A power amplifier arrangement (100) for amplifying an input signal (Pin) to produce an output signal (Pout) is disclosed. The amplifier arrangement (100) comprise an input port (IN) for receiving the input signal; an output transmission line (110) having a first terminal (111) and a second terminal (112); an output port (OUT) coupled to the second terminal (112) of the output transmission line (110) for providing the output signal; and a plurality N of amplifying devices (121, 122, . . . 12N) distributed along the output transmission line (110). The power amplifier arrangement (100) is configured such that the plurality N of amplifying devices are active sequentially for amplifying the input signal with increasing amplitude of the input signal.

A solid-state direct cavity combiner (DCC) transmitter system for providing megawatts of power is featured. The system includes a resonant cavity including at least one high-power output transmission line, hundreds of high-power transistors each generating an amount of RF power input directly into the resonant cavity, and a plurality of modules each including at least one pair of high-power transistors differentially driving a transmission line and a coupling loop. Each said transmission line and coupling loop extends into the resonant cavity to match an impedance of each said high-power transistors of each said module to an impedance of said resonant cavity to electromagnetically couple power into the resonant cavity to provide the megawatts of power to the high-power output transmission line.

Disclosed are an output network of a Doherty amplifier, a Doherty amplifier including the output network, and a design method of the Doherty amplifier. The output network of a Doherty amplifier including a main amplifier and an auxiliary amplifier, and the output network includes a combination node; a main output network connected between an output port of the main amplifier and the combination node; an auxiliary output network connected between an output port of the auxiliary amplifier and the combination node; and a merging matching network connected between the combination node and a radio frequency output port of the Doherty amplifier; the merging matching network is configured for the node impedance at the combination node being a complex impedance, and the main output network and the auxiliary output network are configured for the node impedance being matching with the goal load impedances of the main amplifier and the auxiliary amplifier.

A Doherty power amplifier includes a first amplifier with a first output capacitance, a second amplifier with a second output capacitance, a reconfigurable impedance inverter, and a variable output impedance transformer. The reconfigurable impedance inverter includes a combining node and first, second, and third variable networks. The first variable network and the first amplifier output capacitance establish a first amplifier effective output capacitance that is less than the first output capacitance. The second variable network provides a series inductance between the first amplifier output and the combining node. The third variable network and the second amplifier output capacitance establish a second amplifier effective output capacitance that is less than the second output capacitance. The output impedance transformer includes a fourth variable network that establishes a combining node impedance. The first, second, and third variable networks and the output impedance transformer may be reconfigured based on traffic loading conditions.

A Doherty power amplifier includes a combining node is coupled to a carrier amplifier output and to a peaking amplifier output, and a reconfigurable output impedance transformer coupled between the combining node and a radio frequency (RF) output. The combining node is configured to combine an amplified carrier signal and an amplified peaking signal to produce a combined amplified signal. The reconfigurable output impedance transformer includes a phase shift element, a first variable capacitor, and a second variable capacitor. The phase shift element has an input end coupled to the combining node and an output end coupled to the RF output, and the phase shift element is configured to apply a phase shift to the combined amplified signal. The first variable capacitor is coupled to the input end of the first phase shift element, and the second variable capacitor coupled to the output end of the first phase shift element.

An amplifying circuit includes a first divider that divides an input signal into a first signal and a second signal, a first amplifier that amplifies the first signal, a second amplifier that amplifies the second signal, a combiner that combines the first signal and the second signal to output the combined signal as an output signal, and at least one composite right/left-handed transmission line connected to at least one of a first line connecting the first divider to the first amplifier or a second line connecting the first divider to the second amplifier, the at least one composite right/left-handed transmission line adjusting a phase of at least one of the first signal flowing through the first line and the second signal flowing through the second line.

An amplifier device may include at least one two-stage amplifier package, where an amplifier of a first amplification stage of the amplifier package may be aligned opposite to amplifiers of a second amplification stage of the amplifier package. The amplifier device may be a three-stage amplifier device, where the second stage of the two-stage amplifier package is coupled to amplifiers of a final (third) stage, which may be in a Doherty configuration. The amplifiers of the second stage may be arranged in any of a class AB configuration, a Doherty configuration, a multi-stage Doherty configuration (with amplifiers of the final amplification stage), or a multi-driver, multi-stage Doherty configuration. One or more passive components used for inter-stage impedance matching may be disposed outside of the two-stage amplifier package. Amplifiers of the first, second, and third amplification stages may each be gallium nitride (GaN) amplifiers, in some embodiments.

In some examples, a hybrid Chireix-Doherty amplifier comprises a first and second input network, a main amplifier coupled to a first output of the first input network, an auxiliary amplifier coupled to a second output of the second input network, and a combiner network. The combiner network is coupled to a first output of the main amplifier and an output of the auxiliary amplifier. The combiner network includes an output node for coupling to a load, e.g., an antenna of a base station for a radio network. The main amplifier is implemented as an inverse class-F amplifier.

A Doherty power amplifier includes a combining node that combines amplified output signals from first and second amplifiers. A reconfigurable impedance inverter circuit is coupled between the first amplifier and the combining node. The impedance inverter circuit includes an inductive element coupled between a first node and a second node, and a switching circuit coupled between the first node and the second node. A fundamental frequency tuning circuit and a harmonic frequency resonance circuit are coupled between the switching circuit and a ground reference node. When the switching circuit is configured in a first state, the fundamental frequency tuning circuit and the harmonic frequency resonance circuit are electrically coupled through the switching circuit to the first and second nodes. When the switching circuit is configured in a second state, the fundamental frequency tuning circuit and the harmonic frequency resonance circuit are electrically disconnected from the first and second nodes.

Methods and apparatus are provided. In an example aspect, a method of operating an amplifier circuit is provided. The amplifier circuit comprises a first amplifier configured to receive a first signal, a balanced amplifier comprising second and third amplifiers and configured to receive a second signal, and a first directional coupler. An output of the first amplifier is connected to a transmitted port of the first directional coupler, an output of the second amplifier is connected to an input port of the first directional coupler, an output of the third amplifier is connected to an isolated port of the first directional coupler, and a coupled port of the first directional coupler is connected to an output of the amplifier circuit. The method comprises operating the amplifier circuit in a first output peak amplitude range of the amplifier circuit wherein, in the first output peak amplitude range, the first signal is based on a signal to be amplified and has an amplitude that increases across the first output peak amplitude range from substantially zero to a first amplitude, and the second signal is substantially zero, and operating the amplifier circuit in a second output peak amplitude range of the amplifier circuit, wherein the second output peak amplitude range is higher than the first output peak amplitude range and wherein, in the second output peak amplitude range, the first signal is based on the signal to be amplified and has an amplitude that decreases across the second output peak amplitude range from the first amplitude to a second amplitude, and the second signal is based on the signal to be amplified and has an amplitude that increases across the second output peak amplitude range from a third amplitude to a fourth amplitude.