RF power amplifier and methods for improving the efficiency thereof
First Claim
1. A method comprising:
- varying the power of an input signal to an outphasing system at a first range of output power values; and
adjusting a phase of said outphasing system at a second range of output power values.
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Accused Products
Abstract
A radio frequency power amplifier characterized by an efficiency and operative to produce an output signal at a desired output power includes an outphasing system with shunt reactance and a controller. The outphasing system with shunt reactance has a variable phase and is operative to produce the output signal from an input signal. The controller is operative to control the variable phase and the amplitude of the input signal in order to achieve high efficiency at low desired output powers. A method for controlling the output power of a radio frequency power amplifier includes reducing the power of an input signal to the power amplifier when a desired output power is below a threshold and performing outphasing when the desired output power is not below the threshold.
148 Citations
35 Claims
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1. A method comprising:
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varying the power of an input signal to an outphasing system at a first range of output power values; and
adjusting a phase of said outphasing system at a second range of output power values. - View Dependent Claims (2)
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3. A method comprising:
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varying the power of an input signal to a power amplifier when a desired output power is below a threshold; and
performing outphasing when said desired power is at said threshold and above said threshold.
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4. A method comprising:
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providing a first method of power control in a radio frequency power amplifier for a desired output power at a first range of power values which is below a threshold; and
providing a second method of power control in said power amplifier for a desired output power at a second range of power values which is above or at said threshold.
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5. A method comprising:
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providing a first method of power control in a radio frequency power amplifier for a desired output power at a first range of power values which is below a threshold; and
providing a second method of power control in said power amplifier for a desired output power at a second range of power values which is above or at said threshold, wherein said first method is reducing the power of an input signal to said power amplifier and said second method is outphasing. - View Dependent Claims (6, 7)
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8. A method comprising:
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providing a first method of power control in a radio frequency power amplifier for a desired power at a first range of power values which is below a threshold; and
providing a second method of power control in said power amplifier for a desired output power at a second range of power values which is above or at said threshold, wherein said first method is reducing the power of an input signal to said power amplifier and said second method is outphasing and reducing the power of the input signal.
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9. A method comprising:
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modifying the amplitude of an input signal to an outphasing system having shunt reactance. - View Dependent Claims (10)
adjusting a gain of at least one of said RF preamplifier and said IF amplifier.
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11. A method comprising:
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modifying the amplitude of input to at least one of two branch amplifiers of an outphasing system having shunt reactance. - View Dependent Claims (12)
adjusting a gain of said first radio frequency preamplifier and adjusting a gain of said second radio frequency preamplifier.
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13. A method comprising:
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modifying the input to an outphasing system having shunt reactance; and
performing bias control in said outphasing system. - View Dependent Claims (14, 15)
reducing an internal bias current of at least one branch amplifier in said outphasing system.
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15. The method of claim 13, wherein said performing comprises:
reducing a supply voltage of at least one branch amplifier in said outphasing system.
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16. A radio frequency (RF) power amplifier comprising:
a controller coupled to an outphasing system to provide a variation of the power of an input signal to said outphasing system at a first range of output power values and to provide an adjustment of a phase of the outphasing system at a second range of output power. - View Dependent Claims (17)
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18. A radio frequency (RF) power amplifier comprising:
a controller coupled to an outphasing system to provide a variation of the power of an input signal to said outphasing system when a desired output power is below a threshold and said controller performs outphasing when said desired output power is at said threshold and above said threshold. - View Dependent Claims (19, 20, 21, 22, 23, 24)
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25. A radio frequency (RF) power amplifier comprising:
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a controller coupled to at least one of a radio frequency (RF) preamplifier and an intermediate frequency (IF) amplifier and to an outphasing system having shunt reactance to provide a modification of the amplitude of an input signal to said outphasing system. - View Dependent Claims (26)
a splitter coupled to at least two RF preamplifiers;
at least two phase shifters each coupled to a respective one of said at least two RF preamplifiers; and
at least two branch amplifiers each coupled to a respective one of said at least two phase shifters;
wherein said controller is coupled to at least one of said at least two RF preamplifiers to provide a gain modification of said at least one of said at least two RF preamplifiers.
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27. A radio frequency (RF) power amplifier comprising:
an outphasing system having shunt reactance coupled to a controller wherein said controller is coupled to said outphasing system to provide a modification of an input signal to said outphasing system and to perform bias control in said outphasing system. - View Dependent Claims (28, 29)
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30. A method comprising:
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when a desired output power is below a threshold, setting a variable phase of an outphasing system having shunt reactance to a fixed value and reducing the power of an input signal to a power amplifier including said outphasing system; and
performing outphasing when said desired output power is at said threshold and above said threshold. - View Dependent Claims (31, 32, 33, 34, 35)
lowering a gain of at least one of said RF preamplifier and said IF amplifier.
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33. The method of claim 30, wherein said variable phase is a collection of discrete phase values.
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34. The method of claim 33, wherein said outphasing system has a peak efficiency at an upper power at a first value of said variable phase and at a lower power at a second value of said variable phase, wherein said threshold is said lower power and said fixed value is said second value.
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35. The method of claim 33, wherein said outphasing system is coupled to at least one of a radio frequency (RF) preamplifier and to an intermediate frequency (IF) amplifier and reducing the power of the input signal comprises:
lowering a gain of at least one of said RF preamplifier and said IF amplifier.
Specification