Abstract: A power amplifier module includes an amplifier transistor and a bias circuit. A first power supply voltage based on a first operation mode or a second power supply voltage based on a second operation mode is supplied to the amplifier transistor. The amplifier transistor receives a first signal and outputs a second signal obtained by amplifying the first signal. The bias circuit supplies a bias current to the amplifier transistor. The bias circuit includes first and second resistors and first and second transistors. The first transistor is connected in series with the first resistor and is turned ON by a first bias control voltage which is supplied when the first operation mode is used. The second transistor is connected in series with the second resistor and is turned ON by a second bias control voltage which is supplied when the second operation mode is used.

Abstract: A power amplifier module includes an amplifier transistor and a bias circuit. A first power supply voltage based on a first operation mode or a second power supply voltage based on a second operation mode is supplied to the amplifier transistor. The amplifier transistor receives a first signal and outputs a second signal obtained by amplifying the first signal. The bias circuit supplies a bias current to the amplifier transistor. The bias circuit includes first and second resistors and first and second transistors. The first transistor is connected in series with the first resistor and is turned ON by a first bias control voltage which is supplied when the first operation mode is used. The second transistor is connected in series with the second resistor and is turned ON by a second bias control voltage which is supplied when the second operation mode is used.

Abstract: Improvement in linearity is achieved at low costs in a power amplifier module employing an envelope tracking system. The power amplifier module includes a first power amplifier circuit that amplifies a radio frequency signal and that outputs a first amplified signal, a second power amplifier circuit that amplifies the first amplified signal on the basis of a source voltage varying depending on amplitude of the radio frequency signal and that outputs a second amplified signal, and a matching circuit that includes first and second capacitors connected in series between the first and second power amplifier circuit and an inductor connected between a node between the first and second capacitors and a ground and that decreases a gain of the first power amplifier circuit as the source voltage of the second power amplifier circuit increases.

Abstract: Improvement in linearity is achieved at low costs in a power amplifier module employing an envelope tracking system. The power amplifier module includes a first power amplifier circuit that amplifies a radio frequency signal and that outputs a first amplified signal, a second power amplifier circuit that amplifies the first amplified signal on the basis of a source voltage varying depending on amplitude of the radio frequency signal and that outputs a second amplified signal, and a matching circuit that includes first and second capacitors connected in series between the first and second power amplifier circuit and an inductor connected between a node between the first and second capacitors and a ground and that decreases a gain of the first power amplifier circuit as the source voltage of the second power amplifier circuit increases.

Abstract: Improvement in linearity is achieved at low costs in a power amplifier module employing an envelope tracking system. The power amplifier module includes a first power amplifier circuit that amplifies a radio frequency signal and that outputs a first amplified signal, a second power amplifier circuit that amplifies the first amplified signal on the basis of a source voltage varying depending on amplitude of the radio frequency signal and that outputs a second amplified signal, and a matching circuit that includes first and second capacitors connected in series between the first and second power amplifier circuit and an inductor connected between a node between the first and second capacitors and a ground and that decreases a gain of the first power amplifier circuit as the source voltage of the second power amplifier circuit increases.

Abstract: A power amplifier module includes an amplifier transistor and a bias circuit. A first power supply voltage based on a first operation mode or a second power supply voltage based on a second operation mode is supplied to the amplifier transistor. The amplifier transistor receives a first signal and outputs a second signal obtained by amplifying the first signal. The bias circuit supplies a bias current to the amplifier transistor. The bias circuit includes first and second resistors and first and second transistors. The first transistor is connected in series with the first resistor and is turned ON by a first bias control voltage which is supplied when the first operation mode is used. The second transistor is connected in series with the second resistor and is turned ON by a second bias control voltage which is supplied when the second operation mode is used.

Abstract: Improvement in linearity is achieved at low costs in a power amplifier module employing an envelope tracking system. The power amplifier module includes a first power amplifier circuit that amplifies a radio frequency signal and that outputs a first amplified signal, a second power amplifier circuit that amplifies the first amplified signal on the basis of a source voltage varying depending on amplitude of the radio frequency signal and that outputs a second amplified signal, and a matching circuit that includes first and second capacitors connected in series between the first and second power amplifier circuit and an inductor connected between a node between the first and second capacitors and a ground and that decreases a gain of the first power amplifier circuit as the source voltage of the second power amplifier circuit increases.

Abstract: An envelope tracking system is employed in a power amplification module that supports multiple frequency bands. The power amplification module includes multiple power amplification circuits, each of which includes: a first transformer to which a radio frequency signal is input; a differential amplification circuit, in which a first radio frequency signal output from transformer is input to a control electrode and in which a second radio frequency signal output from the transformer is input to a control electrode, the differential amplification circuit outputting an amplified signal obtained by amplifying a difference between the first and second radio frequency signals; and a second transformer for supplying, to the first differential amplification circuit, power-supply voltage varying according to the amplitude of the radio frequency signal and to which the first amplified signal is input.

Abstract: When a power amplifier mounted in mobile communications equipment, such as a mobile-phone, is composed of a balanced amplifier, technology with which the loss of the electric power composition in a power combiner can be reduced is provided. According to the technical idea of the present embodiment, by dividing an isolation capacitor element into two capacitor elements with high symmetry and coupled in parallel, it is possible to make almost equal parasitic capacitance arising from these capacitor elements, even when the capacitor elements are formed as interlayer capacitor elements of the wiring substrate.

