1. Harm to electronic systems and equipment Strong electromagnetic interference may cause sensitive electronic equipment to be damaged due to overload. General silicon transistor emitter and base of the reverse breakdown voltage between 2 ~ 5V, it is easy to damage, and its reverse breakdown voltage with the temperature increases and decreases. Electromagnetic interference caused by the spike voltage can make the emitter junction and collector junction in a point of impurity concentration increases, resulting in transistor breakdown or internal short circuit. Transistors operating under strong RF electromagnetic fields will absorb enough energy to cause the junction temperature to exceed the allowable temperature rise and cause damage.
2. Hazards to Weapons and Equipment Modern radio transmitters and radar can produce a strong electromagnetic radiation field. This radiation field can cause installed in the weaponry system in the sensitive electronic detonation device out of control and premature start; on the guided missile will lead to deviation from the flight path and increase the distance error; on the aircraft, it will cause the operating system is unstable, heading is not allowed, the height of the display is wrong, the radar antenna tracking position offset.
3. The hazards of electromagnetic fields on the human body once the electromagnetic radiation into the human body cells and tissues to cause biological effects, that is, the local thermal effect and non-thermal effect. Non-thermal effect mechanism is more complex, to be further explored. Thermal effect depends on the peak power of radiation, but also with the frequency. In the range of 1~3GHz, the thermal effect is the most serious, and the energy absorbed by the biological effect can reach 20%~100% of the incident energy. In other frequency ranges, the energy absorbed by the biological effect is about 40% of the incident energy. Different frequencies of electromagnetic radiation on the human body is not the same degree of harm. For radiation below 1GHz, skin tissue sensory retardation, energy permeability, easy to produce deep tissue heat and damage. For 1~3GHz radiation, the human body surface tissues and deep tissues will absorb energy, such as the eye and internal tissues are very easy to damage. The thermal effect of electromagnetic fields can make the human body temperature rise, the human body over the normal body temperature, metabolism and oxygen needs quickly increase, such as temperature rise.
4. In the electromagnetic environment, the harm caused by electromagnetic interference is various, may be from the simplest annoying phenomenon up to a serious disaster. Two examples from the United States illustrate the seriousness of electromagnetic interference. Once there was a steel mill, due to the lifting of molten molten steel ladle crane control circuit by electromagnetic interference, so that a ladle of molten steel was completely out of control dumped on the floor of the workshop, and caused casualties. In another example, a disabled person with bioelectrically controlled prosthetic limbs was driving a motorcycle underneath a high-voltage power line when he lost control of the motorcycle due to interference in the control circuits of the prosthetic limbs, resulting in an unforeseen catastrophe. Of course, the above two examples are the more prominent ones. The following can also cite some electromagnetic interference may cause harm: a) Disturbance of television viewing, radio listening. In China, there have been due to plastic processing high-frequency thermal laminating machine interference with television viewing caused by residents and factory disputes. b) In the number of sub-systems and data transmission process data loss. c) In the equipment, sub-systems, or the destruction of the normal work of the system level. d) Medical electronic equipment (eg: medical monitoring motion, pacemaker, etc.) of the work of the malfunctioning. e) Automated microprocessor control systems (eg: automobile brake system, crash airbag protection system). f) Automated control systems (eg: automobile brake system, crash airbag protection system). (e) Automated microprocessor control systems (e.g., automobile brake systems, airbag protection systems) operating out of control. f) Malfunctioning of detonation devices. g) Unintentional explosions of detonation devices. h) Failure of industrial process control functions (e.g., petroleum or chemical industry). In addition to the above examples, strong electromagnetic fields can also affect living organisms, it is generally recognized that the effects can be divided into thermal and non-thermal effects. For thermal effects, with the gradual increase in RF incident power density, there can be accelerated blood flow, blood distribution less parts of the local temperature, enzyme activity, protein denaturation, heart rate changes and even thermoregulation ability to be inhibited, local tissue damage until death and so on. And for non-thermal effects. Its effects are much more extensive. These include effects on the central nervous system (e.g., metabolism of brain tissue, bioelectricity of brain tissue, etc.), on the blood and immune system, on the cardiovascular system, and on the reproductive system and embryonic development. These effects are not only at the individual and organ level, but also at the cellular level. From the above, it is clear that the deterioration of the electromagnetic environment can lead to various consequences. Developing electromagnetic compatibility research, strengthening electromagnetic compatibility management, reducing electromagnetic nuisance, avoiding electromagnetic interference, is a priority.