An amplification circuit for RF power amplifiers is provided. The circuit includes two PMOS amplification modules and two NMOS amplification modules; each module includes a CSCG structure composed of a stack of K transistors. The first PMOS module and the first NMOS module are connected in series between a supply voltage and ground; gates of main amplification transistors of the first PMOS module and the first NMOS module are connected to a non-inverting input, and outputs of the first PMOS module and the first NMOS module are connected together to form an inverting output. The second PMOS module and the second NMOS module are similarly connected. Both the first and the second modules will be connected side-by-side as a pseudo differential structure to provide double push-pull function to the load. The present disclosure simultaneously achieves high power efficiency, and high linearity.

In one aspect, an apparatus includes: a first power amplifier to receive a first voltage signal and to output a first current; a second power amplifier to receive a second voltage signal and to output a second current; and a transformer coupled to the first power amplifier and the second power amplifier. The transformer may have multiple differential input ports to realize a controllable impedance based on a desired output power level.

An apparatus includes a multi-stage amplifier. The multi-stage amplifier includes first, second, and third amplifier circuits coupled in a cascade configuration. The multi-stage amplifier further includes first, second, and third compensation networks. The first compensation network is coupled between the output of the third amplifier circuit and the input of the second amplifier circuit. The second compensation network is coupled between the output of the third amplifier circuit and the input of the third amplifier circuit. The third compensation network is coupled between the output of the second amplifier circuit and the input of the second amplifier circuit.

An apparatus includes a multi-stage amplifier. The multi-stage amplifier includes first, second, and third amplifier circuits coupled in a cascade configuration. The multi-stage amplifier further includes first, second, and third compensation networks. The first compensation network is coupled between the output of the third amplifier circuit and the input of the second amplifier circuit. The second compensation network is coupled between the output of the third amplifier circuit and the input of the third amplifier circuit. The third compensation network is coupled between the output of the second amplifier circuit and the input of the second amplifier circuit.