Abstract: There are provided a conductive nanowire network, a conductive board and transparent electrode utilizing it, and a method for producing the same. The conductive nanowire network of the invention has essentially unbroken, continuous conductive nanowires randomly formed into a network. In the method for producing a conductive nanowire network according to the invention, nanofibers are applied in a random network-like fashion onto a substrate covered with a conductive layer, the conductive layer regions that are not covered with the nanofibers are removed, and then the nanofibers are removed. The network structure (wire diameter and network density) are also controlled to obtain a transparent electrode exhibiting both transparency and conductivity.

Abstract: Linearity and power efficiency in a power amplifier circuit are enhanced. The power amplifier circuit includes a first transistor that amplifies a signal input to the base and that outputs the amplified signal from the collector and a first capacitor that is disposed between the base and the collector of the first transistor and that has voltage dependency of a capacitance value lower than that of a base-collector parasitic capacitance value of the first transistor.

Abstract: Linearity and power efficiency in a power amplifier circuit are enhanced. The power amplifier circuit includes a first transistor that amplifies a signal input to the base and that outputs the amplified signal from the collector and a first capacitor that is disposed between the base and the collector of the first transistor and that has voltage dependency of a capacitance value lower than that of a base-collector parasitic capacitance value of the first transistor.

Abstract: Improvement in linearity is achieved at low costs in a power amplifier module employing an envelope tracking system. The power amplifier module includes a first power amplifier circuit that amplifies a radio frequency signal and that outputs a first amplified signal, a second power amplifier circuit that amplifies the first amplified signal on the basis of a source voltage varying depending on amplitude of the radio frequency signal and that outputs a second amplified signal, and a matching circuit that includes first and second capacitors connected in series between the first and second power amplifier circuit and an inductor connected between a node between the first and second capacitors and a ground and that decreases a gain of the first power amplifier circuit as the source voltage of the second power amplifier circuit increases.

Abstract: An air-conditioning duct for vehicles with one duct mutually connected and fixed to the other duct is provided. One duct is formed by incorporating a first unit duct with a flange formed around an opening periphery thereof and a second unit duct with a flange formed around an opening periphery thereof in parallel. The other duct is formed by incorporating a third unit duct with a flange formed around an opening periphery thereof and a fourth unit duct with a flange formed around an opening periphery thereof in parallel. The flange formed on the boundary side of the second unit duct are fixed with one over another, and the flange formed on the boundary side of the third unit duct and the flange formed on the boundary side of the fourth unit duct are fixed with one over another.

Abstract: A transparent body inspecting device includes a light application unit, an image capturing unit, an image capture driving unit, and a defect determining unit. The image capturing unit is moved in the directions in which the image capturing unit is brought close to and away from the upper surface of the transparent body, and the image capturing unit captures a plurality of images of the transparent body during the movement. The images are captured while the position of the depth of field of the image capturing unit is adjusted to more than one spots inside the transparent body. When brightness of pixels in the captured image is nonuniform, the defect determining unit determines that a defect exists within the depth of field at the time of capture of the image.

Abstract: A duct installation structure in which an air conditioning duct for sending warm air or cold air into a vehicle interior of an automobile is attached to a vehicle interior structure member and an outlet grill is attached to an outlet opening end portion of the air conditioning duct. A grill fixing portion to which the outlet grill is to be fixed is integrally molded with a duct main body portion at the outlet opening end portion of the air conditioning duct. The outlet grill is directly fixed to the grill fixing portion. The outlet opening end portion of the air conditioning duct including, at one point near its center in a width direction, a fastening fixing portion that is fastened and fixed to the vehicle interior structure member and including, at its opposite ends in the width direction, a pair of contact portions for coming in contact with the vehicle interior structure member.

Abstract: A high frequency power amplifier maintains an excellent linearity regardless of a fluctuation of a load impedance and is downsized. The high frequency power amplifier detects an AC voltage amplitude at an output terminal of a final amplification stage transistor, and suppresses an input signal amplitude of a power amplifier when the voltage amplitude exceeds a predetermined threshold value.

Abstract: A high frequency power amplifier maintains an excellent linearity regardless of a fluctuation of a load impedance and is downsized. The high frequency power amplifier detects an AC voltage amplitude at an output terminal of a final amplification stage transistor, and suppresses an input signal amplitude of a power amplifier when the voltage amplitude exceeds a predetermined threshold value.

Abstract: A high frequency power amplifier maintains an excellent linearity regardless of a fluctuation of a load impedance and is downsized. The high frequency power amplifier detects an AC voltage amplitude at an output terminal of a final amplification stage transistor, and suppresses an input signal amplitude of a power amplifier when the voltage amplitude exceeds a predetermined threshold value.

Abstract: When a power amplifier mounted in mobile communications equipment, such as a mobile-phone, is composed of a balanced amplifier, technology with which the loss of the electric power composition in a power combiner can be reduced is provided. According to the technical idea of the present embodiment, by dividing an isolation capacitor element into two capacitor elements with high symmetry and coupled in parallel, it is possible to make almost equal parasitic capacitance arising from these capacitor elements, even when the capacitor elements are formed as interlayer capacitor elements of the wiring substrate.