Method and system for down-converting an electromagnetic signal
First Claim
1. A method for frequency down-converting a modulated carrier signal to a demodulated baseband signal, comprising:
- controlling a first switch with a first control signal which comprises a first sampling aperture with a specified frequency, wherein the first switch is on during the first sampling aperture and wherein the first switch is off outside the first sampling aperture;
outputting from a first energy storage element coupled to said first switch a down-converted in-phase baseband signal portion of said modulated carrier signal;
controlling a second switch with a second control signal which comprises a second sampling aperture with a specified frequency, wherein the second switch is on during the second sampling aperture and wherein the second switch is off outside the second sampling aperture;
outputting from a second energy storage element coupled to said second switch a down-converted inverted in-phase baseband signal portion of said modulated carrier signal;
wherein the first and second control signals each control a charging and discharging cycle of their respective energy storage element so that for each switch a portion of energy from the modulated carrier signal is transferred to the respective energy storage element when the respective switch is on during the charging cycle, and a portion of previously transferred energy is discharged during the discharging cycle for each respective switch when the switch is off;
wherein for each respective energy storage element, the energy discharged during any given discharge cycle is not completely discharged, with the remaining undischarged energy from the given discharge cycle becoming an initial condition for a next charging cycle that begins immediately following the given discharge cycle;
wherein said down-converted in-phase baseband signal portion is derived from energy accumulated at said first energy storage element during both the charging and the discharging cycles for the first energy storage element;
wherein said down-converted inverted in-phase baseband signal portion is derived from energy accumulated at said second energy storage element during both the charging and the discharging cycles for the second energy storage element; and
combining with a first differential amplifier circuit said down-converted in-phase baseband signal portion with said down-converted inverted in-phase baseband signal portion and outputting a first channel down-converted differential in-phase baseband signal.
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Accused Products
Abstract
Methods, systems, and apparatus for down converting a modulated carrier signal to a demodulated baseband signal are described herein. A first switch is controlled with a first control signal which comprises a first sampling aperture with a specified frequency, wherein the first switch is on during the first sampling aperture and wherein the first switch is off outside the first sampling aperture. A second switch is controlled with a second control signal which comprises a second sampling aperture with a specified frequency, wherein the second switch is on during the second sampling aperture and wherein the second switch is off outside the second sampling aperture. The first and second control signals each control a charging and discharging cycle of a respective energy storage element so that for each switch a portion of energy is transferred to the respective energy storage element when the respective switch is on during the charging cycle, and a portion of previously transferred energy is discharged during the discharging cycle for each respective switch when the switch is off. A down-converted in-phase baseband signal portion is derived from energy accumulated at said first energy storage element during both the charging and the discharging cycles for the first energy storage element and a down-converted inverted in-phase baseband signal portion is derived from energy accumulated at said second energy storage element during both the charging and the discharging cycles for the second energy storage element, and the two portions are combined with a first differential amplifier circuit to form a down-converted differential in-phase baseband signal.
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Citations
28 Claims
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1. A method for frequency down-converting a modulated carrier signal to a demodulated baseband signal, comprising:
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controlling a first switch with a first control signal which comprises a first sampling aperture with a specified frequency, wherein the first switch is on during the first sampling aperture and wherein the first switch is off outside the first sampling aperture; outputting from a first energy storage element coupled to said first switch a down-converted in-phase baseband signal portion of said modulated carrier signal; controlling a second switch with a second control signal which comprises a second sampling aperture with a specified frequency, wherein the second switch is on during the second sampling aperture and wherein the second switch is off outside the second sampling aperture; outputting from a second energy storage element coupled to said second switch a down-converted inverted in-phase baseband signal portion of said modulated carrier signal; wherein the first and second control signals each control a charging and discharging cycle of their respective energy storage element so that for each switch a portion of energy from the modulated carrier signal is transferred to the respective energy storage element when the respective switch is on during the charging cycle, and a portion of previously transferred energy is discharged during the discharging cycle for each respective switch when the switch is off; wherein for each respective energy storage element, the energy discharged during any given discharge cycle is not completely discharged, with the remaining undischarged energy from the given discharge cycle becoming an initial condition for a next charging cycle that begins immediately following the given discharge cycle; wherein said down-converted in-phase baseband signal portion is derived from energy accumulated at said first energy storage element during both the charging and the discharging cycles for the first energy storage element; wherein said down-converted inverted in-phase baseband signal portion is derived from energy accumulated at said second energy storage element during both the charging and the discharging cycles for the second energy storage element; and combining with a first differential amplifier circuit said down-converted in-phase baseband signal portion with said down-converted inverted in-phase baseband signal portion and outputting a first channel down-converted differential in-phase baseband signal. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28)
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Specification