Mixer gain calibration method and apparatus
First Claim
1. A gain calibration circuit for a radio frequency (RF) mixer in a wireless transceiver, comprising:
- a constant overdrive voltage generator that biases said mixer;
a reference signal generator that generates a reference signal;
a comparator that receives said reference signal and a second signal that is proportional to a mixer bias current flowing through said RF mixer and that generates a difference signal; and
an adjustment circuit that adjusts a transconductance gain of said RF mixer based on said difference signal.
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Accused Products
Abstract
A gain calibration circuit for a radio frequency mixer in a wireless transceiver includes a reference signal generator that generates a reference signal. A comparator receives the reference signal and a second signal that is proportional to current flowing through the transmitter mixer and generates a difference signal. An adjustment circuit adjusts a transconductance gain of the mixer based on the difference signal. The adjustment circuit includes a plurality of binary weighted transconductance cells. The transconductance gain is calibrated during idle time between data packets or after power on, hardware reset, or software reset.
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Citations
62 Claims
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1. A gain calibration circuit for a radio frequency (RF) mixer in a wireless transceiver, comprising:
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a constant overdrive voltage generator that biases said mixer; a reference signal generator that generates a reference signal; a comparator that receives said reference signal and a second signal that is proportional to a mixer bias current flowing through said RF mixer and that generates a difference signal; and an adjustment circuit that adjusts a transconductance gain of said RF mixer based on said difference signal. - View Dependent Claims (2, 3, 4, 5, 6)
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7. A wireless receiver that receives data packets, comprising:
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a receiver including a radio frequency (RF) receiver mixer having an input transconductance stage that is biased by a constant overdrive voltage; and a receiver gain calibration circuit that includes a reference signal generator that generates a reference signal, a comparator that receives said reference signal and a second signal that is proportional to a mixer bias current flowing through said RF receiver mixer and that generates a difference signal, and an adjustment circuit that adjusts a transconductance gain of said RF receiver mixer based on said difference signal. - View Dependent Claims (8, 9, 10, 11, 12, 13, 14)
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15. A wireless transmitter that transmits data packets, comprising:
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a transmitter including a radio frequency (RF) transmitter mixer having an input transconductance stage that is biased by a constant overdrive voltage; and a transmitter gain calibration circuit that includes a reference signal generator that generates a reference signal, a comparator that receives said reference signal and a second signal that is proportional to a mixer bias current flowing through said RF transmitter mixer and that generates a difference signal, and an adjustment circuit that adjusts a transconductance gain of said RF transmitter mixer based on said difference signal. - View Dependent Claims (16, 17, 18, 19, 20, 21, 22)
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23. A gain calibration circuit for a radio frequency (RF) mixer in a wireless transceiver, comprising:
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constant overdrive voltage generating means for biasing said RF mixer; reference signal generating means for generating a reference signal; comparing means for receiving said reference signal and a second signal that is proportional to a mixer bias current flowing through said mixer and for generating a difference signal; and adjustment means for adjusting a transconductance gain of said mixer based on said difference signal. - View Dependent Claims (24, 25, 26, 27, 28)
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29. A wireless receiver for receiving data packets, comprising:
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receiving means for receiving data packets and including a radio frequency (RF) receiver mixer having an input transconductance stage that is biased by a constant overdrive voltage; and receiver gain calibration means for calibrating a gain of said RF receiver mixer and that includes reference signal generating means for generating a reference signal, comparing means for receiving said reference signal and a second signal that is proportional to a mixer bias current flowing through said RF receiver mixer and for generating a difference signal, and adjustment means for adjusting a transconductance gain of said RF receiver mixer based on said difference signal. - View Dependent Claims (30, 31, 32, 33, 34, 35, 36)
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37. A wireless transmitter that transmits data packets, comprising:
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transmitting means including a radio frequency (RF) transmitter mixer having an input transconductance stage that is biased by a constant overdrive voltage; and transmitter gain calibration means for calibrating a gain of said mixer and that includes reference signal generating means for generating a reference signal, comparing means for receiving said reference signal and a second signal that is proportional to a mixer bias current flowing through said RF transmitter mixer and for generating a difference signal, and adjustment means for adjusting a transconductance gain of said RF transmitter mixer based on said difference signal. - View Dependent Claims (38, 39, 40, 41, 42, 43, 44)
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45. A method of operating a gain calibration circuit for a radio frequency (RF) mixer in a wireless transceiver, comprising:
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biasing an input transconductance stage of a mixer with a constant overdrive voltage; generating a reference signal; generating a difference signal by comparing said reference signal and a second signal that is proportional to a mixer bias current flowing through said mixer; and adjusting a transconductance gain of said mixer based on said difference signal. - View Dependent Claims (46, 47, 48, 49, 50)
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51. A method for operating a wireless radio frequency (RF) receiver for receiving data packets, comprising:
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biasing an input transconductance stage of an RF receiver mixer using a constant overdrive voltage; and generating a reference signal; comparing said reference signal and a second signal that is proportional to a mixer bias current flowing through said RF receiver mixer and generating a difference signal; and adjusting a transconductance gain of said receiver mixer based on said difference signal. - View Dependent Claims (52, 53, 54, 55, 56)
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57. A method for operating a wireless radio frequency (RF) transmitter that transmits data packets, comprising:
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biasing an input transconductance stage of an RF transmitter mixer using a constant overdrive voltage; and generating a reference signal; comparing said reference signal and a second signal that is proportional to a mixer bias current flowing through said RF transmitter mixer and generating a difference signal; and adjusting a transconductance gain of said RF transmitter mixer based on said difference signal. - View Dependent Claims (58, 59, 60, 61, 62)
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Specification