Patent · US Expired

Radar warning receiver

US4581769A · kind A · utility

80Cited by
2References
20Claims
0Family size

Assignee

Inventors

Key dates

Filing dateJan 31, 1984
Grant dateApr 8, 1986
Priority date
Expiry dateJan 31, 2004

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG01S7/022
  • WIPO fieldMeasurement
  • WIPO sectorInstruments

Abstract

A radar warning receiver includes means for distinguishing pulsed or continuous fixed frequency radar signals emanating from a radar transmitter from variable frequency signals such as those radiated from a nearby superhomodyne receiver. This invention includes a superheterodyne receiver having a local oscillator that is repeatedly varied in frequency over a range of frequencies sufficiently large and at a rate fast enough to cause any signals within an input range of frequencies to be detected by a sensitive, limited bandwidth detector. If an input signal is fixed in frequency, that signal will be detected at the same time during successive sweeps of the local oscillator, and a correlated output will be generated; otherwise, an uncorrelated output will be generated. If the number of correlated outputs equal or exceed the uncorrelated outputs detected, then an alarm is provided. Even when the receiver of this invention is receiving signals from a superhomodyne receiver, if a fixed frequency signal is detected for a predetermined number of consecutive sweeps of the local oscillator, then an alarm, indicating the presence of that fixed frequency signal, is again provided.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.