| 摘要 |
A circuit assembly (10) for generating a phase-locked frequency-modulatable carrier frequency signal contains a voltage-controlled oscillator (50) generating the carrier frequency signal as a function of a control signal. It furthermore contains a phase detector (44) which compares a reference frequency signal to a signal derived from the carrier frequency signal in phase therewith to thus produce the control signal so that the difference in phase between the signal derived from the carrier frequency signal and the reference frequency signal is zero. A reference frequency generator (36) is provided whose output signal is applied as the reference frequency signal directly to the phase detector (44). To generate the derived signal a mixer stage (30, 32, 38) is provided which mixes a signal output from a digital frequency generator (16) for modulating by digital signals in its frequency with a signal generated by frequency division from the carrier frequency signal output by the voltage-controlled oscillator (50) so that a signal materializes whose frequency equals the reference frequency.
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