Title :
Notes on the Theory of Modulation
Author_Institution :
Department of Development and Research, American Telephone and Telegraph Company, New York
Abstract :
The transmission system of "frequency modulation" (transmission by variation of the frequency of the radiated wave) is mathematically analyzed, and the width of the band of frequencies occupied by this method of transmission at a given speed is compared with the width of the corresponding band for transmission by amplitude variation. It is proved that the frequency modulation system using a spacing or compensating wave is inferior to the amplitude variation system both as to the width of the frequency band occupied and as to distortion of signal wave form.
Keywords :
Amplitude modulation; Demodulation; Frequency; RF signals; Telegraphy; Telephony; Tuning; Wire;
Journal_Title :
Radio Engineers, Proceedings of the Institute of
DOI :
10.1109/JRPROC.1922.219793
