A Shared NFC Antenna Using Metal Frame of Smartphone

This paper proposes a technology for operating the NFC antenna function by sharing the LTE (Long Term Evolution) metal frame antennas of a smartphone. It is to operate two functions of NFC and LTE with one antenna by connecting NFC circuit to the existing metal frame antenna through RF choke. By doing this, it is possible to remove the FPCB (Flexible Printed Circuits Board) NFC antenna, which can help to reduce costs and minimize smartphones. In the proposed structure that removes the FPCB NFC antenna and uses a metal frame, it was confirmed that it satisfies the EMV (Europay, Mastercard and Visa) certification standard, and there was no deterioration in the transmission and reception performance of the LTE antenna.