| 摘要 |
<p>PROBLEM TO BE SOLVED: To set the gain of an amplifier to be almost constant by means of a frequency setting signal and a temperature difference by transmitting the frequency setting signal from an indoor unit to an outdoor unit with a cable and controlling a temperature compensation circuit and a variable attenuator, which are installed in the outdoor unit by means of the frequency setting signal. SOLUTION: A frequency setting signal being channel information of a synthesizer in an indoor unit IDU is D/A-converted in a D/A converter 1 and the converted signal is converted into a frequency signal. The converted signal is inputted to the control terminal of a voltage control oscillator 2. Thus, channel information can be converted into a frequency signal A. The converted frequency signal A is overlapped with an IF signal and power supply DC by a multiplexer 3 and it is transmitted to the outdoor unit ODU from the IDU with a cable 7. In the ODU, a signal transmitted by the cable 7 is separated by a multiplexer 4.</p> |
