Analysis of Rectifiers for RF Energy Harvesting Aiming Low Power Sensing Applications

Seeking to increase the autonomy of wireless sensing devices, this article analyzes different RF rectifier topologies for ambient energy harvesting applications at 2.45 GHz, focusing on scenarios where the input received power level of the RF rectifier is between -10 dBm and -20 dBm. For this propose, an equivalent diode RF model is taken into account for better describing the diode effect on the efficiency of each rectifier topology, presenting the impedance curve of four commercial diodes, and the respective conducting thresholds, without loss of generality. Furthermore, a computational rectifier optimization methodology is given, discussing the relation of the load impedance with the resulting circuit efficiency.