Twist‐Tuned Strong Coupling in Sub‐GHz Wire Metasurface Bilayers

ABSTRACT Twist‐angle control offers a bias‐free route to reconfigurable metasurfaces, yet its extension to deeply subwavelength resonant platforms at VHF/UHF remains limited. We demonstrate a sub‐GHz double‐layer wire metasurface formed by two identical wire grids separated by a gap , with in‐plane rotation as the sole tuning parameter. One‐port, loop‐coupled measurements supported by full‐wave simulations reveal twist‐driven hybridization of the dominant resonant manifold into in‐phase (symmetric) and out‐of‐phase (antisymmetric) branches. For small , the lower hybrid resonance redshifts continuously from MHz to MHz ( tuning), enabling compact, twist‐programmable resonant surfaces. Simulations further show that twisting imprints moiré‐like magnetic near‐field super‐modulations whose dominant electromagnetic superperiod is obtained directly from field maps and can deviate from the geometric moiré scale. From resonance frequencies, linewidths, and normal‐mode splitting extracted from the complex response, and interpreted within a minimal coupled‐resonator picture (yielding effective coupling parameters), we obtain normalized coupling up to with cooperativity exceeding unity over broad angular ranges, meeting the resolved‐splitting criterion. The rapid collapse of tunability at larger confirms the near‐field origin of the interaction.