A stacked amplifier circuit includes an input stage having first and second input ports respectively defined by inputs of first and second transistors. A transformer arrangement includes first and second primary windings and first and second secondary windings. The first secondary winding is connected to an output of the first input transistor and the second secondary winding is connected to an output of the second input transistor. Portions of the magnetic fields generated by the primary windings couple to their respective secondary windings. An output stage is AC coupled to the first and second secondary windings and has an output connected to the first and second primary windings. The input stage and the output stage are arranged in a stacked configuration such that a bias current of the output stage is reused as bias current for the input stage.

An amplifier circuit including a first amplifier having a first amplifier input and a first amplifier output and a transformer including a first transformer component having a first primary winding in series with the first amplifier output and a first secondary winding coupled to the first amplifier input. The first primary winding and the first secondary winding are arranged such that a portion of a first magnetic field generated by the first primary winding couples to the first secondary winding through a first magnetically coupled feedback loop. The transformer further includes a second transformer component having a second primary winding in series with an output of a second amplifier and a second secondary winding coupled to an input of the second amplifier input. A portion of a second magnetic field generated by the second primary winding couples to the second secondary winding through a second magnetically coupled feedback loop.

Disclosed are crest factor reduction (CFR) implementations that include a method comprising getting communication system data representative of characteristics of a communication system comprising one or more radio transmission bands, and optimizing, based at least in part on the input communication system data, a plurality of updateable parameters that determine respective pulse shapes for one or more pulses as well as other certain algorithm execution parameters for use in the CFR system. Optimizing the plurality of updateable parameters includes iteratively updating the plurality of updateable parameters based on iterative evaluation of a plurality of performance parameters. The method further includes providing the optimized plurality of updateable parameters to configure the crest reduction system for use in processing signals for radio transmission using a pulse subtraction approach applied to one or more signals communicated through the communication system.

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.

The present disclosure relates to an amplifier arrangement comprising a first amplifier, a second amplifier and an output combiner arranged to combine respective output signals of the first amplifier and the second amplifier into an output signal of the amplifier arrangement. An amplifier arrangement input signal is arranged as input signal to the first amplifier, and a difference signal, representing a difference between the amplifier arrangement input signal and a scaled output signal of the first amplifier, is arranged as input to the second amplifier. The output combiner is arranged to modulate the loads of the first amplifier and the second amplifier in dependence of the output signal of the second amplifier.

A method and base station transmitter for providing offline tuning of a base station transmitter. The base station transmitter includes a feed-forward power amplifier comprising a Radio Frequency (RF) input and an RF output. The base station transmitter also includes a simulated carrier generator operatively coupled to the feed-forward power amplifier prior to the carrier cancellation loop. The simulated carrier generator provides a simulated carrier signal including one or more individual carrier frequencies to the RF input. The base station transmitter also includes a processor that is operatively coupled to the feed-forward power amplifier and the simulated carrier generator. The processor performs tuning of a carrier cancellation loop using the simulated carrier signal when the processor determines that a carrier signal is not present.

Apparatus and method for extended operational bandwidth amplifiers with fractional instantaneous bandwidth feed forward correction. In one embodiment, the method includes amplifying a radio frequency (RF) input signal to provide an amplified RF signal and introducing a first delay in the amplified RF signal. The method also includes receiving an error signal of the amplified RF signal and centering a correction bandwidth with respect to the amplified RF signal. The method also includes amplifying the error signal and combining the amplified RF signal and the amplified error signal to reduce an error in the amplified RF signal. The first delay is smaller than a second delay caused by the error path.

Apparatus and method for extended operational bandwidth amplifiers with fractional instantaneous bandwidth feed forward correction. In one embodiment, the method includes amplifying a radio frequency (RF) input signal to provide an amplified RF signal and introducing a first delay in the amplified RF signal. The method also includes receiving an error signal of the amplified RF signal and centering a correction bandwidth with respect to the amplified RF signal. The method also includes amplifying the error signal and combining the amplified RF signal and the amplified error signal to reduce an error in the amplified RF signal. The first delay is smaller than a second delay caused by the error path.

Disclosed are crest factor reduction (CFR) implementations that include a method comprising getting communication system data representative of characteristics of a communication system comprising one or more radio transmission bands, and optimizing, based at least in part on the input communication system data, a plurality of updateable parameters that determine respective pulse shapes for one or more pulses as well as other certain algorithm execution parameters for use in the CFR system. Optimizing the plurality of updateable parameters includes iteratively updating the plurality of updateable parameters based on iterative evaluation of a plurality of performance parameters. The method further includes providing the optimized plurality of updateable parameters to configure the crest reduction system for use in processing signals for radio transmission using a pulse subtraction approach applied to one or more signals communicated through the communication system.

A distortion compensation device includes: a first distributor configured to distribute an input signal into a first route signal and a second route signal; a distortion generation circuit configured to generate a distortion component has non-linear characteristics opposite to those of a device to be compensated in the input first route signal; a second distributor configured to receive the first route signal including the distortion component, distribute the first route signal including the distortion component into a third route signal and a fourth route signal; a first combiner configured to receive the second route signal and the third route signal, and extract and output the distortion component included in the third route signal; a frequency characteristic adjustment circuit configured to unbalance the distortion component output from the first combiner; and a second combiner configured to combine the distortion component unbalanced by the frequency characteristic adjustment circuit with the fourth route signal.