Abstract: A power amplifier circuit amplifies a radio-frequency signal in a transmit frequency band. The power amplifier circuit includes an amplifier, a bias circuit, and an impedance circuit. The amplifier amplifies power of a radio-frequency signal and outputs an amplified signal. The impedance circuit is connected between a signal input terminal of the amplifier and a bias-current output terminal of the bias circuit and has frequency characteristics in which attenuation is obtained in the transmit frequency band. The impedance circuit includes first and second impedance circuits. The first impedance circuit is connected to the signal input terminal. The second impedance circuit is connected between the first impedance circuit and the bias-current output terminal.

Abstract: A high-frequency signal processing apparatus and a wireless communication apparatus can achieve a decrease in power consumption. For example, when an indicated power level to a high-frequency power amplifier is equal to or greater than a second reference value, envelope tracking is performed by causing a source voltage control circuit to control a high-speed DCDC converter using a detection result of an envelope detecting circuit and causing a bias control circuit to indicate a fixed bias value. The source voltage control circuit and the bias control circuit indicate a source voltage and a bias value decreasing in proportion to a decrease in the indicated power level when the indicated power level is in a range of the second reference value to the first reference value, and indicate a fixed source voltage and a fixed bias value when the indicated power level is less than the first reference value.

Abstract: An amplifier circuit including a semiconductor element is formed on a substrate. A protection circuit is formed including a plurality of protection diodes that are formed on the substrate and that are connected in series with each other, the protection circuit being connected to an output terminal of the amplifier circuit. A pad conductive layer is formed that at least partially includes a pad for connecting to a circuit outside the substrate. An insulating protective film covers the pad conductive layer. The insulating protective film includes an opening that exposes a partial area of a surface of the pad conductive layer, and that covers another area. A first bump is formed on the pad conductive layer on a bottom surface of the opening, and a second bump at least partially overlaps the protection circuit in plan view and is connected to a ground (GND) potential connected to the amplifier circuit.

Abstract: A semiconductor device includes two cell rows, each of which is formed of a plurality of transistor cells aligned in parallel to each other. Each of the plurality of transistor cells includes a collector region, a base region, and an emitter region that are disposed above a substrate. A plurality of collector extended wiring lines are each connected to the collector region of a corresponding one of the plurality of transistor cells and are extended in a direction intersecting an alignment direction of the plurality of transistor cells. A collector integrated wiring line connects the plurality of collector extended wiring lines to each other. A collector intermediate integrated wiring line that is disposed between the two cell rows in plan view connects the plurality of collector extended wring lines extended from the plurality of transistor cells that belong to one of the two cell rows to each other.

Abstract: A power amplifier includes initial-stage and output-stage amplifier circuits, and initial-stage and output-stage bias circuits. The initial-stage amplifier circuit includes a first high electron mobility transistor having a source electrically connected to a reference potential, and a gate to which a radio-frequency input signal is inputted, and a first heterojunction bipolar transistor having an emitter electrically connected to a drain of the first high electron mobility transistor, a base electrically connected to the reference potential in an alternate-current fashion, and a collector to which direct-current power is supplied and from which a radio-frequency signal is outputted.

Abstract: A high-frequency signal processing apparatus and a wireless communication apparatus can achieve a decrease in power consumption. For example, when an indicated power level to a high-frequency power amplifier is equal to or greater than a second reference value, envelope tracking is performed by causing a source voltage control circuit to control a high-speed DCDC converter using a detection result of an envelope detecting circuit and causing a bias control circuit to indicate a fixed bias value. The source voltage control circuit and the bias control circuit indicate a source voltage and a bias value decreasing in proportion to a decrease in the indicated power level when the indicated power level is in a range of the second reference value to the first reference value, and indicate a fixed source voltage and a fixed bias value when the indicated power level is less than the first reference value.

