Analysis Of EM Characteristic Of Electrically Large Complex Termination Cavity With IPO-MOM

The analysis of electrically large complex cavity is an important topic in the field of computational electromagnetics. It is meaningful to the development of stealth and anti-stealth technology, electromagnetic compatibility of electronic equipments as well as the design of some relevant microwave devices. Method of moments (MOM) is an efficient numerical method for the analyses of electromagnetic characteristics of complex objects. Aiming at efficient analyses of electromagnetics of electrically large complex cavities, some hybrid techniques are developed based on MOM, including IPO-MOM and iterative MOM. A novel hybrid approach is proposed in which iterative physical optics (IPO) technique is combined with MOM, the mathematical model of the proposed IPO-MOM is established by some approximate methods. It is applied to the analyses of electromagnetic scattering by electrically large complex cavityies. With the hybrid method, the effects of rotor-blade modulation on electromagnetic signal about the cavity with rotor-blade can also be studied. For the first time, Kirchhoff approximate formula is combined with MOM, which is applied to analyze the inner problem of the electrically large complex cavity. With this method, all kind of electrically large complex cavity can be analyzed without considering the Green function of the cavities. Lots of problems about the cavity can be solved easily. The diffraction field for the aperture fringe is analyzed by Kirchhoff formula with line integral form. With the iterative MOM, the electromagnetic field of the inner aperture and the outer aperture reach continuum. This progress considers the effects about the figure of the cavity and reduces the error which is produced by the Kirchhoff formula. The surface meshing of the cavity is accomplished automatically by triangular patch, with which iterative physical optics (IPO) subdomain-splicing technique can treat with all kinds of geometrically simple cavities. It extends the applicability of IPO and makes it possible to analyze the arbitrary electrically large cavity with complex terminal by IPO-MOM.