A Demodulator for Complex-Modulated Pulses

A Complex-Modulated-Pulse Demodulator has been developed to demodulate pulse signals with respect to pulse amplitude, pulse position, pulse width, pulse period, and pulse frequency over a pulse-repetition-rate range of 20cycles to 1 Mc and a pulse-width range from 0.1 to 100,000sec. This range is covered by a two-position switch; no tuning is required within the ranges. A gating system is included which, in conjunction with a multiple slave-sweep type display, enables the operator to visually select for demodulation any desired pulse from a pulse train. Slicing circuits are provided for reducing the effects of receiver noise so that information from tangential signals can often be obtained. The output signal from the demodulator, derived from a boxcar generator having a linear frequency response from 2 cycles to 800 kc, is an accurate reproduction of the modulation envelope carried by the original video pulse signals. It is expected that this demodulator will be an invaluable tool in detecting information carried by complex-modulated-pulse signals, and it is probable that future secured guided missile and communications systems will utilize some kind of pulse modulation that can be handled by this demodulator.