Phenomenon of anomalous diffraction radiation in the metal-dielectric grating

Conditions for occurrences of a diffraction radiation (DR) exclusively into the dielectric of metal-dielectric grating (we have named this phenomenon an anomalous DR or ADR) are shown and analyzed. Contrary to the Cerenkov radiation, an ADR may occur at ultra low electron velocities (β≪1/√ε). Electromagnetic field, energy density and other characteristics of the ADR are found as the exact solution of the strict mathematical task. A number of ADR characteristics have been calculated. The use of the ADR phenomenon is suggested for the miniaturization of diffraction electronic devices, e.g. in the design of semiconductor oscillators.