Optimum design of low energy harvesting detector at 5.8 GHz suitable for COTS devices

In this paper the authors introduce a new method to optimize RF to DC energy conversion in a COTS-based energy harvesting system. The system under investigation is composed by an RF envelope detector, cascaded with a commercial DCDC module. Being the latter characterized by a low impedance input stage, which is hardly modeled by a linear time-invariant resistance, this imposes stringent requirements to the energy conversion optimization. The paper shows how to approach this constraint by involving source-pull technique, and provides experimental validation and results discussion. The developed prototype operating at 5.8 GHz RF, with carrier power of -5dBm, results capable to drive devices, having supply requirements of Vdc =3.3V and Idc ≥q5mA.