Cloaking in Periodic Epsilon-Near-Zero Waveguide with Smith-Purcell Radiation

The challenge of engineering and manipulating the electromagnetic (EM) properties of materials has long been a central focus in materials science and engineering. Among various strategies, materials with near-zero refractive indices have garnered significant interest due to their diverse applications in controlling EM waves. However, few studies have examined the effects of periodic arrangements on these materials. This study investigates the integration of photonic doping within a periodic epsilon-near-zero (ENZ) waveguide to elucidate the unique properties of Smith-Purcell radiation (SPR) at 5.8 GHz. By employing a structure with a relative permittivity of 37, we achieve uniform input signal phases across the ENZ medium and realize cloaking. Our findings reveal a coherent phase relationship between incident and output waves, paving the way for potential cloaking applications that prioritize fabrication simplicity and cost-effectiveness, even in hard-to-reach regimes. This research not only enhances our understanding of periodic ENZ structures but also opens new avenues for innovative applications in electromagnetic wave manipulation.