amplifier 13, and an output end of a preamplifier 14 is connected with a radio frequency signal input end of the vector network analyzer 17. The vector network analyzer 17 can generate a radio frequency signal with a preset frequency, and can process the received radio frequency signal to obtain corresponding absolute power. The tester adjusts the vector network analyzer 17 to change the frequency of the radio frequency signal, and the tester can directly read the absolute power of the received radio frequency signal from the display screen of the vector network analyzer 17.
The foregoing is merely illustrative of the present invention, and the present invention is not limited thereto, and any person skilled in the art will readily recognize that variations or substitutions are within the scope of the present invention.
Claims (11)
1. The method for testing the shielding effectiveness of the radio frequency cable in the automobile environment is characterized by comprising the following steps of:
determining a transmission attenuation reference value SE of a radio frequency signal with a preset frequency in a current test environment 0 The method comprises the steps of carrying out a first treatment on the surface of the The preset frequency is the frequency which is actually applied to the automobile and needs to be tested;
determining a first transmission power P of the radio frequency signal transmitted by the radio frequency cable (1) to be tested placed on a first test table (3) ref The method comprises the steps of carrying out a first treatment on the surface of the Wherein the first test table board (3) is an insulating board;
determining a second transmission power P of the radio frequency signal transmitted by the radio frequency cable (1) to be tested placed on a second test table board (4) dut The method comprises the steps of carrying out a first treatment on the surface of the The second test table board (4) is a metal plate simulating the actual assembly environment of the radio frequency cable on the automobile;
using the formula: se=se 0 -(P ref -P dut ) Calculating to obtain shielding effectiveness SE of the radio frequency cable (1) to be tested in an actual assembly environment of the automobile;
and taking the shielding effectiveness SE as the shielding effectiveness of the radio frequency cable in the automobile environment.
2. The method for testing shielding effectiveness of a radio frequency cable in an automotive environment according to claim 1, wherein said transmission attenuation reference value SE is determined 0 The method of (1) comprises:
a radio frequency transmitting antenna (5), a radio frequency receiving antenna (6) and a balun (7) are arranged on a first test table board (3), the radio frequency transmitting antenna (5) is connected with a transmitting end of a radio frequency signal receiving and transmitting processing device, and the radio frequency receiving antenna (6) is connected with an input end of the balun (7);
the output end of the balun (7) is connected with the receiving end of the radio frequency signal receiving and transmitting processing device; the transmitting end of the radio frequency signal receiving and transmitting processing device transmits a radio frequency signal with preset frequency through a radio frequency transmitting antenna (5), a radio frequency receiving antenna (6) receives the radio frequency signal with preset frequency, and the radio frequency signal is converted by a balun (7) and transmitted to the receiving end of the radio frequency signal receiving and transmitting processing device to obtain a first calibration power P through processing mt ；
Placing a first calibration cable (2) on a first test table board (3), and connecting one end of the first calibration cable (2) with the output end of the balun (7) and the other end of the first calibration cable with the receiving end of the radio frequency signal receiving and transmitting processing device; the transmitting end of the radio frequency signal receiving and transmitting processing device transmits radio frequency signals with preset frequency through a radio frequency transmitting antenna (5), a radio frequency receiving antenna (6) receives the radio frequency signals with preset frequency, the radio frequency signals are converted by a balun (7) and transmitted to the receiving end of the radio frequency signal receiving and transmitting processing device through a first calibration cable (2), and second calibration power P is obtained through processing cal The method comprises the steps of carrying out a first treatment on the surface of the The first calibration cable (2) is a copper core wire formed by removing a shielding layer of a radio frequency cable;
using the formula: SE (SE) 0 =P mt -P cal Calculating the transmission attenuation reference value SE 0 。
3. The method for testing shielding effectiveness of a radio frequency cable in an automotive environment according to claim 2, whereinDetermining the first transmission power P ref The method of (1) comprises:
the method comprises the steps that a radio frequency transmitting antenna (5), a radio frequency receiving antenna (6), a balun (7) and a radio frequency cable (1) to be tested are placed on a first test table board (3), the radio frequency transmitting antenna (5) is connected with a transmitting end of a radio frequency signal receiving and transmitting processing device, the radio frequency receiving antenna (6) is connected with an input end of the balun (7), one end of the radio frequency cable (1) to be tested is connected with an output end of the balun (7), and the other end of the radio frequency cable is connected with a receiving end of the radio frequency signal receiving and transmitting processing device;
