Based on the technology analyses of strengthening reinforced concrete beams with carbon fiber sheet, and the research of calculate theory, The paper raises the technology of Relief method.

Effects of the dielectric loading on the transmission properties of frequency selective surfaces(FSS) were preliminarily explored by experiment, especially in the thickness, loading patterns of the dielectric and the sensitivities of the forementioned parameters to the varying angle of incidence.

The in-band transmission loss of one side dielectric loading is induced mainly by a mismatch loss or by a dielectric loss that depend on the dielectric thickness and the way of dielectric loading.

The gain computation for the traveling wave tube with dielectric-loaded rectangular waveguide grating;