Abstract: Systems and methods related to linear load modulated power amplifiers. A power amplifier (PA) system can include a divider that splits a signal into two portions, a first portion directed to an attenuator that attenuates the first portion so that the first portion and the second portion have different powers and a second portion directed to a phase shift component that shifts a phase of the second portion so that the first portion and the second portion have different phases. The PA system can also include a Doherty amplifier circuit where a carrier amplifier amplifies the attenuated first portion and a peaking amplifier amplifies the phase-shifted second portion. The carrier amplifier includes a Class AB driver stage and a Class B output. The peaking amplifier includes a Class B driver stage a Class B output stage.

Abstract: Systems and methods related to linear load modulated power amplifiers. A power amplifier (PA) system can include a divider that splits a signal into two portions, a first portion directed to an attenuator that attenuates the first portion so that the first portion and the second portion have different powers and a second portion directed to a phase shift component that shifts a phase of the second portion so that the first portion and the second portion have different phases. The PA system can also include a Doherty amplifier circuit where a carrier amplifier amplifies the attenuated first portion and a peaking amplifier amplifies the phase-shifted second portion. The carrier amplifier includes a Class AB driver stage and a Class B output. The peaking amplifier includes a Class B driver stage a Class B output stage.

Abstract: Systems and methods related to linear load modulated power amplifiers. A power amplifier (PA) system can include a divider that splits a signal into two portions, a first portion directed to an attenuator that attenuates the first portion so that the first portion and the second portion have different powers and a second portion directed to a phase shift component that shifts a phase of the second portion so that the first portion and the second portion have different phases. The PA system can also include a Doherty amplifier circuit where a carrier amplifier amplifies the attenuated first portion and a peaking amplifier amplifies the phase-shifted second portion. The carrier amplifier includes a Class AB driver stage and a Class B output. The peaking amplifier includes a Class B driver stage a Class B output stage.

Abstract: Systems and methods related to linear load modulated power amplifiers. A power amplifier (PA) system can include a divider that splits a signal into two portions, a first portion directed to an attenuator that attenuates the first portion so that the first portion and the second portion have different powers and a second portion directed to a phase shift component that shifts a phase of the second portion so that the first portion and the second portion have different phases. The PA system can also include a Doherty amplifier circuit where a carrier amplifier amplifies the attenuated first portion and a peaking amplifier amplifies the phase-shifted second portion. The carrier amplifier includes a Class AB driver stage and a Class B output. The peaking amplifier includes a Class B driver stage a Class B output stage.

Abstract: Matching network for broadband power amplifier. In some embodiments, a power amplifier can include an amplifying transistor having an input and an output, and a matching circuit coupled to the output of the amplifying transistor. The matching circuit can include a first capacitance, an inductance, and a second capacitance connected in series. The matching circuit can further include a third capacitance implemented in a shunt path from a node between the first capacitance and the inductance to a ground, and a fourth capacitance implemented in a shunt path from a node between the inductance and the second capacitance to the ground.

Abstract: Systems and methods related to linear load modulated power amplifiers. A power amplifier (PA) system can include an input circuit configured to receive a radio-frequency (RF) signal and split the RF signal into a first portion and a second portion. The PA system can further include a Doherty amplifier circuit including a carrier amplifier coupled to the input circuit to receive the first portion and a peaking amplifier coupled to the input circuit to receive the second portion. The first portion and the second portion can have different phases and/or different powers. The PA system can further include an output circuit coupled to the Doherty amplifier circuit. The output circuit can be configured to combine outputs of the carrier amplifier and the peaking amplifier to yield an amplified RF signal.

Abstract: Systems and methods related to linear and efficient broadband power amplifiers are disclosed. In some embodiments, a method for amplifying a radio-frequency signal includes providing a Doherty amplifier circuit having a carrier amplification path and a peaking amplification path. The method includes receiving an radio-frequency signal and splitting the radio-frequency signal into a first portion and a second portion, the first portion provided to the carrier amplification path, the second portion provided to the peaking amplification path. The method further includes combining, using a balance to unbalance circuit, outputs of the carrier amplification path and the peaking amplification path to yield an amplified radio-frequency signal.

Abstract: Radio frequency (RF) amplification devices and methods of amplifying RF signals are disclosed. In one embodiment, an RF amplification device includes a control circuit and a Doherty amplifier configured to amplify an RF signal. The Doherty amplifier includes a main RF amplification circuit and a peaking RF amplification circuit. The control circuit is configured to activate the peaking RF amplification circuit in response to the RF signal reaching a threshold level. In this manner, the activation of the peaking RF amplification circuit can be precisely controlled.

Abstract: Circuits and devices related to multi-harmonic control of amplified signals. In some embodiments, an amplifier circuit assembly can include an amplifier configured to provide a signal at an output. The amplifier circuit assembly can further include a matching network configured to provide impedance matching for the signal having a fundamental frequency, a broadband harmonic trap configured to substantially trap a plurality of harmonics associated with the fundamental frequency, and a dipole network configured to tune reactances associated with the broadband harmonic trap. The matching network, the broadband harmonic trap and the dipole network can be implemented in series from the output of the amplifier.

