Patent attributes
An apparatus includes a front-end circuit and a digital processing circuit. The front-end circuit includes an antenna and a modulation switch. The digital processing circuit is configured to transmit data to a remote unit using inductive coupling of an Alternating Current (AC) magnetic field generated by the remote unit, by modulating a load impedance of the antenna using the modulation switch. The front-end circuit is configured to supply to the digital processing circuit a voltage signal, which has a frequency of the AC magnetic field and which has a non-zero envelope both during intervals in which the modulation switch is closed and during intervals in which the modulation switch is open, and wherein the digital processing circuit is configured to derive a clock signal from the voltage signal.
