ABSTRACT
The increasing demands of electromagnetic compatibility (EMC) for electronic devices with various electromagnetic environments have greatly augmented the number of applications, which require electromagnetic interference (EMI) absorbing materials in frequencies ranging from the kilohertz to gigahertz of micrometer and millimeter waves. Conventional conductive shielding materials, such as metal gaskets, conductive foams, and board-level shields, become less effective at increased frequency range. EMI absorbing materials differ from conductive materials. Rather than harnessing, capturing, and grounding the EMI energy, absorber materials are designed to attenuate and absorb electromagnetic energy and convert the absorbed energy into heat. In fact, the design for absorbers has been incorporated with different loss mechanisms over wide bandwidths. Therefore, absorbers come with many different shapes and structures from thick pyramidal structures to single coatings and multilayer materials.
