Abstract: There is provided a power amplifier capable of improving harmonics characteristics of an output signal of an amplifier circuit by compensating a phase of the output signal. A power amplifier according to an aspect of the invention may include: an amplification section having a plurality of amplification units each amplifying a radio frequency (RF) signal according to a gain being controlled; a phase correction section performing phase correction by removing harmonic components of respective output signals from the plurality of amplification units of the amplification section; and a coupling section coupling the respective output signals phase-corrected by the phase correction section.

Abstract: There is provided a power amplifier that can increase power efficiency by preventing power consumption caused by DC components from an RF input signal. A power amplifier according to an aspect of the invention may include: an inverter amplification section amplifying an input signal according to an inverter method to thereby remove DC components from the input signal; an impedance matching section matching an impedance of a transmission path of the input signal amplified by the inverter amplification section; and an amplification section amplifying an impedance-matched signal from the impedance matching section according to a gain set beforehand.

Abstract: There is provided a wireless apparatus having a shielding function for shielding signal interference between driving power from a power amplifier and a conductive wire of a coupler. The wireless apparatus having a shielding function, includes an amplifying unit receiving preset driving power and amplifying a radio frequency (RF) input signal according to a preset gain, an impedance matching unit including at least one coil, receiving the driving power from the amplifying unit, and matching the impedance of a path of a signal, amplified from the amplifying unit, through the coil, and a shielding unit eliminating signal interference between the coil and a transmission path of the driving power from the amplifying unit.

Abstract: There is provided a multi-stage CMOS power amplifier including: a driver amplifier having differential output terminals, inverting differential signals input through first and second input terminals and outputting the respective inverted signals through the differential output terminals; a transformer for power matching having a primary coil connected between the differential output terminals of the driver amplifier and a secondary coil coupled with the primary coil using electromagnetic induction, having a predetermined turns ratio to the primary coil, and connected to a direct current (DC) tuning voltage terminal; and a power amplifier power-amplifying differential signals passing through one end and the other end of the secondary coil of the transformer and outputting the respective power-amplified differential signals through first and second output terminals.

Abstract: A transformer includes at least one input conductive line having both ends provided as input ports of a positive (+) signal and a negative (?) signal, respectively, one output conductive line disposed adjacent to the at least one input conductive line to be electromagnetically coupled to the at least one input conductive line, and having one end connected to the ground, a first resonator disposed between the other end of the output conductive line and the ground, and a second resonator having one end connected to the other end of the output conductive line and the other end provided as an output port.