Calculation Of The Radar Cross Section For Large Open-ended Cavities

The open-ended cavity is a very strong scatter mechanism. Analysis of the electromagnetic plane wave scattered by large open-ended cavities plays a significant role in designing the stealth aircraft. This thesis focuses on the calculation of the radar cross section (RCS) of large open-ended cavities. After a simple anlysis of the methods used in calculating RCS of large open-ended cavities, the shooting and bouncing ray (SBR) and complex ray expansion (CRE) techniques are adopted. The SBR can be used in the analysis of cavities with optional forms or cavities coated with materials. The speed of CRE is much faster than that of the SBR in calculation of the RCS for two reasons. One is that it traces much less rays than the SBR does, and the other is that the far fields got by apartial optical integral in SBR is replaced by direct calculations in CRE. The following calculations of RCS of rectangular waveguide cavities and circler waveguide cavities with programs developed from the two techniques shows the advantage of CRE over SBR in speed. The caculating results agree well with the results given by other literature.