| 摘要 |
A variable-deviation-sensitivity voltage controlled oscillator includes an AC voltage divider that selectively decreases deviation sensitivity. Above a pre-determined roll-off frequency, the AC voltage divider attenuates voltage spi kes and other electrical noise, thereby decreasing undesirable incidental frequency modulation. Below the roll-off frequency, the voltage dividing function ceases, and full deviation sensitivity of the voltage controlled oscillator returns. Whe n used in a phase locked loop,, the voltage controlled oscillator responds to loop frequencies as well as modulation frequencies with decreased deviation sensitivity, thereby attenuating voltage spikes and other electrical noise, and thereby attenuating incidental frequency modulation. At loop control frequencies below the pre-determined roll-off, including DC, the oscillator responds at full deviation sensitivity thereby providing an unattenuated range o f capture.
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