Apple Inc.
High sensitivity NFC reader

Abstract:

A device and method for mitigating the effects of carrier leakage and improving a near-field communications ("NFC"). The device includes a transmitter configured to generate an output signal including an output carrier signal, a receiver configured to demodulate a received signal including a received carrier signal, and an antenna configured to transmit the output signal and receive the received signal. The device further includes circuitry configured to electrically connect the transmitter via a transmit path to the antenna and the receiver via a receive path to the antenna, wherein the output carrier signal leaks into the receive path as a leakage signal, the circuitry comprising a phase shifter connecting the transmit path to the receive path and configured to phase shift the leakage signal with respect to the received carrier signal to reduce a voltage of a combined leakage signal and received signal received by the receiver.