Abstract: A semiconductor device includes a substrate, a source electrode, a drain electrode, a first gate electrode extending in a first direction and provided between the source electrode and the drain electrode, a second gate electrode provided in a region between the source electrode and the drain electrode positioned in the first direction from the first gate electrode, a gate pad provided so as to dispose the first gate electrode between the gate pad and the second gate electrode, and electrically connected to the first gate electrode, a first gate line provided above the source electrode, a second gate line provided above the source electrode and extending in a second direction that crosses the first direction, and a first guard metal layer provided between the second gate line and the drain electrode, and having at least a portion provided between the drain electrode and the source electrode.

Abstract: A Doherty amplifier includes a divider configured to divide input power into first input power and second input power, and a carrier amplifier configured to amplify the first input power. The Doherty amplifier includes an adaptive attenuator configured to attenuate the second input power, the adaptive attenuator being configured to increase an attenuation amount upon detecting that the second input power is less than a predetermined value. The Doherty amplifier includes a peaking amplifier configured to amplify the attenuated second input power, and a combiner configured to combine output power of the carrier amplifier with output power of the peaking amplifier.

Abstract: A semiconductor device and an amplifier assembly implementing the semiconductor device are disclosed. The semiconductor device, which is a type of Doherty amplifier, includes first transistor elements for a carrier amplifier of the Doherty amplifier and second transistor elements for a peak amplifier. A feature of the Doherty amplifier is that the first transistor elements and the second transistor elements are disposed alternatively on a common semiconductor substrate.

Abstract: A power amplifier includes a first transistor with a gate to which input power is applied and a drain from which output power is provided, a bias circuit configured to apply a bias to the gate of the first transistor, and a coupler configured to distribute the input power to the gate of the first transistor and to the bias circuit. The bias circuit includes a voltage generator circuit including a second transistor with a gate to which the power distributed to the bias circuit by the coupler is applied, the voltage generator circuit being configured to generate a first DC voltage increasing in accordance with an increase in the power distributed to the bias circuit. The bias circuit includes a level shifter circuit configured to generate a second DC voltage increasing in accordance with an increase in the first DC voltage.

Abstract: A gas detect ion system includes: a sending aerial vehicle in which a light-emitting unit is installed; a small unmanned aerial vehicle including a receiving aerial vehicle in which a light-receiving unit is installed; a gas computing and displaying unit that computes and displays gas information; and a photographing-route computing unit that computes a photographing route for the small unmanned aerial vehicle. The receiving aerial vehicle receives light from the light-emitting unit of the sending aerial vehicle by using the light-receiving unit thereof and sends the result as gas data to the gas computing and displaying unit. The gas computing and displaying unit computes the gas information from the gas data. The photographing-route computing unit computes the photographing route from the position of the small unmanned aerial vehicle and the amount of energy remaining in the small unmanned aerial vehicle.

Abstract: A Doherty amplifier includes a divider configured to divide input power into first input power and second input power, and a carrier amplifier configured to amplify the first input power. The Doherty amplifier includes an adaptive attenuator configured to attenuate the second input power, the adaptive attenuator being configured to increase an attenuation amount upon detecting that the second input power is less than a predetermined value. The Doherty amplifier includes a peaking amplifier configured to amplify the attenuated second input power, and a combiner configured to combine output power of the carrier amplifier with output power of the peaking amplifier.

Abstract: A power amplifier includes a first transistor with a gate to which input power is applied and a drain from which output power is provided, a bias circuit configured to apply a bias to the gate of the first transistor, and a coupler configured to distribute the input power to the gate of the first transistor and to the bias circuit. The bias circuit includes a voltage generator circuit including a second transistor with a gate to which the power distributed to the bias circuit by the coupler is applied, the voltage generator circuit being configured to generate a first DC voltage increasing in accordance with an increase in the power distributed to the bias circuit. The bias circuit includes a level shifter circuit configured to generate a second DC voltage increasing in accordance with an increase in the first DC voltage.

Abstract: In order to facilitate impedance matching even when using a magnetic field antenna for power transmission in a medium, this underwater wireless power supply device 101 wirelessly transmits energy by resonating at a frequency determined by the impedance of a power transmission antenna 103, the impedance of a power receiving antenna 104, and the impedance of a good conductor medium 102. The power transmission antenna 103 and the power receiving antenna 104 have multiple antenna coils 1061, and multiple resonant antenna units 1051 to 1054 having at least one dielectric 1071 arranged between the multiple antenna coils 1061, and, at least one of the multiple resonant antenna units 1051 to 1054 is provided with a load adjustment mechanism 1081 for adjusting the load.

Abstract: In order to reduce a power transmission antenna and power receiving antenna of a wireless power supply device for supplying power underwater to a size suitable for an underwater mobile body and sensor, this underwater wireless power supply device 101 wirelessly transmits energy by resonating at a frequency determined by the impedance of a power transmission antenna 103 that transmits energy wirelessly in a good conductor medium 102, the impedance of a power receiving antenna 104 which receives energy transmitted from the power transmission antenna 103, and the impedance of the good conductor medium 102. The power transmission antenna 103 and the power receiving antenna 104 have the multiple antenna coils 105, 106, and at least one dielectric 107, 108 arranged between the multiple antenna coils 105, 106, and the multiple antenna coils 105, 106 each has multiple laminated coils 109.

