Design and development of fluidic frequency-agile polarization-dependent FSS using FDM-based 3D-printing

Abstract A fused deposition modeling (FDM)-based polarization-dependent frequency-agile Frequency Selective Surface using distilled water is proposed in this paper. The FSS consists of a periodic array of vertically meandered square loops with two rectangular fluidic cavities embedded within the substrate. The resonant frequency is dynamically tuned across three distinct operating states by selectively filling one or both embedded cavities with distilled water, achieving a 47.42% tuning range in TE mode (2.15–3.45 GHz) and a 10.28% range in TM mode (3.32–3.68 GHz). An equivalent circuit model is developed to explain this tuning behavior by emphasizing the impact of fluid-induced permittivity changes in the substrate. Experimental results from a fabricated prototype validate the simulated performance, demonstrating angular stability up to 45 ∘ . The proposed geometry is low-cost, lightweight, and energy-efficient, making it ideal for integration into adaptive communication systems, reconfigurable antennas, and electromagnetic shielding applications.