High Optical Transparent and Shielding Effectiveness Using Metal Mesh and Saltwater for Transparent EMI Shielding Applications

Optically transparent electromagnetic applications, such as EMC windows, require high optical transparency (OT) while maintaining good electrical performance which is difficult to achieve due to trade-off between them. This paper presents a feasibility study on transparent electrodes (TE) for transparent EMI shielding applications. The proposed TEs are metal mesh film and saltwater representing solid and liquid TEs, respectively. The electrical and optical characterizations of the TEs are experimentally investigated with good agreement to numerical simulation. The MMF shows an average OT of 68.4% and strong SE of 31.4 dB, whereas the saltwater has an excellent average OT of 91.8% which is significantly higher than the conventional TEs. Moreover, the SE of planar saltwater is maintained above 22 dB with only 3 mm of thickness at the C-band (salinity 200 ppt) and it can be significantly improved by an increase in the thickness of the planar saltwater. The results prove that the proposed TEs can be considered as potential candidates for transparent electromagnetic shielding applications for different purposes.