چكيده به لاتين
According to performance of electromagnetic radars – transmitting the electromagnetic waves and processing of the scattered ones – reducing the radar cross section (RCS) is an important topic in stealth applications.
In this project, as one of hotspots of the targets, RCS reduction of planar metallic plates has been considered. Unlike previous studies in this area, both of monostatic and bistatic RCSs are evaluated in this work. The desired frequency bands are set to be X and Ku bands and the minimum RCS reduction level is considered as 10 dB.
In sections II&III, the conventional RCS reduction methods -based on controlling the amplitude and phase of incident waves- are reviewed. In section IV, a novel circular configuration is proposed for controlling the scattering pattern. Using the proposed structure, both of monostatic and bistatic RCSs are redused by more than 10 dB in an ultrabroad bandwidth of 92%. In section V, reducing the RCS is studied by the reflective polarization conversion metasurfaces (PCMs). A novel perfect PCM (PPCM) is proposed with a wide frequency bandwidth of 66%, which is more than previous studies in this area. The polarization conversion ratio of the proposed metasurface is more than 99% in the desired frequency band. Section VI, introduces the “digital metasurfaces” as a novel tool for controlling the scattering pattern. Combination of PPCMs and coding configuration provides a novel structure, which reduces both monostatic and bistatic RCSs by more than 10 dB in the desired frequency band. Conclusion ends this thesis.
