Abstract: Apparatus and methods for biasing power amplifiers are provided herein. In certain embodiments, a power amplifier includes a bipolar transistor having a base biased by a bias network having a reactance that controls an impedance at the transistor base to achieve substantially flat phase response over large dynamic power levels. For example, the bias network can have a frequency response, such as a high-pass or band-pass response, that reduces the impact of power level on phase distortion (AM/PM).

Abstract: Apparatus and methods for biasing power amplifiers are provided herein. In certain embodiments, a power amplifier includes a bipolar transistor having a base biased by a bias network having a reactance that controls an impedance at the transistor base to achieve substantially flat phase response over large dynamic power levels. For example, the bias network can have a frequency response, such as a high-pass or band-pass response, that reduces the impact of power level on phase distortion (AM/PM).

Abstract: Apparatus and methods for bias switching of power amplifiers are provided herein. In certain configurations, a power amplifier system includes a power amplifier that provides amplification to a radio frequency (RF) signal and a bias control circuit that biases the power amplifier. The power amplifier includes an amplification transistor that receives the RF signal at an input, and a first bias network and a second bias network each connected to the input. The bias control circuit includes a first switch, a first reference current source that provides the first reference current to the first bias network through the first switch, a second switch, and a second reference current source that provides the second reference current to the second bias network through the second switch.

Abstract: Aspects of this disclosure relate to detecting power associated with an individual carrier of a carrier aggregated signal. In an embodiment, an aggregated carrier including at least a first carrier and a second carrier is provided. An indication of power of the first carrier of the aggregated carrier is detected. Separately from detecting the indication of power of the first carrier, an indication of power of the second carrier of the aggregated carrier is detected. The power associated with a radio frequency (RF) signal provided to an RF source associated with the first carrier can be adjusted based on the indication of power of the first carrier.

Abstract: Circuits and methods related to radio-frequency (RF) architectures having carrier aggregation. In some implementations, a method for performing carrier aggregation (CA) can include providing a duplexer configured to provide duplexing functionality for a first frequency band and a second frequency band with a common antenna. The method can further include providing a first amplification path and a second amplification path coupled to respective ports of the duplexer, each of the first amplification path and the second amplification path configured to amplify a signal in its respective frequency band, each amplification path including a transmit/receive (TX/RX) switch configured to provide time-division duplexing (TDD) functionality for the amplified signal and a received signal. In some implementations, the first frequency band includes a B39 band, and the second frequency band includes a B41 band.

Abstract: In some embodiments, stability in power amplifiers can be achieved under high out-of-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 output side of the second stage and configured to provide stability in operation of the amplifier under a high out-of-band voltage standing wave ratio condition.

Abstract: 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.

Abstract: In some embodiments, stability in power amplifiers can be achieved under high voltage standing wave ratio conditions, with an amplifier circuit that includes an amplifier having a selected stage among a plurality of stages, and either or both of a first stabilizing circuit implemented on an input side of the selected stage to provide stability in operation of the amplifier under a high in-band voltage standing wave ratio condition, and a second stabilizing circuit implemented on an output side of the selected stage to provide stability in operation of the amplifier under a high out-of-band voltage standing wave ratio condition.

Abstract: Apparatus and methods for bias switching of power amplifiers are provided herein. In certain configurations, a power amplifier system includes a power amplifier that provides amplification to a radio frequency (RF) signal and a bias control circuit that biases the power amplifier. The power amplifier includes an amplification transistor that receives the RF signal at an input, and a first bias network and a second bias network each connected to the input. The bias control circuit includes a first switch, a first reference current source that provides the first reference current to the first bias network through the first switch, a second switch, and a second reference current source that provides the second reference current to the second bias network through the second switch.

Abstract: Apparatus and methods for bias switching of power amplifiers are provided herein. In certain configurations, a power amplifier system includes a power amplifier that provides amplification to a radio frequency (RF) signal, a power management circuit that controls a voltage level of a supply voltage of the power amplifier, and a bias control circuit that biases the power amplifier. The power management circuit is operable in multiple supply control modes, such as an average power tracking (APT) mode and an envelope tracking (ET) mode. The bias control circuit is configured to switch a bias of the power amplifier based on the supply control mode of the power management circuit.

Abstract: Aspects of this disclosure relate to detecting power associated with an individual carrier of a carrier aggregated signal. In an embodiment, an aggregated carrier including at least a first carrier and a second carrier is provided. An indication of power of the first carrier of the aggregated carrier is detected. Separately from detecting the indication of power of the first carrier, an indication of power of the second carrier of the aggregated carrier is detected. The power associated with a radio frequency (RF) signal provided to an RF source associated with the first carrier can be adjusted based on the indication of power of the first carrier.

