Theory And Application Of RF / Microwave Absorbers

Absorbers in the RF/microwave realm are materials that attenuate the energy in an electromagnetic wave. Absorbers are used in a wide range of applications to eliminate stray or unwanted radiation that could interfere with a system’s operation. Absorbers can be used externally to reduce the reflection from or transmission to particular objects and can also be used internally to reduce oscillations caused by cavity resonance. They can also be used to recreate a free space environment by eliminating reflections in an anechoic chamber.

Absorbers can take many different physical forms including flexible elastomers or foam or rigid epoxy or plastics. They can be made to withstand weather and temperature extremes. Absorbers have become a critical element in some systems to reduce interference between circuit components. This paper will attempt to cover all aspects of absorbers from basic theory through absorber applications and types plus testing methods.