Simulation of electromagnetic scattering by the structure of two perfectly conducting three-axes ellipsoids

The problem of electromagnetic scattering by a structure of two perfectly conducting three-axes ellipsoids is solved in the resonance frequency range by means of the discrete sources method. The gist of the method to be used is the following. The unknown scattered field in the outer medium D_e is represented as a sum of the fields of the pairs of auxiliary elementary electric dipoles placed at the points {M^}^ and {M_n;2}^Nj on the auxiliary surfaces S_e1 and S_e2 introduced inside each ellipsoid; N₁ and N₂ are the numbers of dipole pairs on S_e1 and S_e2, respectively. The form of auxiliary surface is similar to the form of ellipsoid's surface, and electric dipoles are oriented tangentially to the auxiliary surfaces. This way, we have the following representations for scattered field {E_e,H_e}: f N₁ N ₂ 1 N₁ N₂ Ee (M) = (i / MSe )j J V X (V X Пn,i ) + J V X (V X Пn,2 ) | , He (M) = J V X Пщ + JV X Пn,2, [n=1 n=1 ^J n=1 n=1 Пn,1 = Ye(M,M^n¹, П= Ye(M,M, % (M,M_пЛ) = expO^R^ )/(4Rm,,1 ) , %(M,Mn,2) = exp(ikeRMM„,₂)/(4Rm„,₂) , p" ¹ = p.¹ + p";¹?" ¹, p"² = p\ ^ ² + p^Z² Here M e D_e, k_e = <»^/s_e|_e is the wave number in the outer medium D_e; R_MMn; is the distance from the point M_n1 on S_e1 to the point M in D_e; R_MMn2 is the distance from the point M_n,₂ on S_e2 to the same point M in D_e; pⁿ¹,pⁿ¹(n = 1,N₁) and p"²,p"^,2(n = 1,n₂) are unknown complex constants (dipole moments). The chosen representa- ^т1 ^т2 ^т1 ^т2 tions of the field satisfy to the Maxwell equations and radiation conditions. To find the unknown dipole moments of the auxiliary dipoles, we use the boundary conditions on the ellipsoid's surfaces which are satisfied according to the collocation method. Based on the method described above, we developed a computer program for calculating the scattered-field components. To verify results produced by developed computer program, we have compared theirs with known results for structure consisting of two spheres. At last, we present some results concerning the influence of structure form deviations from axisymmetric one on scattering cross-section. In particular, it is discovered even if these deviations are small, their influence on scattering cross-section can be significant, especially in the lateral scattering directions.

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