Components on a chip. Magnetic-inductive coupling is a simple technique that is easy to implement in silicon. Thus, vendors can handily integrate an NFC system's antenna, analog modulator/demodulator (for sending and receiving signals), and digital circuitry onto a single chip, as Figure 1 shows.
Other components of the chip include an RF-level detector that is tuned to recognize 13.56-MHz signals and that can thus identify the presence of a nearby NFC radio field.
The card-mode detector recognizes what type of contactless technology—such as Philips' Mifare or Sony's FeliCa—is sending the incoming signal and prepares the receiver to demodulate it.
Range and data rate. Because inductive coupling works only at short distances, NFC's operating range is just 10 cm, compared to Bluetooth's 10 meters and Wi-Fi's 100 meters.
NFC transfers data at a maximum of 424 Kbits per second, compared to Bluetooth's 3 Mbps and Wi-Fi's 54 Mbps. Thus, NFC is not suitable for many types of data transfer.
Security. Because NFC requires the close proximity of two devices, intercepting signals is difficult, which gives the technology some inherent security, said Christopher Duverne, chair of the NFC Forum, an industry association.
Also, contactless payments eliminate the need for a purchaser to give a credit card to a merchant, thereby reducing fraud opportunities, noted Marcus Torchia, senior analyst with the Yankee Group, a market research firm.