Abstract: A semiconductor device includes a plurality of unit transistors that are arranged on a surface of a substrate in a first direction. Input capacitive elements are arranged so as to correspond to the unit transistors. An emitter common wiring line is connected to emitter layers of the unit transistors. A via-hole extending from the emitter common wiring line to a back surface of the substrate is disposed at a position overlapping the emitter common wiring line. A collector common wiring line is connected to collector layers of the unit transistors. The input capacitive elements, the emitter common wiring line, the unit transistors, and the collector common wiring line are arranged in this order in a second direction. Base wiring lines that connect the input capacitive elements to base layers of the corresponding unit transistors intersect the emitter common wiring line without physical contact.

Abstract: A bipolar transistor includes a collector layer, a base layer, and an emitter layer that are formed in this order on a compound semiconductor substrate. The emitter layer is disposed inside an edge of the base layer in plan view. A base electrode is disposed on partial regions of the emitter layer and the base layer so as to extend from an inside of the emitter layer to an outside of the base layer in plan view. An insulating film is disposed between the base electrode and a portion of the base layer, with the portion not overlapping the emitter layer. An alloy layer extends from the base electrode through the emitter layer in a thickness direction and reaches the base layer. The alloy layer contains at least one element constituting the base electrode and elements constituting the emitter layer and the base layer.

Abstract: A wiring is disposed above operating regions of plural unit transistors arranged on a substrate in a first direction. An insulating film is disposed on the wiring. A cavity entirely overlapping with the wiring as viewed from above is formed in the insulating film. A metal member electrically connected to the wiring via the cavity is disposed on the insulating film. The centroid of the cavity is displaced from that of the operating region of the corresponding unit transistor in the first direction. When the cavity having a centroid the closest to the operating region of a unit transistor is defined as the closest proximity cavity, the amount of deviation of the centroid of the closest proximity cavity from that of the operating region of the corresponding unit transistor in the first direction becomes greater from the center to the ends of the arrangement direction of the unit transistors.

Abstract: An amplifier circuit including a semiconductor element is formed on a substrate. A protection circuit formed on the substrate includes a plurality of protection diodes that are connected in series with each other, and the protection circuit is connected to an output terminal of the amplifier circuit. A pad conductive layer at least partially includes a pad for connecting to a circuit outside the substrate. The pad conductive layer and the protection circuit at least partially overlap each other in plan view.

Abstract: A bipolar transistor includes a collector layer, a base layer, and an emitter layer that are formed in this order on a compound semiconductor substrate. The emitter layer is disposed inside an edge of the base layer in plan view. A base electrode is disposed on partial regions of the emitter layer and the base layer so as to extend from an inside of the emitter layer to an outside of the base layer in plan view. An insulating film is disposed between the base electrode and a portion of the base layer, with the portion not overlapping the emitter layer. An alloy layer extends from the base electrode through the emitter layer in a thickness direction and reaches the base layer. The alloy layer contains at least one element constituting the base electrode and elements constituting the emitter layer and the base layer.

Abstract: A first wiring is disposed above operating regions of plural unit transistors formed on a substrate. A second wiring is disposed above the substrate. An insulating film is disposed on the first and second wirings. First and second cavities are formed in the insulating film. As viewed from above, the first and second cavities entirely overlap with the first and second wirings, respectively. A first bump is disposed on the insulating film and is electrically connected to the first wiring via the first cavity. A second bump is disposed on the insulating film and is electrically connected to the second wiring via the second cavity. As viewed from above, at least one of the plural operating regions is disposed within the first bump and is at least partially disposed outside the first cavity. The planar configuration of the first cavity and that of the second cavity are substantially identical.

Abstract: A high-frequency signal processing apparatus and a wireless communication apparatus can achieve a decrease in power consumption. For example, when an indicated power level to a high-frequency power amplifier is equal to or greater than a second reference value, envelope tracking is performed by causing a source voltage control circuit to control a high-speed DCDC converter using a detection result of an envelope detecting circuit and causing a bias control circuit to indicate a fixed bias value. The source voltage control circuit and the bias control circuit indicate a source voltage and a bias value decreasing in proportion to a decrease in the indicated power level when the indicated power level is in a range of the second reference value to the first reference value, and indicate a fixed source voltage and a fixed bias value when the indicated power level is less than the first reference value.

