Energy harvesting circuit, corresponding system and method

An energy harvester circuit, comprising:

• a first radio-frequency-to-direct-current (RF2DC) transducer configured to receive a first signal from a first radio-frequency sensing antenna;
• an energy storage circuit coupled to an output of the first RF2DC transducer and supplied with energy derived from the first signal;
• energy transfer circuitry coupled to the energy storage circuit;
• driver circuitry coupled to the energy transfer circuitry, the driver circuitry configured to controllably switch the energy transfer circuitry between an energy storage operation where energy from the first RF2DC transducer is stored in the energy storage circuit and an energy transfer operation where the stored energy in the energy storage circuit is transferred towards an output node, a voltage at the energy storage circuit varying between an upper value and a lower value around a voltage setting point;
• and
• a second RF2DC transducer comprising a down-scaled replica of the first RF2DC transducer, the second RF2DC transducer configured to produce a second signal indicative of an open-circuit voltage of the first RF2DC transducer;
• wherein the driver circuitry receives the second signal from the second RF2DC transducer and sets said voltage setting point set in response to the second signal indicative of the open-circuit voltage of the first RF2DC transducer.