Abstract: Aspects of this disclosure relate to detecting power associated with an individual carrier of a carrier aggregated signal. In an embodiment, an aggregated carrier including at least a first carrier and a second carrier is provided. An indication of power of the first carrier of the aggregated carrier is detected. Separately from detecting the indication of power of the first carrier, an indication of power of the second carrier of the aggregated carrier is detected. The power associated with a radio frequency (RF) signal provided to an RF source associated with the first carrier can be adjusted based on the indication of power of the first carrier.

Abstract: Circuits and methods related to radio-frequency (RF) architectures having carrier aggregation. In some implementations, a method for performing carrier aggregation (CA) can include providing a duplexer configured to provide duplexing functionality for a first frequency band and a second frequency band with a common antenna. The method can further include providing a first amplification path and a second amplification path coupled to respective ports of the duplexer, each of the first amplification path and the second amplification path configured to amplify a signal in its respective frequency band, each amplification path including a transmit/receive (TX/RX) switch configured to provide time-division duplexing (TDD) functionality for the amplified signal and a received signal. In some implementations, the first frequency band includes a B39 band, and the second frequency band includes a B41 band.

Abstract: Apparatus and methods for biasing power amplifiers are provided herein. In certain embodiments, a power amplifier includes a bipolar transistor having a base biased by a bias network having a reactance that controls an impedance at the transistor base to achieve substantially flat phase response over large dynamic power levels. For example, the bias network can have a frequency response, such as a high-pass or band-pass response, that reduces the impact of power level on phase distortion (AM/PM).

Abstract: A power amplifier module can include one or more switches, a coupler module, input signal pins, and a controller having first and second output terminals. The input signal pins can receive a voltage input/output signal, a clock input signal, and a data input signal. The controller can (i) set a mode of the one or more switches using a synchronous communication protocol in which the controller outputs a synchronous clock signal on the first output terminal and a data signal on the second output terminal, when the power amplifier module is in a first operating mode, or (ii) set a mode of the coupler module using an asynchronous communication protocol in which the controller outputs a first asynchronous control signal on the first output terminal and a second asynchronous control signal on the second output terminal, when the power amplifier module is in a second operating mode.

Abstract: Circuits and methods related to radio-frequency (RF) architectures having carrier aggregation. In some implementations, a carrier aggregation (CA) architecture can include a duplexer configured to provide duplexing functionality for a first frequency band and a second frequency band with a common antenna. The CA architecture can further include a first amplification path and a second amplification path coupled to respective ports of the duplexer, each of the first amplification path and the second amplification path configured to amplify a signal in its respective frequency band, each amplification path including a transmit/receive (TX/RX) switch configured to provide time-division duplexing (TDD) functionality for the amplified signal and a received signal. In some implementations, the first frequency band includes a B39 band, and the second frequency band includes a B41 band.

Abstract: Apparatus and methods for biasing power amplifiers are provided herein. In certain embodiments, a power amplifier includes a bipolar transistor having a base biased by a bias network having a reactance that controls an impedance at the transistor base to achieve substantially flat phase response over large dynamic power levels. For example, the bias network can have a frequency response, such as a high-pass or band-pass response, that reduces the impact of power level on phase distortion (AM/PM).

Abstract: A power amplifier module can include one or more switches, a coupler module, input signal pins, and a controller having first and second output terminals. The input signal pins can receive a voltage input/output signal, a clock input signal, and a data input signal. The controller can (i) set a mode of the one or more switches using a synchronous communication protocol in which the controller outputs a synchronous clock signal on the first output terminal and a data signal on the second output terminal, when the power amplifier module is in a first operating mode, or (ii) set a mode of the coupler module using an asynchronous communication protocol in which the controller outputs a first asynchronous control signal on the first output terminal and a second asynchronous control signal on the second output terminal, when the power amplifier module is in a second operating mode.

Abstract: Apparatus and methods for bias switching of power amplifiers are provided herein. In certain configurations, a power amplifier system includes a power amplifier that provides amplification to a radio frequency (RF) signal, a power management circuit that controls a voltage level of a supply voltage of the power amplifier, and a bias control circuit that biases the power amplifier. The power management circuit is operable in multiple supply control modes, such as an average power tracking (APT) mode and an envelope tracking (ET) mode. The bias control circuit is configured to switch a bias of the power amplifier based on the supply control mode of the power management circuit.

Abstract: Aspects of this disclosure relate to detecting power associated with an individual carrier of a carrier aggregated signal. In an embodiment, an aggregated carrier including at least a first carrier and a second carrier is provided. An indication of power of the first carrier of the aggregated carrier is detected. Separately from detecting the indication of power of the first carrier, an indication of power of the second carrier of the aggregated carrier is detected. The power associated with a radio frequency (RF) signal provided to an RF source associated with the first carrier can be adjusted based on the indication of power of the first carrier.