Reconfigurable circuit to compensate for a low noise amplification input matching variation and a method for its configuration
AssigneeTexas Instruments Incorporated
InventorsSalvatore Pennisi, Khurram Muhammad
Life of this patent
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Abstract
A method for changing an effective capacitance of an amplifier circuit having a match transistor and a coupled cascode transistor includes changing an on-state of at least one of a plurality of sub-transistors of the match transistor. The method further includes changing a transconductance of the match transistor as a function of the change of the on-state. The method further includes changing an equivalent resistance, as measured between a source and a drain of the cascode transistor, as a function of the change of the transconductance of the match transistor.
Claims14
A method of changing an effective capacitance of an input of an amplifier circuit having a match transistor and a coupled common source (“CS”) transistor, comprising:
- changing an on-state of at least one of a plurality of sub-transistors of said match transistor;
- changing a transconductance of said match transistor as a function of said change of said on-state;
- changing an equivalent resistance, as measured at a drain of said CS transistor, as a function of said change of said transconductance of said match transistor;
- changing a gain of said coupled CS transistor as a function of a change of said equivalent resistance;
- and
- changing a gate input impedance of said CS transistor as a function of said changed effective capacitance;
- wherein said sub-transistors on-states are changed by an output of an adaptive algorithmic processor.
A low noise amplification input-matching variation compensation circuit, comprising:
- a common source (“CS”) transistor having an intrinsic capacitance and coupled between a drain and a gate of said CS transistor, said intrinsic capacitance having a corresponding effective capacitance, said effective capacitance affecting an amplification characteristic of said CS transistor;
- a match transistor, including a plurality of sub-transistors, coupled to said CS transistor and configured to alter said effective capacitance of said CS transistor to a new effective capacitance as a function of a number of said sub-transistors in said match transistor that are enabled;
- and
- a second capacitor coupled to said gate and said source of said cascode transistor.
Dependencies are inferred from the claim text.