Triad of Z -shaped metamaterials: achieving radar cross-section reduction at terahertz frequencies

Abstract This study presents the design, development, and performance analysis of three types of Z-shaped metamaterial unit cell arrangements operating at terahertz frequencies. These unit cells were developed to evaluate their electromagnetic responses, and corresponding coding sequences were designed using the 1-bit coding method. In this method, 0-bit and 1-bit unit cells are defined by comparing the phase responses between different unit cells. All unit cell designs, numerical analyses of S-parameters, and radar cross-section (RCS) evaluations of the coding metamaterials were carried out using the Finite Integration Technique (FIT). The S-parameter results were further validated with the Finite Element Method (FEM). The investigation was conducted over the frequency range of 0–5 THz. Additionally, the transmission coefficient and RCS values of 6 × 6 coding sequences were analyzed to compare the performance of the different Z-shaped unit cells. The results showed slight variations depending on the specific unit cell type and coding sequence. Notably, coding sequence 2, which incorporates a Z-shaped resonator inside a square-ring element, achieved an RCS reduction of –48.65 dBm 2 . Overall, the findings demonstrate that 1-bit coding metamaterials based on optimized Z-shaped unit cells with carefully designed coding sequences can effectively manipulate electromagnetic waves and provide significant RCS reduction.