Radio frequency power amplifier circuit and method
First Claim
1. A radio frequency power amplifier circuit comprising:
- a constant envelope modulation providing circuitry;
a power amplifier driver having a driver gain control input, a driver signal output, and a driver signal input coupled to the constant envelope modulation providing circuitry;
a power amplifier having an amplifier input coupled to the driver signal output;
a sensor having a sensor output and a sensor input coupled with the amplifier input; and
a feedback circuit having an input coupled to the sensor output and an output coupled to the driver gain control input, wherein in operation the sensor output provides a radio frequency output proportional to an amplitude of an amplified constant envelope modulated radio frequency signal provided to the amplifier input from the driver signal output, and wherein the feedback circuit provides a gain control voltage to the driver gain control input, the gain control voltage having a value dependent on the radio frequency output thereby substantially maintaining the amplified constant envelope modulated radio frequency signal at a constant pre-defined amplitude.
1 Assignment
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Accused Products
Abstract
A method (200) and circuit (100) for substantially maintaining an amplified constant envelope modulation signal at a constant pre-defined amplitude. The circuit (100) comprises a constant envelope modulation providing circuitry (104), a power amplifier (102), a power amplifier driver (106), a coupler (108) and a feedback circuit (110). In operation the sensor (110) has an output (120) that provides a radio frequency output signal proportional to an amplitude of an amplified constant envelope modulated radio frequency signal provided to the amplifier input (118) from the power amplifier driver (106). The feedback circuit (110) provides a gain control voltage a driver gain control input to maintain the constant envelope modulation signal at a constant pre-defined amplitude supplied to the amplifier input (118).
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Citations
20 Claims
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1. A radio frequency power amplifier circuit comprising:
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a constant envelope modulation providing circuitry;
a power amplifier driver having a driver gain control input, a driver signal output, and a driver signal input coupled to the constant envelope modulation providing circuitry;
a power amplifier having an amplifier input coupled to the driver signal output;
a sensor having a sensor output and a sensor input coupled with the amplifier input; and
a feedback circuit having an input coupled to the sensor output and an output coupled to the driver gain control input, wherein in operation the sensor output provides a radio frequency output proportional to an amplitude of an amplified constant envelope modulated radio frequency signal provided to the amplifier input from the driver signal output, and wherein the feedback circuit provides a gain control voltage to the driver gain control input, the gain control voltage having a value dependent on the radio frequency output thereby substantially maintaining the amplified constant envelope modulated radio frequency signal at a constant pre-defined amplitude. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. A method for substantially maintaining a constant pre-defined amplitude of a constant envelope modulated radio frequency signal at an amplifier input of a radio frequency amplifier, the method comprising:
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selecting a voltage value provided at a control input of a feedback circuit;
providing a radio frequency output signal that is proportional to an amplitude of a constant envelope modulated radio frequency signal from a power amplifier driver having an output coupled to the input of a power amplifier; and
providing a gain control voltage to a gain control input of the driver, the gain control voltage having a value dependent on the radio frequency output signal and voltage value provided at the control input. - View Dependent Claims (10, 11, 12, 13, 14, 15)
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16. A method for substantially maintaining a constant pre-defined amplitude of a constant envelope modulated radio frequency signal, at an amplifier input to a radio frequency amplifier, the method comprising:
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determining a desired power output value of a power amplifier;
selecting a voltage level provided to a supply input of a power amplifier, the voltage level being dependent on the desired power output value;
selecting a voltage value provided at a control input of a feedback circuit, the voltage value being dependent on the desired power output value;
providing a radio frequency output signal that is proportional to an amplitude of a constant envelope modulated radio frequency signal from a power amplifier driver having an output coupled to input of power amplifier; and
providing a gain control voltage to a gain control input of the driver, the gain control voltage having a value dependent on the radio frequency output signal and voltage value provided at the control input. - View Dependent Claims (17, 18, 19, 20)
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Specification