DEFINING THE FREQUENCY DEPENDENCIES OF THE RADAR CROSS SECTION OF LENS SIMULATORS OF AIR TARGETS FOR VARIOUS DIELECTRIC MATERIALS

The main characteristic of air attack weapons, such as radar targets is their radar cross section. This parameter characterises the reflective properties of the target and determines its energy characteristics in terms of secondary radiation at the reception point and does not depend on the intensity of the primary wave. One of the most acceptable and promising passive simulators of the radar cross section of air targets in the radar wave range is the multilayered Luneburg lens. However, when manufacturing spherical lens-based simulators as multilayer structures, the discreteness of dielectric permittivity and additional technological errors lead to a reduction in their radar cross section compared to theoretically achievable values. A methodological approach has been proposed to evaluate the influence of these factors on the deviation of the actual radar cross section of lens-based simulators from their theoretical values. An algorithm for a computational and experimental method has been developed to estimate the real values of the radar cross section of passive simulators based on multilayered spherical Luneburg lenses using anechoic chambers. The measurement and evaluation of the real radar cross section of lens-based simulators rely on a reference reflector in the form of a metal sphere with a known radar cross section. The experimental results demonstrated that the reduction in radar cross section of air target simulators compared to theoretical values depends on both the dielectric material (such as PET and PETG) and the irradiation frequency. The average radar cross section reduction coefficient for simulators made of PET-type dielectric material is approximately 2.9 dB. The obtained research results will be used in practice in the design of compact and cheap air target simulators with specified reflective characteristics, as well as in the creation of false targets that complicate the work of enemy air defenses.