Reconfigurable RCS Reduction from Curved Structures Using Plasma Based FSS

Abstract

The radar cross section (RCS) reduction from curved surfaces using plasma based frequency selective surfaces (FSS) is investigated. A frequency reconfigurable plasma based FSS unit-cell element with target-shaped structure is proposed. The operating frequency of the FSS is governed by the plasma ionization degree (i.e. plasma frequency). zero crossing frequency of the FSS unit-cell has a tuning range extending from 9.6 GHz to 11.3 GHz with an average bandwidth of 1.1 GHz. Planar and curved metallic surfaces are investigated. The curves structures include cylindrical (convex and concave), and spherical (convex and concave) surfaces. Single ionization source is applied at the rare end of the plasma FSS array design is optimized to maintain uniform plasma flow over the metallic surfaces by applying a single ionization source at the rare end of the array. The plasma FSS arrangement with ωp = 9 × 1011 rad/Sec loading a planar sheet reduces the RCS by 23 dB at 10.2 GHz and the (− 5 dB) frequency band of 14.7% for planar plate compared with the unloaded plate case. Different hybrid arrangements are investigated for wideband RCS reduction of 36.4% by superimposing reduction bands of three different plasma frequencies. A 21.5 dB reduction is achieved at 9.8 GHz for FSS arrangements (III). The effect of changing the radii of curvature for convex and concave cylindrical and spherical metallic surfaces is studied at different plasma frequencies. A full-wave analysis of the loaded metallic plates with plasma FSS is used to calculate the backscattered and bistatic RCS for different surfaces.