| 摘要 |
PURPOSE: To make it possible not only to send data over the entire 500 MHz band having the bandwidth of a satellite communication repeater without correcting a VSAT system terminal device or RF part, but also to lower the price by obtaining immunity to satellite noise and spuriousness and simply making the size to practicable size. CONSTITUTION: This transmission reference frequency oscillator (TRO) is equipped with a 15 frequency divider 22 which divides the frequency of an inputted reference signal by 15, a voltage-controlled oscillator 25 which outputs an oscillation signal, a 4 frequency divider 26 which divides the frequency of the oscillation signal outputted from the voltage-controlled oscillator 25 by four, an N frequency divider 27 which further divides the frequency of the 4-divided signal of the 4 frequency divider 26 by N, a phase detector 23 which compares the phase of the output signal of the N frequency divider 27 with that of the output signal of the 15 frequency divider and outputs their difference signal, and a low-frequency filter 24 which filters the difference signal outputted from the phase detector 23 and applies the resulting signal to the voltage-controlled oscillator 25 to vary the oscillation frequency of the voltage- controlled oscillator 25. |
