In some embodiments, stability in power amplifiers can be achieved under high in-band voltage standing wave ratio condition, with an amplifier circuit that includes an amplifier having a first stage and a second stage, with each stage including an input and an output, such that the output of the first stage is coupled to the input of the second stage. The amplifier circuit further includes a stabilizing circuit implemented on the input side of the second stage and configured to provide stability in operation of the amplifier under a high in-band voltage standing wave ratio condition.

Disclosed is a reconfigurable power amplifier having a 2.sup.N−1 number of input-side reconfigurable quadrature couplers connected in a tree structure, wherein a 2.sup.(N−1) number of the input-side reconfigurable quadrature couplers have coupler output terminals, and a root of the tree structure is one of the input-side reconfigurable quadrature couplers having a main input terminal. Also included is a 2.sup.N−1 number of output-side reconfigurable quadrature couplers connected in a tree structure, wherein a 2.sup.(N−1) number of the output-side reconfigurable quadrature couplers have coupler input terminals, and a root of the tree structure is one of the output-side reconfigurable quadrature couplers having a main output terminal. Further included is a 2.sup.N number of constituent amplifiers divided into amplifier pairs having amplifier input terminals connected to corresponding ones of the coupler output terminals and having amplifier output terminals coupled to corresponding ones of the coupler input terminals.

An active electronic device that enables bidirectional communication over a single antenna or path is disclosed. The device may be characterized by a forward path (from an input to an antenna port) offering high gain, and a reverse path (to a receiver port) that can be configured as an finite impulse response (“FIR”) filter. An amplifier of the device is disclosed, the amplifier allowing for tuning of output resistance using passive mixers.

Power amplification system with adjustable common base bias. A power amplification system can include a cascode amplifier coupled to a radio-frequency input signal and coupled to a radio-frequency output. The power amplification system can further include a biasing component configured to apply one or more biasing signals to the cascode amplifier, the biasing component including a bias controller and one or more bias components. Each respective bias component may be coupled to a respective bias transistor.

Power amplification system with adjustable common base bias. A power amplification system can include a cascode amplifier coupled to a radio-frequency input signal and coupled to a radio-frequency output. The power amplification system can further include a biasing component configured to apply one or more biasing signals to the cascode amplifier, the biasing component including a bias controller and one or more bias components. Each respective bias component may be coupled to a respective bias transistor.

A method of a wireless transmitter is disclosed. The method is for mitigation of distortion caused by non-linear hardware components of the transmitter, wherein mitigation of distortion comprises mitigating at least one intermodulation component, wherein the transmitter is configured to process an input signal having an input signal spectrum, and wherein the transmitter comprises two or more signal branches, each signal branch comprising a respective non-linear hardware component. The method comprises modifying the input signal for a first one of the signal branches by applying a first phase shift to a first part of the input signal spectrum, wherein the first phase shift has a first sign and a first absolute value, and applying a second phase shift to a second part of the input signal spectrum. The second phase shift has a second sign which is opposite to the first sign, and a second absolute value which is equal to the first absolute value. The first and second parts are non-overlapping. The method also comprises modifying the input signal for a second one of the signal branches by applying the first phase shift to the second part of the input signal spectrum, and applying the second phase shift to the first part of the input signal spectrum. The method further comprises feeding the modified input signals to respective ones of the signal branches. Corresponding apparatus, wireless transmitter, communication device, and computer program product are also disclosed.

In some embodiments, an amplifier system can include an amplifier circuit having first and second amplifiers configured to amplify respective first and second portions of an input signal. Each of the first and second amplifiers can include a cascode stage with input and output transistors arranged in a cascode configuration. The amplifier system can further include an envelope tracking bias circuit coupled to the amplifier circuit and configured to provide a bias signal to the output transistor of the cascode stage of at least one of the first and second amplifiers. The amplifier system can further include a supply circuit configured to provide a non-envelope tracking supply voltage to the output transistor of the cascode stage of the at least one of the first and second amplifiers.

In some embodiments, an amplifier system can include an amplifier circuit having first and second amplifiers configured to amplify respective first and second portions of an input signal. Each of the first and second amplifiers can include a cascode stage with input and output transistors arranged in a cascode configuration. The amplifier system can further include an envelope tracking bias circuit coupled to the amplifier circuit and configured to provide a bias signal to the output transistor of the cascode stage of at least one of the first and second amplifiers. The amplifier system can further include a supply circuit configured to provide a non-envelope tracking supply voltage to the output transistor of the cascode stage of the at least one of the first and second amplifiers.

An apparatus is provided that includes circuitry for decomposing an input signal to multiple substantially constant-envelope components and an outphasing path for each substantially constant-envelope component. The apparatus also includes a modulator for discrete phase control in each outphasing path, an amplifier in each outphasing path and a combiner for combining output signals from the outphasing paths. A system and method are also provided.

Technologies directed to cable-loss compensation are described. An apparatus includes a triplexer, a front-end module (FEM) circuit, and a control circuit. The triplexer is coupled to a radio frequency (RF) cable. The triplexer receives a first RF signal and a DC power signal from a device via the RF cable and sends a detection signal being indicative of a transmit power level of the first RF signal to the device via the RF cable. The transmit power level includes an insertion loss of the RF cable. The FEM circuit is coupled to the triplexer and includes a power amplifier (PA). The control circuit is coupled to the triplexer and measures the transmit power level of the first RF signal and converts the first RF signal into the detection signal. The control circuit sends the detection signal back to the device via the RF cable and enables the PA.