Abstract: Provided is a current output circuit that includes: a first FET that has a power supply voltage supplied to a source thereof, that has a first voltage supplied to a gate thereof and that outputs a first current from a drain thereof; a second FET that has the power supply voltage supplied to a source thereof, that has the first voltage supplied to a gate thereof and that outputs an output current from a drain thereof; a first control circuit that controls the first voltage such that the first current comes to be at a target level; and a second control circuit that performs control such that a drain voltage of the first FET and a drain voltage of the second FET are made equal to each other.

Abstract: A semiconductor device includes the following elements. A chip has a main surface substantially parallel with a plane defined by first and second directions intersecting with each other. A power amplifier amplifies an input signal and outputs an amplified signal from plural output terminals. First and second filter circuits attenuate harmonics of the amplified signal. The first filter circuit includes a first capacitor connected between the plural output terminals and a ground. The second filter circuit includes a second capacitor connected between the plural output terminals and a ground. On the main surface of the chip, the plural output terminals are disposed side by side in the first direction, and the first capacitor is disposed on a side in the first direction with respect to the plural output terminals, while the second capacitor is disposed on a side opposite the first direction with respect to the plural output terminals.

Abstract: A semiconductor device includes a plurality of unit transistors that are arranged on a surface of a substrate in a first direction. Input capacitive elements are arranged so as to correspond to the unit transistors. An emitter common wiring line is connected to emitter layers of the unit transistors. A via-hole extending from the emitter common wiring line to a back surface of the substrate is disposed at a position overlapping the emitter common wiring line. A collector common wiring line is connected to collector layers of the unit transistors. The input capacitive elements, the emitter common wiring line, the unit transistors, and the collector common wiring line are arranged in this order in a second direction. Base wiring lines that connect the input capacitive elements to base layers of the corresponding unit transistors intersect the emitter common wiring line without physical contact.

Abstract: In a radio frequency power amplifier, a semiconductor chip includes at least one first transistor amplifying a radio frequency signal, a first external-connection conductive member connected to the first transistor, a bias circuit including a second transistor that applies a bias voltage to the first transistor, and a second external-connection conductive member connected to the second transistor. The second external-connection conductive member at least partially overlaps with the second transistor when viewed in plan.

Abstract: A first wiring is disposed above operating regions of plural unit transistors formed on a substrate. A second wiring is disposed above the substrate. An insulating film is disposed on the first and second wirings. First and second cavities are formed in the insulating film. As viewed from above, the first and second cavities entirely overlap with the first and second wirings, respectively. A first bump is disposed on the insulating film and is electrically connected to the first wiring via the first cavity. A second bump is disposed on the insulating film and is electrically connected to the second wiring via the second cavity. As viewed from above, at least one of the plural operating regions is disposed within the first bump and is at least partially disposed outside the first cavity. The planar configuration of the first cavity and that of the second cavity are substantially identical.

Abstract: A first sub-collector layer functions as an inflow path of a collector current that flows in a collector layer of a heterojunction bipolar transistor. A collector ballast resistor layer having a lower doping concentration than the first sub-collector layer is disposed between the collector layer and the first sub-collector layer.

Abstract: A power amplifier module includes a first substrate and a second substrate, at least part of the second substrate being disposed in a region overlapping the first substrate. The second substrate includes a first amplifier circuit and a second amplifier circuit. The first substrate includes a first transformer including a primary winding having a first end and a second end and a secondary winding having a first end and a second end; a second transformer including a primary winding having a first end and a second end and a secondary winding having a first end and a second end; and multiple first conductors disposed in a row between the first transformer and the second transformer, each of the multiple first conductors extending from the wiring layer on a first main surface to the wiring layer on a second main surface of the substrate.