A radio frequency module includes: a module board that includes a first principal surface and a second principal surface on opposite sides of the module board; a power amplifier configured to amplify a transmission signal; a first circuit component; and a power amplifier (PA) control circuit configured to control the power amplifier. The power amplifier and the PA control circuit are stacked on the first principal surface, and the first circuit component is disposed on the second principal surface.

An envelope tracking (ET) radio frequency (RF) front-end circuit is provided. The ET RF front-end circuit includes an ET integrated circuit(s) (ETIC(s)), a local transceiver circuit, a target voltage circuit(s), and a number of power amplifiers. The local transceiver circuit receives an input signal(s) from a coupled baseband transceiver and generates a number of RF signals. The target voltage circuit(s) generates a time-variant ET target voltage(s) based on the input signal(s). The ETIC(s) generates multiple ET voltages based on the time-variant ET target voltage(s). The power amplifiers amplify the RF signals based on the ET voltages. Given that the time-variant ET target voltage(s) is generated inside the self-contained ET RF front-end circuit, it is possible to reduce distortion in the time-variant ET target voltage(s), thus helping to improve operating efficiency of the power amplifiers, especially when the RF signals are modulated with a higher modulation bandwidth (e.g., ≥200 MHz).

A power amplifier arrangement (200) for amplifying an input signal to produce an output signal comprises a plurality N of amplifier sections (212, 213), a first input transmission line (221) comprising multiple segments and a first output transmission line (231) comprising multiple segments. Each amplifier section comprises one or more first transistors (T1) distributed along the first input transmission line (221) and the first output transmission line (231). Each amplifier section is configured to amplify a portion of the input signal to produce a portion of the output signal. A portion of the input signal is one of N portions of the input signal partitioned on any one or a combination of an amplitude basis and a time basis. The output signal is produced at an end of the first output transmission line (231) by building up N potions of the output signal from each amplifier section.

A wireless communication device includes a signal generator supply a signal to an input node to which a power amplifier is connected. The power amplifier includes an inverter including a first transistor with a gate connected to the input node via a first signal path and a second transistor with a gate electrode connected to the input node via a second signal path. An output signal corresponding to the signal supplied to the input node is supplied from an output node between the first and second transistors. A filter is connected to the output node and outputs a filtered signal having a high frequency component removed. A bias application unit applies a first bias voltage to the first signal path and a second bias voltage to the second signal path. Levels of the bias voltages being set according to a direct current component in the filtered signal.

A package or a chip including a linear amplifier and a power amplifier is provided, wherein the linear amplifier is configured to receive an envelope tracking signal to generate an amplified envelope tracking signal, the power amplifier is supplied by an envelope tracking supply voltage comprising a DC supply voltage and the amplified envelope tracking signal, and the power amplifier is configured to receive an input signal to generate an output signal.

A radio frequency module includes: a module board that includes a first principal surface and a second principal surface on opposite sides of the module board; a power amplifier configured to amplify a transmission signal; a first circuit component; and a power amplifier (PA) control circuit configured to control the power amplifier. The power amplifier and the PA control circuit are stacked on the first principal surface, and the first circuit component is disposed on the second principal surface.

An active electronically scanned array (AESA) includes a plurality of power amplifiers including first power amplifiers and second power amplifiers. The first power amplifiers are biased by a first drain voltage. The second power amplifiers are biased by a second drain voltage. The second drain voltage is different from the first drain voltage.

An output circuit includes a first transistor, a second transistor, an operational amplifier that outputs a control voltage, and a switch circuit that controls voltage output in accordance with a control signal. When the control signal is in a first state, the switch circuit supplies the control voltage to the gate of the first transistor to turn on the first transistor and electrically connects the drain of first transistor to the operational amplifier so that a first output voltage is output from the drain of the first transistor. When the control signal is in a second state, the switch circuit supplies the control voltage to the gate of the second transistor to turn on the second transistor and electrically connects the drain of the second transistor to the operational amplifier so that a second output voltage is output from the drain of the second transistor.

A power amplifier circuit includes a first transistor, a second transistor, a first bias circuit supplying a first bias current or voltage, a second bias circuit supplying a second bias current or voltage, a first inductor, and a first capacitor. A power supply voltage is supplied to a collector of the first transistor, and an emitter thereof is grounded. A radio frequency signal and the first bias current or voltage are supplied to a base of the first transistor. The power supply voltage is supplied to a collector of the second transistor, and an emitter thereof is connected to the collector of the first transistor via the first capacitor and is grounded via the first inductor. The second bias current or voltage is supplied to a base of the second transistor. An amplified radio frequency signal is output from the collector of the second transistor.

A Class-D amplifier includes a plurality of power rails, a quantizer, and a driver stage. The quantizer and the driver stage have a combined gain. For each power rail of the plurality of power rails, the Class-D amplifier senses a voltage value for the power rail and determines a ramp amplitude based on the sensed voltage value. The Class-D amplifier concurrently switches from the driver stage using a first power rail to a second power rail of the plurality of power rails and switches from the quantizer using the ramp amplitude associated with the first power rail to using the ramp amplitude associated with the second power rail so that the combined gain is constant.