A power amplification device capable of detaching an element relating to the power amplification of an RF signal from an element relating to the combining of RF signals. The amplifying unit 1 is provided with a plurality of groups of amplifier circuits 2 that amplifies the power of a RF signal and the plurality of groups of amplifier circuits each includes a predetermined number of the amplifier circuits 2. A combining unit 5 includes a first combiner 7 and a second combiner 8. The first combiner 7 is provided in association with the group of the amplifier circuits 2, combines RF signals output from the amplifier circuits 2 belonging to the corresponding group, and outputs the RF signal after combining. The second combiner 8 combines the RF signals output from each first combiner 7 and outputs the RF signal after combining. Each first combiner 7 is a combiner usable for an RF signal in a specific frequency band. The amplifying unit 1 is attachable to and detachable from the combining unit 5.

A power amplifier includes a carrier amplifier that operates from when an input signal is small, a peak amplifier that starts to operate when the input signal becomes large, a phase adjusting circuit that adjusts phases of an output of the carrier amplifier and an output of the peak amplifier, an impedance transforming line that transforms a load of the carrier amplifier when the input signal is small, and has a characteristic impedance close to an optimum load impedance of the carrier amplifier, and a circuit that is arranged between the output of the carrier amplifier and the impedance transforming line and reduces an output capacitance of the carrier amplifier.

The present invention provides a wideband Doherty power amplifier comprising: a main power amplification device; an auxiliary power amplification device arranged in parallel with the main power amplification device; and a coupled phase compensation network configured for compensating a phase shift between the main power amplification device and the auxiliary power amplification device. The phase compensation network comprising a first transmission line section; a second transmission line section extending substantially collinearly with the first transmission line section; and two pairs of end-connected coupled transmission lines connected in parallel between the first transmission line section and the second transmission line section. The provided Doherty power amplifier demonstrated operation at 6 dB back-off between 1.3-2.3 GHz with efficiency in excess of 41%, which can be used in modern and future wireless communication systems which require power amplifiers operating over a wide frequency range.

A power amplification device, including a first amplification branch, a second amplification branch, a harmonic injection circuit, and a first output matching circuit. A first amplifier in the first amplification branch supports a first frequency. A second amplifier in the second amplification branch supports the first frequency and a second frequency, and the second amplifier is turned off for a signal of the first frequency that has a power value lower than an enabling threshold. The harmonic injection circuit injects a signal of the second frequency that is input from a second input terminal (I2) to a signal of the first frequency that is input from a first input terminal (I1) to obtain a signal of the first frequency that has undergone harmonic injection.

A power amplification device, including a first amplification branch, a second amplification branch, a harmonic injection circuit, and a first output matching circuit. A first amplifier in the first amplification branch supports a first frequency. A second amplifier in the second amplification branch supports the first frequency and a second frequency, and the second amplifier is turned off for a signal of the first frequency that has a power value lower than an enabling threshold. The harmonic injection circuit injects a signal of the second frequency that is input from a second input terminal (I2) to a signal of the first frequency that is input from a first input terminal (I1) to obtain a signal of the first frequency that has undergone harmonic injection.

Systems and methods that cancel distortion in the amplified outputs of a node by equalizing the distortion characteristics amplifiers in the node, so as to improve the effectiveness of predistortion applied to a downstream signal amplified by the node.

In some embodiments, a power divider/combiner assembly includes a divider network, a plurality of amplifiers, and a combiner network. The divider network divides a received divider-network input signal into N divider-network output signals. The divider network includes at least one divider and at least one divider phase-shift circuit. The plurality of amplifiers include N amplifiers for amplifying the divider-network signals. The combiner network is for combining the N amplified signals into a combiner-network output signal. The combiner network includes at least one combiner and at least one combiner phase-shift circuit. Each phase-shift circuit is configured to produce a respective non-zero phase shift between divider output signals or between combiner input signals.

Provided is a load modulation amplifier including: a high frequency circuit board; and on the board, an input distribution circuit unit (DC) including: a distributor for dividing one input signal into two signals IS1 and IS2; and a phase delay circuit formed on a signal line for the divided IS2; a carrier amplifier (CA) including a first high frequency transistor for amplifying the IS1; a peak amplifier (PA) including a second high frequency transistor and for amplifying the IS2; and an output combination circuit (OCCU) including: a 90-degree phase delay circuit (90DC) formed on a signal line for output of the CA; a combiner for combining output of the 90DC and output of the PA; and an impedance conversion circuit for converting an output impedance of the combiner. The CA and the PA are directly connected to the OCCU without converting an output impedance.

Provided is a load modulation amplifier including: a high frequency circuit board; and on the board, an input distribution circuit unit (DC) including: a distributor for dividing one input signal into two signals IS1 and IS2; and a phase delay circuit formed on a signal line for the divided IS2; a carrier amplifier (CA) including a first high frequency transistor for amplifying the IS1; a peak amplifier (PA) including a second high frequency transistor and for amplifying the IS2; and an output combination circuit (OCCU) including: a 90-degree phase delay circuit (90DC) formed on a signal line for output of the CA; a combiner for combining output of the 90DC and output of the PA; and an impedance conversion circuit for converting an output impedance of the combiner. The CA and the PA are directly connected to the OCCU without converting an output impedance.

An inverted symmetrical four-stage Doherty amplifier is disclosed. The Doherty amplifier includes a carrier amplifier and a plurality of peak amplifiers. Outputs of the carrier amplifier and the peak amplifiers are provided to the combining unit through the offset unit including offset transmission lines each connected with the carrier amplifier and the peak amplifiers. The offset transmission lines have characteristic impedance and electrical lengths equal to each other such that the impedance seeing the amplifiers at the ends of the offset transmission lines become substantially short-circuited.