Accession Number:

ADA003677

Title:

Radio-Frequency Interference from Linear-FM Pulses.

Descriptive Note:

Interim technical rept.,

Corporate Author:

MASSACHUSETTS INST OF TECH LEXINGTON LINCOLN LAB

Personal Author(s):

Report Date:

1974-07-16

Pagination or Media Count:

119.0

Abstract:

Approximate expressions are obtained for the power spectrum and the phase spectrum of a rectangular pulse with linear FM. It is shown that the phase spectrum outside the nominal frequency band of the pulse is very different from the in-band spectrum, and that consequently interference picked up from the skirt of the spectrum will not undergo pulse compression. If a chirp receiver and a chirp pulse have center frequencies differing by at least the larger of the two bandwidths, calculations of radio-frequency interference can be made with good accuracy by ignoring the FM. The response of a chirp receiver to a nonmatching linear-FM or constant-frequency pulse can readily be calculated, even when the difference of the center frequencies is small. The calculation is discussed, first for rectangular pulses in receivers matched to rectangular pulses, and then for rectangular pulses in receivers with Hamming or similar weighting.

Subject Categories:

  • Active and Passive Radar Detection and Equipment
  • Electromagnetic Pulses

Distribution Statement:

APPROVED FOR PUBLIC RELEASE