Abstract

This paper presents a highly flexible and transparent ultra-wideband (UWB) antenna based on a hybrid silver (Ag) nanonetwork (NN) electrode that simultaneously resolves the competing requirements of transparency, conductivity, flexibility, and broadband operation. The electrode is fabricated through a scalable process combining thermal evaporation, electrospun poly(methyl methacrylate) (PMMA) nanofiber networks, and ion beam etching, followed by dielectric hybridization with silver oxide (Ag2O) and molybdenum trioxide (MoO3) layers. Unlike conventional transparent conductive oxide (TCO), AgNW, and metal-mesh approaches, the fused-junction NN architecture eliminates inter-wire contact resistance, while the Ag2O/MoO3 double-insulating coating provides both index matching and electrode passivation. The optimized electrode achieves an optical transmittance of 90.74 % at 550 nm and a sheet resistance of 1.83 Ω/sq, while maintaining stable resistance down to a 1 mm bending radius and after 10,000 bending cycles. The fabricated antenna exhibits a wide impedance bandwidth from 3.2 to 10.6 GHz and a peak measured radiation efficiency of 76.4 % at 5.9 GHz. This combination of high transparency, low sheet resistance, wideband operation, and mechanical robustness is not simultaneously attained by existing transparent antenna technologies, enabling seamless integration into diverse Internet-of-Things (IoT) environments such as smart windows, transparent consumer electronics, and wearable devices.