Ultra Wide Band RCS Optimization of Multilayerd Cylindrical Structures for Arbitrarily Polarized Incident Plane Waves

Abstract

Abstract-The addition theorems are applied to analyze the normal incidence of plane waves onto infinitely long conducting or dielectric circular cylinders with multilayer coatings made of common and uncommon materials (ε r , µ r , σ) with the objective of minimization and maximization of radar cross-section (RCS). TE, TM and circular polarizations of the incident wave are considered. Optimization of RCS by the method of least squares leads to the determination of layer thicknesses and the material complex permittivities and permeabilities. A sensitivity analysis of RCS with respect to the geometrical and material parameters of the multilayer coated conducting cylinder is also performed. It is observed that broadband reduction of RCS is mostly achievable by a combination of conventional materials (ε r , µ r > 1), and unconventional materials (0 < ε r , µ r < 1) and lossy materials (σ > 0). It is seen that RCS reduction is due to the diversion and dissipation of radar signals. The results agree very well with the experimental and theoretical data available in the literature.

COMBINATION OF MLS , GA & CG FOR THE REDUCTION OF RCS OF MULTILAYERED CYLINDRICAL STRUCTURES COMPOSED OF DISPERSIVE METAMATERIALS

“…The RCS is drawn in 3-D in Fig. 23 in [9] as a function of ε r and µ r for their values of 0.05 to 30 at frequency f = 5 GHz and normal incidence of a TE plane wave. It is seen that there are many extrema in this complex figure, which make the process of optimization very difficult.…”

“…We use the combination of common materials and metamaterials designated as Double Positive (DPS), Double Negative (DNG), ε Negative (ENG) [7], and µ Negative (MNG) [8] as RAM for the reduction of RCS. In many studies the quasi-static values of ε and µ are used [9], which are constants at all frequencies. However, here we use their various dispersive relations, which lead to accurate results in the entire frequency spectrum.…”

“…The frequency spectrum for RCS is divided into three regions [3]: (1) Low frequency or Rayleigh region; (2) High frequency region (or visible light); (3) The middle frequency region or resonance region, where the object dimensions are comparable with the wavelengths and the common low frequency and high frequency approximations are not applicable. Computation of radar cross-section in the middle frequency range requires the application of full-wave numerical techniques, such as MOM, FDTD, TLM, FEM, etc [8,9]. Several studies have been performed for the analysis of electromagnetic and optical scattering of layered cylinders composed of isotropic and anisotropic materials and also arrays of such structures in various configurations [10][11][12][13][14].…”

Application of Double Zero Metamaterials as Radar Absorbing Materials for the Reduction of Radar Cross Section

“…The DZR metamaterials are first assumed dispersionless and then the computation is extended to dispersive media. We use the full-wave matrix method for the analysis of this structure [15][16][17][18] and present several examples of plane wave incidence on it [19][20][21]. Subsequently, we study the applicability of DZR metamaterials for the fabrication of radar absorbing materials (RAMs) for the reduction of radar cross section (RCS) of various objects [22][23][24][25][26][27], coating the interior walls and objects inside anechoic chambers, design of antennas with low side lobe levels and protection against electromagnetic interference in high speed circuits.…”

Using Genetic Algorithm to Reduce the Radar Cross Section of Three-Dimensional Anisotropic Impedance Object

“…Radar cross section (RCS) reduction of various objects is the key technique in radar counterwork and is of great importance in military fields [1][2][3][4][5][6][7][8][9][10][11][12][13]. Two major means for radar cross section (RCS) reduction is shaping and radar absorbing material (RAM) coating.…”