A low-power double-quadrature receiver is disclosed. The double-quadrature receiver includes a quadrature signal generator configured to generate a first quadrature signal and a second quadrature signal based on each component of a differential input signal, and a switching stage configured to perform down-conversion on the first quadrature signal and the second quadrature signal.

An multistage amplifier includes first to third FETs, a drain of the second FET is connected to a gate of the third FET in an AC manner, a source thereof is grounded in a DC manner, a drain of the first FET is connected to a gate of the second FET in an AC manner, a source thereof is grounded in a DC manner, a gate thereof receives a high frequency signal, a drain of the third FET receives a bias current and outputs an amplified signal, a source thereof is grounded in an AC manner, the drains of the first and second FETs are connected to the source of the third FET in a DC manner via a transmission line having an electrical length of /4 when a wavelength of the high frequency signal is , and a size of third FET is greater than other FETs.

An multistage amplifier includes first to third FETs, a drain of the second FET is connected to a gate of the third FET in an AC manner, a source thereof is grounded in a DC manner, a drain of the first FET is connected to a gate of the second FET in an AC manner, a source thereof is grounded in a DC manner, a gate thereof receives a high frequency signal, a drain of the third FET receives a bias current and outputs an amplified signal, a source thereof is grounded in an AC manner, the drains of the first and second FETs are connected to the source of the third FET in a DC manner via a transmission line having an electrical length of /4 when a wavelength of the high frequency signal is , and a size of third FET is greater than other FETs.

A low noise amplifier circuit includes an input stage circuit, a first output stage circuit, and a second output stage circuit. The input stage circuit is configured to receive an input signal and to generate a bias signal. The first output stage circuit corresponding to a first wireless communication and is configured to be biased according to the bias signal and a first control signal, in order to generate a first output signal, in which the first control signal is for setting a first gain of the first output stage circuit. The second output stage circuit corresponding to a second wireless communication and is configured to be biased according to the bias signal and a second control signal, in order to generate a second output signal, in which the second control signal is for setting a second gain of the second output stage circuit.

The present disclosure describes a method and system for linearizing an amplifier using transistor-level dynamic feedback. The method and system enables nonlinear amplifiers to exhibit linear performance using one or more of gain control elements and phase shifters in the feedback path. The disclosed method and system may also allow an amplifier to act as a pre-distorter or a frequency/gain programmable amplifier.

The present disclosure describes a method and system for linearizing an amplifier using transistor-level dynamic feedback. The method and system enables nonlinear amplifiers to exhibit linear performance using one or more of gain control elements and phase shifters in the feedback path. The disclosed method and system may also allow an amplifier to act as a pre-distorter or a frequency/gain programmable amplifier.

An outphasing amplifier includes a first amplifier, a second amplifier, a first coupler coupling a first signal and a third signal, a second coupler coupling a second signal and a fourth signal, a first impedance converter inputting the first signal coupled with the third signal, a second impedance converter inputting the second signal coupled with the fourth signal, a combiner combining the first and the second signals output from the first and the second impedance converters and outputting an output signal, and a signal processor outputting the first signal having a first phase to the first amplifier, outputting the second signal having a second phase to the second amplifier, outputting the third signal having at least one of a third phase and a first amplitude to the first coupler, and outputting the fourth signal having at least one of a fourth phase and a second amplitude to the second coupler.

An outphasing amplifier includes a first amplifier, a second amplifier, a first coupler coupling a first signal and a third signal, a second coupler coupling a second signal and a fourth signal, a first impedance converter inputting the first signal coupled with the third signal, a second impedance converter inputting the second signal coupled with the fourth signal, a combiner combining the first and the second signals output from the first and the second impedance converters and outputting an output signal, and a signal processor outputting the first signal having a first phase to the first amplifier, outputting the second signal having a second phase to the second amplifier, outputting the third signal having at least one of a third phase and a first amplitude to the first coupler, and outputting the fourth signal having at least one of a fourth phase and a second amplitude to the second coupler.

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 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.