摘要:
A field effect transistor and a ballistic transistor using semiconductor whiskers each having a desired diameter and formed at s desired location, a semiconductor vacuum microelectronic device using the same as electron emitting materials, a light emitting device using the same as quantum wires and the like are disclosed.
摘要:
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.
摘要:
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.
摘要:
A transparent body inspecting device includes: a light application unit for applying light to a transparent body; an image capturing unit which captures an image of the transparent body and in which a depth of field is smaller than a height of the transparent body; an image capture driving unit for moving the image capturing unit in a direction in which the image capturing unit is brought close to the transparent body and in a direction in which the image capturing unit is brought away from the transparent body; and a defect determining unit for determining existence or nonexistence of a defect in the transparent body based on whether or not brightness of pixels in the image captured by the image capturing unit is nonuniform, wherein: the image capturing unit carries out image capture more than once while moving in the direction in which the image capturing unit is brought close to the transparent body or in the direction in which the image capturing unit is brought away from the transparent body; and when the brightness of pixels in the image captured by the image capturing unit is nonuniform, the defect determining unit determines that a defect exists within the depth of field at the time of capture of this image.
摘要:
The present invention provides a semiconductor device which comprises active components, passive components, wiring lines and electrodes and are satisfactory in terms of mechanical strength, miniaturization and thermal stability. In the semiconductor device, openings are formed just below active components. These openings are filled with conductor layers. Conductor layers are also formed where openings are not formed.
摘要:
Disclosed is a power amplifier having highly stable and excellent controllability, and having low noise in comparison with conventional power amplifiers. With the power amplifier, a differential amplifier made up of transistors Q1, Q2 is provided in the initial stage thereof, and baluns doubling as inter-stage matching circuits, comprised of Cp1, Cp2, Lp1, and Ct1, Ct2, Lt1, respectively, are provided between the initial stage, and a second stage while an unbalanced single-ended circuit is provided in the second stage. The differential amplifier has an emitter-coupled type configuration for coupling both emitters with each other, and output control of the amplifier in the initial stage is executed by varying current of a current source coupled to both the emitters.
摘要:
The RF power amplifier includes first and second amplifiers Q1 and Q2 as final-stage amplification power devices connected in parallel between an input terminal RF_In and an output terminal RF_Out. The amplifiers Q1 and Q2 are formed on one semiconductor chip. The first bias voltage Vg1 of the amplifier Q1 is set to be higher than the second bias voltage Vg2 of the amplifier Q2 so that the amplifier Q1 is operational between Class B and AB, and Q2 is operational in Class C. The first effective device size Wgq1 of the amplifier Q1 is intentionally set to be smaller than the second effective device size Wgq2 of the amplifier Q2 beyond a range of a manufacturing error of the semiconductor chip. An RF power amplifier that exhibits a high power-added efficiency characteristic regardless of whether the output power is High or Low can be materialized.
摘要:
In a base-bias-control-type high-frequency power amplifier with a plural stage configuration, a rising voltage of a base bias current supplied to an initial stage transistor is made lower than a rising voltage of a base bias current supplied to a second stage transistor by a bias circuit, and a difference between the both voltages is set to be smaller than a base-emitter voltage of an amplifying stage transistor. Also, a rising voltage of a base bias current supplied to a third stage transistor is made equal to the rising voltage of the base bias current supplied to an initial stage transistor. Accordingly, a technology capable of improving the power control linearity can be provided in a high-frequency power amplifier used in a polar-loop transmitter or the like.
摘要:
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.
摘要:
For use in an amplifier configuration including a high-power amplifier and a low-power amplifier which are always interconnected in terms of high frequencies and between which switching is made using no switches, a highly stable high-frequency power amplifier module with high isolation between the amplifiers is provided. To reduce wrapping around from a low-power amplifier section in an activated state to a high-power amplifier section in a deactivated state or from the high-power amplifier section in an activated state to the low-power amplifier section in a deactivated state, an input matching circuit having high isolation characteristics is included in an input matching circuit portion which does not have much to do with amplifier efficiency. Switching of each of the amplifier sections between an activated state and a deactivated state is effected by control using bias input terminals.