Multi-mode power amplifier
A power amplifier module that includes a power amplifier and a controller is presented herein. The power amplifier module may include a set of transistor stages and a plurality of bias circuits. At least one transistor stage from the set of transistor stages may be in electrical communication with a first bias circuit and a second bias circuit from the plurality of bias circuits. The first bias circuit can be configured to apply a first bias voltage to the at least one transistor stage and the second bias circuit can be configured to apply a second bias voltage to the at least one transistor stage. The controller may be configured to activate one of the first bias circuit and the second bias circuit.
1. A method for controlling a power amplifier, the method comprising:
receiving a mode selection signal from a controller;
determining whether the mode selection signal indicates a saturation operation state or a linear operation state;
in response to the mode selection signal indicating the saturation operation state, providing a first voltage to a voltage input of a first bias circuit of the power amplifier and configuring a current source of a second bias circuit of the power amplifier with a first current; and
in response to the mode selection signal indicating the linear operation state, providing a second voltage to the voltage input of the first bias circuit and configuring the current source of the second bias circuit with a second current.
2. The method of claim 1 wherein the first voltage is a non-zero voltage value and the first current is zero.
3. The method of claim 1 wherein the second voltage is zero and the second current is a non-zero current value.
4. The method of claim 1 further comprising receiving a feedback signal from a sense circuit in communication with an output of the power amplifier.
5. The method of claim 4 wherein the first voltage is determined based at least in the part on the feedback signal.
6. The method of claim 4 further comprising deactivating the sense circuit when the mode selection signal indicates the linear operation state.
7. The method of claim 1 wherein, in response to the mode selection signal indicating the linear operation state, floating the voltage input of the first bias circuit.
8. The method of claim 1 further comprising:
maintaining the first bias circuit in an active state and the second bias circuit in an inactive state when the mode selection signal indicates the saturation operation state; and
maintaining the first bias circuit in an inactive state and the second bias circuit in an active state when the mode selection signal indicates the linear operation state.
9. The method of claim 1 wherein the first bias circuit provides different bias values to different stages of the power amplifier when the mode selection signal indicates the saturation operation state and the second bias circuit provides different bias values to the different stages of the power amplifier when the mode selection signal indicates the linear operation state.
10. The method of claim 1 wherein the first voltage is determined based at least in part on a control voltage received from the controller.
11. The method of claim 1 wherein a value of the mode selection signal corresponds to a selected wireless communication technology in use by a wireless device that includes the power amplifier.
12. The method of claim 1 wherein the current source is configured based at least in part on a voltage received at the controller.
13. The method of claim 1 further comprising, in response to determining that the power amplifier is to operate in the linear operation state, floating the first bias circuit.
14. The method of claim 1 wherein the second voltage is generated based at least in part on a voltage received at the controller.
15. The method of claim 1 wherein the power amplifier includes a plurality of transistors.
16. The method of claim 15 wherein each transistor of the plurality of transistors is configured to operate in the saturation operation state in response to determining that the power amplifier is to operate in the saturation operation state.
17. The method of claim 15 wherein each transistor of the plurality of transistors is configured to operate in the linear operation state in response to determining that the power amplifier is to operate in the linear operation state.
18. The method of claim 1 wherein the mode selection signal is received from a baseband system.