Design of 1-Bit Coding Engineered Reflectors for EM-Wave Shaping and RCS Modifications

In this paper, the engineered reflectors are designed and characterized for cross polarization rotation, RCS modification, and EM-wave shaping at W-band. The multiple plasmon resonances, cross-polarization rotation, reflection phase cancellation, and coding sequence principles are combined together to design the presented reflectors. First, an anisotropic unit cell consisting of a two E-shaped metallic resonators on the top side of a PEC-backed dielectric substrate is precisely designed and optimized. The unit cell operates in a linear cross-polarization scheme from about 86 GHz to 94 GHz and has multiple plasmon resonances at 86.5 GHz, 89.2 GHz, 92.2 GHz, and 93.2 GHz with 100% cross-polarization conversion efficiency at these frequencies. Then this unit cell and its mirrored unit cell are used to compose a number of 1-bit coding reflective engineered reflectors to generate the “1”and “0”elements of the coding sequence required for EM-wave shaping. Four engineered reflectors of various coding sequences are designed to shape the backscattered energy to achieve one lobe, two lobes, three lobes, and four lobes. Furthermore, the low-scattering diffuse reflection pattern is also achieved under both normal and oblique incidence by using a random distribution (random coding sequence) of the unit cells across the engineered reflector aperture. Both 3D full wave simulations and measurement results verify the capability of the presented surfaces in shaping the backscattered EM-wave.