Single- and Wide-Band Cooperative Rectifiers Harvesting Ambient Electromagnetic-Photovoltaic Energy for Powering Battery-Less Sensors

Hybrid energy harvesting from ambient electromagnetic (EM), thermal, kinetic, photovoltaic (PV) and wind is a promising green energy solution for powering IoT devices to achieve battery-less operation. However, existing harvesters face limitations in efficiency, input power range and bandwidth. This paper proposes for the first time a cooperative voltage doubler rectifying topology using hybrid EM-PV energy harvesting to address these challenges. Theoretical analysis indicates that the proposed topology can realize high power conversion efficiencies (PCEs) and considerable efficiency gains (EGs) under hybrid input power excitation and with an extended power range. In addition, a post-matching technique for the proposed topology to extend operating bandwidth is presented for the first time. For validation, single-and wide-band cooperative rectifiers are fabricated and measured. In a room with a light intensity of 232 lux, the single-band cooperative rectifier maintains PCEs higher than 46% at 2.4 GHz with the input power range of 25 dB, while the wide-band one realizes PCEs of over 30% with an ultra-wide bandwidth of 0.8 to 2.4 GHz covering GSM, WCDMA, LTE and WLAN. Compared to existing state-of-the-art works, the implemented cooperative rectifiers achieve the largest input power range and widest bandwidth for hybrid ambient energy harvesting.