Method and apparatus of an input resistance of a passive mixer to broaden the input matching bandwidth of a common source/gate LNA
First Claim
1. A method of operating a receiver, comprising:
- amplifying an input signal in a Low Noise Amplifier (LNA) coupled to a resonant circuit;
coupling a switched capacitance circuit to the resonant circuit to reduce a quality factor of the resonant circuit comprising;
coupling current from the resonant circuit through a first switch to a first capacitor integrating a first voltage; and
coupling current from the resonant circuit through a second switch to a second capacitor integrating a second voltage;
enabling the first switch with a clock signal;
enabling the second switch with an inverse clock signal;
applying a first voltage to a positive input of a differential amplifier;
applying a second voltage to a negative input of the differential amplifier; and
providing a sum and a difference frequency spectrum between a signal spectrum carried within the current and a frequency of the clock signal.
1 Assignment
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Accused Products
Abstract
A receiver comprises a Low Noise Amplifier (LNA) configured to amplify an input signal and a resonant circuit coupled to the LNA. A first switch couples current from the resonant circuit to a first capacitor integrating a first voltage, wherein the first switch is enabled with a clock signal. A second switch couples current from the resonant circuit to a second capacitor integrating a second voltage, wherein the second switch is enabled with an inverse clock signal. A differential amplifier comprises a positive input for receiving the first voltage and a negative input for receiving the second voltage in order to produce a sum and a difference frequency spectrum between a signal spectrum carried within the current and a frequency of the clock signal.
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Citations
18 Claims
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1. A method of operating a receiver, comprising:
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amplifying an input signal in a Low Noise Amplifier (LNA) coupled to a resonant circuit; coupling a switched capacitance circuit to the resonant circuit to reduce a quality factor of the resonant circuit comprising; coupling current from the resonant circuit through a first switch to a first capacitor integrating a first voltage; and coupling current from the resonant circuit through a second switch to a second capacitor integrating a second voltage; enabling the first switch with a clock signal; enabling the second switch with an inverse clock signal; applying a first voltage to a positive input of a differential amplifier; applying a second voltage to a negative input of the differential amplifier; and providing a sum and a difference frequency spectrum between a signal spectrum carried within the current and a frequency of the clock signal. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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10. A receiver apparatus, comprising:
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a Low Noise Amplifier (LNA) configured to amplify an input signal; a resonant circuit coupled to the LNA; a switched capacitance circuit configured to reduce a quality factor of the resonant circuit, the switched capacitance circuit comprising; a first switch coupling current from the resonant circuit to a first capacitor integrating a first voltage, the first switch enabled with a clock signal; and a second switch coupling current from the resonant circuit to a second capacitor integrating a second voltage, the second switch enabled with an inverse clock signal; and a differential amplifier comprising a positive input for receiving the first voltage and a negative input for receiving the second voltage, the differential amplifier providing a sum and a difference frequency spectrum between a signal spectrum carried within the current and a frequency of the clock signal. - View Dependent Claims (11, 12, 13, 14, 15, 16, 17, 18)
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Specification