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. Conducted noise propagates along power lines, whereas radiated noise is emitted from power lines into the air. The main methods for reducing radiated noise are as follows.

1. Reduce the length of components and cables through which noise current flows.
2. Limit the noise current using resistance or inductance.
3. Place components and conductors that are susceptible to radiated noise at a distance from components and 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.