Mobile

NFC Phones Couple With Nearby Tags Through Magnetic Fields

Tapping a phone against a payment terminal, transit gate, or small sticker looks like a tiny version of ordinary wireless communication. The radio behavior is different from a Wi-Fi or cellular link, though. NFC is built for very short distances and commonly relies on magnetic coupling between antennas placed close together. That short operating range shapes both the hardware and the interaction. A phone can exchange data with another powered NFC device, but it can also communicate with a passive tag that has no battery of its own.