Review of Metamaterial Enabled Electromagnetic Absorbers for Microwave to Millimeter-wave Applications.

Electromagnetic (EM) absorbers are specially designed structures that dissipate the absorbed EM energy into heat by minimizing the reflection as well as transmission. The absorbers operating in microwave and millimetre wave regimes have been found essential in applications such as radar, communication systems, EM interference prevention, and stealth technologies. Design concepts such as Salisbury, Jaunman screens, and impedance-matching layers are discussed. As a game-changing innovation in wave attribute manipulation, metamaterial behaviour provides an unprecedented command over how waves interact with matter. This review examines the significant hurdles and restrictions metamaterial absorbers must overcome, like fabrication, the tradeoff between absorption bandwidth and thickness, and material losses. Broadband absorption, tunability, and feasibility of producing thin, lightweight absorbers all contribute to their desirability for various applications. Different losses responsible for the absorption phenomena are detailed for both narrowband and broadband cases. This critical analysis highlights the enormous promise of metamaterial absorbers while emphasizing the ongoing research efforts needed to overcome the associated obstacles. Its goal is to advance state-of-the-art designs by critically assessing the existing status of the field, thereby guiding future research, development, making it easier to implement microwave and millimetre wave absorbers in a wide range of real-time applications. [ABSTRACT FROM AUTHOR]