Radiated noise

Noise can be broadly classified into normal mode noise and common mode noise, each of which is further divided into conducted noise and radiated noise. While conducted noise propagates along power lines, radiated noise is emitted from power lines into the air. The main countermeasures for radiated noise are as follows:

1. Reduce the length of components or cables through which noise current flows.
2. Limit the noise current using resistors or inductance.
3. Place components or conductors susceptible to radiated noise at a distance from components or cables carrying noise current.
4. Lower the frequency of the noise current.
5. Adopt a soft switching method.
6. Add a capacitor in parallel with the main switch.