Abstract: A semiconductor device and an amplifier assembly implementing the semiconductor device are disclosed. The semiconductor device, which is a type of Doherty amplifier, includes first transistor elements for a carrier amplifier of the Doherty amplifier and second transistor elements for a peak amplifier. A feature of the Doherty amplifier is that the first transistor elements and the second transistor elements are disposed alternatively on a common semiconductor substrate.

Abstract: A spectroscopic device and the like that are capable of fast spectral dispersion are provided. The spectroscopic device includes: a modulation unit for converting wavefront shapes of light according to wavelengths; and a demodulation unit for changing a phase of light of a selected wavelength within the light whose wavefront shapes have been converted, in such a way that the light changes into a predetermined state.

Abstract: A semiconductor device and an amplifier assembly implementing the semiconductor device are disclosed. The semiconductor device, which is a type of Doherty amplifier, includes first transistor elements for a carrier amplifier of the Doherty amplifier and second transistor elements for a peak amplifier. A feature of the Doherty amplifier is that the first transistor elements and the second transistor elements are disposed alternatively on a common semiconductor substrate.

Abstract: In order to provide an underwater radio communication system which stably uses wideband modulated signal to communicate with electromagnetic waves, this underwater radio communication system, for communicating underwater between a transmission unit and a receiving unit with electromagnetic waves, has a distortion compensation unit which compensates for distortion resulting from propagation in water in accordance with the frequency of the electromagnetic waves.

Abstract: A spectroscopic device and the like that are capable of fast spectral dispersion are provided. The spectroscopic device includes: a modulation unit for converting wavefront shapes of light according to wavelengths; and a demodulation unit for changing a phase of light of a selected wavelength within the light whose wavefront shapes have been converted, in such a way that the light changes into a predetermined state.

Abstract: Provided are a gas detection system and a gas detection method utilizing a plurality of aerial vehicles, which enable precise detection in a short time. The gas detection system includes: a sending aerial vehicle in which a light-emitting unit is installed; a small unmanned aerial vehicle including a receiving aerial vehicle in which a light-receiving unit is installed; a gas computing and displaying unit that computes and displays gas information; and a photographing-route computing unit that computes a photographing route for the small unmanned aerial vehicle. The receiving aerial vehicle receives light from the light-emitting unit of the sending aerial vehicle by using the light-receiving unit thereof and sends the result as gas data to the gas computing and displaying unit. The gas computing and displaying unit computes the gas information from the gas data.

Abstract: In order to facilitate impedance matching even when using a magnetic field antenna for power transmission in a medium, this underwater wireless power supply device 101 wirelessly transmits energy by resonating at a frequency determined by the impedance of a power transmission antenna 103, the impedance of a power receiving antenna 104, and the impedance of a good conductor medium 102. The power transmission antenna 103 and the power receiving antenna 104 have multiple antenna coils 1061, and multiple resonant antenna units 1051 to 1054 having at least one dielectric 1071 arranged between the multiple antenna coils 1061, and, at least one of the multiple resonant antenna units 1051 to 1054 is provided with a load adjustment mechanism 1081 for adjusting the load.

Abstract: In order to reduce a power transmission antenna and power receiving antenna of a wireless power supply device for supplying power underwater to a size suitable for an underwater mobile body and sensor, this underwater wireless power supply device 101 wirelessly transmits energy by resonating at a frequency determined by the impedance of a power transmission antenna 103 that transmits energy wirelessly in a good conductor medium 102, the impedance of a power receiving antenna 104 which receives energy transmitted from the power transmission antenna 103, and the impedance of the good conductor medium 102. The power transmission antenna 103 and the power receiving antenna 104 have the multiple antenna coils 105, 106, and at least one dielectric 107, 108 arranged between the multiple antenna coils 105, 106, and the multiple antenna coils 105, 106 each has multiple laminated coils 109.

Abstract: In order to provide an underwater radio communication system which stably uses wideband modulated signal to communicate with electromagnetic waves, this underwater radio communication system 1, for communicating underwater between a transmission unit 10 and a receiving unit 20 with electromagnetic waves, has a distortion compensation unit 12 which compensates for distortion resulting from propagation in water in accordance with the frequency of the electromagnetic waves.

Abstract: A semiconductor device and an amplifier assembly implementing the semiconductor device are disclosed. The semiconductor device, which is a type of Doherty amplifier, includes first transistor elements for a carrier amplifier of the Doherty amplifier and second transistor elements for a peak amplifier. A feature of the Doherty amplifier is that the first transistor elements and the second transistor elements are disposed alternatively on a common semiconductor substrate.

Abstract: The present invention provides a power transfer system capable of reducing electromagnetic energy that disappears into a medium as a resistor when the coil of a power transmitting device and the coil of a power receiving device are apart from each other, in such a way that the power transmitting device of the power transfer system is equipped with a backside dielectric body and a shield body. A power transmitting device (11) faces a power receiving device (12) through a medium.