Abstract
A reflective dual-band linear-to-circular polarizer for C and X-band application is presented. The proposed elliptical Frequency Selective Surface (FSS) is capable of enhancing the polarization control and minimizes the cross-polarization compared to traditional circular or square geometries. The linear-to-circular polarization is achieved through two elliptical apertures, where each shape generates orthogonal modes with a 90° phase shift. The inner element targets higher frequencies while the outer element handles lower frequencies, enabling efficient polarization conversion across both bands. The proposed unit cell comprises 14 mm × 14 mm and is fabricated on Rogers RT5880 substrate. It exhibits a reflective polarizer at a center frequency of 7.70 GHz with a bandwidth of (7.64-7.76 GHz) and other at 9.42 GHz with a bandwidth of (9.27-9.57 GHz), respectively. In the proposed FSS, the 7.70 GHz exhibits LH-CP, and RH-CP conversion is provided at 9.42 GHz. In addition, an axial ratio of the FSS of (< 3 dB) demonstrated a circular polarization with a polarization conversion ratio (PCR) of 99.9%. In addition, an equivalent circuit model (ECM) of a reflective polarizer has been verified. Furthermore, angular stability of the FSS can be achieved at various incident angles at 0°, 30°, 60°, and 90°. The polarization conversion operates in frequency bands of C-/X, suitable for wireless systems, radar systems, electromagnetic shielding, and satellite communications.