Abstract: There is provided a power amplifier capable of increasing linear output power and efficiency without sacrificing an overall gain by employing a vector modulation function in a driving stage, with no separate vector modulator. The power amplifier includes a driving stage performing vector-modulation on an input RF signal to provide an I channel signal and a Q channel signal having different phases and amplifying the I channel signal and the Q channel signal to set gains; and a power stage amplifying power levels of the signals amplified by the driving stage.

Abstract: There is provided a power amplifier including an amplifying unit having at least two cascode amplifiers connected in parallel to amplify an input signal; and a bias supply unit supplying bias power to a common gate node of the two cascode amplifiers, and removing a signal of a pre-set frequency band corresponding to a baseband at the common gate node by controlling impedance of the common gate node.

Abstract: There is provided a power amplifier capable of increasing linear output power and efficiency without sacrificing an overall gain by employing a vector modulation function in a driving stage, with no separate vector modulator. The power amplifier includes a driving stage performing vector-modulation on an input RF signal to provide an I channel signal and a Q channel signal having different phases and amplifying the I channel signal and the Q channel signal to set gains; and a power stage amplifying power levels of the signals amplified by the driving stage.

Abstract: There is provided a multi-mode power amplifier operable in a low power mode having a preset power range and in a high power mode having a power range higher than the power range of the low power mode. The multi-mode power amplifier includes: a high power amplifying unit including at least one cascode amplifier to amplify an input signal to a high power level having a preset power range; a low power amplifying unit sharing a common source node of the at least one cascode amplifier to amplify the input signal to a low power level having a power range lower than the high power level; and a coupling unit coupling a transfer path of a signal output from the high power amplifying unit and a transfer path of a signal output from the low power amplifying unit to each other.

Abstract: There is provided a power amplifier capable of supplying variable bias to an amplifier circuit by accurately transferring the envelope components of an input signal during the supply of active bias power to the amplifier circuit. The power amplifier includes: an envelope detector detecting an envelope of an input signal; a bias power generator including at least one P-type MOSFET and one N-type MOSFET connected to each other in an inverter manner between a driving power terminal supplying driving power having a preset voltage level and a reference bias power terminal supplying preset reference bias power to generate bias power varied according to detection results from the envelope detector; and an amplifier amplifying the input signal according to the bias power level from the bias power generator.

Abstract: There is provided a multi-mode power amplifier operable in a low power mode having a preset power range and in a high power mode having a power range higher than the power range of the low power mode. The multi-mode power amplifier includes: a high power amplifying unit including at least one cascode amplifier to amplify an input signal to a high power level having a preset power range; a low power amplifying unit sharing a common source node of the at least one cascode amplifier to amplify the input signal to a low power level having a power range lower than the high power level; and a coupling unit coupling a transfer path of a signal output from the high power amplifying unit and a transfer path of a signal output from the low power amplifying unit to each other.

Abstract: There is provided a power amplifier including an amplifying unit having at least two cascode amplifiers connected in parallel to amplify an input signal; and a bias supply unit supplying bias power to a common gate node of the two cascode amplifiers, and removing a signal of a pre-set frequency band corresponding to a baseband at the common gate node by controlling impedance of the common gate node.

Abstract: There is provided a power amplifier capable of supplying variable bias to an amplifier circuit by accurately transferring the envelope components of an input signal during the supply of active bias power to the amplifier circuit. The power amplifier includes: an envelope detector detecting an envelope of an input signal; a bias power generator including at least one P-type MOSFET and one N-type MOSFET connected to each other in an inverter manner between a driving power terminal supplying driving power having a preset voltage level and a reference bias power terminal supplying preset reference bias power to generate bias power varied according to detection results from the envelope detector; and an amplifier amplifying the input signal according to the bias power level from the bias power generator.

Abstract: There is provided a power amplifier reducing a gain mismatch in order to reduce a gain mismatch between an N MOS amplifier and a P MOS amplifier by cross-connecting outputs from a two-stage amplification unit in a power amplifier having amplification units with a stacked structure in which the N MOS amplifier and the P MOS amplifier are connected in series with each other.

Abstract: Disclosed is a power amplifier. A power amplifier according to an aspect of the invention may include: a first amplification section having a first N metal oxide semiconductor (MOS) amplifier and a second N MOS amplifier connected in a cascode configuration and amplifying an input signal; a second amplification section having a first P MOS amplifier and a second P MOS amplifier connected in a cascode configuration and amplifying the input signal; and a power combining section combining respective output signals of the first amplification section and the second amplification section.