US 6,983,135 B1
Mixer gain calibration method and apparatus
King Chun Tsai, San Jose, Calif. (US); Lawrence Tse, Fremont, Calif. (US); and George Chien, Cupertino, Calif. (US)
Assigned to Marvell International, Ltd., Hamilton (Bermuda)
Filed on Nov. 11, 2002, as Appl. No. 10/292,087.
Int. Cl. H04B 1/06 (2006.01)
U.S. Cl. 455—234.1 62 Claims
OG exemplary drawing
 
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.