A multiband radio-frequency energy harvester for self-powered biosensor.

This paper presents a novel nano-structure of radio frequency (RF) to direct current (DC) converter for the energy control unit in the biosensor. It is based on the Graëtz Bridge supplied with three-phase power (DP3). This circuit can be considered as the result of the proper combination of a common anode assembly and a common cathode assembly. In fact, the same three-phase converter structure was kept. The diodes have been replaced by six NMOS transistors connected in diodes. A number of capacitors have been added for each stage to boost voltage. The benefit of using this type of circuit is to obtain a powerful DC output signal with the smallest number of stages. The proposed architecture also enables MOS transistors to be driven by external 2.45 GHz voluntary signals originating from the implant's personal assistant. This would allow avoiding the use of transistor control circuits which are already power-consuming. For more power, the proposed converter receives two more involuntary global system for mobile signals (GSM) with 900 MHz and 1800 MHz frequencies bands in order to take advantage of the ambient energy. The proposed RF-DC converter efficiency reaches 62.8% for an input power equal to 10 dbm.