Transfer functions for amplitude-modulated signals

THE purpose of this paper is to derive the general theoretical requirements which must be met by linear networks which are to perform specified operations on amplitude modulated signals. In particular, an exact correspondence will be established between a realizable transfer function A (s) which performs a given operation on any modulating function fm(t) and the network which performs an identical operation on the envelope of the modulated function fm(t) sin ω0 t where ω0/2 π is the carrier frequency.