A power amplifier module includes an output-stage amplifier, a driver-stage amplifier, an input switch, an output switch, an input matching circuit, an inter-stage matching circuit, an output matching circuit, and a control circuit. The input switch selectively connects one of a plurality of input signal paths to an input terminal of the driver-stage amplifier. The output switch selectively connects one of a plurality of output signal paths to an output terminal of the output-stage amplifier. The control circuit controls operations of the driver-stage amplifier and the output-stage amplifier. The input switch, the output switch, and the control circuit are integrated into an IC chip. The control circuit is disposed between the input switch and the output switch.

A power amplifier module includes an output-stage amplifier, a driver-stage amplifier, an input switch, an output switch, an input matching circuit, an inter-stage matching circuit, an output matching circuit, and a control circuit. The input switch selectively connects one of a plurality of input signal paths to an input terminal of the driver-stage amplifier. The output switch selectively connects one of a plurality of output signal paths to an output terminal of the output-stage amplifier. The control circuit controls operations of the driver-stage amplifier and the output-stage amplifier. The input switch, the output switch, and the control circuit are integrated into an IC chip. The control circuit is disposed between the input switch and the output switch.

A power amplifier module includes a substrate including, in an upper surface of the substrate, an active region and an element isolation region. The power amplifier module further includes a collector layer, a base layer, and an emitter layer that are stacked on the active region; an interlayer insulating film that covers the collector layer, the base layer, and the emitter layer; a pad that is thermally coupled to the element isolation region; and an emitter bump that is disposed on the interlayer insulating film, electrically connected to the emitter layer through a via hole provided in the interlayer insulating film, and electrically connected to the pad. In plan view, the emitter bump partially overlaps an emitter region which is a region of the emitter layer and through which an emitter current flows.

A power amplifier module includes a substrate including, in an upper surface of the substrate, an active region and an element isolation region. The power amplifier module further includes a collector layer, a base layer, and an emitter layer that are stacked on the active region; an interlayer insulating film that covers the collector layer, the base layer, and the emitter layer; a pad that is thermally coupled to the element isolation region; and an emitter bump that is disposed on the interlayer insulating film, electrically connected to the emitter layer through a via hole provided in the interlayer insulating film, and electrically connected to the pad. In plan view, the emitter bump partially overlaps an emitter region which is a region of the emitter layer and through which an emitter current flows.

A device that includes a substrate and a power amplifier coupled to the substrate. The substrate includes at least one dielectric layer, a plurality of interconnects, and a capacitor configured to operate as an output match element, where the capacitor is defined by a plurality of capacitor interconnects. The power amplifier is coupled to the capacitor. The capacitor is configured to operate as an output match element for the power amplifier. The substrate includes an inductor coupled to the capacitor, where the inductor is defined by at least one inductor interconnect. The capacitor and the inductor are configured to operate as a resonant trap or an output match element.

A device that includes a substrate and a power amplifier coupled to the substrate. The substrate includes at least one dielectric layer, a plurality of interconnects, and a capacitor configured to operate as an output match element, where the capacitor is defined by a plurality of capacitor interconnects. The power amplifier is coupled to the capacitor. The capacitor is configured to operate as an output match element for the power amplifier. The substrate includes an inductor coupled to the capacitor, where the inductor is defined by at least one inductor interconnect. The capacitor and the inductor are configured to operate as a resonant trap or an output match element.

An envelope tracking method and device are provided. The envelope tracking method includes: acquiring, by a boost circuit, a target envelope tracking input current signal, and transmitting, by the boost circuit, the target envelope tracking input current signal to an amplifier circuit, where the amplifier circuit includes an operational amplifier and a feedback network, and the operational amplifier operates in a mode of floating ground; and performing, by the amplifier circuit, closed-loop conversion and amplification on the target envelope tracking input current signal and outputting, by the amplifier circuit, an envelope tracking output voltage.

According to an embodiment, An integrated circuit comprising a first cascode radio frequency (RF) power amplifier that includes a first common source transistor having a gate configured to receive a first RF signal, and a source connected to a neutral point; a first common gate transistor having a gate and a drain connected to a power source node, and a source connected to a drain of the first common source transistor; and a first resistor coupled between a bulk of the first common gate transistor and a first bulk bias node configured to provide a voltage that is greater than or equal to a voltage at the source of the first common gate transistor, wherein the first resistor is configured to obtain a floating point.

According to an embodiment, An integrated circuit comprising a first cascode radio frequency (RF) power amplifier that includes a first common source transistor having a gate configured to receive a first RF signal, and a source connected to a neutral point; a first common gate transistor having a gate and a drain connected to a power source node, and a source connected to a drain of the first common source transistor; and a first resistor coupled between a bulk of the first common gate transistor and a first bulk bias node configured to provide a voltage that is greater than or equal to a voltage at the source of the first common gate transistor, wherein the first resistor is configured to obtain a floating point.

Disclosed are apparatuses and methods for fabricating the apparatuses. In one aspect, an apparatus includes a high-power die mounted on a backside of a package substrate. A heat transfer layer is disposed on the backside of the high-power die. A plurality of heat sink interconnects is coupled to the heat transfer layer, where each of the plurality of heat sink interconnects is directly coupled to the heat transfer layer in a vertical orientation.