What is EMI & EMC:
EMC: Electromagnetic compatibility is the ability of any Electrical or Electronic equipment to operate in its and nearby device’s Electromagnetic environment.
EMI: Electromagnetic Interference basically are the radio frequency signals that generates from any Electrical or Electronic devices or components. EMC can be divided in two parts Emission and Immunity.
Emission: Electromagnetic waves consist of a sinusoidal variation of the electric and magnetic field at right angles to each other and right angles to the direction of propagation of waves. All electronic and electromechanical devices generate magnetic field (because of switching of semiconductor components populated on the board), when current flows through them. This electric and magnetic field propagates together and results in electromagnetic emission.
Electromagnetic Emission can be categorizes in two parts-
a. Conducted Emission: It is basically refers to the emission through conduction, that can be AC or DC power line, signal lines that carries signal in electric form.
b. Radiated Emission: This is the form of emission radiates in air through device enclosure, cables associated with the device etc.
Immunity: Immunity can be defined as ability of any equipment to work in its and nearby equipment's electromagnetic environment.
As shown in the figure above, source equipment emits in the air as well as through conductive lines and victim equipment receives these electromagnetic signals and if their design is not proper they can get affected and their performance can be disturbed.