Abstract: The backward diffraction on the shadow area of aircraft and its components having low radar-cross-section(RCS)is one of the main contributions of their RCS.If the backward diffraction is curbed effeetively,the RCS can forther be redueed.With the aid of geometric diffraction theory and equivalent electromagnetic current method,the mechanism of camber and edge diffraction on the shadow area for equal-section low-RCS fu selage is analyzed,a method to calculate the RCS of the backward diffraction is proposed,and examples of numerical analysis are given.Through experiments,it is proved that the analysis method proposed is appropriate for the vast majority of the equal-scction low-RCS fuselage.

Key words: fuselage, diffraction, shadows-area, radar cross sections