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Journal Article

The Frequency Modulation Spectrum of an Exponential Voltage-Controlled Oscillator

Authors: Hutchins, Jr., Bernard A.

Journal of the Audio Engineering Society · Volume 23 · Issue 3 · pp. 200–206 · April 1975

Abstract

As the amplitude of a modulating voltage to an exponential VCO is increased, the pitch of the modulated signal arises, making dynamic depth FM unrealistic. The pitch rise is proportional to I/o, the first of the modified Bessel functions. Higher order terms involving additional modified Bessel functions can be used to compute the entire spectrum. Various methods of correcting for the pitch shift are possible, but the most useful solution to the dynamic depth FM problem with exponential VCO's is to add some form of auxiliary linear control.

Details

Publication
Journal of the Audio Engineering Society
Volume
23
Issue
3
Pages
200–206
Publication date
April 6, 1975
Affiliation
Electronotes, Ithaca, NY (See document for exact affiliation information.)
Type
Journal Article