Abstract: A differential amplifying apparatus includes an input matching circuit serving as an input balun to which a signal inputted to an input terminal is input, an output matching circuit serving as an output balun that outputs a signal to an output terminal, first and second amplifiers provided in parallel between the input balun and the output balun and configured to output a differential signal, a diode provided between a reference potential and a path between the input balun and the first amplifier, a second diode provided between a reference potential and a path between the input balun and the second amplifier, and a bias circuit that applies a bias to the first diode and the second diode, in which a cathode of the first diode and a cathode of the second diode are connected to the reference potential side.

Abstract: A power amplifier circuit includes a first power supply terminal electrically connected to a first power amplifier; a second power supply terminal electrically connected to a second power amplifier subsequent to the first power amplifier; a first external power supply line configured to electrically connect a power supply circuit configured to output a power supply potential corresponding to an amplitude level of a high-frequency input signal and the first power supply terminal; and a second external power supply line configured to electrically connect the power supply circuit and the second power supply terminal. An inductance value of the first external power supply line is higher than an inductance value of the second external power supply line.

Abstract: A power amplifier includes power amplification circuits in a plurality of stages including a first stage and a second stage, each power amplification circuit including a transistor. The power amplification circuit in the first stage includes a first impedance circuit between an emitter of the transistor and a reference potential. The first impedance circuit has an impedance that does not vary with frequency or an impedance that varies with frequency. The power amplification circuit in the second stage includes a second impedance circuit between an emitter of the transistor and a reference potential. The second impedance circuit has an impedance that does not vary with frequency or an impedance that varies with frequency.

Abstract: A power amplifier circuit includes an amplifier transistor, a bias circuit that supplies a bias current or voltage to the amplifier transistor, and a resistance element connected between a base of the amplifier transistor and the bias circuit. The bias circuit includes a voltage generation circuit, a first transistor having a base to which a first direct-current voltage is supplied and an emitter from which the bias current or voltage is supplied, a second transistor having a base to which a second direct-current voltage is supplied and an emitter connected to the emitter of the first transistor, a signal supply circuit that supplies an input signal to the base of the second transistor, and an impedance circuit disposed between the base of the first transistor and the base of the second transistor.

Abstract: Reduction in impedance in a lead connected to a semiconductor element is achieved while achieving anchor effect. The semiconductor device includes a heatsink, a semiconductor element, a lead disposed on an upper side of the heatsink, and a molding material formed to cover the lead, the heatsink, and the semiconductor element. Formed on an edge portion of a lower surface in a position, in the heatsink, overlapping with the lead in a plan view is a first convex portion protruding more than an edge portion of an upper surface in the position, and formed on an edge portion of an upper surface in a position, in the heatsink, which does not overlap with the lead in a plan view is a second convex portion protruding more than an edge portion of a lower surface in the position.

Abstract: A power amplifier circuit includes an amplifier transistor, a bias circuit that supplies a bias current or voltage to the amplifier transistor, and a resistance element connected between a base of the amplifier transistor and the bias circuit. The bias circuit includes a voltage generation circuit, a first transistor having a base to which a first direct-current voltage is supplied and an emitter from which the bias current or voltage is supplied, a second transistor having a base to which a second direct-current voltage is supplied and an emitter connected to the emitter of the first transistor, a signal supply circuit that supplies an input signal to the base of the second transistor, and an impedance circuit disposed between the base of the first transistor and the base of the second transistor.

Abstract: A power amplifier circuit includes a first power supply terminal electrically connected to a first power amplifier; a second power supply terminal electrically connected to a second power amplifier subsequent to the first power amplifier; a first external power supply line configured to electrically connect a power supply circuit configured to output a power supply potential corresponding to an amplitude level of a high-frequency input signal and the first power supply terminal; and a second external power supply line configured to electrically connect the power supply circuit and the second power supply terminal. An inductance value of the first external power supply line is higher than an inductance value of the second external power supply line.

Abstract: A power amplifier circuit includes an amplifier transistor, a bias circuit that supplies a bias current or voltage to the amplifier transistor, and a resistance element connected between a base of the amplifier transistor and the bias circuit. The bias circuit includes a voltage generation circuit, a first transistor having a base to which a first direct-current voltage is supplied and an emitter from which the bias current or voltage is supplied, a second transistor having a base to which a second direct-current voltage is supplied and an emitter connected to the emitter of the first transistor, a signal supply circuit that supplies an input signal to the base of the second transistor, and an impedance circuit disposed between the base of the first transistor and the base of the second transistor.

Abstract: Reduction in impedance in a lead connected to a semiconductor element is achieved while achieving anchor effect. The semiconductor device includes a heatsink, a semiconductor element, a lead disposed on an upper side of the heatsink, and a molding material formed to cover the lead, the heatsink, and the semiconductor element. Formed on an edge portion of a lower surface in a position, in the heatsink, overlapping with the lead in a plan view is a first convex portion protruding more than an edge portion of an upper surface in the position, and formed on an edge portion of an upper surface in a position, in the heatsink, which does not overlap with the lead in a plan view is a second convex portion protruding more than an edge portion of a lower surface in the position.

Abstract: A power amplifier module includes a first transistor that amplifies and outputs a radio frequency signal, a second transistor smaller in size than the first transistor and connected in parallel with the first transistor, a third transistor that supplies a bias current to the first and second transistors, a current detection circuit that detects a current flowing through a collector of the second transistor, and a bias control circuit that controls the bias current supplied from the third transistor to the first and second transistors by supplying a current corresponding to a detection result of the current detection circuit to a collector or a drain of the third transistor. In a case that a current flowing through the collector of the second transistor is larger than a predetermined threshold value, the bias control circuit reduces the current supplied to the collector or the drain of the third transistor.

