Analysis of delay circuits and systems using operators and causality

This paper presents a method of analysis for delay circuits and systems using operators. By assuming all operators are causal, we show that the operator approach is rigorous and-at the same time-more general than the transform approach. Our analysis is couched in terms of delay operators acting upon continuous time signals; in this manner, the resulting theory is applicable to continuous time delay structures and the usual discrete time methods are seen to follow at once from the continuous time case.