RF-to-DC Converter

• Main Authors: Manuel Pinuela Rangel, Bruno Roberto Franciscatto
• Format: Patent
• Language: English
• Published: 23.11.2016
• Subjects: CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTINGELECTRIC POWER; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER; ELECTRICITY; GENERATION; SYSTEMS FOR STORING ELECTRIC ENERGY

An energy harvesting system 200 for converting a received RF signal from an antenna 100 into a DC signal for powering a load 300 includes a rectifier 220 to generate the DC signal and harmonics of the RF signal, and to output the DC signal and the harmonics together with a component of the RF signal. A first planar transmission line 210 guides the received RF signal to the rectifier 220, and a second planar transmission line 230 receives the DC signal, the component of the RF signal and the harmonics from the rectifier 220, and is arranged to reflect the harmonics back towards the rectifier 220. The first planar transmission line 210 is further arranged to reflect back towards the rectifier 220 RF signals from the rectifier 220 that are based on the reflected signals. The system 200 has a low-pass filter 250 for supplying the DC signal to the load 300, the low-pass filter 250 comprising an inductor 256 and a third planar transmission line 254 that connects the second transmission line 230 to the inductor 256. The third planar transmission line 254 and the inductor 256 are arranged to transmit the DC signal and to substantially block the component of the RF signal and the harmonics of the RF signal. The system offers improved efficiency since the energy in the harmonics produced by the rectifier 220 contributes to the DC output instead of being lost.