Abstract: A microstrip antenna includes a first metal layer that constitutes an antenna element, a second metal layer that constitutes a ground, and a flexible member that separates the first metal layer and the second metal layer by a predetermined distance. The first metal layer and the second metal layer each are made of a metal or a metal foil. At least one of the first metal layer and the second metal layer is not adhered to the flexible member but is in close contact with the flexible member by a close contact unit. The close contact unit is a clamping mechanism including a first plate, a second plate, and a connecting member. The first plate and the second plate are connected to each other by the connecting member. The connecting member is an elastic body.

Abstract: A power receiving device is disposed underwater. The power receiving device includes a housing formed of a weak magnetic material, a ferromagnetic body that surrounds an outer side of the housing and is formed of a ferromagnetic material, and a power receiving coil wound around an outer side of the ferromagnetic body.

Abstract: A power transmitting device transmits power to a power receiving device having a power receiving coil in water. The power transmitting device includes a power transmitting coil configured to transmit the power to the power receiving coil via a magnetic field. The power transmitting device also includes a support member that supports the power transmitting coil, and one or more spacers that hold the transmitting coil and the support member.

Abstract: A wireless power transmitter includes an antenna that transmits a radio wave, a phase shift circuit that changes a phase of the radio wave transmitted from the antenna, a control device that controls the phase shift circuit, and a backscatter signal receiver that receives a backscatter signal. The control device executes phase optimization processing of controlling the phase shift circuit so that a strength of the backscatter signal received by the wireless power transmitter is maximized.

Abstract: A wearable terminal includes a support body, an antenna having a first metal layer and a second metal layer, a board, and a covering film. The first metal layer constitutes an antenna element and the second metal layer constitutes a ground. The first metal layer and the second metal layer each are made of a metal having flexibility or a metal foil formed on a material having flexibility. The first metal layer is bonded to the covering film. The support body or the antenna includes a cushion member. The cushion member is sandwiched between the first metal layer and the second metal layer. The covering film is bonded to the support body. A composite of the second metal layer and the board is not bonded to the cushion member.

Abstract: A microstrip antenna includes a first metal layer that constitutes an antenna element, a second metal layer that constitutes a ground, and a flexible member that separates the first metal layer and the second metal layer by a predetermined distance. The first metal layer and the second metal layer each are made of a metal or a metal foil. At least one of the first metal layer and the second metal layer is not adhered to the flexible member but is in close contact with the flexible member by a close contact unit. The close contact unit is a clamping mechanism including a first plate, a second plate, and a connecting member. The first plate and the second plate are connected to each other by the connecting member. The connecting member is an elastic body.

Abstract: A power receiving device is disposed underwater. The power receiving device includes a housing formed of a weak magnetic material, a ferromagnetic body that surrounds an outer side of the housing and is formed of a ferromagnetic material, and a power receiving coil wound around an outer side of the ferromagnetic body.

Abstract: An electric power transmission device transmits electric power to an electric power reception device including an electric power reception coil in water. The electric power transmission device includes one or more transmission coils which include an electric power transmission coil configured to transmit electric power to the electric power reception coil via a magnetic field, an electric power transmitter, configured to transmit AC power to the electric power transmission coil, a capacitor which is connected to the transmission coil and forms a resonance circuit which resonates with the transmission coil, a first tubular member which is waterproof and seals a periphery of the transmission coil, a second tubular member which surrounds the first tubular member and includes a plurality of holes, and an adjuster, configured to adjust an amount of air in a gap between the first tubular member and the second tubular member.

Abstract: A power transmitting device transmits power to a power receiving device having a power receiving coil in water. The power transmitting device includes a power transmitting coil configured to transmit the power to the power receiving coil via a magnetic field. The power transmitting device also includes a support member that supports the power transmitting coil, and one or more spacers that hold the transmitting coil and the support member.

Abstract: A power transmitting device transmits power to a power receiving device having a power receiving coil, in water. The power transmitting device includes one or more annular transmitting coils including a power transmitting coil configured to transmit the power to the power receiving coil via a magnetic field, a support member located in an inner space of the transmitting coil, which is formed by the annular transmitting coil, the support member including an outer periphery along an inner periphery of the annular transmitting coil, and supporting the transmitting coil from the inner space, a power transmitting unit configured to supply A/C power to the power transmitting coil, and a capacitor connected to the transmitting coil, and forming a resonance circuit resonating together with the transmitting coil.

