Abstract: A power amplification circuit (10) includes a scalable power amplifier (20) to produce an RF output signal (50) at an output of the power amplification circuit (10), and a variable impedance circuit (30) coupled to the output of the power amplification circuit (10). The scalable power amplifier (20) includes a plurality of selectively activated amplifier elements (22), (24), (26) to produce the RF output signal (50) in accordance with a desired RF output signal power level. The power amplification circuit (10) selectively activates individual amplifier elements by, for example reducing power or increasing power to at least one amplifier element. The variable impedance circuit (30) varies an impedance of the variable impedance circuit (30) to dynamically load the output of the scalable power amplifier (20).

Abstract: A power amplification circuit (10) includes a scalable power amplifier (20) to produce an RF output signal (50) at an output of the power amplification circuit (10), and a variable impedance circuit (30) coupled to the output of the power amplification circuit (10). The scalable power amplifier (20) includes a plurality of selectively activated amplifier elements (22), (24), (26) to produce the RF output signal (50) in accordance with a desired RF output signal power level. The power amplification circuit (10) selectively activates individual amplifier elements by, for example reducing power or increasing power to at least one amplifier element. The variable impedance circuit (30) varies an impedance of the variable impedance circuit (30) to dynamically load the output of the scalable power amplifier(20).

Abstract: The present invention provides a method and apparatus for supplying power to a load at a plurality of different power levels. The method includes changing between high and low power outputs of the power amplifier when amplifying a signal having a common modulation format. A different bias is applied to the power amplifier at the low power output than the bias applied to the power amplifier at the high power output. The output of the power amplifier is loaded with a different impedance at the low power output than the impedance loaded at the output of the power amplifier output at the high power output. In at least one embodiment, the power amplifier changes between high and low power outputs at a different threshold level dependant upon whether the power amplifier is transitioning from the high power output to the low power output, or whether the power amplifier is transitioning from the low power output to the high power output.

Abstract: The present invention provides a method and apparatus for supplying power to a load at a plurality of different power levels. The method includes changing between high and low power outputs of the power amplifier when amplifying a signal having a common modulation format. A different bias is applied to the power amplifier at the low power output than the bias applied to the power amplifier at the high power output. The output of the power amplifier is loaded with a different impedance at the low power output than the impedance loaded at the output of the power amplifier output at the high power output. In at least one embodiment, the power amplifier changes between high and low power outputs at a different threshold level dependant upon whether the power amplifier is transitioning from the high power output to the low power output, or whether the power amplifier is transitioning from the low power output to the high power output.

Abstract: The present invention provides a method and apparatus for supplying power to a load at a plurality of different power levels. The method includes changing between high and low power outputs of the power amplifier when amplifying a signal having a common modulation format. A different bias is applied to the power amplifier at the low power output than the bias applied to the power amplifier at the high power output. The output of the power amplifier is loaded with a different impedance at the low power output than the impedance loaded at the output of the power amplifier output at the high power output. In at least one embodiment, the power amplifier changes between high and low power outputs at a different threshold level dependant upon whether the power amplifier is transitioning from the high power output to the low power output, or whether the power amplifier is transitioning from the low power output to the high power output.