Analysis and optimization of electromagnetic scattering characteristics of two-dimensional metal airfoil covered with metamaterial

Airfoil is one of the strong scattering sources of aircraft, so it is of great significance to study the stealth characteristics of airfoil for the reduction of the radar cross section of the whole aircraft. As is known, the airfoil of aircraft is the main component that generates lift. Shaping the airfoil will reduce the aerodynamic performance of the aircraft. However, the emergence of metamaterials allows aircraft designers to achieve a good balance between stealth and aerodynamics. Considering the high cost of stealth test, numerical simulation is proposed to guide the design of metamaterial stealth. Then, the bistatic radar cross section (RCS) of airfoil covered with metamaterial is researched in this paper. We employ the 2-D auxiliary differential equation finite-difference time-domain (ADE-FDTD) to simulate the airfoil’s stealth characteristics. The two-dimensional situation can be regarded as a special approximate when electromagnetic waves are perpendicularly incident on the three-dimensional infinitely long airfoil. The tuning parameters including coating thickness, Drude frequency and collision frequency are considered on the airfoil’s bistatic RCS. The calculation program verified its correctness by simulating the perfect lens characteristics of electromagnetic waves propagating in the metamaterial plate. The numerical experiments show that the meta-material Drude frequency and collision frequency mechanism are more complicated than the coating thickness. The dual-station RCS increases at some angles and decreases at other angles than metal airfoils. But by choosing appropriate metamaterial parameters, airfoils with excellent stealth effect can be obtained.