RF POWER HARVESTING CIRCUIT

• US 20110101789A1
• Filed: 12/01/2009
• Published: 05/05/2011
• Est. Priority Date: 12/01/2008
• Status: Abandoned Application

• Current Assignee: National Security Agency
• Original Assignee: National Security Agency
• Inventors: Goldsman, Neil, Bo, Li, Salter, Thomas Steven JR., Peckerar, Martin, Choi, Kwangsik, Dilli, Zeynep, Metze, George M., Ngu, Yves
• Application Number:
  US12/628,585
• Publication Number:
  US 20110101789A1
• Time in Patent Office: Days
• US Class Current: 307/104
• CPC Class Codes: H02J 7/345 using capacitors as storage or buffering devices
• CPC Class Codes: H02M 7/217 using semiconductor devices only

Abstract

Provided is an RF power harvesting circuit with improved sensitivity to RF energy. The RF power harvesting device includes an inductor, a first capacitor connected to the inductor, a first MOSFET connected to a first node, and a second MOSFET connected to the first node. The inductor or the first capacitor are connected to the first node.

Claims

1. An RF power harvesting device comprising:

an inductor;

a first capacitor connected to the inductor;

a first MOSFET connected to a first node, and

a second MOSFET connected to the first node,

wherein the inductor or the first capacitor are connected to the first node.

2. The RF power harvesting device of claim 1, wherein values of the first MOSFET and the second MOSFET are such that intrinsic capacitances of the first MOSFET and the second MOSFET and the inductor constitute a substantially resonant circuit during operation of the RF power harvesting device.

3. The RF power harvesting device of claim 1, further comprising:

a second capacitor connected to a second node, and the second MOSFET is connected to the second node,

wherein the second MOSFET is a PMOSFET.

4. The RF power harvesting device of claim 1, further comprising:

a receiver which detects and receives ambient RF energy,

wherein the first capacitor and the receiver are connected at a third node, the first capacitor and the inductor are connected in series at a fourth node, and the inductor is connected to the first node.

5. The RF power harvesting device of claim 1, further comprising:

a first set of resisting elements connected to a first gate of the first MOSFET to apply a first DC bias to the first gate; and

a second set of resisting elements connected to a second gate of the second MOSFET to apply a second DC bias to the second gate.

6. A receiver comprising:

an impedance matching circuit connected to a first node;

a first MOSFET connected to the first node; and

a second MOSFET connected to the first node, wherein

the first MOSFET is a diode-connected p type MOSFET.

7. The receiver of claim 6, wherein the impedance matching circuit comprises an inductor and a capacitor in series, the inductor connected to the first node.

8. The receiver of claim 6, wherein a resistive biasing network provides a bias voltage to gate terminals of the first MOSFET and the second MOSFET.

9. A system comprising:

a receiver;

a voltage converter; and

an energy storage device, wherein

the receiver is configured to receive a high frequency signal and supply a first voltage to the voltage converter, and

the voltage converter is configured to amplify the first voltage supplied by the receiver and supply the amplified voltage to the energy storage device.

10. The system of claim 9, wherein the voltage converter includes a switched capacitor circuit.