ENERGY HARVESTING UNIT AND OPERATING METHOD THEREOF

An energy harvesting unit includes a plurality of antennas configured to receive one or more signals and a plurality of first charge pumps, in which each of the first charge pumps is operatively coupled to one of the antennas, thereby forming pairs of antennas and first charge pumps. The energy harvesting unit also includes a selection unit configured to measure and compare output voltages of the first charge pumps and to select, from the antennas, a specific antenna. The specific antenna is coupled to the first charge pump that produces the highest output voltage. The energy harvesting unit also includes a multiplexer configured to couple the specific antenna selected by the selection unit to a second charge pump.