Comparative study on metamaterial-based absorbers made of alloys of titanium powders

Absorbers are important for many practical applications, from increasing the efficiency of solar cells to aerospace-oriented needs. Among the various types of absorbers, of particular interest are electrically thin absorbers based on metamaterials, suitable for use in harsh environments and being resistant to high temperatures and corrosion. The absorbers made from titanium alloys can satisfy criteria suitable for working in such extreme conditions. The main functional component of metamaterial-based absorbers is an impedance-matching layer that is made of a dense array of conductive patches. In this paper, we propose a comparative study on the absorption performance of structures composed of patches made from titanium alloys fabricated by using different (non-powder and powder) metallurgy methods. The absorber is assumed to operate in the microwave part of the spectrum. We describe in detail techniques used for preparing titanium alloys, manufacturing patches and structures based on them, as well as theoretical and experimental methods involved in characterizing such structures. We show that dense arrays consisting of patches made from titanium alloys produced by powder metallurgy methods can be used to realize efficient impedance matching between a lossy layer and free space, which makes it possible to implement electrically thin absorbers of microwave radiation.