the transmitting end of the radio frequency signal receiving and transmitting processing device transmits a radio frequency signal with preset frequency through a radio frequency transmitting antenna (5), a radio frequency receiving antenna (6) receives the radio frequency signal with preset frequency, the radio frequency signal is converted by a balun (7) and is transmitted to the receiving end of the radio frequency signal receiving and transmitting processing device through a radio frequency cable (1) to be detected, and the first transmission power P is obtained through processing ref 。
4. The method for testing shielding effectiveness of a radio frequency cable in an automotive environment according to claim 2, wherein the second transmission power P is determined dut The method of (1) comprises:
the radio frequency transmitting antenna (5), the radio frequency receiving antenna (6), the balun (7) and the radio frequency cable (1) to be tested are placed on the second test table top (4), the radio frequency transmitting antenna (5) is connected with the transmitting end of the radio frequency signal receiving and transmitting processing device, the radio frequency receiving antenna (6) is connected with the input end of the balun (7), one end of the radio frequency cable (1) to be tested is connected with the output end of the balun (7), and the other end of the radio frequency cable is connected with the receiving end of the radio frequency signal receiving and transmitting processing device;
the transmitting end of the radio frequency signal receiving and transmitting processing device transmits a radio frequency signal with preset frequency through a radio frequency transmitting antenna (5), a radio frequency receiving antenna (6) receives the radio frequency signal with preset frequency, the radio frequency signal is converted by a balun (7) and is transmitted to the receiving end of the radio frequency signal receiving and transmitting processing device through a radio frequency cable (1) to be detected, and the second transmission power P is obtained through processing dut 。
5. According toThe method for testing shielding effectiveness of a radio frequency cable in an automotive environment according to claim 1, wherein said transmission attenuation reference value SE is determined 0 The method of (1) comprises:
the method comprises the steps that a first current clamp (8), a first impedance load (10), a second current clamp (9) and a second impedance load (11) are placed on a first test table board (3), the first current clamp (8) is connected with a transmitting end of a radio frequency signal receiving and transmitting processing device, and the second current clamp (9) is connected with a receiving end of the radio frequency signal receiving and transmitting processing device;
placing a second calibration cable (12) on the first test table top (3), connecting one end of the second calibration cable (12) with a first impedance load (10) and the other end of the second calibration cable with a second impedance load (11), clamping one end part of the second calibration cable (12) by a first current clamp (8), and clamping the other end part of the second calibration cable (12) by a second current clamp (9); the transmitting end of the radio frequency signal receiving and transmitting processing device transmits radio frequency signals with preset frequency through the first current clamp (8), and the radio frequency signals are coupled and transmitted to the receiving end of the radio frequency signal receiving and transmitting processing device through the second calibration cable (12) and the second current clamp (9) to obtain the first calibration power P through processing mt The method comprises the steps of carrying out a first treatment on the surface of the Wherein the second calibration cable (12) is a double-layer shielding cable with shielding effectiveness greater than or equal to a preset effectiveness threshold;
placing a first calibration cable (2) on a first test table board (3), connecting one end of the first calibration cable (2) with a first impedance load (10), connecting the other end of the first calibration cable with a second impedance load (11), and clamping one end part of the first calibration cable (2) by a first current clamp (8) and the other end part of the first calibration cable (2) by a second current clamp (9); the transmitting end of the radio frequency signal receiving and transmitting processing device transmits radio frequency signals with preset frequency through a first current clamp (8), and the radio frequency signals are coupled and transmitted to the receiving end of the radio frequency signal receiving and transmitting processing device through a first calibration cable (2) and a second current clamp (9) to obtain second calibration power P through processing cal The method comprises the steps of carrying out a first treatment on the surface of the The first calibration cable (2) is a copper core wire formed by removing a shielding layer of a radio frequency cable;
using the formula: SE (SE) 0 =P mt -P cal Calculating the transmission attenuation reference value SE 0 。
6. The method for testing shielding effectiveness of a radio frequency cable in an automotive environment according to claim 5, wherein the first transmission power P is determined ref The method of (1) comprises:
