Contactless communication device by active load modulation

A method, comprising:

• receiving a reception signal at a clock signal extraction circuit;
• outputting, from the clock signal extraction circuit, a clock signal having a first value when the reception signal is greater than a threshold of the clock signal extraction circuit and having a second value when the reception signal is smaller than the threshold;
• and
• modifying, with a circuit, the threshold by decreasing the threshold when the value of the clock signal is equal to the first value and increasing the threshold when the value of the clock signal is equal to the second value.

A device, comprising:

• a clock extraction circuit including:
• a differential input coupled to receive a reception signal from the matching circuit;
• a feedback input;
• and
• an output configured to provide a clock signal based on the reception signal and an internal threshold;
• and
• a feedback circuit having an input coupled to receive the clock signal and an output coupled to the feedback input of the clock extraction circuit.