| 摘要 |
A tuner for a wireless receiver is provided, which may include an input interface that is adapted to receive wireless signals, a mixer that is adapted to select a specific frequency from signals received at the input interface, and a controllable switch that is adapted to lead an output from the mixer towards a base-band unit of the receiver and to disconnect the output. The tuner may further include a controller which may be adapted to operate the controllable switch to disconnect the output of the mixer when the controller studies characteristics of the tuner and to reconnect the output of the mixer at other times. The studied characteristics may be associated with parasitic direct current voltages in the tuner, which may be associated with a low noise amplifier of the tuner, or programmable gain amplifier of the tuner or with both amplifiers. The controller may cause a compensation direct current voltage to be generated and applied to the mixer's output based on the ratio between programmed gain and actual/measured gain of the programmable gain amplifier. |
