Nonlinear electromagnetic wave scattering by loaded dipole antennas

Summary form only given. The present report is devoted to a study of the electromagnetic wave backscattering by dipole antennas with local nonlinear load. We consider the processes in the approximation of a weak nonlinearity that permits using only first harmonics in the field spectral representation as dependent on the type of nonlinearity. For example, for a nonlinear contact of two metals via an oxide film the highest intensity has the spectral component at the third harmonic and for the semiconductor diode at the second harmonic. We have studied two model problems of nonlinear scattering, the results of which can have a useful application. The first problem is the scattering of plane electromagnetic waves by different systems of nonlinear oscillators placed in free space. The second is the influence of an air-soil boundary on the backscattered field from loaded dipole located near the interface. The experimental measurements in all the mentioned cases have been carried out under field conditions at the special automated facility. The experimental data and the corresponding. theoretical calculations are in qualitative and quantitative agreement.