A Multifunctional Hybrid Frequency-Selective Rasorber With a High-Efficiency Cross-Polarized Passband/Co-Polarized Specular Reflection Band

A novel multifunctional hybrid frequency-selective rasorber (MHFSR) which shows a broadband high-efficiency cross-polarized passband/co-polarized specular reflection band besides a wideband radar cross section (RCS) reduction is designed and analyzed. The passband/reflection band is realized by the bottom transmissive polarization converter (TPC) which exhibits a broadband cross-polarized transmission window for the x-polarized incidence and a co-polarized specular reflection window for the y-polarized incidence. The design methodology and four-port equivalent circuit model (ECM) are proposed and investigated. By arranging the top layer in the checkerboard-like distribution, the -1 dB cross-polarized transmission band is 9.5-11.7 GHz, and the 10 dB monostatic RCS reduction band is 2.8-20 GHz with a 151% fractional bandwidth (FBW) for the x-polarized incidence. While for the y-polarized incidence, two 10 dB monostatic RCS reduction bands locate at 3.3-8.5 and 15-20 GHz, and the middle -1 dB co-polarized reflection bands locate at 10-11.5 GHz. Meanwhile, the periodicity of the proposed MHFSR is only 0.07 lambda(L), lambda(L) is the free-space wavelength at the lowest working frequency (2.8 GHz). The experimental results of the fabricated sample agree with the simulation results well, which proves the design validity. The proposed design combines the design of FSR, diffusion-like metasurface, and TPC to present an extra cross-polarized passband/co-reflection band besides the ultrabroadband RCS reduction.