Calculation On Radar Cross Section Of Complex Targets

This thesis puts emphasis on studying prediction techniques of radar cross section of complex targets. Large and complex targets are studied, so do line-surface structure objects.The open-ended cavity, a very strong scatter mechanism, plays a significant role in targets'stealth technology. So it is important to research the scattering characteristic of cavities. This thesis focuses on the calculation of the radar cross section (RCS) of open-ended cavities. After a simple analysis of the methods used in calculating the RCS of open-ended cavities, iterative physical optics (IPO), as a kind of high frequency methods, is adopted for its simple physical process and easy to program. Then some improved algorithms of IPO are introduced: Forward-backward iterative physical optics (FBIPO). Finally both algorithms are applied separately to calculate the RCS of different cavities models. All results agree well with the literatures.Recently, more and more attentions are paid on the scattering problems of various kinds of wire antennas mounted on the complex-shaped PEC platform and the scattering problems of complex-shaped electrically-large PEC targets based on the theory of Method of Moments. With the development of modern antenna technology, a warship is fully equipped with various kinds of antennas working in different frequency bands, which greatly improve the ability of communication, navigation, defending and weapon control. However, the problem of simulation or prediction of EM behavior of onboard antennas is very important and urgent to be solved because the antennas will not function normally when their radiation pattern is distorted severely by the structures around. On the other hand, the RCS parameters of the targets (i.e. war ship, aero plane, etc.) will also meet all the computational difficulties mentioned above. Based on EFIE-MoM, a whole target which concludes simple shape metal model and antennas mounted on it is studied about its electromagnetic effect. A numerical electromagnetic program is developed and its correctness is proved.