Dual-band, dual-mode power amplifier

A power amplifier circuit for amplifying RF signals, said power amplifier circuit selectively operable in a linear mode or a nonlinear mode and selectively operable to amplify RF signals in a first frequency band or a second frequency band, comprising:

• a first driver amplifier for amplifying RF signals in a first frequency band;
• first and second final amplifiers;
• a diplex matching circuit coupled to said first final amplifier;
• a switching network for selectively coupling said first driver amplifier to said first and second final amplifiers in response to said amplifier circuit being placed in a linear or nonlinear mode of operation, respectively;
• a low pass matching circuit coupled to an output of said second final amplifier;
• and
• switching circuitry, coupled to a first output of said diplex matching circuit and an output of said low pass matching circuit, for selectively coupling said first diplex matching circuit output or said low pass matching circuit output to an output line when said amplifier circuit is selectively placed in linear mode or nonlinear mode, respectively.

A method for operating a power amplifier selectively operable in a linear mode or a nonlinear mode and selectively operable to amplify RF signals in a first frequency band or a second frequency band, the method comprising:

• amplifying RF signals in the first frequency band;
• selectively coupling the RF signals in the first frequency band to one of a first final amplifier or a second final amplifier in response to the power amplifier being placed in linear or nonlinear mode of operation, respectively;
• generating a first diplex output for RF signals amplified by the first final amplifier corresponding to the first frequency band,
• generating a second diplex output for RF signals amplified by the first final amplifier corresponding to the second frequency band;
• low pass filtering an output of the second final amplifier;
• and
• selectively coupling one of the first diplex output or the low pass filtered output of the second final amplifier to an output line when the amplifier is selectively placed in a linear mode or nonlinear mode respectively.

A power amplifier for amplifying RF signals, the power amplifier being selectively operable in a linear mode or a nonlinear mode and selectively operable to amplify RF signals in a first frequency band or a second frequency band, comprising:

• a first driver amplifier that amplifies RF signals in the first frequency band to generate amplified RF signals in the first frequency band;
• a second driver amplifier that amplifies RF signals in the second frequency band to generate amplified RF signals in the second frequency band;
• a first final amplifier;
• a second final amplifier;
• a switching network coupled between the first and second driver amplifiers and the first and second final amplifiers wherein the switching network selectively couples one of the driver amplifiers to one of the final amplifiers, wherein the switching network couples the amplified RF signals in the first frequency band to the first final amplifier when transmitting in the first frequency band during linear mode operations and to the second final amplifier when transmitting in the first frequency band during nonlinear mode operations;
• a diplex matching circuit coupled to an output of the first final amplifier wherein the diplex matching circuit generates a first diplex output at a first diplex node when transmitting in the first frequency band and wherein the diplex matching circuit generates a second diplex output at a second diplex node when transmitting in the second frequency band;
• and
• a switch that selectively couples one of the first diplex output and an output of the second final amplifier to an output line when transmitting in the first frequency band.

A method for operating a power amplifier selectively operable in a linear mode or a nonlinear mode and selectively operable to amplify RF signals in a first frequency band or a second frequency band, the method comprising:

• generating amplified RF signals in the first frequency band when transmitting in the first frequency band;
• generating amplified RF signals in the second frequency band when transmitting in the second frequency band;
• coupling the amplified RF signals in the first frequency band to a first final amplifier when transmitting in the first frequency band and operating in the linear mode;
• coupling the amplified RF signals in the first frequency band to a second final amplifier when transmitting in the first frequency band and operating in the nonlinear mode;
• and
• coupling the amplified RF signals in the second frequency band to the first final amplifier when transmitting in the second frequency band.