DEVELOPMENT OF A METHOD FOR SPHERICAL APPROXIMATION OF LUNEBERG SPHERICAL LENSES

The use of a Luneberg lens allows you to significantly increase the effective scattering surface of unmanned aerial vehicles, thus simulating more significant targets. This effect is achieved by smoothly decreasing the dielectric constant from the center of the lens to its edge. It is quite difficult to manufacture a classic Luneberg lens with a continuous law of change of the dielectric constant (refractive index) along its radius. In practice, to ensure a decrease in the dielectric constant of a spherical Luneberg lens as its radius increases, they switch to a stepwise approximation of the law of change of the dielectric constant using a multilayer lens design. The technical implementation of a multilayer spherical Luneberg lens is carried out by dividing it into layers with different dielectric constants, which increase from the outer radius of the sphere to the center. Within one layer, the dielectric constant remains constant. To implement the stepwise approximation of the law of change of dielectric permittivity, various methods of layer-by-layer approximation of the body of a spherical Luneberg lens are used. The following methods of dividing the lens into layers are possible: uniform division by refractive index; uniform division by dielectric permittivity; uniform division by radius. A method of layer-by-layer approximation is proposed for different methods of dividing the lens into layers and algorithms are presented. The average absolute error of approximation is chosen as the criterion for the effectiveness of the approximation of the stepwise approximation of the law of change of dielectric permittivity to the theoretical one. The conducted studies have shown that the best approximation of the dielectric permittivity to the theoretical law of change is ensured by uniformly dividing the Luneberg lens into layers by radius. For a six-layer spherical Luneberg lens, the absolute error in the approximation of the dielectric constant to the theoretical value with a uniform distribution along the radius is no more than 0.0663 (6.7%).