Korea Advanced Institute of Science and Technology

Changkun Park

Songcheol Hong

Ki Yong Son

Younsuk Kim

Disclosed herein is a power amplifier using a power combiner, which is capable of minimizing power loss and improving efficiency of the power amplifier with a large output power, by combining powers generated by a plurality of power amplifiers used in a wireless communication system using a transmission line transformer.

Power amplifier using power combiner

A power amplifier based on a voltage-coupling scheme is disclosed. The power amplifier includes two active elements connected to each other via a primary part of a transformer, in which one of the two active elements is connected to a power-supply voltage of the amplifier, the other one is connected to a ground terminal of the amplifier, and an output power appears in a secondary part of the transformer. Therefore, a potential difference between ports of the active elements is decreased, resulting in increased reliability of the power amplifier.

Power amplifier

A transmission line transformer is disclosed. The transformer improves efficiency and a dynamic range of a power amplifier. The transformer is formed to have a plurality of load impedances as the primary side of the transmission line transformer is separated to form a plurality of primary transmission lines with parasitic components which are different from each other. The transformer is used as an impedance matching circuit of the power amplifier requiring a plurality of load impedances.

Transmission line transformer

A power amplifier with automatic switching functions is disclosed. The power amplifier can variably control output power of circuits as all of the circuits are operated when relatively large power is needed, and the circuits are partially turned off when relatively small power is needed, according to magnitude of an envelope signal, such that the circuits can be smoothly and automatically switched so as not to affect operations of the circuit, and to improve efficiency and operation range thereof, as parts of the circuit can be turned off/on depending on magnitudes of output power.

Power amplifier with automatic switching function

Disclosed herein is a power amplifier which is used in a wireless communication system and is capable of improving efficiency in an entire output power range and extending the dynamic range without additional switches, by including a drive amplification unit and a power amplification unit, connecting the drive amplification and the power amplification unit to a matching circuit, and a power coupler included in a transmission line transformer such that the drive amplification unit drives the power amplification unit, or directly outputs power to an output terminal, through the transmission line transformer, that is, the output power of the drive amplification unit is outputted to a load by switching on/off the power amplification unit and the drive amplification unit.

Growing community of inventors

Gyeongsangnam-do, South Korea

Changkun Park