  A simple model for calculating the diffraction radiation characteristics from
an ultrarelativistic charged particle moving close to a tilted ideally
conducting strip is developed. Resonant diffraction radiation (RDR) is treated
as a superposition of the radiation fields for periodically spaced strips. The
RDR characteristics have been calculated as a function of the number of grating
elements, tilted angle, and initial particle energy. An analogy with both the
resonant transition radiation in absorbing medium and the parametric X-ray
radiation is noted.
