| 摘要 |
An apparatus such as a television signal receiver provides an AGC function which reduces cross-modulation distortion. According to an exemplary embodiment, the apparatus includes first and second amplifiers coupled in series and a gain control circuit. The gain control circuit controls the gains of the first and second amplifiers in response to the magnitude of the input signal. The gain of the first amplifier remains substantially unchaged at a first level while the magnitude of the input signal is within a first range. The gain of the second amplifier is gradually reduced in the first range. The gain of the first amplifier remains substantially unchaged at a second level, which is lower than the first level, while the magnitude of the input signal is within a second range. The gain of the second amplifier gradually reduced in the second range. The gain of first amplifier is gradually reduced at least in part of a third range while the magnitude of the input signal is within the third range. The gain of the second amplifer remains substantially unchaged in the third range. |
