Stacked PA power control
First Claim
1. A method for controlling an output power of an amplifier arrangement, the method comprising:
- providing a stack of a plurality of transistors arranged in a cascode configuration, comprising an input transistor and one or more cascoded transistors, the one or more cascoded transistors comprising an output transistor;
providing a gate voltage control module;
coupling voltage control nodes of the gate voltage control module to gates of the one or more transistors of the stack;
supplying a supply voltage across the stack;
based on the coupling, providing gate voltages to the one or more cascoded transistors;
inputting a constant envelope radio frequency (RF) signal to the input transistor;
based on the inputting, obtaining an amplified RF signal at the output transistor;
varying, independently from the supply voltage, at least one gate voltage of the gate voltages to the one or more cascoded transistors; and
based on the varying, controlling the output power of the amplified RF signal,wherein a voltage control node of coupled voltage control nodes of the gate voltage control module is configured to provide the at least one gate voltage, andwherein a control voltage to the gate voltage control module varies the at least one gate voltage for controlling of the output power of the amplified RF signal.
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Accused Products
Abstract
Systems, methods and apparatus for efficient power control of an RF amplifier for amplification of a constant envelope RF signal are described. A reduction in a size of a pass device of an LDO regulator is obtained by removing the pass device of the LDO regulator from a main current conduction path of the RF amplifier. Power control is provided by varying one or more gate voltages to cascoded transistors of a transistor stack of the RF amplifier according to a power control voltage. Various configurations for controlling the gate voltages are presented by way of a smaller size LDO regulator or by completely removing the LDO regulator. In a case where a supply voltage to the transistor stack varies, such as in a case of a battery, a compensation circuit is used to adjust the power control voltage in view of a variation of the supply voltage, and therefore null a corresponding drift in output power of the RF amplifier.
23 Citations
13 Claims
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1. A method for controlling an output power of an amplifier arrangement, the method comprising:
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providing a stack of a plurality of transistors arranged in a cascode configuration, comprising an input transistor and one or more cascoded transistors, the one or more cascoded transistors comprising an output transistor; providing a gate voltage control module; coupling voltage control nodes of the gate voltage control module to gates of the one or more transistors of the stack; supplying a supply voltage across the stack; based on the coupling, providing gate voltages to the one or more cascoded transistors; inputting a constant envelope radio frequency (RF) signal to the input transistor; based on the inputting, obtaining an amplified RF signal at the output transistor; varying, independently from the supply voltage, at least one gate voltage of the gate voltages to the one or more cascoded transistors; and based on the varying, controlling the output power of the amplified RF signal, wherein a voltage control node of coupled voltage control nodes of the gate voltage control module is configured to provide the at least one gate voltage, and wherein a control voltage to the gate voltage control module varies the at least one gate voltage for controlling of the output power of the amplified RF signal. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12)
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13. A method for controlling an output power of an amplifier arrangement, the method comprising:
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providing a stack of a plurality of transistors arranged in a cascode configuration, comprising an input transistor and one or more cascoded transistors, the one or more cascoded transistors comprising an output transistor; providing a gate voltage control module; coupling voltage control nodes of the gate voltage control module to gates of the one or more transistors of the stack; supplying a varying supply voltage across the stack; based on the coupling, providing gate voltages to the one or more cascoded transistors; inputting a constant envelope radio frequency (RF) signal to the input transistor; based on the inputting, obtaining an amplified RF signal at the output transistor; varying at least one gate voltage of the gate voltages to the one or more cascoded transistors; based on the varying, controlling the output power of the amplified RF signal, determining a voltage level of the supply voltage; based on the determining, further varying the at least one gate voltage; and based on the further varying, maintaining the output power of the amplified RF signal wherein a voltage control node of coupled voltage control nodes of the gate voltage control module is configured to provide the at least one gate voltage, wherein a control voltage to the gate voltage control module varies the at least one gate voltage for controlling of the output power of the amplified RF signal.
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Specification