| US 7,603,096 B2 | ||
| Mixer with self-calibrating carrier leakage mechanism | ||
| Yuan-Hung Chung, Jhudong Township, Hsinchu County (Taiwan); and Jie-Wei Lai, Taipei (Taiwan) | ||
| Assigned to Mediatek Inc., Hsin-Chu (Taiwan) | ||
| Filed on Feb. 16, 2007, as Appl. No. 11/675,688. | ||
| Prior Publication US 2008/0200135 A1, Aug. 21, 2008 | ||
| Int. Cl. H04B 1/06 (2006.01); H04B 7/00 (2006.01) | ||
| U.S. Cl. 455—262 [455/232.1; 361/93.1; 330/252] | 29 Claims |
| 1. A mixer with self-calibrating carrier leakage, comprising:
a double balanced mixer;
a gm stage comprising a first processing unit and a second processing unit;
a current duplicating circuit to select the first processing unit or the second processing unit and duplicate a duplicated
current of the selected processing unit; and
a current measurement circuit for respectively receiving the duplicated current to generate a compensation current based on
a current difference between the currents of the first processing unit and the second processing unit, wherein the current
measurement circuit comprises:
a capacitor having a first terminal and a second terminal, wherein the second terminal is grounded and the first terminal
receives the duplicated current;
a controller determining a charge time of the capacitor to generate a compensation signal, wherein the charge time is the
time that the voltage of the capacitor is charged to equal to a reference voltage; and
a current compensation unit receiving the compensation signal to generate a compensation current to the mixer.
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