金属外壳手机低干扰NFC天线设计

Design of Low Interference NFC Antenna for Mobile Phone with Metal Shell

文中提出了一种适用于金属外壳手机的低干扰近场通信(Near Field Communication,NFC)天线设计方案。在金属外壳手机环境下,NFC天线会给相邻的功能天线带来额外的寄生效应。更为严重的是,NFC天线严重影响了相邻天线的工作频率和工作效率,严重干扰了相邻天线的正常工作。本文中NFC天线被切割成若干部分以抵消由寄生效应产生的工作频带漂移。此外,这些切割部件与多个表面贴装器件(SMD)电感串联在一起,作为低通滤波器来切割高频电流以使NFC天线在对其他天线低干扰的情况下可以正常工作。实测结果表明,本文设计的NFC天线大幅减小了对相邻天线的工作影响,提高了工作效率,设计简单有效,具有良好的应用前景。

A low interference near field communication(NFC) antenna design for metal shell mobile phone is proposed. Under an undesired metal environment,NFC antenna brings some extra parasitic effects into adjacent functional antennas. More seriously,both working frequency and working efficiency of adjacent antennas are strongly influenced by NFC antenna,which seriously disturbs the normal work of adjacent antennas. Herein,NFC antenna is cut into several parts to offset the working frequency band drift derive from parasitic effects. Furthermore,these cutting parts are connected together with several surface mount device(SMD) inductors in series,serving as low-pass filter to cut high frequency current for the NFC antenna to function properly. The actual measurement results show that the proposed NFC antenna inhibits the working frequency drift of adjacent antennas,thereby resulting in a high working efficiency. The proposed NFC antenna design is simple and effective,suggesting a good prospect in practical use.