Compact Ambient RF Energy Scavenger for WSNs

Here, a full-wave voltage-doubler in conjunction with a lumped LC matching network has been thoroughly examined and found to be a superior option for the rectifier section of the antenna. This can be used to harvest DC power from the freely available wild RF energy in the surrounding environment while on the move. Following a number of diodes’ auditions, HSMS-285B Schottky diodes were ultimately selected as the best options for rectification due to its great sensitivity to extremely low-input power, fast-operating speed, lack of a turn-on voltage requirement, and low loss at high frequencies. The matching network’s lumped parts and the full-wave rectifier’s charging capacitors were carefully optimized and tuned, and the result was an encouraging maximum overall rectifier efficiency of 49.5% at −10 dBm input power at 2.1 GHz and 62.52% at 0dBm input power at 2.3 GHz. Despite the L-C matching network’s lumped elements restricting the design to narrow band, it has been demonstrated conclusively that in the presence of multi-tone signals—which is quite normal given that the harvester harvests DC power from the ambient environment where multiple RF bands coexist—that the maximum overall rectifier efficiency obtained is 81.9% at input power of 0 dBm per band and 79.5% at input power of −10 dBm per band which is quite overwhelming. Even the highest unloaded DC output voltage of 2.1 V at −10 dBm input power and 3.8 V at 0 dBm input power has been measured. Further research has revealed that the rectifier can harvest DC power from a larger variety of radio frequencies when its input power rises from −10 to 0 dBm. Further research has shown that the performance of the single-ended load configuration (with balanced source) and floating-load configuration (with differential outputs) for full-wave voltage-doubler architecture is nearly equal. Compared to other recent designs, the suggested design is the most straightforward and small.