Cherenkov Effect and Narrow-Line VHF Oscillations in a Ferrite-Filled Coaxial Line

The paper presents results of a new set of numerical simulations, plus first experimental data concerning excitation of lasting VHF oscillations by an electromagnetic shock which travels through a coaxial guiding structure. The structure is characterized by radial nonuniformity of its filling material and a nonlinear electrodynamic response of the gyrotropic fraction of that (ferrite). The physical effect underlying the excitation is the Cherenkov-type speed synchronism between the driver (the shock wave) and the wave mode existing in the ferrite medium.