Detection of Orthogonal Sine and Cosine Pulses by Linear Active RC-Networks

Abstract

An active RC matched filter, particularly useful for phase-coherent, coded or uncoded, binary or non-binary communication channels, is described. One detector circuit performs the equivalent of two simultaneous cross-correlations, avoiding the need for electronic multipliers, reference wave generation and phase synchronization. For example, only I circuits are needed in a receiver that is required to detect the polarity or presence of an orthogonal set of I sine and I cosine pulses. In view of the circuits realizability with linear IC technologies, the sensitivities with respect to circuit component variations are analyzed in detail. The results of the sensitivity analysis are presented in graphical form. Experimental results confirm the predicted performance; i.e. Q-factors in excess of 4000 were obtained with small, general-purpose operational amplifiers.