Understanding Metasurface-Based Microwave Absorbers Using Transmission Line Theory

In this chapter, the concept of Metasurface-based microwave absorbers is introduced using the foundations of applied electromagnetics and transmission line (TL) theory. First, some historical perspectives on the microwave absorbers and their applications in Anechoic chambers for a wide range of antenna measurements are provided. Next, the operating principles of Salisbury screen and Jaumann absorbers are explained with relevant analytical computations and numerical examples. After that, the importance of high impedance Metasurfaces in the synthesis of electrically thin microwave absorbers is highlighted with elaborate discussions on the underlying physical mechanism. Furthermore, the equivalent circuit models for narrowband and wideband Metasurface Absorbers are developed using TL model. Finally, the aspects of Radar Cross Section (RCS) reduction using Metasurface absorbers are demonstrated using CST Microwave Studio simulations.