Abstract: A power amplifying circuit includes a switching circuit, an amplifier and a load. The switching circuit receives a first supply voltage and a second supply voltage. When the switching circuit is in a first operation mode, the first supply voltage is provided to a node. When the switching circuit is in a second operation mode, the second supply voltage is provided to the node. The amplifier receives a first input signal and a second input signal, and outputs a first output signal and a second output signal from a first output terminal and a second output signal, respectively. The load includes a first inductor and a second inductor. The first inductor is connected between the node and the first output terminal. The second inductor is connected between the node and the second output terminal.

Abstract: A power amplifier is provided. The power amplifier comprises a plurality of power amplifier units and a bias unit. The power amplifier units are connected in parallel with each other to receive a differential input signal. The power amplifier units perform a power amplifying so as to output a differential output signal. The bias unit is coupled to the power amplifier units and supplies a plurality of bias signals to the power amplifier units respectively. At least two of the power amplifier units are enable to operate in different class regions in according with the corresponding bias signals.

Abstract: A power amplifier is provided. The power amplifier comprises a plurality of power amplifier units and a bias unit. The power amplifier units are connected in parallel with each other to receive a differential input signal. The power amplifier units perform a power amplifying so as to output a differential output signal. The bias unit is coupled to the power amplifier units and supplies a plurality of bias signals to the power amplifier units respectively. At least two of the power amplifier units are enable to operate in different class regions in according with the corresponding bias signals.

Abstract: A RF front-end circuit and a low noise amplifier thereof configured for a receiver are provided. The circuit includes a low noise amplifier and a quadrature passive mixer. The low noise amplifier provides two RF output differential signals to the quadrature passive mixer. The RF signals are down-converted to the differential in-phase baseband signals and the differential quadrature-phase baseband signals. The structure of the RF front-end circuit can avoid the signal and noise interfering between in-phase channel and quadrature-phase channel without using a 25% duty cycle local oscillation generator circuit.

Abstract: A RF front-end circuit and a low noise amplifier thereof configured for a receiver are provided. The circuit includes a low noise amplifier and a quadrature passive mixer. The low noise amplifier provides two RF output differential signals to the quadrature passive mixer. The RF signals are down-converted to the differential in-phase baseband signals and the differential quadrature-phase baseband signals. The structure of the RF front-end circuit can avoid the signal and noise interfering between in-phase channel and quadrature-phase channel without using a 25% duty cycle local oscillation generator circuit.