Interaction of high-frequency and low-frequency oscillations: Threats and benefits

We review the effects caused by the interaction of high-frequency (HF) and low-frequency (LF) oscillations. The formation of chaotic instabilities and the LF to HF transformation are considered as the most important manifistations of such interection. The roads to chaos and properties of chaotic oscillations are illustrated by considering the destruction of both trains of pulses in a nonlinear oscillator and a harmonic oscillation in a two-mode system. We propose a novel method of the generation of HF oscillations by using a LF pumping of two coupled linear oscillators. A theory of such generation mechanism is proposed, and its feasibility is proved experimentally. Although the experiment has been performed at the frequences around 20 MHz, the discussed solution is especially interesting for the development of generators for much higher frequencies.