What are EMC Absorbers?
EMC Absorbers are used in an enclosed room to reduce the reflection of EM waves. These absorbers are made of such material which helps them to absorb the EM waves to give precise and repeatable test conditions for EMC (Electromagnetic Compatibility) and antenna measurements. The absorbers are given desired shape and size to suit the frequency range of the EMC testing. Many EMC testing sites prefer pyramidal-shaped absorbers. The tapered top part of the absorber allows the EM wave to reflect and gradually absorb as they penetrate.
There are two main categories of absorbers:
- Narrowband absorbers: These are flat resonant absorbers of a typical thickness ranging from 1 mm to 4.3 mm. They function within a narrow frequency band from 1.5 GHz to 24 GHz.
- Broadband absorbers: These types of absorbers are made from pyramidally shaped material that covers an extended frequency range from 50 MHz to 110 GHz. Their thickness can vary from a few centimeters to over two meters depending upon the frequency range for which they are being used.
EMC absorbers are made of various materials such as carbon-impregnated low-density Polyurethane foam, ferrite, etc. to provide excellent performance in normal incidence and off-angle incidence in an Anechoic chamber with a desirable impedance matching. These absorbers are usually weatherproof and leakproof (leakage of carbon particles) during their life cycle to provide a clean working laboratory.