An Ultra-Thin Metal Materials for Stable Shielding of Near- and Far-Field Electromagnetic Waves

High-speed operation of the chip in the signal transmission frequency is high will produce serious electromagnetic interference problems. Pursuing thinner, lighter and stable electromagnetic (EM) shielding materials with both near and far field shielding effects has become the most important solution. In this article, a special metal shielding framework is designed, and a near-field shielding effectiveness (SE) test method based on patch antenna is proposed. The electric field SE of silver (Ag) nanowire composite films with a thickness of about 50 nm is measured using this method. To gain insight into the difference between the near- and far-field EM shielding of ultrathin metallic materials, the theoretical values of EM shielding of ultrathin metallic materials were derived. The measurement results show that due to the unique equipartition exciton effect of metal nanowires, the near- and far-field SEs of Ag nanowire composite films can reach about 32 dB at frequencies of 2–3 GHz. In addition, the SE is more stable compared with that of copper foils or copper-nickel alloy.