Design of X-Band Bandpass Frequency Selective Surface and Optimization Using Spider Monkey Algorithm

This paper presents a novel bandpass Frequency Selective Surface (FSS) designed to operate at 10 GHz. The proposed FSS is constructed on a flexible polyimide substrate with a compact footprint of 0.233λ × 0.233λ where λ is the free- space wavelength, making it suitable for conformal and lightweight applications. The unit cell features a spoke-wheel configuration integrated within a decagonal slot, which enhances frequency selectivity and miniaturization. To optimize the unit cell parameters for improved performance, the Spider Monkey Algorithm (SMA) is employed, ensuring an optimal balance between bandwidth and transmission characteristics. The designed FSS exhibits a fractional bandwidth (FBW) of 6.8% centered at 10 GHz, offering stable frequency response. The flexibility of the polyimide substrate enables conformal integration onto curved surfaces, making it ideal for applications in aerospace, wearable technology, and adaptive electromagnetic structures. The combination of flexibility, compactness, and optimized frequency response makes this FSS a promising candidate for advanced electromagnetic shielding, filtering, and antenna applications.