Patent ID: 8369778

Claim:
A portable object comprising: an antenna inductively coupled to a fixed station of a remote transmission device, a variable load impedance connected in parallel to terminals of the antenna, a rectifier with an input connected to one of the terminals of the antenna, a gain control loop connected between an output of the rectifier and a control terminal of the variable load impedance and configured to control the voltage at terminals of the variable load impedance, the gain control loop comprising, connected in series: a circuitry configured to generate a first signal representative of a difference between a setpoint voltage and an output voltage of the rectifier, a one-bit analog-to-digital converter arranged to convert said first signal into a digital signal, a gain control circuitry configured to provide a variable gain according to a second signal representative of the first signal, a gain command circuitry of integrator type having a first input coupled to an output of the converter, a second input coupled to an output of the gain control circuitry and an output coupled to the control terminal of the variable load impedance, and demodulation means connected so as to receive the digital signal from the output of the converter.