Communications: electrical – Condition responsive indicating system – Specific condition
Patent
1999-06-04
2000-12-19
Trieu, Van T.
Communications: electrical
Condition responsive indicating system
Specific condition
340551, 3405721, G08B 1314
Patent
active
061632597
ABSTRACT:
A non-linear junction detector designed for counter surveillance measures achieves superior performance by transmitting a series of pulses and receiving harmonics of the transmitted pulse signals that are re-radiated by a non-linear junction such as would be found in an eavesdropping device containing a semiconductor. The transmit power of the series of pulses is varied and the amplitudes of the harmonics received at the different power levels are compared to determine the type of non-linear junction detected. The received harmonic signals are demodulated to create signals having a frequency in the audible range of human ears. The demodulated signals are broadcast so that an operator of the non-linear junction detector can audibly distinguish between the noise responses produced by the different types of non-linear junctions. The harmonic signals are analyzed to determine if the harmonic, signals correspond to signals produced by a known type of non-linear junction device such as a video camera or tape recorder. Data generated by the non-linear junction detector is displayed to an operator of the detector and may be stored for later analysis.
REFERENCES:
patent: 3631484 (1971-12-01), Augenblick
patent: 4053891 (1977-10-01), Optiz
patent: 4063229 (1977-12-01), Welsh et al.
patent: 4123749 (1978-10-01), Hartmann et al.
patent: 4331957 (1982-05-01), Enander et al.
patent: 4413254 (1983-11-01), Pinneo et al.
patent: 4471344 (1984-09-01), Williams
patent: 4595915 (1986-06-01), Close
patent: 4700179 (1987-10-01), Fancher
patent: 5191343 (1993-03-01), Danzer et al.
patent: 5414410 (1995-05-01), Davies et al.
patent: 5990791 (1999-11-01), Endreasen et al.
AUDIOTEL Brochure, SuperBroom and Broom ECM (2 pp.) (undated).
BOOMERANG.sup.4 Brochure, Information Security Associates, Inc., 1992.
Operating Instructions Boomerang.TM. Non-Linear Junction Detector NJD-4, Oct. 1, 1994, Information Security Associates, Inc., 13 pp.
"Hawk" Non-Linear Junction Detector Model 400/B Guidance Manual, 8 pp. (undated).
Locator Pro Non-Linear Junction Detector with Third Harmonic Guidance Manual, International Procurement Services Ltd. Locator Pro, Jul. 24, 1996, 9 pp., London.
Nonlinear Radio Locator NR 900 E (Russian language), 12 pp. (undated).
N.S. Vernigorov, Method of Detection of the Subjects by Nonlinear Radar (Russian language), 6 pp. (undated).
Russian language page containing at the top a 4-column table and at the bottom text and a drawing (undated).
Barsumian Bruce R.
Jones Thomas H.
Research Electronics International
Trieu Van T.
LandOfFree
Pulse transmitting non-linear junction detector does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Pulse transmitting non-linear junction detector, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Pulse transmitting non-linear junction detector will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-274483