| 摘要 |
A charge pump is configured to convert a high frequency signal to a substantially direct current (DC) voltage. The charge pump includes an input capable of receiving the high frequency signal, and a plurality of stages parallel connected to the charge pump input. Charge from the high frequency signal is accumulated in the plurality of stages during a first half cycle of the high frequency signal, and is passed from a nth stage of the plurality of stages to a (n+1)th stage of the plurality of stages during a second half cycle of said high frequency signal, the (n+1)th stage being closer to the charge pump output than the nth stage. The accumulated charge increases as it moves through the plurality of stages to the charge pump output to produce a DC output voltage that is sufficiently stable to be utilized as a power supply. In embodiments of the invention, the charge pump is configured on a radio frequency (RF) identification (ID) tag, and the DC voltage provides the power supply for the RF ID tag. The DC output voltage is regulated by removing charge from the stages if a threshold voltage is exceeded, which has the effect of reducing the efficiency of the charge pump. In embodiments of the invention, the charge pump is implemented using one or more MOSFET diodes. The MOSFET diodes can be configured to have a dynamically adjustable threshold voltage, thereby facilitating operation of the charge pump in a low power environment.
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