Destruction of quasiperiodic oscillations in weakly nonlinear oscillators

The results of theoretical and experimental investigations of conditions and scenarios of chaotic oscillation occurrence in active nonautomonotonous oscillators with weak nonlinearity are presented. The theoretical analysis is based on application of averaged equations. A classical resonance generator of radio-frequency range has been chosen to carry out experimental investigations. The results obtained permit to revise some representations about dynamic properties of such oscillations. General laws of quasiperiodical oscillation destruction connected with bifurcations of two- and three-dimensional torri are studied. The role of nonisochronous features of oscillators when forming their chaotic dynamic is explained. The possibility of occurrence of dynamical chaos in the weakly nonlinear isochronous van der Pole oscillator is proved