Electromagnetic wave is a wave type wave composed of electric field and magnetic field as shown in Figure 1 below.
These electromagnetic waves are divided into various waves, and the frequency range considered by the electromagnetic wave absorber is 3KHz to 300GHz.
In addition, electromagnetic wave noise means unwanted noise that occurs when generating or transmitting a desired electromagnetic wave signal. Such noise is divided into conducted noise and radiated noise according to the noise transmission path, and among them, electromagnetic wave radiation noise is effectively blocked as a possible method, use an electromagnetic wave absorber.

Figure-1

RF Frequencies

Path of electromagnetic noise

Conduction Noise and Radiation Noise

• Conducted noise is propagated along with the flowing current.
• Radiated noise is when noise generated inside and outside the device is transmitted in the form of electromagnetic waves to other places in the air to cause interference.