A radio frequency module includes a mounting board, a power amplifier, a plurality of transmission filters, a first switch, an output matching circuit, a low-noise amplifier, and an external-connection terminal. The mounting board includes a first principal surface and a second principal surface on opposite sides of the mounting board. The first switch switches a connection between the power amplifier and the transmission filters. The output matching circuit is connected between the power amplifier and the first switch. The low-noise amplifier is disposed on the second principal surface of the mounting board. The external-connection terminal is disposed on the second principal surface of the mounting board. The power amplifier, the output matching circuit, the first switch, and the transmission filters are disposed on the mounting board in stated order in a direction that is orthogonal to a thickness direction of the mounting board.

A front-end module including a power amplifier, first and second couplers, an antenna switch, and a switch sub-assembly. The power amplifier has an input to receive a radio frequency signal and an output to provide an amplified radio frequency signal. The first coupler has an input port coupled to the output of the power amplifier, an output port coupled to an input of the antenna switch, a coupled port, and an isolated port. The second coupler has an input port coupled to an output of the antenna switch, an output port coupled to an antenna port, a coupled port, and an isolated port. The switch sub assembly connects one of the coupled port and the isolated port of the second coupler to an output of the switch assembly and the other one of the coupled port and the isolated port of the second coupler to a first termination impedance.

A front-end module including a power amplifier, first and second couplers, an antenna switch, and a switch sub-assembly. The power amplifier has an input to receive a radio frequency signal and an output to provide an amplified radio frequency signal. The first coupler has an input port coupled to the output of the power amplifier, an output port coupled to an input of the antenna switch, a coupled port, and an isolated port. The second coupler has an input port coupled to an output of the antenna switch, an output port coupled to an antenna port, a coupled port, and an isolated port. The switch sub assembly connects one of the coupled port and the isolated port of the second coupler to an output of the switch assembly and the other one of the coupled port and the isolated port of the second coupler to a first termination impedance.

Apparatus and method for detecting and clamping power of a power amplifier are disclosed. In certain embodiments, a power amplifier system includes a power amplifier that amplifies a radio frequency input signal to generate a radio frequency output signal, a bias circuit that controls a bias of the power amplifier, a radio frequency coupler that generates a radio frequency coupled signal based on the radio frequency output signal, a clamp that selectively clamps the bias of the power amplifier, and a power detector that controls the clamp based on the radio frequency coupled signal.

Apparatus and method for detecting and clamping power of a power amplifier are disclosed. In certain embodiments, a power amplifier system includes a power amplifier that amplifies a radio frequency input signal to generate a radio frequency output signal, a bias circuit that controls a bias of the power amplifier, a radio frequency coupler that generates a radio frequency coupled signal based on the radio frequency output signal, a clamp that selectively clamps the bias of the power amplifier, and a power detector that controls the clamp based on the radio frequency coupled signal.

An electronic device includes an antenna, a communication circuit, and a processor. The communication circuit includes a first amplifier configured to amplify a radio frequency signal; a first coupler configured to output a first amplifier output signal output from the first amplifier, to the antenna through a first port, and output at least a part of the first amplifier output signal to a first switch through a second port; and a second amplifier configured to amplify the second portion of the first amplifier output signal, output from the first switch. The processor is operably connected to the antenna and the communication circuit, wherein the processor is configured to, based on a magnitude of the first amplifier output signal, control the first switch and the second switch to use the first amplifier, or to use the first amplifier and the second amplifier.

A transistor stack can include a combination of floating and body tied devices. Improved performance of the RF amplifier can be obtained by using a single body tied device as the input transistor of the stack, or as the output transistor of the stack, while other transistors of the stack are floating transistors. Transient response of the RF amplifier can be improved by using all body tied devices in the stack.

A transistor stack can include a combination of floating and body tied devices. Improved performance of the RF amplifier can be obtained by using a single body tied device as the input transistor of the stack, or as the output transistor of the stack, while other transistors of the stack are floating transistors. Transient response of the RF amplifier can be improved by using all body tied devices in the stack.

This application discloses a wireless communication apparatus and a signal processing method. The wireless communication apparatus includes a power amplifier and a bias circuit. The power amplifier includes a signal input port, a signal output port, a power supply port, and a bias port. The power amplifier is configured to: receive a power supply signal through the power supply port, receive a bias signal through the bias port, receive a radio frequency signal through the signal input port, and output a power amplified radio frequency signal. The bias circuit is configured to generate the bias signal. A timing feature of the bias signal is synchronized with a timing feature of a switch signal of a power amplifier, to compensate for a nonlinear change in the TDD scenario.

A tracker module is provided that includes an external connection terminal, a tracker, and a variable low pass filter. The external connection terminal is connected to a power amplifier. The tracker supplies a power supply voltage to the power amplifier via the external connection terminal by using an envelope tracking method. The variable low pass filter is disposed on a path between the tracker and the external connection terminal. In the variable low pass filter, a first block includes at least one electronic component. A second block is a block that varies a cutoff frequency of the variable low pass filter. The second block is integrated with the tracker into one package. The first block is disposed separately from the tracker.