| 摘要 |
<p>A variable-gain mixer (210) for down-converting a modulated input signal (SRF) into a modulated output signal (SIF) in a wireless receiver (120) is proposed. The mixer includes means (310) for selecting a mixer gain (Gv) according to a power level of the input signal, amplifying means (305) for amplifying the input signal into a modulated intermediate current (IRF +,IRF -) in response to a control signal indicative of the selected mixer gain, the intermediate current having an intermediate component, consisting of a direct current, varying according to the selected mixer gain, means (315,320) for generating the output signal from the intermediate current, the output signal having an output component, consisting of a direct current or voltage, depending on the intermediate component; in the solution according to an embodiment of the invention, the mixer further includes means (415i,Sji) for setting a compensation current in response to the control signal for compensating the variation of the intermediate component, and means (Mji +,Mji -) for adding the compensation current to the intermediate current.</p> |
