A system is presented for harvesting electromagnetic energy propagating in surroundings. The system comprises an antenna unit, a harvesting unit, and an input signal adapting circuit. The antenna unit is configured for receiving external electromagnetic radiation from the surroundings and producing a corresponding electric output. The harvesting unit comprises at least one energy harvesting circuit each configured and operable for receiving signals indicative of the output of the antenna unit and generating and storing corresponding electric charge, the harvesting circuit comprising: a rectifying unit comprising a plurality of rectifiers each configured and operable to receive AC electric signals and generate corresponding DC electric power and a charge collection unit configured and operable to receive the plurality of DC electric powers from said rectifying unit and converting and accumulating them into the electric charge presenting harvested energy. The input signal adapting circuit has an input connected to the antenna unit and an output connected to the rectifying unit, the input signal adapting circuit being configured and operable for adjusting a predetermined electrical property of the antenna unit and rectifying unit to thereby optimize receipt of the electric output of the antenna unit to the harvesting circuit.