Dynamic bias for a power amplifier
AssigneeSkyworks Solutions, Inc.
InventorsApostolos Samelis, Kevin Choi
Life of this patent
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Abstract
A dynamic bias controller dynamically biases a plurality of amplifiers residing in a power amplifier. Based upon a communication signal amplitude, the dynamic bias controller turns off (removes bias from) selected amplifiers when the communication device is to transmit a low power communication signal, and turns on (applies bias to) selected amplifiers when the communication device is to transmit a higher power communication signal. A plurality of dynamic bias controllers may control a plurality of amplifiers such that a plurality of communication signal strengths can be realized. Another embodiment employs a dynamic bias controller to control at least one prematching impedance network coupled to the selected amplifier, thereby adjusting the system impedance to a desired value.
Claims24
A system that controls power amplifiers, comprising:
- a bias controller for outputting a control signal, the bias controller coupled to a node in a communication device such that a communication signal is sensed;
- a first power amplifier configured to amplify the communication signal;
- a second power amplifier configured to amplify the communication signal and responsive to the control signal, such that the bias controller activates the second power amplifier when an amplitude of the communication signal is at least equal to a predetermined amplitude, and such that the bias controller deactivates the second power amplifier when the amplitude of the communication signal is less than the predetermined amplitude;
- and
- a coupler coupled to the first power amplifier and the second power amplifier such that a first amplified communication signal output by the first amplifier and a second amplified communication signal output by the second amplifier are combined.
A system that controls at least one power amplifier, comprising:
- a bias controller for outputting a control signal;
- a power amplifier responsive to the control signal;
- a threshold detector configured to output a portion of a detected communication signal that is at least equal to a predetermined amplitude, and such that the threshold detector outputs no signal when the amplitude of the detected communication signal is less than the predetermined amplitude;
- and
- a switch for providing the control signal from the bias controller to the power amplifier, such that when an output of the threshold detector is the portion of the detected communication signal that is at least equal to the predetermined amplitude the switch is actuated to a first state such that the control signal activates the power amplifier, and such that when the threshold detector outputs no signal the switch is actuated to a second state such that the control signal is not provided and the power amplifier deactivates.
A system that controls power amplifiers, comprising:
- a bias controller for outputting a control signal, the bias controller coupled to a node in a communication device such that a communication signal is sensed;
- a power amplifier responsive to the control signal, such that the bias controller activates the power amplifier when an amplitude of the communication signal is at least equal to a predetermined amplitude, and such that the bias controller deactivates the power amplifier when the amplitude of the communication signal is less than the predetermined amplitude;
- and
- a prematching impedance element coupled to the power amplifier such that when the bias controller activates the power amplifier the prematching impedance element adjusts a system impedance to a first value, and such that when the bias controller deactivates the power amplifier the prematching impedance element adjusts the system impedance to second value.
A system for controlling power amplifiers, comprising:
- means for detecting a communication signal;
- means for activating a first power amplifier when the communication signal is detected;
- means for detecting an amplitude of the communication signal;
- means for generating a control signal in a first state when the amplitude of the communication signal is less than a predetermined amplitude;
- means for generating the control signal in a second state when the amplitude of the communication signal is at least equal to the predetermined amplitude;
- means for providing the control signal to a second power amplifier;
- means for activating the second power amplifier when the control signal is in the first state;
- means for deactivating the second power amplifier when the control signal is in the second state;
- and
- means for coupling an output of the first power amplifier to an output of the second power amplifier.
A method for controlling power amplifiers, the method comprising the steps of:
- activating a first power amplifier when a communication signal is detected;
- detecting an amplitude of the communication signal;
- generating a control signal in a first state when the amplitude of the communication signal is less than a predetermined amplitude;
- generating the control signal in a second state when the amplitude of the communication signal is at least equal to the predetermined amplitude;
- providing the control signal to a second power amplifier;
- deactivating the second power amplifier when the control signal is in the first state;
- activating the second power amplifier when the control signal is in the second state;
- and
- combining an output of the first power amplifier with an output of the second power amplifier via a coupler that couples an output connection of the first power amplifier with an output connection of the second power amplifier.
Dependencies are inferred from the claim text.