Power generation circuit for generating and storing electric power utilizing radio wave energy

• US 8,513,927 B2
• Filed: 04/14/2011
• Issued: 08/20/2013
• Est. Priority Date: 05/12/2004
• Status: Active Grant

• Current Assignee: Ablic Inc. (Minebea Mitsumi, Inc.)
• Original Assignee: Makoto Ishida, Seiko Instruments Incorporated (Seiko Group)
• Inventors: Ishida, Makoto, Sawada, Kazuaki, Takao, Hidekuni, Sudo, Minoru
• Primary Examiner(s): Berhane, Adolf
• Assistant Examiner(s): PHAM, EMILY P
• Application Number:
  US13/066,418
• Publication Number:
  US 20110193420A1
• Time in Patent Office: 859 Days
• Field of Search: 257/330, 438/270, 323/222, 323271-274, 323/284, 323/285, 323/288, 323/295, 323/301, 323/302, 323/906, 320/133, 320/134, 320/143, 320/158, 320/163, 322/24, 322/25, 322/27, 322/28
• US Class Current: 323/222
• CPC Class Codes: H02J 50/001 Energy harvesting or scavenging
• CPC Class Codes: H02J 50/12 of the resonant type
• CPC Class Codes: H02J 50/20 using microwaves or radio frequency waves

Abstract

A power generation circuit has one of an antenna or a coil that receives an ambient radio wave. A rectifying circuit is connected to the antenna or the coil for rectifying a signal from the antenna or the coil receiving the ambient radio wave. A booster circuit is connected to and boosts an output of the rectifying circuit. A storage circuit is connected to the booster circuit and stores an output power obtained from the rectifying circuit for driving a load without the use of a power source or a battery. A switching circuit is operable in an ON-state thereof to connect the storage circuit to the load when a voltage of the storage circuit is equal to or greater than a preselected voltage.

Claims

1. A power generation circuit for generating and storing electric power utilizing radio wave energy, the power generating circuit, comprising:

one of an antenna or a coil that receives an ambient radio wave;

a rectifying circuit that is formed on a silicon substrate and is connected to the antenna or the coil and that rectifies a signal from the antenna or the coil receiving the ambient radio wave;

a storage circuit that stores an output power obtained from the rectifying circuit for driving a load without the use of a power source or a battery; and

a MOS transistor having a source and a drain connected to an output of the storage circuit and the load, respectively, and a gate connected to another terminal of the storage circuit, so that the load is connected to the storage circuit in accordance with a threshold voltage of the MOS transistor.

2. A power generation circuit according to claim 1, wherein the MOS transistor is an enhanced MOS transistor.

3. A power generation circuit according to claim 1, wherein a recess is formed in the silicon substrate;

a projecting terminal that conforms to a shape of the recess in the silicon substrate is formed on one of the antenna and the coil; and

an electrical connection is established between the antenna or the coil and an element formed on the silicon substrate by inserting the projecting terminal of the antenna into the recess in the silicon substrate.

4. A power generation circuit according to claim 2, wherein a recess is formed in the silicon substrate;

a projecting terminal that conforms to a shape of the recess in the silicon substrate is formed on one of the antenna and the coil; and

an electrical connection is established between the antenna or the coil and an element formed on the silicon substrate by inserting the projecting terminal of the antenna into the recess in the silicon substrate.

5. A power generation circuit according to claim 1, wherein the electromagnetic wave exists in a space for living.

6. A power generation circuit according to claim 2, wherein the electromagnetic wave exists in a space for living.

7. A power generation circuit according to claim 3, wherein the electromagnetic wave exists in a space for living.

8. A power generation circuit according to claim 4, wherein the electromagnetic wave exists in a space for living.

9. A power generation circuit for generating and storing electric power utilizing radio wave energy, the power generating circuit comprising:

one of an antenna or a coil that receives an ambient radio wave;

a rectifying circuit that is formed on a silicon substrate and is connected to the antenna or the coil and that rectifies a signal from the antenna or the coil receiving the ambient radio wave;

a booster circuit that is connected to the rectifying circuit and that boosts an output of the rectifying circuit;

a storage circuit that is connected to the booster circuit and that stores an output power obtained from the rectifying circuit for driving a load without the use of a power source or a battery;

a detector circuit that detects a voltage of the storage circuit; and

a switching circuit that connects the storage circuit to the load in an ON-state of the switching circuit when the detector circuit detects that the voltage of the storage circuit is equal to or greater than a preselected voltage.

10. A power generation circuit for generating and storing electric power utilizing radio wave energy, the power generating circuit comprising:

one of an antenna or a coil that receives an ambient radio wave;

a rectifying circuit that is connected to the antenna or the coil and that rectifies a signal from the antenna or the coil receiving the ambient radio wave;

a booster circuit that is connected to the rectifying circuit and that boosts an output of the rectifying circuit;

a storage circuit that is connected to the booster circuit and that stores an output power obtained from the rectifying circuit for driving a load without the use of a power source or a battery; and

a switching circuit operable in an ON-state thereof to connect the storage circuit to the load when a voltage of the storage circuit is equal to or greater than a preselected voltage.

11. A power generation circuit according to claim 10;

further comprising means for detecting a voltage of the storage circuit; and

wherein the switching circuit connects the storage circuit to the load when the voltage detected by the detecting means is equal or greater than the preselected voltage.