| 摘要 |
PCT No. PCT/JP80/00224 Sec. 371 Date May 27, 1981 Sec. 102(e) Date May 22, 1981 PCT Filed Sep. 26, 1980 PCT Pub. No. WO81/00942 PCT Pub. Date Apr. 2, 1981.A transmitter having a transmitting phase synchronizing system. To one input of a frequency mixer is applied the output of a phase synchronizing type digital frequency synthesizer, through a first frequency divider. A modulating signal is applied to another input of the frequency mixer. The output from the mixer is connected via a bandpass filter to a phase synchronizing system having in series, along a main route, a phase detector, a lowpass filter, and a voltage controlled oscillator, and thence to an amplifier system. In a feedback route from another outlet of the voltage controlled oscillator to the phase detector is a second fixed frequency divider. The digital frequency synthesizer itself may have a reference oscillator connected in series to a third fixed frequency divider, a second phase detector, a second lowpass filter and a second voltage controlled oscillator, from which a feedback circuit leads back to the phase detector via the first fixed frequency divider and a variable frequency divider. |
