Performances Comparison of Shottky Voltage Doubler Rectifier to support RF Energy Harvesting

Abstract

Electromagnetic waves are increasingly the preferred source for charging the battery of wireless sensor nodes. Given the small amount of harvestable energy, much work has been proposed to optimize the energy efficiency of radiofrequency energy converter circuits. Among these researches, Voltage Doubler (VD) rectifier occupies a predominant place. This work then proposes to compare the performance of the two types of VD that are the Greinacher Voltage Doubler (GVD) and the Delon Voltage Doubler (DVD). Performance criteria are DC output voltage, RF/DC conversion efficiency, and matching losses. A Rectenna Figure of Merit (RFoM) that considers these three parameters is defined for an overall comparison of the rectifiers. The analyzes are carried out in the 900 MHz, 2.45 GHz ISM and 5.8 GHz frequency bands and the performances of the two circuits when they are perfectly adapted are also analyzed. As a result, it is obtained that the DVD rectifier is more suitable for miniature designs without a matching filter. The two voltage doublers when they are matched have almost similar performances in terms of DC voltage and RF/DC conversion efficiency. However, the insertion losses are higher in the GVD.