An efficient small size electromagnetic energy harvesting sensor for low-DC-power applications

An efficient small size electromagnetic energy harvesting sensor for low-DC-power applications is proposed. The sensor consists of two main parts: a dual polarisation square patch antenna used to collect the RF energy at a central frequency of 2.45 GHz, and two voltage doublers rectifier circuit for the RF-to-DC conversion. The overall size of the design is 50 × 50 × 6.2 mm3. Firstly, the antenna is designed using high-frequency structure simulator software; followed by the design of the rectifier circuit in advanced design system. After simulations, a sensor prototype is fabricated using F4B as the antenna substrate. Measurements show that the sensor achieves a comparatively high maximum measured efficiency of 41% for a power level of −10 dBm. The sensor has a simple structure, it is compact sized, light weight, and presents a high RF-to-DC conversion efficiency for low-RF-power levels which can be used to charge different low-DC-power devices.