Frequency selective binary metasurface with two high-selectivity transmission passbands and wideband RCS reduction

The integration of multiband transmission channels with broadband radar cross-section (RCS) reduction is a pivotal yet challenging goal for advanced stealth radomes. This paper proposes a frequency-selective binary metasurface (FSBM) that synergizes a binary coding metasurface with a frequency-selective surface (FSS) to simultaneously achieve high-selectivity dual-passband transmission and wideband RCS suppression. The top-layer binary metasurface, composed of two artificial magnetic conductors (AMC) units arranged in an optimized sequence, facilitates destructive interference for broadband backscattering suppression. The bottom-layer FSS, functioning as a second-order dual-band filter with aperture-coupled resonators, provides the desired passbands and acts as a near-perfect electric conductor (PEC) reflector in the stopband to enable AMC operation. A prototype is fabricated and measured, demonstrating two transmission bands at 5.14 GHz and 7.61 GHz with low insertion loss (IL) and steep roll-off, alongside a fractional bandwidth exceeding 76.3% for -10 dB RCS reduction. This work presents a viable path forward for developing low-scattering platforms for multiband radar and communication systems.