On the axial aperture electric field resonances of open-ended missile-like structures

The objective of this paper is to develop a basic understanding of the resonances in the axial aperture electric field of an open-ended body of revolution (BOR) excited via plane wave illumination. Four distinct perfectly-conducting BORs are studied in this paper: (1) a straight cylinder, (2) a straight cylinder closed on one end, (3) a tapered cylinder open on both ends and (4) a tapered cylinder which is closed on the nontapered end. The incident plane wave is assumed to be transverse magnetic to the BOR axis. The fundamental characteristics of the first three dominant aperture field resonances for each of the four BORs are presented. The surface currents which produce these resonances are also given. The axial electric field along the BOR axes are compared for four distinct models. All of the aforementioned data is given for various angles of plane wave incidence.