A comparative study: voltage multipliers for rf energy harvesting system

Voltage multipliers are widely used for energy harvesting processesto convert the received AC signal to DC signal, also enhanced the low levelreceived signal. In this study, Villard, Dickson and Greinacher type voltagemultipliers are analyzed without impedance matching and substrate materials todecide the effective voltage multiplier type depending on the inputs of theharvester. So, load resistance, input power and input frequencies’ effects areanalyzed and compared with each other. Agilent Advanced Design System (ADS)is used for simulations. HSMS 2852 Schottky diode and capacitors are used forthese voltage multipliers. Results show that, determining load resistance isimportant for evaluating high efficiency, e.g. efficiency differences are reached33% between 2kΩ and 20 kΩ for Dickson voltage multiplier at 100 MHz inputfrequency. Furthermore, the best efficiency is obtained by Greinacher voltagemultiplier for low input frequencies which is lower than 1 GHz but there are nosignificant differences are observed for high frequencies. This study shows thatload resistance, input frequency and input power are important parameters forvoltage multiplier selection and Greinacher voltage multiplier is the best choice toobtain high efficiency for low frequency application of RF harvesting.