Accession Number : ADD003710

Title :   Phase-Locking Midpulse Detector.

Descriptive Note : Patent,


Personal Author(s) : Roberts,James L

Report Date : 18 Jan 1977

Pagination or Media Count : 7

Abstract : Apparatus, in a receiver, for detecting the mid-pulse phase reversal of an input signal s(t)=a(t)BLTCOS (omega(c)t + theta). The signal a(t)BLT is a modulating signal a(t), having a phase-reversal at its midpoint, after band-limiting by a transmitter, and cos (omega(c)t + theta) relates to a carrier having a frequency fc and arbitrary phase angle theta. The apparatus comprises a hard-limiter and amplifier, a phase-lock loop circuit, a multiplier circuit, a low-pass filter, a comparator, serving the function of a threshold detector, a delay timing logic circuit, and a comparator, serving as a zero crossing detector, whose input is connected to the output of the low-pass filter, which detects the mid-pulse zero-crossing of a(t)BLTR and therefore of a(t). The apparatus further includes an AND gate, whose input comprises a positive-going pulse whose trailing edge represents the mid-pulse of a(t)BLTR; and a one-shot, whose output is a sharp pulse representing the mid-pulse of A(t). (Author)

Descriptors :   *Patents, *Phase locked systems, *Phase detectors, *Pulse analyzers, Timing devices, Receivers, Low pass filters, Comparators

Subject Categories : Electrical and Electronic Equipment

Distribution Statement : APPROVED FOR PUBLIC RELEASE