Low Power RF Energy Harvesting Circuit for 2.45 GHz ISM Frequency Band

Today, smart devices are commonplace and wireless systems typically require portable supply sources for mobility. An alternative for the battery as a supply source is the energy harvesting system, which does not require periodic replacement, increasing the lifespan. This approach is beneficial for IoT applications such as wireless environmental sensors, wearable devices, and low-power-agricultural monitoring systems, where battery replacement can be impractical. This work presents the impedance matching and measurement of an energy harvesting circuit implemented in 180 nm CMOS. The circuit was designed as a series of 10 Cross-Coupled Charge-Pump-Rectifier cells. After matching, a sensitivity of -4.4 dBm was achieved with a maximum voltage output of 2.2 V and a charging time of 4.5 min.