Evaluation and discussion of electromagnetic wave radiation

The impact of electromagnetic radiation environmental pollution on the reliability of electronic products emphasizes the need to ensure the reliability of electronic products. In addition to the product`s requirements for temperature, humidity, dust, vibration and other conditions in the use environment, attention should also be paid to the working environment of electronic products. The degree of electromagnetic radiation pollution to avoid unnecessary losses. With the rapid development of science and technology and the electronics industry nowadays, various digital and high-frequency electronic and electrical equipment radiate a large number of electromagnetic waves of different wavelengths and frequencies to the space when they are working, resulting in new environmental pollution-electromagnetic interference (EMI) and Radio Frequency Interference (RFI). At the same time, electronic components are also developing in the direction of miniaturization, light weight, digitization and high-density integration. The sensitivity is getting higher and higher, and they are susceptible to malfunction due to external electromagnetic interference. Electronic instruments and precision equipment are exposed to radar radiation. The problem of interference, leading to the failure or damage of electronic instruments and precision equipment is becoming more and more serious. The computer room and the computer powered on by the radar can still be affected by serious interference, which affects its normal operation; TV room, TV signal (image and sound) Severe interference affects normal viewing; TV signals, communication signals, cable broadcasting and telephones within 2km of the 1.6 radar position are all interfered to varying degrees.

How to use scientific data as the basis to solve the problems faced, the interference of radio frequency radiation to computers comes from two sources. One way is that the electrical noise interference of the radiation field enters the computer directly. Experiments show that when the field strength reaches 5v/m, the computer system will definitely make mistakes. Electromagnetic interference is enough to change the value of the CPU program counter PC, causing the microcomputer to mistakenly "jump" out of the executing program, especially for small signal circuits such as magnetic tape, etc. The impact is great, and the memory cannot work normally when the field strength is 15v/m. Electronic products are affected by radar radiation and cannot work normally, resulting in the destruction of components. The fundamental cause of the electronic product`s working environment is that the radiation field is too high. All electrical appliances and electronic equipment will have intermittent or continuous voltage and current changes during operation, resulting in Electromagnetic energy is generated in different frequencies or between a frequency band, and the corresponding circuit will emit this energy into the surrounding environment. These high-frequency interferences between instruments are electromagnetic interference (EMI). Electromagnetic compatibility (EMC) refers to "the performance of a device, equipment or system, which can make it work normally in its own environment and at the same time will not cause strong electromagnetic interference to any other equipment in this environment. There are two ways to EMI Leaving or entering a circuit for radiation and conduction. Signal radiation leaks out through slits, slots, openings or other gaps in the housing; while signal conduction leaves the housing by fusing to power, signal and control lines, in an open space Free radiation, thereby causing interference.

A lot of EMI suppression is achieved by combining shell shielding and slot shielding. Most of the time, the following simple principles can help achieve EMI shielding: reduce interference from the source; isolate and enhance the interference generating circuit through shielding, filtering or grounding Anti-interference ability of sensitive circuits, etc. The electromagnetic interference generated by electromagnetic radiation not only affects the performance of electronic products, but also the electromagnetic pollution caused by this will cause serious harm to humans and other organisms. To this end, international organizations have proposed a series of technical regulations that require electronic products to comply with strict magnetic susceptibility and emission standards. Products that comply with these regulations are called EMC with electromagnetic compatibility. Electromagnetic compatibility (EMC) refers to "the performance of a device, equipment or system, which can make it work normally in its own environment and at the same time will not produce strong electromagnetic interference with any other equipment in this environment. All electrical and electronic equipment During operation, there will be intermittent or continuous voltage and current changes, resulting in electromagnetic energy within different frequencies or between a frequency band, and the corresponding circuit will emit this energy into the surrounding environment. These high-frequency interferences between instruments Electromagnetic interference (EMI). EMI has two ways to leave or enter a circuit to radiate and conduct. Signal radiation leaks out through slits, slots, openings or other gaps in the housing; and signal conduction is fused to power and signal Leave the enclosure with the control line and radiate freely in an open space, thereby causing interference. A lot of EMI suppression is achieved by combining enclosure shielding and slot shielding. Most of the time, these simple principles can help achieve EMI shielding: Reduce interference from the source; isolate the interference generating circuit through shielding, filtering or grounding, and enhance the anti-interference ability of sensitive circuits. To ensure the reliability of electronic products, the most effective method is to create a suitable electromagnetic working environment for electronic products. To solve these problems, electromagnetic radiation composite absorbing materials (10-28dB attenuation) can be used .