The electromagnetic scattering characteristics for spherical converging flap nozzle (SCFN) were studied using the methods of iterative physical optics and equivalent edge current. A study on the structure and scattering mechanism of electromagnetic scattering

spatial distribution characteristic of scattering field

and frequency characteristics of scattering for SCFN was presented. The scattering characteristics of electromagnetic wave for SCFN in middle state and maximum state on yaw plane and pitch plane were separately calculated and analyzed. Studies show that the edge diffraction field contributes to the whole scattering field in large angles under vertical polarization. The more frequently electromagnetic wave incidence enters

the more intense the nozzle backscatters

and the more sensitive the radar cross section distribution is to the attitude angle.