the method comprises the steps that a first current clamp (8), a first impedance load (10), a second current clamp (9), a second impedance load (11) and a radio frequency cable (1) to be tested are placed on a first test table board (3), the first current clamp (8) is connected with a transmitting end of a radio frequency signal receiving and processing device, the second current clamp (9) is connected with a receiving end of the radio frequency signal receiving and processing device, one end of the radio frequency cable (1) to be tested is connected with the first impedance load (10), the other end of the radio frequency cable is connected with the second impedance load (11), the first current clamp (8) clamps one end of the radio frequency cable (1) to be tested, and the second current clamp (9) clamps the other end of the radio frequency cable (1) to be tested;
the transmitting end of the radio frequency signal receiving and transmitting processing device transmits a radio frequency signal with preset frequency through a first current clamp (8), is coupled with a radio frequency cable (1) to be tested and a second current clamp (9) and is transmitted to the receiving end of the radio frequency signal receiving and transmitting processing device, and the first transmission power P is obtained through processing ref 。
7. The method for testing shielding effectiveness of a radio frequency cable in an automotive environment according to claim 5, wherein the second transmission power P is determined dut The method of (1) comprises:
the method comprises the steps that a first current clamp (8), a first impedance load (10), a second current clamp (9), a second impedance load (11) and a radio frequency cable (1) to be tested are placed on a second test table board (4), the first current clamp (8) is connected with a transmitting end of a radio frequency signal receiving and processing device, the second current clamp (9) is connected with a receiving end of the radio frequency signal receiving and processing device, one end of the radio frequency cable (1) to be tested is connected with the first impedance load (10), the other end of the radio frequency cable is connected with the second impedance load (11), the first current clamp (8) clamps one end of the radio frequency cable (1) to be tested, and the second current clamp (9) clamps the other end of the radio frequency cable (1) to be tested;
the transmitting end of the radio frequency signal receiving and transmitting processing device transmits a radio frequency signal with preset frequency through the first current clamp (8), is coupled with the radio frequency cable (1) to be tested and the second current clamp (9) and is transmitted to the receiving end of the radio frequency signal receiving and transmitting processing device, and the second transmission power P is obtained through processing dut 。
8. The method for testing the shielding effectiveness of a radio frequency cable in an automotive environment according to any one of claims 2 to 7, wherein: the radio frequency signal receiving and transmitting processing device comprises a radio frequency signal source (16), a radio frequency power amplifier (13), a preamplifier (14) and a receiving processor (15); the output end of the radio frequency signal source (16) is connected with the input end of the radio frequency power amplifier (13), and the output end of the radio frequency power amplifier (13) is used as the transmitting end of the radio frequency signal receiving and transmitting processing device; the input end of the preamplifier (14) is used as the receiving end of the radio frequency signal receiving and transmitting processing device, and the output end of the preamplifier (14) is connected with the receiving processor (15).
9. The method for testing the shielding effectiveness of a radio frequency cable in an automotive environment according to any one of claims 2 to 7, wherein: the radio frequency signal receiving and transmitting processing device comprises a vector network analyzer (17), a radio frequency power amplifier (13) and a preamplifier (14), wherein the radio frequency signal output end of the vector network analyzer (17) is connected with the input end of the radio frequency power amplifier (13), the output end of the radio frequency power amplifier (13) is used as the transmitting end of the radio frequency signal receiving and transmitting processing device, the input end of the preamplifier (14) is used as the receiving end of the radio frequency signal receiving and transmitting processing device, and the output end of the preamplifier (14) is connected with the radio frequency signal input end of the vector network analyzer (17).
10. A system for testing shielding effectiveness of a radio frequency cable in an automotive environment, for implementing the testing method according to any one of claims 1 to 4, the testing system comprising a radio frequency transmitting antenna (5), a radio frequency receiving antenna (6), a balun (7), a first testing table (3), a second testing table (4), a radio frequency cable (1) to be tested, a first calibration cable (2) and a radio frequency signal transceiving processing device.
11. A radio frequency cable shielding effectiveness test system in an automotive environment, for implementing the test method according to claim 1, 5, 6 or 7, the test system comprising a first current clamp (8), a first impedance load (10), a second current clamp (9), a second impedance load (11), a first test bench (3), a second test bench (4), a radio frequency cable to be tested (1), a first calibration cable (2), a second calibration cable (12) and a radio frequency signal transceiving processing device.
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| CN118483508A (en) * | 2024-07-11 | 2024-08-13 | 青岛海兴电子有限公司 | Automobile wire harness performance detection system based on product production quality inspection |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| CN118483508A (en) * | 2024-07-11 | 2024-08-13 | 青岛海兴电子有限公司 | Automobile wire harness performance detection system based on product production quality inspection |
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