Frequency conversion of amplitude demodulated input signal with side band - selects frequency of conversion signals w.r.t. final values of lower and upper side bands

摘要

The amplitude demodulated input signal with a lower sideband, an upper side band and a carrier, is converted into an output signal. The conversion uses a quadrature demodulator with two conversion signals with a 90 degree phase shift, for frequency conversion into an in-phase signal, and in a quadrature signal. The conversion signal frequency is so chosen that it equals a lower value for frequency conversion of the lower side band, and a higher value for the upper side band, with the lower value smaller than the carrier frequency by a difference frequency. The upper value frequency is larger by the same difference frequency.