Abstract: Aspects of this disclosure relate to a front end architecture for selectively adding an external carrier aggregation band. A switch element can connect a radio frequency signal path to an antenna path through a frequency domain multiplexer, such as a diplexer, in a first mode. The switch element can connect the radio frequency path to the antenna path and bypass the frequency domain multiplexer in a second mode. The frequency domain multiplexer can be external to a front end module that include the radio frequency signal path. In the first mode, a front end system can support carrier aggregation with a band associated with circuitry implemented external to the front end module.

Abstract: Aspects of this disclosure relate to a dual connectivity power amplifier system. The power amplifier system includes first and second power amplifiers that are concurrently active in a dual connectively mode. The first power amplifier is active in a different mode. A switch electrically connects the first power amplifier to different radio frequency signal paths in the dual connectivity mode and the different mode. Related methods, power amplifier modules, and wireless communication devices are disclosed.

Abstract: Apparatus and methods for adaptive power amplifier biasing are provided. In certain embodiments, a power amplifier system includes a power amplifier that provides amplification to a radio frequency (RF) signal, and a power amplifier bias control circuit that generates a bias signal of the power amplifier based on a bandwidth signal indicating a bandwidth of the RF signal. The power amplifier bias control circuit has a bandwidth that adapts to the bandwidth of the RF signal as indicated by the bandwidth signal.

Abstract: Configurable filter bands for radio frequency communication are disclosed. In one aspect, a radio frequency module includes a plurality of n-plexers, each of the n-plexers including n filters, each of the filters configured to pass at least one radio frequency band, and at least two of the radio frequency bands having overlapping frequencies, an antenna terminal, and an antenna switch module configured to connect two or more of the n-plexers to the antenna terminal.

Abstract: An RF front-end module including a first transceiver unit, a second transceiver unit, a first antenna, a second antenna, a first diplexer, and a second diplexer. The first transceiver unit has a first transmitter and a first receiver and is configured to transmit at a first LTE 4G band, and the second transceiver unit has a second transmitter and a second receiver and is configured to transmit at a first new radio 5G (NR) band. The first antenna is connected via the first diplexer to the first transmitter and the first receiver, the first receiver being configured to receive at the first new radio 5G band, and the second antenna is connected via the second diplexer to the second transmitter and the second receiver, the second receiver being configured to receive at the first LTE 4G band.

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: A tunable vector recombination amplifier comprises an input, an output, first and second amplifier circuit paths each including a respective phase shifter to receive a respective input signal from the input and to apply a respective phase shift to produce a respective phase-shifted signal, a respective interstage impedance matching network, and a respective amplifier connected between the respective phase shifter and interstage impedance matching network to receive and amplify the respective phase-shifted signal to produce a respective amplified signal, first and second controllable DC voltage sources each coupled to a respective amplifier and configured to provide a respective supply voltage to the respective amplifier, values of the supply voltages being independently controllable, and an output amplifier stage to receive, amplify, and vectorially combine the amplified signals to produce a combined signal having a specified phase determined by the phase shifts and supply-voltage values and a specified ampli

Abstract: A front-end module including a power amplifier, first and second couplers, an antenna switch, and a switch sub-assembly. The power amplifier has an input to receive a radio frequency signal and an output to provide an amplified radio frequency signal. The first coupler has an input port coupled to the output of the power amplifier, an output port coupled to an input of the antenna switch, a coupled port, and an isolated port. The second coupler has an input port coupled to an output of the antenna switch, an output port coupled to an antenna port, a coupled port, and an isolated port. The switch sub assembly connects one of the coupled port and the isolated port of the second coupler to an output of the switch assembly and the other one of the coupled port and the isolated port of the second coupler to a first termination impedance.

Abstract: Apparatus and methods for power amplifier envelope tracking systems with automatic control of a slew rate and a mode of an error amplifier of the envelope tracking system. The envelope tracker can include a signal bandwidth detection circuit that processes the envelope signal to generate a detected bandwidth signal, and a control circuit that controls the slew rate of the error amplifier based on the detected signal bandwidth.

Abstract: Apparatus and methods for power amplifier envelope tracking systems with automatic control of a slew rate and a mode of an error amplifier of the envelope tracking system. The envelope tracker can include a signal bandwidth detection circuit that processes the envelope signal to generate a detected bandwidth signal, and a control circuit that controls the slew rate of the error amplifier based on the detected signal bandwidth.