Abstract: A transmission coil configured to transmit electric power in water includes an annular electric wire through which an alternating current flows, and a first cover which includes non-conductive resin or non-magnetic resin and seals a periphery of the electric wire. The electric wire transmits the electric power via a magnetic field generated by flowing of the alternating current. The first cover includes a second cover which surrounds an outer peripheral surface of the electric wire in a radial direction with the non-conductive resin or the non-magnetic resin, and a self-bonding tape configured to seal an outer peripheral surface of the second cover.

Abstract: Provided is a transmission coil which can inhibit reduction in transmission efficiency during underwater non-contact electric power transmission. A transmission coil configured to transmit electric power in water includes an annular electric wire through which an alternating current flows, and a first cover which includes non-conductive resin or non-magnetic resin and seals a periphery of the electric wire. The electric wire transmits the electric power via a magnetic field generated by flowing of the alternating current.

Abstract: An antenna device includes a substrate having a ground conductor, an antenna conductor disposed approximately parallel with the ground conductor with an air layer or a dielectric layer, plural short-circuiting conductors that connect the antenna conductor to the ground conductor, and a feed conductor disposed in a vicinity of one of the plural short-circuiting conductors and that feeds the antenna conductor with power. When a wavelength of frequency used in the antenna device is represented by ?, an outer circumferential length of the slot is approximately 1? to 2? and a width of the slot is 0.005? to 0.05?, an interval between the plural short-circuiting conductors is shorter than or equal to ?/2, and a distance between the antenna conductor and the ground conductor is 0.005? to 0.05?.

Abstract: An electric power transmission device capable of efficiently performing contactless electric power transmission to an underwater vehicle in water is provided. The electric power transmission device, which is an electric power transmission device transmitting electric power to an electric power reception device including an electric power reception coil in water, includes one or more transmission coils including an electric power transmission coil which transmits electric power to an electric power reception coil via a magnetic field, an electric power transmission unit which transmits AC power to an electric power transmission coil, a capacitor which is connected to the transmission coil and forms a resonant circuit which resonates with the transmission coil, and a buoyant body connected to at least one of the transmission coils.

Abstract: Provided is a transmission coil which can inhibit reduction in transmission efficiency during underwater non-contact electric power transmission. A transmission coil configured to transmit electric power in water includes an annular electric wire through which an alternating current flows, and a first cover which includes non-conductive resin or non-magnetic resin and seals a periphery of the electric wire. The electric wire transmits the electric power via a magnetic field generated by flowing of the alternating current.

Abstract: An electric power transmission device transmits electric power to an electric power reception device including an electric power reception coil in water. The electric power transmission device includes one or more transmission coils which include an electric power transmission coil configured to transmit electric power to the electric power reception coil via a magnetic field, an electric power transmitter, configured to transmit AC power to the electric power transmission coil, a capacitor which is connected to the transmission coil and forms a resonance circuit which resonates with the transmission coil, a first tubular member which is waterproof and seals a periphery of the transmission coil, a second tubular member which surrounds the first tubular member and includes a plurality of holes, and an adjuster, configured to adjust an amount of air in a gap between the first tubular member and the second tubular member.

Abstract: A power transmission device transmits power underwater to a power reception device including a power reception coil. The power transmission device includes: a power transmission coil that transmits power to the power reception coil through a magnetic field; a power transmitter that transmits an alternating current power having a predetermined frequency to the power transmission coil; and a first capacitor that is connected to the power transmission coil and forms a resonance circuit resonating with the power transmission coil. The predetermined frequency is a frequency between a first frequency at which a geometric mean value of a Q value of the power transmission coil and a Q value of the power reception coil are the maximum and a second frequency at which the Q value of the power transmission coil and the Q value of the power reception coil are the same.

Abstract: A power transmitting device transmits power tower power receiving device having a power receiving coil, in water. The power transmitting device includes one or more annular transmitting coils including a power transmitting coil configured to transmit the power to the power receiving coil via a magnetic field, a support member located in an inner space of the transmitting coil, which is formed by the annular transmitting coil, the support member including an outer periphery along an inner periphery of the annular transmitting coil, and supporting the transmitting coil from the inner space, a power transmitting unit configured to supply A/C power to the power transmitting coil, and a capacitor connected to the transmitting coil, and forming a resonance circuit resonating together with the transmitting coil.