Abstract: Circuits and devices related to multi-harmonic control of amplified signals. In some embodiments, an amplifier circuit assembly can include an amplifier configured to provide a signal at an output. The amplifier circuit assembly can further include a matching network configured to provide impedance matching for the signal having a fundamental frequency, a broadband harmonic trap configured to substantially trap a plurality of harmonics associated with the fundamental frequency, and a dipole network configured to tune reactances associated with the broadband harmonic trap. The matching network, the broadband harmonic trap and the dipole network can be implemented in series from the output of the amplifier.

Abstract: Systems and methods related to linear and efficient broadband power amplifiers are disclosed. In some embodiments, a method for amplifying a radio-frequency signal includes providing a Doherty amplifier circuit having a carrier amplification path and a peaking amplification path. The method includes receiving an radio-frequency signal and splitting the radio-frequency signal into a first portion and a second portion, the first portion provided to the carrier amplification path, the second portion provided to the peaking amplification path. The method further includes combining, using a balance to unbalance circuit, outputs of the carrier amplification path and the peaking amplification path to yield an amplified radio-frequency signal.

Abstract: Matching network for broadband power amplifier. In some embodiments, a power amplifier can include an amplifying transistor having an input and an output, and a matching circuit coupled to the output of the amplifying transistor. The matching circuit can include a first capacitance, an inductance, and a second capacitance connected in series. The matching circuit can further include a third capacitance implemented in a shunt path from a node between the first capacitance and the inductance to a ground, and a fourth capacitance implemented in a shunt path from a node between the inductance and the second capacitance to the ground.

Abstract: Systems and methods related to linear and efficient broadband power amplifiers. A power amplifier (PA) system can include an input circuit configured to receive a radio-frequency (RF) signal and split the RF signal into a first portion and a second portion. The PA system can further include a Doherty amplifier circuit including a carrier amplification path coupled to the input circuit to receive the first portion and a peaking amplification path coupled to the input circuit to receive the second portion. The PA system can further include an output circuit coupled to the Doherty amplifier circuit. The output circuit can include a balance to unbalance (BALUN) circuit configured to combine outputs of the carrier amplification path and the peaking amplification path to yield an amplified RF signal.

Abstract: Circuits and methods related to power amplifier efficiency based on multi-harmonic approximation. In some embodiments, an output network circuit can be provided for multi-harmonic control of a radio-frequency (RF) power amplifier. The output network circuit can include an impedance matching network configured for a fundamental frequency of the power amplifier. The output network circuit can further include a broadband harmonic trap in communication with the impedance matching network. The broadband harmonic trap can be configured to substantially trap a plurality of harmonics associated with the fundamental frequency. The output network circuit can further include a dipole network in communication with the broadband harmonic trap. The dipole network can be configured to tune reactances resulting from the operation of the broadband harmonic trap.

Abstract: Systems and methods related to linear load modulated power amplifiers. A power amplifier (PA) system can include an input circuit configured to receive a radio-frequency (RF) signal and split the RF signal into a first portion and a second portion. The PA system can further include a Doherty amplifier circuit including a carrier amplifier coupled to the input circuit to receive the first portion and a peaking amplifier coupled to the input circuit to receive the second portion. The first portion and the second portion can have different phases and/or different powers. The PA system can further include an output circuit coupled to the Doherty amplifier circuit. The output circuit can be configured to combine outputs of the carrier amplifier and the peaking amplifier to yield an amplified RF signal.

Abstract: Systems and methods related to linear and efficient broadband power amplifiers. A power amplifier (PA) system can include an input circuit configured to receive a radio-frequency (RF) signal and split the RF signal into a first portion and a second portion. The PA system can further include a Doherty amplifier circuit including a carrier amplification path coupled to the input circuit to receive the first portion and a peaking amplification path coupled to the input circuit to receive the second portion. The PA system can further include an output circuit coupled to the Doherty amplifier circuit. The output circuit can include a balance to unbalance (BALUN) circuit configured to combine outputs of the carrier amplification path and the peaking amplification path to yield an amplified RF signal.

Abstract: Circuits and methods related to power amplifier efficiency based on multi-harmonic approximation. In some embodiments, an output network circuit can be provided for multi-harmonic control of a radio-frequency (RF) power amplifier. The output network circuit can include an impedance matching network configured for a fundamental frequency of the power amplifier. The output network circuit can further include a broadband harmonic trap in communication with the impedance matching network. The broadband harmonic trap can be configured to substantially trap a plurality of harmonics associated with the fundamental frequency. The output network circuit can further include a dipole network in communication with the broadband harmonic trap. The dipole network can be configured to tune reactances resulting from the operation of the broadband harmonic trap.