Influence of Graphene Coating of the Elements in a Two-Dimensional Parabolic Mirror Consisting of Parallel Cylinders on Radio Wave Focusing

We model the diffraction of a plane TE-polarized electromagnetic wave by a parabolic structure consisting of N parallel circular cylinders, where N ∼ 50. The problem of diffraction of a plane wave by a cylinder with arbitrary coordinates of its center is solved. The coupling of individual structural elements is not allowed for in the performed calculations. The field behavior in the vicinity of the focus of the considered parabolic antenna is studied for cylinders made of a dielectric, a dielectric with a graphene monolayer, and perfectly conducting cylinders. It is found that a layer of graphene can lead to an almost twofold increase in the maximum amplitude of the field in the focus, which makes the focusing properties of the dielectric antenna rather close to those of an antenna consisting of perfectly conducting cylinders. It is shown that the field amplitude in the focus oscillates strongly as the frequency increases, and the focus itself moves slightly off the center of the reflector system. The size of the focal spot is studied as a function of the incident-field frequency, cylinder radii, and the distance between the individual reflectors. It is shown that the field in the vicinity of the considered structure has certain features, such as slow and fast oscillations of the field amplitude, which occur as the frequency of the incident wave varies.