System for ambient energy harvesting

摘要

A method and apparatus is disclosed herein for harvesting ambient energy. In one embodiment, an energy harvester comprises: a first RF rectifier to output a first voltage determined by rectified RF energy in response to received RF energy; a first energy reservoir coupled to the first RF rectifier to store energy at the first voltage; a DC/DC converter coupled to the first energy reservoir to convert the first voltage to a second voltage; a second reservoir coupled to the DC/DC converter to store energy at the second voltage, the second voltage being greater than the first voltage; and a third reservoir coupled to the second reservoir to receive energy transferred from the second reservoir periodically.

主权项

1. An energy harvester to convert incident radio frequency (RF) energy associated with an RF signal to direct current energy, the energy harvester comprising:
a first RF rectifier to output a first voltage determined by rectified RF energy in response to received RF energy; a first energy reservoir coupled to the first RF rectifier to store energy at the first voltage; a DC/DC converter coupled to the first energy reservoir to convert the first voltage to a second voltage; a second reservoir coupled to the DC/DC converter to store energy at the second voltage, the second voltage being greater than the first voltage; and a third reservoir coupled to the second reservoir to receive energy transferred from the second reservoir periodically and coupled to a load, wherein the third reservoir comprises a capacitor having a capacitance value chosen to control an amount of usable energy stored in the third reservoir as a function of an RF transmission duration, the impedance of the load, and a threshold voltage, the usable energy being a portion of the stored energy above the threshold voltage.