A power amplifier using multi-path common-mode feedback loops for radio frequency linearization is disclosed. In one aspect, a complementary metal oxide semiconductor (CMOS) power amplifier containing cascoded n-type field effect transistors (NFETs) and cascoded p-type FETs (PFETs) may have a common-mode feedback network and provides bias voltages that are dynamically varying with the signal power to keep the output common-mode fixed around a half-supply level, while the small-signal and large-signal transconductances of the FET's are kept balanced. A further feedback network may be associated with the supply voltage to assist in providing a symmetrical supply signal. The symmetrical supply signal allows for supply variations without introducing distortion for the power amplifier stage.

A power amplifier using multi-path common-mode feedback loops for radio frequency linearization is disclosed. In one aspect, a complementary metal oxide semiconductor (CMOS) power amplifier containing cascoded n-type field effect transistors (NFETs) and cascoded p-type FETs (PFETs) may have a common-mode feedback network and provides bias voltages that are dynamically varying with the signal power to keep the output common-mode fixed around a half-supply level, while the small-signal and large-signal transconductances of the FETs are kept balanced. A further feedback network may be associated with the supply voltage to assist in providing a symmetrical supply signal. The symmetrical supply signal allows for supply variations without introducing distortion for the power amplifier stage.

A transconductance-transimpedance (TAS-TIA) amplifier includes a TAS amplifier, a TIA amplifier, and a first common-mode feedback (CMFB) circuit. The TIA amplifier includes a first transistor and a second transistor. The first transistor is coupled between a first TIA output node and a reference voltage. The second transistor is coupled between a second TIA output node and the reference voltage. The first CMFB circuit has a first operational amplifier, a first capacitor, and a first resistor. The first operational amplifier has a first input node for receiving a TIA output common-mode voltage, a second input node, and a first output node coupled to control terminals of the first and second transistors. The first capacitor is coupled between the first output node and the second input node of the first operational amplifier. The first resistor is coupled between the second input node of the first operational amplifier and a reference common-mode voltage.