Application Of Soft Magnetic Shielding Materials In Near-Field Communication(NFC) Systems

Near field communication technology is a contactless identification andinterconnection technology and it can exchange and identify data in a very short distancewith compatible devices. Nonetheless, with the development of NFC technolo gy, higherrequirements were raised in the stability and security of NFC systems. Since the softmagnetic materials can shield noise sources from the near field, they have been widelyused in NFC systems. This paper carried out on the research of these soft magneticmaterials.This paper brings in the concept and features of near field communication technology,and then details its development process and some key technologies about the softmagnetic shielding materials. After that we design a square co il with a resonancefrequency of13.56MHz, observe the magnetic intensity which is radiated from the coil,and design different sizes and real part of permeability parameters of soft magneticmaterials. Then we study the effects of the soft magnetic materials through comparing themagnetic intensity. The results show that the ferrite with a thicker or larger dimension or ahigher real permeability, has the better shielding performance.Next we describe two series soft magnetic materials systematically, that is the ferriteand the metal powder, and introduce their milling process, as well as the rolling, and thecurtain coating method. we prepare the Co2Z ferrite powder through solid state reactionand make them into thin sintered ferrite sheets by curtain coating method; we flatten theFe-Si-Al powder through ball grinder process and make them into thin sheets.then,weCharacterize their electromagnetic properties and study how the dimensions and thematerials’ characteristics effects the shielding performance. Finally, we test the readingdistance using the samples to testify the simulation results.