An electrosurgical energy delivery apparatus incudes an energy delivery circuit (210a), a control circuit (210b, 275) and an energy-harvesting system (260) with a plurality of energy-harvesting circuits (250, 350, 450, 550, 750) and a voltage regulator (258, 358, 458, 758) that provides a regulated DC voltage to the energy delivery circuit and/or the control circuit. The energy delivery circuit receives an electrosurgical energy signal having a primary frequency and selectively provides the electrosurgical energy signal to an energy delivery element. The control circuit connects to the energy delivery circuit and selectively enables the flow of electrosurgical energy to the energy delivery element. The plurality of energy-harvesting circuits each include an energy-harvesting antenna (256, 356, 456, 556, 756) tuned to a particular frequency, a matched circuit (252, 352a-352d, 452a-452d, 552a-552d,752a-752d) configured to receive an RF signal from the energy-harvesting antenna, rectify the RF signal and generate a DC signal, and an energy storage device (254, 354a-354d, 454a2-454d, 754) that connects to the voltage regulator to receive and store the DC signal.
