Power generation circuit using electromagnetic wave

• US 7,956,593 B2
• Filed: 05/03/2005
• Issued: 06/07/2011
• Est. Priority Date: 05/12/2004
• Status: Expired due to Fees

• Current Assignee: Makoto Ishida, Ablic Inc. (Minebea Mitsumi, Inc.)
• Original Assignee: Makoto Ishida, Seiko Instruments Incorporated (Seiko Group)
• Inventors: Ishida, Makoto, Sudo, Minoru, Sawada, Kazuaki, Takao, Hidekuni
• Primary Examiner(s): Berhane; Adolf
• Assistant Examiner(s): PHAM, EMILY P
• Application Number:
  US11/121,262
• Publication Number:
  US 20050254183A1
• Time in Patent Office: 2,226 Days
• Field of Search: 257/330, 438/270, 323/284, 323/285, 323/906, 323/288, 323/301, 323/302, 320/132, 320/133, 320/134, 320/143, 320/158, 320/163, 322/24, 322/25, 322/27, 322/28
• US Class Current: 323/284
• 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 generates and stores electric power utilizing electromagnetic wave energy. The power generation circuit has one of an antenna or a coil that receives an electromagnetic wave. A rectifying circuit is formed on a silicon substrate and rectifies a signal from the antenna or the coil. A storage circuit stores an output power obtained from the rectifying circuit for driving a load. A MOS transistor has a source and a drain connected to an output of the storage circuit and the load, respectively, so that the load is connected to the storage circuit in accordance with a threshold voltage of the MOS transistor.

Claims

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

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

a rectifying circuit that is formed on a silicon substrate and that rectifies a signal from the antenna or the coil receiving the ambient electromagnetic 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, so that the load is connected to the storage circuit in accordance with a threshold voltage of the MOS transistor;

wherein the silicon substrate has a recess, and the antenna or the coil has a projecting terminal that conforms to a shape of the recess in the silicon substrate and extends into the recess to establish an electrical connection between the antenna or the coil and an element formed on the silicon substrate.

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

one of an antenna or a coil that receives an electromagnetic wave;

a rectifying circuit that is formed on a silicon substrate and that rectifies a signal from the antenna or the coil;

a booster circuit that boosts an output of the rectifying circuit;

a storage circuit that stores an output power obtained from the booster circuit for driving a load;

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

a switching circuit that connects the storage circuit to the load in an ON-state of the switching circuit; and

a mono-stable multi-vibrator circuit that receives an input signal from the detector circuit and that determines a preselected period of time during which the switching circuit is in the ON-state, the switching circuit being in the ON-state for the preselected period of time when the detecting circuit detects that the voltage of the storage circuit is equal to or greater than a preselected voltage to connect the storage circuit to the load.

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

one of a first antenna or a first coil that receives an electromagnetic wave of a first frequency;

a first rectifying circuit that is formed on a silicon substrate and that rectifies a signal from the first antenna or the first coil;

one of a second antenna or a second coil that receives an electromagnetic wave of a second frequency different from the first frequency;

a second rectifying circuit that is formed on the silicon substrate and that rectifies a signal from the second antenna or the second coil;

a booster circuit that boosts an output of the first rectifying circuit;

a storage circuit that stores an output power obtained from the booster circuit for driving a load; and

a switching circuit that connects the storage circuit to the load;

wherein the first antenna or the first coil performs power generation utilizing the energy of the electromagnetic wave of the first frequency, the energy being accumulated in the storage circuit; and

wherein the switching circuit connects the storage circuit to the load in an ON-state of the switching circuit when power generation is performed by the second rectifying circuit after the second antenna or the second coil receives the electromagnetic wave of the second frequency.

