Design and validation of a novel 2.5‐D miniaturized FSS with angular and superior polarization stability for mobile technology

Abstract This paper presents a novel 2.5D miniaturized frequency‐selective surface (FSS) measuring 6.1 mm × 6.1 mm, designed to effectively shield smartphones and tablets from unwanted electromagnetic radiation. The FSS is notable for its stable attenuation peaks in the high‐frequency stopband under transverse magnetic (TM) polarization, offering dual‐frequency response and exceptional angular stability in both transverse electric and TM modes. An equivalent circuit analysis, prototype fabrication, and empirical evaluation confirmed its effectiveness. The prototype exhibits superior polarization stability and minimal peak attenuation reduction of just 1.9 dB (10%) across a 0°–60° incidence angle, outperforming similar studies.