直到最近,大多数美国制造的通信卫星都在无线电频谱的 C 频段范围内工作,以6GHz 频率接收,以4GHz 频率发射。C 频段的频率与为公共事业和私人电话通信设备服务的地面微波站所使用的频率是相同的。因为 C 频段卫星与地面通信网共用工作频率,卫星发出的信号会干扰地面微波网,所以,卫星给其他地球站传输信号的功率就受到限 Until recently, most U.S.-made communications satellites were operating within the C-band of the radio spectrum, receiving at 6 GHz and transmitting at 4 GHz. The frequency of the C-band is the same frequency used by terrestrial microwave stations serving public utilities and private telephone communications equipment. Because C-band satellites share a common operating frequency with terrestrial networks, signals from satellites interfere with terrestrial microwave networks, so the power of satellites to transmit signals to other earth stations is limited