© T.M. Zaboronkova, E.A. Shorokhova

The electromagnetic wave backscattering by metallic thin loop with a local nonlinear load has been studied in the approximation of weak nonlinearity. The loop is located into uniform free space nearby a water or an earth plane interface. We consider a plane electromagnetic wave of TM - polarization which incidents from the vacuum on the earth or water interface at the some angle as sounding signal (SS). The voltage-current characteristic of the nonlinear element is assumed to be described by a third -degree polynomial. There has been given the numerical calculation results of nonlinear scattered signal at second and third SS harmonics as function of different parameters, such as sounding signal incident angle, the medium permittivity, the diode location on the loop, the distance between the antenna and observation point, the distance between the loop and medium interface. In particular, the calculations have shown that the back scattered electric field at SS harmonic weakly depends on the value of medium permittivity and there is mainly determined by the distance between the antenna and interface. The obtained results can be used for development of nonlinear markers for nonlinear radar system.