| 摘要 |
<p>A variable attenuator system comprises a variable attenuator which attenuates a received signal SRX before conversion into a reception IF signal at an outdoor unit. A control unit is located in the outdoor unit and controls the variable attenuator to change an attenuation rate in response to control data. An operation unit is located in an indoor unit, which is distant form the outdoor unit and connected to the outdoor unit through an IF cable, and produces the control data. The operation unit modulates a control carrier wave with the control data to produce a control IF signal and to transmits the control IF signal to the control unit through the IF cable. The control unit demodulates the control data from the control IF signal. <IMAGE></p> |
