Front-end for processing 2G signal using 3G/4G paths. In some embodiments, a front-end architecture can include a first amplification path and a second amplification path, with each being configured to amplify a 3G/4G signal, and the first amplification path including a phase shifting circuit. The front-end architecture can further include a splitter configured to receive a 2G signal and split the 2G signal into the first and second amplification paths, and a combiner configured to combine amplified 2G signals from the first and second amplification paths into a common output path. The front-end architecture can further include an impedance transformer implemented along the common output path to provide a desired impedance for the combined 2G signal.

Circuits and devices related to radio-frequency amplifiers. In some embodiments, a radio-frequency amplifier can include a plurality of narrow band power amplifiers. Each narrow band power amplifier can be configured to operate with a high voltage in an average power tracking mode and be capable of being coupled to an output filter associated with a respective individual frequency band. Each narrow band power amplifier can be sized smaller than a wide band power amplifier configured to operate with more than one of the frequency bands associated with the plurality of narrow band power amplifiers.

A scalable periphery tunable matching power amplifier is presented. Varying power levels can be accommodated by selectively activating or deactivating unit cells of which the scalable periphery tunable matching power amplifier is comprised. Tunable matching allows individual unit cells to see a constant output impedance, reducing need for transforming a low impedance up to a system impedance and attendant power loss. The scalable periphery tunable matching power amplifier can also be tuned for different operating conditions such as different frequencies of operation or different modes.

Multi-mode power amplifier systems are described. In certain embodiments, a multi-mode power amplifier system shares a power amplifier chain for different communication modes, where the power amplifier chain has a split output matching network with a first power amplifier transistor and a second power amplifier transistor. A bias circuit biases the power amplifier such that the first power amplifier transistor and the second power amplifier transistor are on in a first mode, and the first power amplifier transistor is on and the second power amplifier transistor is off in a second mode.

Multi-mode power amplifier systems are described. In certain embodiments, a multi-mode power amplifier system shares a power amplifier chain for different communication modes. A power amplifier amplifies a radio frequency signal in at least a first mode and a second mode. An output matching network is coupled to an output of the power amplifier, and a bias circuit provides a reference current with a first reference current level to the power amplifier in the first mode and a second reference current level to the power amplifier in the second mode, the multi-mode power amplifier system configured to adjust a power amplifier signal path for the second mode relative to the first mode.

A scalable periphery tunable matching power amplifier is presented. Varying power levels can be accommodated by selectively activating or deactivating unit cells of which the scalable periphery tunable matching power amplifier is comprised. Tunable matching allows individual unit cells to see a constant output impedance, reducing need for transforming a low impedance up to a system impedance and attendant power loss. The scalable periphery tunable matching power amplifier can also be tuned for different operating conditions such as different frequencies of operation or different modes.

A multi-band power amplifier module includes at least one transmission input terminal, at least one power amplifier circuit that receives a first transmission signal and a second transmission signal through the at least one transmission input terminal, a first filter circuit that allows the first transmission signal to pass therethrough, a second filter circuit that allows the second transmission signal to pass therethrough, at least one transmission output terminal through which the first and second transmission signals output from the first and second filter circuits are output, a transmission output switch that outputs each of the first and second transmission signals output from the at least one power amplifier circuit to the first filter circuit or the second filter circuit, and a first tuning circuit that adjusts impedance matching between the at least one power amplifier circuit and the at least one transmission output terminal.

A receiver circuit is disclosed. The receiver circuit includes an amplifier configured to generate an RF signal based on a received signal, where the RF signal includes an information signal and a blocker signal modulating an RF carrier frequency. The receiver circuit also includes an RF filter connected to the amplifier, where the RF filter is configured to selectively attenuate the blocker signal.

The inventive concept relates to a communication device comprising a DPD processor configured to output a plurality of pre-distorted signals by pre-distorting each of a plurality of input signals using an extracted feedback signal, a first signal combiner configured to combine a plurality of feedback signals corresponding to the plurality of pre-distorted signals and output a combined feedback signal, an analog-to-digital converter configured to convert the combined feedback signal into a digital signal and output a digital-converted combined feedback signal and a signal extractor configured to extract the digital-converted combined feedback signal and output the extracted feedback signal.

In some embodiments, radio-frequency amplifiers can include a plurality of narrow band power amplifiers implemented. Each narrow band power amplifier can be configured to operate with a high voltage in an average power tracking mode and be capable of being coupled to an output filter associated with a respective individual frequency band. Each narrow band power amplifier can be sized smaller than a wide band power amplifier configured to operate with more than one of the frequency bands associated with the plurality of narrow band power amplifiers.