Petal-shaped metallic mesh with high electromagnetic shielding efficiency and smoothed uniform diffraction

Abstract

Artificially structured metallic meshes have been widely used in optical transparent devices for electromagnetic interference (EMI) shielding. Traditional meshes have drawbacks such as poor imaging quality from the centralized diffraction distribution and the inferior EMI shielding efficiency. Here, we propose a petal-shaped metallic mesh with anomalistic closed-loop pattern that can effectively improve the EMI shielding efficiency by reducing the equivalent period of the mesh and, meanwhile, suppress the stray light and achieve uniform optical diffraction. By experimentally testing the EMI shielding and diffraction performance of such mesh samples, a Ku-band shielding efficiency (SE) larger than 24 dB with the maximum SE of 32.1 dB at 12.2 GHz is obtained, which is 8 dB higher than that of the classical square mesh, and an optical transmittance as high as 73.4% is achieved at the visible wavelength of 632.8 nm. Petal-shaped metallic mesh with such excellent performance may play important roles in various applications of optical transparent windows.