Embodiments of the disclosure generally relate to a multi-channel Doherty power amplifier, a multi-antenna transmitter, and a method for turning on the multi-channel Doherty amplifier. The multi-channel Doherty power amplifier includes: multiple input ports and the same number of output ports corresponding to multiple channels, the multiple channels having the same characteristics for radio signal amplification and transmission; multiple private peaking amplifiers corresponding to the multiple channels; and a common Doherty core shared by the multiple private peaking amplifiers. The multiple private peaking amplifiers and the common Doherty core are configured to amplify identical multi-channel signal for multiple inputs and multiple outputs, thus higher saving ratio and better channel performance (output power, linearity, efficiency, power gain etc.) consistency would be greatly improved.

A power amplifier apparatus supporting reverse intermodulation product (rIMD) cancellation is provided. The power amplifier apparatus includes an amplifier circuit configured to amplify and output a radio frequency (RF) signal for transmission via an antenna port. The antenna port may receive a reverse interference signal, which may interfere with the RF signal to create a rIMD(s) that can fall within an RF receive band(s). A reverse coupling circuit is provided in the power amplifier apparatus to generate an interference cancellation signal based on the reverse interference signal. The amplifier circuit is configured to amplify the interference cancellation signal and the RF signal to create an intermodulation product(s) to suppress the rIMD(s) to a determined threshold. By suppressing the rIMD(s) in the power amplifier apparatus, it is possible to support concurrent transmissions and receptions in a number of RF spectrums while in compliance with stringent regulatory spurious emissions (SEM) requirements.

An average power tracking (APT) power amplifier apparatus is provided. In a non-limiting example, the APT power amplifier apparatus includes multiple sets of power amplifier circuits configured to amplify a radio frequency (RF) signal(s) for transmission in different polarizations (e.g., vertical and horizontal). In examples disclosed herein, the APT power amplifier apparatus can be configured to employ a single power management integrated circuit (PMIC) to provide an APT voltage to all of the power amplifier circuits for amplifying the RF signal(s). By employing a single PMIC in the APT power amplifier apparatus, it is possible to reduce footprint, power consumption, and costs of the APT power amplifier apparatus.

The present disclosure describes a method and system for linearizing an amplifier using transistor-level dynamic feedback. The method and system enables nonlinear amplifiers to exhibit linear performance using one or more of gain control elements and phase shifters in the feedback path. The disclosed method and system may also allow an amplifier to act as a pre-distorter or a frequency/gain programmable amplifier.

An amplifier circuit for compensating an output signal provided at an output of the amplifier circuit comprises a cascade of sub-amplifiers. Each sub-amplifier of the cascade contributes to a respective part of the output signal. The cascade of sub-amplifiers comprises an end sub-amplifier and at least one preliminary sub-amplifier. At least one error correction block is coupled to apply feedforward error correction to an output of one of the at least one preliminary sub-amplifier.

Examples of an amplifier includes an input divider section having a first path and a second path for branching of an input signal, wherein a passing phase at the first path and a passing phase at the second path are different; a first amplifying element that amplifies a signal input to the first path; a second amplifying element that amplifies a signal input to the second path; an output synthesizing section that performs synthesis of an output of the first amplifying element and an output of the second amplifying element with a third path for transmitting the output of the first amplifying element and a fourth path for transmitting the output of the second amplifying element, wherein a passing phase at the third path and a passing phase at the fourth path are different; and an electromagnetic coupling section that establishes electromagnetic coupling of two signals.

A method for making a wideband Doherty amplifier with reduced plan width, adapted to transport a radio-frequency signal at a frequency value comprised within a frequency range defined between a minimum frequency value and a maximum frequency value, the amplifier including: a signal source adapted to generate an input signal; a hybrid coupler or a splitter network adapted to receive the input signal and divide it into first and second output signals phase-shifted by 90; a carrier amplifier adapted to receive as input the first output signal; a peak amplifier adapted to receive as input the second output signal; an output network arranged between the carrier and peak amplifiers and a delivery node adapted to be connected to a load, the output network including a recombination node adapted to receive the signals output by the carrier amplifier and the peak amplifier, and a transmission line implemented as a printed circuit track applied to an insulating substrate, wherein capacitors are inserted on the track which are adapted to compensate for the non-ideality characteristics of the semiconductor used for making the line.

A directional coupler includes a main line through which a first signal in a first frequency band and a second signal in a second frequency band pass from a first port to a second port, a sub-line electromagnetically coupled to the main line and having a third port and a fourth port, the third port outputting a first coupled signal corresponding to the first signal and a second coupled signal corresponding to the second signal, a first termination circuit connected to the fourth port and used in outputting the first coupled signal, a second termination circuit connected to the fourth port and used in outputting the second coupled signal, and a first filter circuit disposed between the fourth port and the first termination circuit, wherein the first filter circuit has frequency characteristics allowing the first coupled signal to pass therethrough and attenuating the second coupled signal.

An amplifier for a transceiver comprising

plurality of power amplifiers arranged on a base, each power amplifier comprising a power amplifier input port and a power amplifier output port;

a planar power splitter arranged on the base, the power splitter comprising a power splitter input port and a plurality of power splitter output ports;

each power amplifier input port being connected to a power splitter output port by a planar transmission line;

each power amplifier output port being connected to a waveguide transition;

a plurality of waveguides each defined by a waveguide wall, each waveguide being arranged within the base, each waveguide transition being connected to waveguide; and,

a waveguide power combiner arranged within the base, each waveguide being connected to the waveguide power combiner.

According to one aspect, embodiments of the invention provide an amplifier system comprising a first phase shifter configured to generate, based on an input signal, a first signal and a second signal, the second signal being out of phase with the first signal, a first amplifier configured to apply a first gain to the first signal to produce a gain adjusted first signal, a second amplifier configured to apply a second gain to the second signal to produce a gain adjusted second signal, a second phase shifter configured to combine the gain adjusted first and second signals to produce an output signal, and a controller configured to identify a high voltage swing across the first amplifier and, in response to identifying the high voltage swing, adjust the first gain to reduce output power of the first amplifier and adjust the second gain to increase output power of the second amplifier.