04401980 is referenced by 12 patents and cites 9 patents.

An electronic detection system for detecting intruders employs a transmisn line as a sensing element. In one embodiment the transmission line is a modified surface-wave transmission line, for example, a Goubau line which is positioned about the perimeter of the area to be protected. An intruder in the field of the line causes an RF reflection back toward the source, which reflection may be detected by Doppler range-gating techniques. In other embodiments of the invention, the transmission line is an insulated, twisted wire pair or a deformable transmission line. In some instances, the transmission line may be replaced with an active or passive pressure line.

Title
Constant current electronic intruder detection system
Application Number
840206
Publication Number
4401980
Application Date
August 31, 1981
Publication Date
August 30, 1983
Inventor
Reinhard G Olesch
Kronberg
DE
Otto E Rittenbach
Monmouth County
NJ, US
Agent
Michael C Sachs
Jeremiah G Murray
Robert P Gibson
Assignee
The United States of America represented by the Secretary of the Army
DC, US
IPC
G08B 13/10
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