US-20260128617-A1 - ELECTRIC POWER TRANSMISSION DEVICE, ELECTRIC POWER TRANSMISSION ANTENNA DEVICE, AND WIRELESS ELECTRIC POWER SUPPLY SYSTEM

Abstract

An electric power transmission device includes: an oscillator that outputs an AC signal; a controller that outputs a control signal; and a modulator that modulates an AC signal output from the oscillator in response to the control signal. The control signal is a signal for selecting an antenna that radiates the AC signal from among a plurality of antennas.

Inventors

• Manabu Gokan
• Yuki Tanaka
• Takuma Ikeda
• Hiroyuki Tani

Assignees

• PANASONIC INTELLECTUAL PROPERTY MANAGEMENT CO., LTD.

Dates

Publication Date

20260507

Application Date

20251201

Priority Date

20230606

Claims (11)

1. 1 . An electric power transmission device comprising: an oscillator that outputs an AC signal; a controller that outputs a control signal; and a modulator that modulates an AC signal output from the oscillator in response to the control signal, wherein the control signal is a signal for selecting an antenna that radiates the AC signal from among a plurality of antennas.
2. 2 . The electric power transmission device according to claim 1 , wherein in response to the control signal, the modulator (i) changes a length of an electric power transmission time of the AC signal and a length of an electric power transmission pause time of the AC signal, (ii) changes electric power of the AC signal, or (iii) changes transmission and non-transmission of the AC signal in an electric power transmission time of the AC signal.
3. 3 . The electric power transmission device according to claim 1 , further comprising a receiver that receives information indicating received electric power from an electric power reception device that has received the AC signal, wherein the controller outputs the control signal when the received electric power is less than target electric power.
4. 4 . An electric power transmission antenna device comprising: a plurality of antennas, each of which radiates an AC signal; and a controller that selects an antenna that radiates an AC signal from among the plurality of antennas based on a control signal included in the AC signal, wherein the AC signal is modulated in response to the control signal.
5. 5 . The electric power transmission antenna device according to claim 4 , wherein in response to the control signal, the AC signal (i) is changed in a length of an electric power transmission time of the AC signal and a length of an electric power transmission pause time of the AC signal, (ii) is changed in an electric power of the AC signal, or (iii) is changed in transmission and non-transmission of the AC signal in an electric power transmission time of the AC signal.
6. 6 . The electric power transmission antenna device according to claim 4 , further comprising a rectifier circuit that converts the AC signal into a DC signal, wherein the controller demodulates the control signal from the DC signal.
7. 7 . The electric power transmission antenna device according to claim 4 , further comprising a switch that selects an antenna that radiates the AC signal, wherein the controller controls the switch based on the control signal.
8. 8 . The electric power transmission antenna device according to claim 4 , wherein the plurality of antennas include at least one of a vertical polarization antenna that outputs vertically polarized waves and a horizontal polarization antenna that outputs horizontally polarized waves.
9. 9 . The electric power transmission antenna device according to claim 4 , further comprising: a distributor that distributes the AC signal; a filter that reduces noise of the AC signal distributed by the distributor; a rectifier circuit that rectifies an AC signal with the noise that has been reduced into a DC signal; a power storage unit that stores electric power of the DC signal; and a backflow prevention unit that prevents backflow of the electric power from the power storage unit to the rectifier circuit.
10. 10 . A wireless electric power supply system, comprising: the electric power transmission device according to claim 1 ; and a single electric power transmission antenna cable that connects the electric power transmission device and the electric power transmission antenna device.
11. 11 . The wireless electric power supply system according to claim 10 , wherein the single electric power transmission antenna cable is a coaxial cable.

Description

TECHNICAL FIELD The present disclosure relates to an electric power transmission device, an electric power transmission antenna device, and a wireless electric power supply system. BACKGROUND ART Currently, a wireless electric power supply technology for the Internet of Things (IoT) is being studied for practical use. In a wireless electric power supply technology, radio waves radiated from an electric power transmission antenna of an electric power transmission device are received by an electric power reception antenna of an electric power reception device, a value of electric power of the received radio waves is observed in real time, and information of the observed electric power is fed back to the electric power transmission device, thereby electric power of the radio waves to be received can be maintained at a necessary and sufficient magnitude. As a wireless electric power supply system, there is a system that controls a plurality of antennas included in an electric power transmission device to form beams and wirelessly supplies electric power to electric power reception devices (see, for example, PTL 1). FIG. 8 is a diagram illustrating a wireless electric power supply system 800 described in PTL 1. In PTL 1, wireless electric power supply system 800 includes electric power transmission device 810 and electric power reception unit 820. Electric power transmission device 810 includes a plurality of antennas 811 and a plurality of antenna cables 812, and wirelessly supplies electric power to electric power reception unit 820. Electric power transmission device 810 transmits radio waves including an electric power signal to the electric power reception devices of electric power reception unit 820, and transmits radio waves not including an electric power signal to the transmitting-receiving device of electric power reception unit 820. In wireless electric power supply system 800, electric power transmission device 810 controls the directionality with the plurality of antennas 811 connected to the plurality of antenna cables 812, thereby simultaneously transmitting electric power and information to the plurality of electric power reception units 820. CITATION LIST Patent Literature PTL 1: Unexamined Japanese Patent Publication No. 2023-005766 SUMMARY OF THE INVENTION An electric power transmission device in an exemplary embodiment of the present disclosure includes: an oscillator that outputs an AC signal; a controller that outputs a control signal; and a modulator that modulates an AC signal output from the oscillator in response to the control signal, in which the control signal is a signal for selecting an antenna that radiates the AC signal from among a plurality of antennas. An electric power transmission antenna device in an exemplary embodiment of the present disclosure includes: a plurality of antennas, each of which radiates an AC signal; and a controller that selects an antenna that radiates an AC signal from among the plurality of antennas based on a control signal included in the AC signal, in which the AC signal is modulated in response to the control signal. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a diagram illustrating a system configuration of a wireless electric power supply system in a first exemplary embodiment. FIG. 2A is a diagram illustrating envelopes of microwaves output from an electric power transmission device. FIG. 2B is a diagram illustrating electric power transmission times and electric power transmission pause times of microwaves in the first exemplary embodiment. FIG. 3 is a flowchart illustrating a procedure of processing executed by the electric power transmission device. FIG. 4 is a flowchart illustrating a procedure of processing executed by an electric power transmission antenna device. FIG. 5 is a flowchart illustrating a procedure of processing executed by an electric power reception device. FIG. 6 is a sequence diagram illustrating a procedure of processing performed by the wireless electric power supply system in the first exemplary embodiment. FIG. 7 is a diagram illustrating a system configuration of a wireless electric power supply system in a second exemplary embodiment. FIG. 8 is a diagram illustrating a wireless electric power supply system described in PTL 1. DESCRIPTION OF EMBODIMENT In the configuration of FIG. 8, the efficiency of electric power transmission may be reduced due to the influence of the installation location of electric power reception unit 820, such as electric power reception unit 820 being disposed at a location where metal is present in the periphery, or the influence of the orientation of the antenna of electric power reception unit 820. The present disclosure has been made to solve the above problems, and an object of the present disclosure is to provide a wireless electric power supply system that improves electric power transmission efficiency. First Exemplary Embodiment Hereinafter, exemplary embodiments will be described with