Zero reflection from metamaterial sphere

In this study spherical structure is considered and analyzed with full wave method. The plane wave radiates to the structure and the zero reflection condition is deduced as a closed formula. Two theorems and ideas are proofed mathematically, and finally some examples are presented for validating these theorems. Theorems indicate if the double negative metamaterial sphere (DNG) with an arbitrary radius and parameters (Re(ɛ₂) < 0, Re(μ₂) < 0) situate within conventional space with parameters (ɛ₁, μ₁), and ɛ₂/ɛ₁ = μ₂/μ₁ then backscattering radar cross section (RCS) of this metamaterial sphere equals zero whiles the same situation with cylindrical structure has noticeable backscattering. In addition, the bistatic radar cross section of this metamaterial sphere is constant by changing the angle φ. Both theorems are generalized to spherical multilayer structure.