ANALYSIS OF LENGTHENING OF MODULATED REPETITIVE PULSES

摘要

It was shown in Reference (a), Appendix by Ming-Chen Tang and G. E. Uhlenbeck, that if a short pulse with repetition frequency f, periodically modulated by a signal with fundamental frequency f, is put through an ideal "box car" generator (which produces flat-topped pulses lasting until the succeeding pulse), the output frequencies are |sfo + qfm| where s and q are integers; a formula giving the amplitudes was presented. This report contains a derivation of the result in more detail than they gave, and without the restriction to the special case of the ideal box car pulse. In the derivation, the pulse form is taken to be quite general. Both a formula and graphs are then presented for the amplitudes of the output frequencies of the pulse lengthener when the signal amplitude of the output pulse of the lengthener decays exponentially with the time constant cx, and lasts throughout the fraction B of the interval between pulses.