Generally, there are two ways, one is conduction coupling and the other is radiation coupling.
Any occurrence of electromagnetic interference is bound to have the transmission and transmission channels or channels of interference energy. Generally speaking, there are two ways of electromagnetic interference propagation: one is conduction propagation, and the other is radiation propagation. Therefore, from the sensitive period of interference, interference coupling can be divided into two categories: conduction coupling and radiation coupling.
Conductive transmission must have a complete circuit connection between the interference source and the sensitive period, and the interference signal is transmitted to the sensor along this connection circuit, resulting in interference. The transmission circuit can include wires, conductive elements of equipment, power supply, common impedance, grounding plate, resistance, inductance, capacitance and mutual inductance elements.
Radiation transmission is in the form of electromagnetic waves through the ring. According to the law of electromagnetic field, the interference energy is emitted to the surrounding space. There are three common types of radiation coupling:
1. The electromagnetic wave emitted by antenna A is accidentally received by antenna B, which is called inter-antenna coupling.
2. The inductive coupling of space electromagnetic field through wires is called field-line coupling.
3. The high frequency signal induction between two parallel wires is called line-to-line inductive coupling.
In practical engineering, the interference between two devices usually involves many coupling ways. It is precisely because of the coexistence of multiple coupling modes, repeated cross-coupling and * * * interference that electromagnetic interference becomes difficult to control.