Pulse or digital communications – Receivers – Automatic baseline or threshold adjustment
Reexamination Certificate
2005-03-15
2005-03-15
Chin, Stephen (Department: 2634)
Pulse or digital communications
Receivers
Automatic baseline or threshold adjustment
C455S324000
Reexamination Certificate
active
06868128
ABSTRACT:
A novel method and apparatus for calibrating DC offsets in a direct conversion receiver. The present DC offset calibration method and apparatus comprises a direct conversion receiver equipped with a frequency shifter means and a DC offset measurement and correction technique. In accordance with the present invention, DC offsets are calibrated in direct conversion receivers through an inventive method including two steps: a DC offset measurement step and a DC offset correction step. In the DC offset measurement step the frequency of a local oscillation signal (typically generated by a voltage-controlled oscillator (VCO)) is shifted by a selected frequency shift value during the inactive time intervals of the receiver. DC offsets are measured while the frequency of the down-conversion oscillation signal is shifted by the frequency shift value. Before the inactive time interval expires, the frequency of the down-conversion oscillator signal is shifted back to its original value. In the DC offset correction step of the present invention incoming signals are corrected using a correction means that removes the DC offset measured during the DC offset measurement step.
REFERENCES:
patent: 4736390 (1988-04-01), Ward et al.
patent: 4944025 (1990-07-01), Gehring et al.
patent: 4955039 (1990-09-01), Rother et al.
patent: 5241702 (1993-08-01), Dent
patent: 5323425 (1994-06-01), Colamonico et al.
patent: 5422889 (1995-06-01), Sevenhans et al.
patent: 5828955 (1998-10-01), Lipowski et al.
patent: 6240100 (2001-05-01), Riordan et al.
patent: 6298096 (2001-10-01), Burgin
Chin Stephen
RFMD WPAN, Inc.
Wang Ted
Withrow & Terranova , PLLC
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