Abstract: A power amplifier circuit includes an amplifier transistor, a bias circuit that supplies a bias current or voltage to the amplifier transistor, and a resistance element connected between a base of the amplifier transistor and the bias circuit. The bias circuit includes a voltage generation circuit, a first transistor having a base to which a first direct-current voltage is supplied and an emitter from which the bias current or voltage is supplied, a second transistor having a base to which a second direct-current voltage is supplied and an emitter connected to the emitter of the first transistor, a signal supply circuit that supplies an input signal to the base of the second transistor, and an impedance circuit disposed between the base of the first transistor and the base of the second transistor.

Abstract: A power amplifier includes power amplification circuits in a plurality of stages including a first stage and a second stage, each power amplification circuit including a transistor. The power amplification circuit in the first stage includes a first impedance circuit between an emitter of the transistor and a reference potential. The first impedance circuit has an impedance that does not vary with frequency or an impedance that varies with frequency. The power amplification circuit in the second stage includes a second impedance circuit between an emitter of the transistor and a reference potential. The second impedance circuit has an impedance that does not vary with frequency or an impedance that varies with frequency.

Abstract: A power amplifier module includes a first transistor that amplifies and outputs a radio frequency signal, a second transistor smaller in size than the first transistor and connected in parallel with the first transistor, a third transistor that supplies a bias current to the first and second transistors, a current detection circuit that detects a current flowing through a collector of the second transistor, and a bias control circuit that controls the bias current supplied from the third transistor to the first and second transistors by supplying a current corresponding to a detection result of the current detection circuit to a collector or a drain of the third transistor. In a case that a current flowing through the collector of the second transistor is larger than a predetermined threshold value, the bias control circuit reduces the current supplied to the collector or the drain of the third transistor.

Abstract: A comparator 13 that detects the difference between a high frequency signal detected by a detector 12 and a feedback signal A output from a comparator 11; a comparator 14 that detects the difference between the difference detected by the comparator 13 and a feedback signal B output from an adder 18; and a loop filter 15 that passes only a prescribed low frequency band of the output signal of the comparator 14 are provided, in which an amplitude sensitivity adjuster 16 adjusts the amplitude sensitivity of a variable gain amplifier 3 in accordance with the rate of change of the signal passing through the loop filter 15, thereby controlling the gain of the variable gain amplifier 3.

Abstract: An illumination apparatus includes a light emitting unit configured to emit illumination light including a first light having a first peak wavelength of a first peak in a first wavelength range of 495 nm to 510 nm and a second light having a second peak wavelength of a second peak in a second wavelength range of 610 nm to 680 nm. In the illumination apparatus, an intensity of the second light at the second peak wavelength is higher than an intensity of the first light at the first peak wavelength.

Abstract: A plurality of source-grounded transistors (3) are connected in parallel with each other, and a plurality of gate-grounded transistors (4) are connected in parallel with each other. Sources (4s) of the plurality of gate-grounded transistors (4) are connected to drains (3d) of the plurality of source-grounded transistors (3) respectively. Ground pads (5) are connected to sources (3s) of the plurality of source-grounded transistors (3). A plurality of grounding capacitances (6) are connected between gates (4g) of the plurality of gate-grounded transistors (4) and the ground pads (5). The plurality of source-grounded transistors (3) and the plurality of grounding capacitances (6) are alternately arranged between the ground pads (5) and the plurality of gate-grounded transistors (4).

Abstract: A comparator 13 that detects the difference between a high frequency signal detected by a detector 12 and a feedback signal A output from a comparator 11; a comparator 14 that detects the difference between the difference detected by the comparator 13 and a feedback signal B output from an adder 18; and a loop filter 15 that passes only a prescribed low frequency band of the output signal of the comparator 14 are provided, in which an amplitude sensitivity adjuster 16 adjusts the amplitude sensitivity of a variable gain amplifier 3 in accordance with the rate of change of the signal passing through the loop filter 15, thereby controlling the gain of the variable gain amplifier 3.

Abstract: An amplifier circuit is configured in such a manner that the withstand voltage between the terminals of a FET 2 (withstand voltage B) is higher than the withstand voltage between the terminals of a FET 1 (withstand voltage A), and that the gate width of the FET 1 (Wg1) is narrower than the gate width of the FET 2 (Wg2). This makes it possible to increase the gain while maintaining high output power. The narrow gate width of the FET 1 (Wg1) connected to an input terminal 3 enables reducing the size of the cascode amplifier.

Abstract: A high-frequency amplifier module includes a driver-stage amplifier 3 that amplifies an RF signal input thereto from an RF input terminal 1, and a final-stage amplifier 5 that amplifies the signal amplified by the driver-stage amplifier 3 and outputs the signal after the amplification to an RF output terminal 7. The driver-stage amplifier 3 is fabricated on a silicon substrate 11, while the final-stage amplifier 5 is fabricated on a gallium arsenide substrate. This configuration downsizes the cost while maintaining a high-frequency characteristic comparable to that in the case where all components of an entire module are fabricated on a gallium arsenide substrate 71.

Abstract: A front-end amplifier has an impedance detector that detects an impedance seen looking into an antenna side from a power amplifier from a radio-frequency signal output from the power amplifier and a radio-frequency signal reflected from the antenna, in which a control circuit decides on whether the impedance detected by the impedance detector belongs to a specific region or not, and controls, if the impedance belongs to the specific region, at least one of the bias condition of the power amplifier and the impedance of a variable-matching circuit.