Amplifying system
First Claim
1. An amplifying system comprising:
- a first gain stage with a first gain characteristic;
a second gain stage with a second gain characteristic; and
bias circuitry that includes a reference headroom voltage generator and is configured to provide bias responsive to a reference voltage generated by the reference headroom voltage generator such that a voltage difference between a bias point and a threshold voltage of at least one of the first gain stage and the second gain stage is maintained at a constant level to substantially maintain alignment of distortion inflection points between the first gain characteristic and the second gain characteristic to limit total gain variations to less than 0.1 dB per dB of output stage power during operation for an input power to the first gain stage that ranges from −
50 dB to 0 dB.
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Accused Products
Abstract
An amplifying system with increased linearity is disclosed. The amplifying system includes a first gain stage with a first gain characteristic, a second gain stage with a second gain characteristic, and bias circuitry configured to substantially maintain alignment of distortion inflection points between the first gain characteristic and the second gain characteristic during operation. The bias circuitry is configured to further maintain alignment of the distortion inflection points between the first gain characteristic and the second gain characteristic over design corners by providing substantially constant headroom between quiescent bias voltage and turnoff of the first gain stage and the second gain stage. In some embodiments the first gain characteristic is expansive and the second gain characteristic is compressive. In other embodiments the first gain characteristic is compressive and the second gain characteristic is expansive. In some embodiments the first gain stage is configured to provide RF degeneration control of gain.
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Citations
27 Claims
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1. An amplifying system comprising:
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a first gain stage with a first gain characteristic; a second gain stage with a second gain characteristic; and bias circuitry that includes a reference headroom voltage generator and is configured to provide bias responsive to a reference voltage generated by the reference headroom voltage generator such that a voltage difference between a bias point and a threshold voltage of at least one of the first gain stage and the second gain stage is maintained at a constant level to substantially maintain alignment of distortion inflection points between the first gain characteristic and the second gain characteristic to limit total gain variations to less than 0.1 dB per dB of output stage power during operation for an input power to the first gain stage that ranges from −
50 dB to 0 dB. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17)
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18. A method for an amplifying system comprising:
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providing a first gain stage with a first gain characteristic; providing a second gain stage with a second gain characteristic; providing a reference headroom voltage generator; biasing the first gain stage and the second gain stage in response to a reference voltage generated by the reference headroom voltage generator to provide a bias such that a voltage difference between a bias point and a threshold voltage of at least one of the first gain stage and the second gain stage is maintained at a constant level to substantially maintain alignment of distortion inflection points between the first gain characteristic and the second gain characteristic to limit total gain variations to less than 0.1 dB per dB of output stage power during operation for an input power to the first gain stage that ranges from −
50 dB to 0 dB. - View Dependent Claims (19, 20, 21, 22, 23, 24, 25, 26, 27)
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Specification