Cloaking Study of Metal Surface by Liquid Foam Structures in the Millimeter Range

This work is devoted to the study of the characteristics of cloaking by halp of reflection of electromagnetic waves of the millimeter range from dynamic foam structures. This topic has been studied very little because of its complexity, because dynamic foam structures are not stable, they are formed on the basis of foam-forming liquids, which means that they constantly disintegrate within a short time. This requires a very short time of measurements and processing of experimental data. The multi-frequency method of measurement and fast Fourier transformation is used for the research. The method was implemented on an experimental measuring and computing complex in the frequency range from 38 to 52 GHz. Which allows to separately study the reflection from the front and back faces of foam structure samples. Foam samples were produced on a foam generator, which made it possible to obtain structures with quasi-one-dimensional inhomogeneities in the form of bubbles. The obtained research results showed that in the range of millimeter waves, the reflection value is very small, from 0,00001 to 0,056. It is the smaller value of reflection not from the beginning of foam formation, and not at the end of its existence, but in the middle of the time existence of the foam structure. The results of the research can be useful for the development of low-reflective and cloaking coatings.