Effect of Predetection Filtering on Baseband Interference in FDM/FM Systems

Abstract

This paper addresses the subject of the effect of the characteristics of the receive IF bandpass filter on the baseband inter­ ference in FDM/FM signals. Closed form expressions for the interference spectra in the baseband are derived for the IF filters having rectangular and trapezoidal charac­ teristics. The improvement in the baseband interference due to the truncation of interference spectrum by the IF filter is quantified through numerical examples.