Broadband and Broad-Angle Dielectric-Loaded RCS Reduction Structures

This paper proposes a novel broadband and broad-angle radar cross section suppression design. The planar structure comprises two metal and two dielectric layers. The principle mechanism used for backscattering reduction is phase cancellation, which is not a broadband technique in nature. Nevertheless, by loading dielectric slabs of proper thicknesses and electromagnetic properties between metal layers, three adjacent phase-cancellation frequencies can be created to synthesize an approximately 2:1 bandwidth ratio of 20 dB reduction for normal incidence. As to oblique incidence, the random patch approach is adopted for metal layers. By avoiding periodic structures, the likelihood of strong backscattering peaks is diminished. Rigorous parametric studies as well as prototype measurements were conducted to analyze and to verify the design's superb performances. On top of broadband and broad-angle backscattering suppression features, attractive characteristics of the proposed structure include planar configuration, reduced height, ease of fabrication, low cost, and sturdy structure, which are welcome for stealth platforms.