Preface:

With the rapid development of automotive intelligence and electrification, the complexity of automotive electronic systems has increased significantly, and electromagnetic compatibility (EMC) issues have gradually become an important factor affecting the reliability and safety of automotive electronic equipment. As an EMC test engineer in an automotive electronic parts company, how to accurately and effectively conduct EMC tests to ensure that automotive electronic products meet regulatory and standard requirements is an important task in our daily work. In this paper, we will take BBHA 9120D, a product of Schwarzbeck, as the test equipment, to introduce the EMC test process of automotive electronic parts, problems encountered and their solutions, and analyze in-depth the electromagnetic field theory.

Preparation before EMC testing

The first step in EMC testing is the preparation, the installation and commissioning of the test equipment and the object under test, as well as the construction of the test environment all require special attention.BBHA 9120D It's a SchwarzBeckerHigh performance broadband horn antennaThis antenna is commonly used for radiated emissions and radiated immunity testing of automotive electronics. The antenna operates in the frequency range of 1 GHz - 18 GHz, covering the key frequency bands where automotive electronics systems may be subjected to interference, and is suitable for a wide range of EMC tests.

Before formal testing, you first need to confirm that the test site meets the standard requirements. Typically, EMC tests need to be conducted in an anechoic chamber or an open area with electromagnetic shielding to ensure that outside electromagnetic noise will not affect the test results.The BBHA 9120D antenna needs to be used in accordance with the standard requirements.Antenna Mount AM9144 Mount it at the proper height and angle to ensure its maximum test sensitivity.

EMC Test Flow

  1. Selection of appropriate test standards and methods According to the specific functions of automotive electronic components, determine the applicable EMC test standards. For example, for in-vehicle electronic equipment, common standards include "Automotive Electromagnetic Compatibility Test Requirements" (ISO 11452) and "Vehicle Radiated Emission Tests" (ISO 11452) and "Vehicle Radiated Emission Tests" (ISO 11452).CISPR 25). Before testing, you need to set up all the test parameters according to the standard, such as frequency sweep range, power level, gain setting, etc.
  2. Connecting and Commissioning Equipment Connect BBHA 9120D antenna, signal source, receiver and other equipment to ensure the normal operation of the test equipment. Check whether the power system, signal input and output of the sample under test meet the test requirements. At this time, adjust the gain and direction of the BBHA 9120D antenna to ensure that it can correctly receive and transmit the test signal.
  3. Conducting Radiated Emission Tests During a radiated emission test, the BBHA 9120D will act as a receiving antenna to monitor the electromagnetic radiation generated by the product under test. During the test, the frequency range scanned is typically from 30 MHz to 6 GHz, covering the key frequency bands where automotive electronics can cause interference. Test results need to be compared with the appropriate regulatory standards to ensure that the equipment does not cause excessive interference to other electronic equipment such as in-vehicle communications and navigation systems.
  4. Radiation Immunity Test For the radiation immunity test, the BBHA 9120D antenna is used to receive electromagnetic waves from external interference sources, and to determine the stability and anti-interference capability of automotive parts in complex electromagnetic environments by analyzing their ability to withstand electromagnetic interference. In this process, special attention needs to be paid to the electromagnetic shielding effect of the test site to avoid external noise affecting the test results.
  5. Data Recording and Analysis During the testing process, all received signals and frequency scan data need to be recorded and saved in real time. By analyzing these data, it is assessed whether the automotive electronic products comply with the EMC regulations. If the test data exceeds the specified limits, design modifications or additional shielding measures need to be applied to the product.

EMC test common problems and their solutions

When using BBHA 9120D for EMC testing, some problems are often encountered, the following is a list of several common problems and their solutions:

  1. Unstable Frequency Response The response of the BBHA 9120D antenna may fluctuate during frequency sweeps, resulting in unstable test results. This is usually due to an improperly set distance or angle between the antenna and the sample under test, or the presence of strong electromagnetic noise interference in the test environment. The solution is to re-adjust the orientation and height of the antenna and ensure that the electromagnetic environment in the test area is as clean as possible.
  2. Signal Attenuation Problems During high-frequency testing, the signal may exhibit large attenuation due to the gain of the antenna and the shielding effect of the sample under test. This situation can affect the measurement results of radiated emissions, especially at higher frequencies (e.g., above 6 GHz). To solve this problem, testers need to adjust the equipment settings for different frequency bands to ensure that the signal maintains sufficient strength during transmission.
  3. Electromagnetic interference at the test site The electromagnetic environment of the test site itself may cause interference to the test, especially in some open test areas. In order to reduce the influence of external noise, it is recommended to choose a specialized anechoic chamber or a test environment with good electromagnetic shielding effect.
  4. Equipment Calibration Issues The BBHA 9120D antenna needs to be adequately calibrated before use to ensure that it operates within the accuracy range specified in the standard. If the antenna is not properly calibrated, test results may be biased and not accurately reflect the EMC performance of the product. The solution is to perform regular calibration of the equipment and to check the working condition of the equipment before testing.

concluding remarks

Completing EMC tests using standardized EMC test procedures is a key factor in ensuring the proper operation and long-term stability of automotive electronics. The BBHA 9120D antenna from SchwarzBeckert is an important tool for EMC testing of automotive electronic components due to its wide frequency band, high sensitivity and stability. When using BBHA 9120D for radiated emission and immunity testing, engineers need to operate in strict accordance with test standards and methods to ensure the accuracy and reliability of test results. Through effective testing and optimization, the electromagnetic compatibility of automotive electronic equipment can be significantly improved to ensure its normal operation in complex electromagnetic environments.

By continuously improving the testing process and solving problems that arise during testing, the automotive electronics industry will be able to produce high-performance parts that are more in line with the demands of modern automotive electrification, providing consumers with a safer and more stable driving experience.

The frequency scanning, radiation emission and immunity test links in the article all involve the basic theory of electromagnetic fields, including the propagation laws of electric and magnetic fields, antenna gain and radiation directionality. Through in-depth understanding of these principles, test efficiency and accuracy can be effectively improved, promoting the automotive electronics industry to a higher standard.