The development of 5G technology will bring more reliable and lower latency information interaction, human-machine communication will be smoother and more convenient, and the Internet of Things will also play a more important role in daily life, industrial production and the construction of smart cities . At the same time, the innovation of communication technology will also make the surrounding electromagnetic environment more complicated, which puts forward higher requirements for electromagnetic protective materials, especially electromagnetic protective materials that are transparent to visible light. The development trend of 5G to millimeter wave technology with larger bandwidth and higher transmission speed puts forward higher requirements for the existing transparent electromagnetic protection material system in terms of protection bandwidth, working band, visible light transmittance and electromagnetic shielding effectiveness. And greater challenges.
In response to this problem, the flexible optoelectronic materials research team of Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, based on the previous ultra-thin metal research, through material optimization and structural design innovation, while introducing optical antireflection and Fabry-Perot interference These two mechanisms, as shown in Figure 1, achieve a peak transmittance of approximately 90% close to the substrate material in the visible light band, and achieve electromagnetic shielding of about 60dB in the ultra-wide frequency range of 10-40GHz. efficacy. The current team is working hard to further improve its key technical indicators, and at the same time carry out pilot production of the material. Completed the technical verification from a laboratory sample of 100mm×100mm to a pilot test with a width of 600mm. As shown in Figure 2, it has the ability to supply small quantities, and its effectiveness and stability have also been obtained in the application of radio frequency devices. It was confirmed.
A transparent electromagnetic protective material that can achieve a visible light 550 nanometer wavelength transmittance close to 90% and an electromagnetic shielding efficiency of 60dB in the 10-40GHz frequency band
The main academic results of the above work were recently published in the journal ACS Applied Materials & Interfaces (ACS Appl. Mater. Interfaces 2020, 12, 26659) under the title "Record-high transparent electromagnetic interference shielding achieved by simultaneous microwave Fabry–Pérot interference and optical antireflection" -26669. ), and was pushed by the magazine's official website. The tweet commented that the work was "Breakthrough on transparent broadband electromagnetic interference shielding materials!". This work has been strongly supported by the "13th Five-Year" equipment pre-research field fund key projects, the National Natural Science Foundation of China, and other projects, and also received technical support for electromagnetic compatibility testing of the cooperation unit National University of Defense Technology.
Original link: https://dx.doi.org/10.1021/acsami.0c05334