| 主权项 |
1. A communication apparatus, comprising:
a first amplifier to amplify a signal level of a received radio frequency signal and provide a radio frequency output signal; a conversion unit coupled to receive the radio frequency output signal and convert it to an intermediate frequency signal; a second amplifier coupled to amplify the intermediate frequency signal and generate an intermediate frequency output signal; and a gain control unit configured to generate a control signal for controlling a gain of the first amplification part, the gain control unit including a transient characteristics control part configured to control one or more transient characteristics of the control signal including a rising time, a falling time, or both the rising and falling times of the control signal, wherein,
the gain control unit including the transient characteristics control part is connected to the first amplification part via a feedback loop such that the control signal is based at least in part on an output of the first amplification part prior to the second amplification part,in the gain control unit, the rising time is controlled by a first variable current source in series with a first capacitance or a first variable resistance in series with a second capacitance,in the gain control unit, the falling time is controlled by a second variable current source in series with the first capacitance or a second variable resistance in parallel with the second capacitance,the first capacitance extends between the first and second variable current sources and ground, andthe second capacitance and second variable resistance extend between the first variable resistance and ground. |