Abstract: Apparatus and methods for power amplifier envelope tracking systems with automatic control of a slew rate and a mode of an error amplifier of the envelope tracking system. The envelope tracker can include a signal bandwidth detection circuit that processes the envelope signal to generate a detected bandwidth signal, and a control circuit that controls the slew rate of the error amplifier based on the detected signal bandwidth.

Abstract: Aspects of this disclosure relate to a coupler circuit configured to receive an output of a radio frequency coupler. The coupler circuit can be arranged in a daisy chain with other coupler circuits. The coupler circuit can include a switch configured to turn on based on a signal level of a direct current component of a coupler signal from another coupler circuit and pass a radio frequency component of the coupler signal when on. The coupler circuit can pass the coupler signal while a module that includes the coupler circuit is otherwise inactive.

Abstract: Apparatus and methods for adaptive power amplifier biasing are provided. In certain embodiments, a power amplifier system includes a power amplifier that provides amplification to a radio frequency (RF) signal, and a power amplifier bias control circuit that generates a bias signal of the power amplifier based on a bandwidth signal indicating a bandwidth of the RF signal. The power amplifier bias control circuit has a bandwidth that adapts to the bandwidth of the RF signal as indicated by the bandwidth signal.

Abstract: Aspects of this disclosure relate to a coupler circuit configured to receive an output of a radio frequency coupler. The coupler circuit can be arranged in a daisy chain with other coupler circuits. The coupler circuit can include a switch configured to turn on based on a signal level of a direct current component of a coupler signal from another coupler circuit and pass a radio frequency component of the coupler signal when on. The coupler circuit can pass the coupler signal while a module that includes the coupler circuit is otherwise inactive.

Abstract: A tunable vector recombination amplifier comprises an input, an output, first and second amplifier circuit paths each including a respective phase shifter to receive a respective input signal from the input and to apply a respective phase shift to produce a respective phase-shifted signal, a respective interstage impedance matching network, and a respective amplifier connected between the respective phase shifter and interstage impedance matching network to receive and amplify the respective phase-shifted signal to produce a respective amplified signal, first and second controllable DC voltage sources each coupled to a respective amplifier and configured to provide a respective supply voltage to the respective amplifier, values of the supply voltages being independently controllable, and an output amplifier stage to receive, amplify, and vectorially combine the amplified signals to produce a combined signal having a specified phase determined by the phase shifts and supply-voltage values and a specified ampli

Abstract: Apparatus and methods for adaptive power amplifier biasing are provided. In certain embodiments, a power amplifier system includes a power amplifier that provides amplification to a radio frequency (RF) signal, and a power amplifier bias control circuit that generates a bias signal of the power amplifier based on a bandwidth signal indicating a bandwidth of the RF signal. The power amplifier bias control circuit has a bandwidth that adapts to the bandwidth of the RF signal as indicated by the bandwidth signal.

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: Aspects of this disclosure relate to a multi-mode power amplifier system. A first power amplifier is configured to provide a radio frequency signal associated with a different radio access technology in a first mode than in a second mode. A second power amplifier is configured to be active in the first mode such that the first power amplifier and the second power amplifier are concurrently active in the first mode. A switch can electrically connect the output of the first power amplifier to different radio frequency signal path in the first mode than in the second mode. Related methods, power amplifier modules, and wireless communication devices are disclosed.

Abstract: Aspects of this disclosure relate to a dual connectivity power amplifier system. The power amplifier system includes first and second power amplifiers that are concurrently active in a dual connectively mode. The first power amplifier is active in a different mode. A switch electrically connects the first power amplifier to different radio frequency signal paths in the dual connectivity mode and the different mode. Related methods, power amplifier modules, and wireless communication devices are disclosed.

Abstract: Described herein are systems, architectures, circuits, devices, and methods for a DC-DC converter that dynamically adjusts a supply voltage to a power amplifier based on the number of resource blocks in a signal to be transmitted. The disclosed technologies estimate the number of resource blocks in a signal, generate a signal corresponding to the estimated number of resource blocks, and modify a supply voltage based on the generated signal. These technologies can be used to increase the efficiency of power amplifier systems for cellular signals being transmitted that have fewer resource blocks than is typically assumed (e.g., at least 100 resource blocks).