| 摘要 |
PURPOSE:To diversify transmission programs by modulating a video demodulating signal with an output from a phase comparator while using a converted intermediate frequency signal as a reference signal. CONSTITUTION:A local signal from an RF mixer 1 is received from a voltage controlled oscillator 2, an a PLL consists of a programmable divider 3 with a frequency division ratio setting device 6 connected thereto, a phase comparator 4 and an LPF 5. The local signal of an up-converter 20 is received from an oscillator 1 and the PLL loop consists of a fixed frequency divider 22, a phase comparator 23 and an LPF 24. The local signal of an down-converter 26 is received from a voltage controlled oscillator 27 and the PLL loop consists of a programmable divider 28 with a frequency division ratio setting device 31 connected thereto, a phase comparator 29 and an LPF 30. A reference signal for the comparators 4, 23, 29 is supplied from a generator 34 for which a crystal 34 is connected. Thus, no adjustment, channel agile processing and standardized circuit configuration and diversified transmission programs are attained. |
