Method and apparatus for direct conversion receiver correcting direct current offset
First Claim
1. An apparatus for direct current (DC) offset calibration of a direct conversion receiver, the apparatus comprising:
- a plurality of serially connected variable gain amplifiers configured to amplify an input signal based on respective preset gain control values;
a DC offset monitoring unit configured to monitor a DC offset for an output signal of the plurality of variable gain amplifiers;
a plurality of variable digital to analog converters (DACs) configured to control a current applied to each of the plurality of variable gain amplifiers according to respective current control codes; and
a DC offset cancellation unit configured to determine a current control code set which minimizes the DC offset value per each of the preset gain control values,wherein each of the plurality of DACs corresponds to each of the plurality of variable gain amplifiers.
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Abstract
The present invention relates to a method and an apparatus for direct current offset calibration of a direct conversion receiver, a Direct Current (DC) offset calibration apparatus of a direct conversion receiver includes a plurality of variable gain amplifiers for amplifying an input signal based on a gain control value, a DC offset monitoring unit for monitoring a DC offset for an output signal of the plurality of variable gain amplifiers, a plurality of variable Digital to Analog Converters (DACs) for controlling a current applied to each of the plurality of variable gain amplifiers according to a current control code, and a DC offset cancellation unit for determining a current control code set which minimizes the DC offset value per preset gain control value, and thus the DC offset can be precisely cancelled without being affected by external factors such as a signal modulation method and heat and performance degradation of the receiver can be prevented.
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Citations
18 Claims
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1. An apparatus for direct current (DC) offset calibration of a direct conversion receiver, the apparatus comprising:
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a plurality of serially connected variable gain amplifiers configured to amplify an input signal based on respective preset gain control values; a DC offset monitoring unit configured to monitor a DC offset for an output signal of the plurality of variable gain amplifiers; a plurality of variable digital to analog converters (DACs) configured to control a current applied to each of the plurality of variable gain amplifiers according to respective current control codes; and a DC offset cancellation unit configured to determine a current control code set which minimizes the DC offset value per each of the preset gain control values, wherein each of the plurality of DACs corresponds to each of the plurality of variable gain amplifiers. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 16)
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9. A method of operating a direct conversion receiver for direct current (DC) offset calibration, the method comprising:
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controlling, at a plurality of variable digital to analog converters (DACs), a current applied to each of a plurality of serially connected variable gain amplifiers using current control codes; amplifying, at the plurality of variable gain amplifiers, an input signal based on respective preset gain control values; monitoring a DC offset for an output signal amplified through the plurality of variable gain amplifiers; and determining a current control code set which minimizes the DC offset value per each of the preset gain control values based on the DC offset monitoring result, wherein each of the plurality of DACs corresponds to each of the plurality of variable gain amplifiers. - View Dependent Claims (10, 11, 12, 13, 14, 15, 17, 18)
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Specification