Abstract: Low-load-modulation, broadband power amplifiers and method of use are described. The amplifiers can include multiple amplifiers connected in parallel to amplify a signal that has been divided into parallel circuit branches. One of the amplifiers can operate as a main amplifier in a first amplification class and the remaining amplifiers can operate as peaking amplifiers in a second amplification class. The main amplifier can see low modulation of its load between the fully-on and fully backed-off states of the amplifier. With lower load modulation, the power amplifiers described herein exhibit better power-handling capability and RF fractional bandwidth as compared to conventional amplifiers.

Abstract: Apparatus and methods for a low-load-modulation power amplifier are described. Low-load-modulation power amplifiers can include multiple amplifiers connected in parallel to amplify a signal that has been divided into parallel circuit branches. One of the amplifiers can operate as a main amplifier in a first amplification class and the remaining amplifiers can operate as peaking amplifiers in a second amplification class. The main amplifier can see low modulation of its load between the power amplifier's fully-on and fully backed-off states. Improvements in bandwidth and drain efficiency over conventional Doherty amplifiers are obtained.

Abstract: Apparatus and methods for a no-load-modulation power amplifier are described. No-load-modulation power amplifiers can comprise multiple amplifiers connected in parallel to amplify a signal that has been divided into parallel circuit branches. One of the amplifiers can operate as a main amplifier in a first amplification class and the remaining amplifiers can operate as peaking amplifiers in a second amplification class. The main amplifier can see essentially no modulation of its load between the power amplifier's fully-on and fully backed-off states. The power amplifiers can operate in symmetric and asymmetric modes. Improvements in bandwidth and drain efficiency over conventional Doherty amplifiers are obtained. Further improvements can be obtained by combining signals from the amplifiers with hybrid couplers.

Abstract: Apparatus and methods for a no-load-modulation power amplifier are described. No-load-modulation power amplifiers can comprise multiple amplifiers connected in parallel to amplify a signal that has been divided into parallel circuit branches. One of the amplifiers can operate as a main amplifier in a first amplification class and the remaining amplifiers can operate as peaking amplifiers in a second amplification class. The main amplifier can see essentially no modulation of its load between the power amplifier's fully-on and fully backed-off states. The power amplifiers can operate in symmetric and asymmetric modes. Improvements in bandwidth and drain efficiency over conventional Doherty amplifiers are obtained. Further improvements can be obtained by combining signals from the amplifiers with hybrid couplers.

Abstract: Low-load-modulation, broadband power amplifiers and method of use are described. The amplifiers can include multiple amplifiers connected in parallel to amplify a signal that has been divided into parallel circuit branches. One of the amplifiers can operate as a main amplifier in a first amplification class and the remaining amplifiers can operate as peaking amplifiers in a second amplification class. The main amplifier can see low modulation of its load between the fully-on and fully backed-off states of the amplifier. With lower load modulation, the power amplifiers described herein exhibit better power-handling capability and RF fractional bandwidth as compared to conventional amplifiers.

Abstract: Apparatus and methods for a no-load-modulation power amplifier are described. No-load-modulation power amplifiers can comprise multiple amplifiers connected in parallel to amplify a signal that has been divided into parallel circuit branches. One of the amplifiers can operate as a main amplifier in a first amplification class and the remaining amplifiers can operate as peaking amplifiers in a second amplification class. The main amplifier can see essentially no modulation of its load between the power amplifier's fully-on and fully backed-off states. The power amplifiers can operate in symmetric and asymmetric modes. Improvements in bandwidth and drain efficiency over conventional Doherty amplifiers are obtained. Further improvements can be obtained by combining signals from the amplifiers with hybrid couplers.

Abstract: Apparatus and methods for a low-load-modulation power amplifier are described. Low-load-modulation power amplifiers can include multiple amplifiers connected in parallel to amplify a signal that has been divided into parallel circuit branches. One of the amplifiers can operate as a main amplifier in a first amplification class and the remaining amplifiers can operate as peaking amplifiers in a second amplification class. The main amplifier can see low modulation of its load between the power amplifier's fully-on and fully backed-off states. Improvements in bandwidth and drain efficiency over conventional Doherty amplifiers are obtained.

Abstract: Multi-way amplifiers having impedance inverters connected to outputs of one or more peaking amplifiers are described. The output of the main amplifier may connect directly to a combining node and output impedance matching network. The multi-way amplifier configuration can improve efficiency at power back-off and improve RF bandwidth.