The Hybrid IPO-FDTD Method For Calculating The RCS Of The There Dimension Complex Cavities

The electromagnetic scattering calculation of the inlets of aircrafts is one of the difficult problems to analytically predict the RCS of aircrafts. Compared with the wavelength of centimeter wave radar, the inlet of a aircraft is an electrically large object. Furthermore, there are complex structures such as the engine fans at the end of the inlets. It's hard to deal with such problems if we use high frequency method or low frequency numerical value method only. The hybrid IPO-FDTD method is introduced in this paper. The IPO method is used to treat the front part of the cavity, which is slowly varied. The FDTD method is used to treat the end part of the cavity, where the complex structure is involved. Coupling IPO with FDTD, we pick up "background noise" to improve numerical value precision. The data result show that this method is nicety and high efficiency.