Study of cross-sectional shapes of ideally hard cylinders to achieve invisibility for oblique incidence

In this work, the effect of the incidence angle on struts for reducing electromagnetic blockage using ideal hard cylinders in the antenna area is analyzed. Firstly, the characterization of the invisibility of a given object in terms of an equivalent blockage width is discussed. Then, ideally hard cylinders with oblong cross sectional shapes and hard surfaces for different incidence angles are analyzed. It is shown that the variation of incidence angle in azimuth is very sensitive in terms of blockage for TM polarization. Finally, design chart of ideal struts which reduce blockage simultaneously for TE and TM cases that give some performance goals for a final realized struts are presented.