Analysis of the Peculiarities of the Construction and Combat Use of Decoy Enemy AIr Targets - Unmanned Aerial Vehicles With Reflectors Based on Luneburg Lenses

In the ongoing war against Ukraine, Russian troops are actively using unmanned aerial vehicles as decoy air targets to reduce the effectiveness of the air defense systems of the Armed Forces of Ukraine and increase the effectiveness of their attack drones. The use of decoy air targets in the mass barrage of attack drones distracts the attention of the air defense forces and means, provokes an increase in the consumption of anti-aircraft ammunition and anti-aircraft guided missiles. The author examines the structural design and features of the combat use of UAVs - decoy enemy air targets that use radar reflectors based on spherically symmetric Luneburg lenses as an onboard payload. The analysis of the trophy exemplars has showed that lenses of this type are made using 3D printing technology of PLA plastic in the form of a multilayer material with different permittivity parameters with partial metallization in the form of a “hat” covered with high-conductivity foil. The parameters of the dielectric are changed by controlling the density of its layers filling by selected distribution of the layer perforation. Based on the simulations, it has been shown that the use of multilayer spherical Luneburg lenses with a radius of 9-10 cm on board UAVs of the “Gerbera” and “Parodiya” can completely imitate the scattering characteristics of the Russian attack drones like a Shahed-136/131 (Geran-2/1). In order to use such lenses in the interests of the Armed Forces of Ukraine, it is necessary to control the permittivity of the layers of the printed lens by choosing the law of distribution of cubic holes. The parametric optimization of distribution should be carried out by 3D electromagnetic modeling application packages, such as Ansys HFSS. Solving such problems requires evaluation the methodology for layer-by-layer approximation of the permittivity of a lens, as well as conducting a comparative analysis design options.