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

one of a first antenna or a first coil that receives an electromagnetic wave of a first frequency;

a first rectifying circuit that is formed on a silicon substrate and that rectifies a signal from the first antenna or the first coil;

one of a second antenna or a second coil that receives an electromagnetic wave of a second frequency different from the first frequency;

a second rectifying circuit that is formed on the silicon substrate and that rectifies a signal from the second antenna or the second coil;

a booster circuit that boosts an output of the first rectifying circuit;

a storage circuit that stores an output power obtained from the booster circuit for driving a load;

a switching circuit that connects the storage circuit to the load; and

a mono-stable multi-vibrator circuit that receives an input signal from the second rectifying circuit and that determines a preselected period of time during which the switching circuit is in an ON-state;

wherein the first antenna or the first coil performs power generation utilizing the energy of the electromagnetic wave of the first frequency, the energy being stored in the storage circuit; and

wherein the switching circuit is in the ON-state for the preselected period of time determined by the mono-stable multi-vibrator circuit to connect the storage circuit to the load when power generation is performed by the second rectifier circuit after the second antenna or the second coil receives the electromagnetic wave of the second frequency.

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

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

a rectifying circuit that is formed on a silicon substrate and that rectifies a signal from the antenna or the coil receiving the ambient electromagnetic 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, so that the load is connected to the storage circuit in accordance with a threshold voltage of the MOS transistor;

wherein when the MOS transistor is in an ON-state, the load is connected to the storage circuit in parallel and the output power stored in the storage circuit drives the load when a voltage accumulating in the storage circuit becomes higher than the threshold voltage of the MOS transistor; and

wherein the MOS transistor is in an OFF-state when the voltage accumulated in the storage circuit becomes lower than the threshold voltage of the MOS transistor so that no electric power is consumed.

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

one of an antenna coil that receives an ambient electromagnetic wave;

a rectifying circuit that is formed on a silicon substrate and that rectifies a signal from the antenna or the coil receiving the ambient electromagnetic 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, so that the load is connected to the storage circuit in accordance with a threshold voltage of the MOS transistor;

wherein the MOS transistor comprises a first MOS transistor; and

further comprising a second MOS transistor having a drain connected to a gate of the first MOS transistor and a high-resistance resistor connected between the gate and the source of the first MOS transistor;

wherein connection between the storage circuit and the load is established when the storage circuit is charged so that a voltage across the storage circuit reaches a voltage equal to the sum of the threshold voltage of the first MOS transistor and the threshold voltage of the second MOS transistor.

7. A power generation circuit according to claim 6;

further comprising a third MOS transistor having a drain and a source connected to the drain and a source, respectively, of the second MOS transistor;

wherein when the storage circuit is charged to a voltage equal to sum of the threshold voltage of the first MOS transistor and the threshold voltage of the second MOS transistor, the third transistor is turned ON in accordance with a signal from a control circuit contained in the load at the moment when the storage circuit and the load are connected so that the connection between the storage circuit and the load is maintained until the voltage across the storage circuit drops below the threshold voltage of the first MOS transistor.

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

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

a rectifying circuit that is formed on a silicon substrate and that rectifies a signal from the antenna or the coil receiving the ambient electromagnetic 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, so that the load is connected to the storage circuit in accordance with a threshold voltage of the MOS transistor;

wherein the MOS transistor comprises a P-channel MOS transistor; and

wherein the source, the drain and a gate of the P-channel MOS transistor are connected to a positive terminal of the storage circuit, the load, and a negative terminal of the storage circuit, respectively.

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

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

a rectifying circuit that is formed on a silicon substrate and that rectifies a signal from the antenna or the coil receiving the ambient electromagnetic 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, so that the load is connected to the storage circuit in accordance with a threshold voltage of the MOS transistor;

wherein the MOS transistor comprises an N-channel MOS transistor, wherein the source, a gate and the drain of the N-channel MOS transistor are connected to a negative terminal of the storage circuit, a positive terminal of the storage circuit, and the load, with the load being connected to the positive terminal of the storage circuit; and

wherein when a voltage across the storage circuit becomes higher than the threshold voltage of the N-channel MOS transistor, the N-channel MOS transistor turns ON and connects the storage circuit to the load.