Patent
Intrusion detection apparatus having supervisory control means
TLDR
In this article, a radio frequency transmitter and a receiver having an amplifier having a constant gain portion and a following roll-off above the highest motion Doppler frequency signal to be detected.Abstract:
The illustrated detection apparatus includes a radio frequency transmitter and a receiver having an amplifier which has a constant gain portion and a following roll-off above the highest motion Doppler frequency signal to be detected. The transmitter is a Clapp oscillator. A free running multi-vibrator is coupled into a voltage regulator of the bias supply of the Clapp oscillator to superimpose a supervisory signal which falls within the roll-off portion.read more
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FM/CW surveillance radar system with range gating
TL;DR: In this article, a single FM/CW radar antenna and accompanying electronics are positioned within a space that is to be guarded, and a moving object within the space under surveillance produces a doppler frequency shift in the echo return signal which return signal is, in turn, analyzed for signal content.
Patent
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Patent
On-line test circuit for intrusion alarm systems
L Dennis Shapiro,Aaron A Galvin +1 more
TL;DR: In this paper, the transmitted signal is frequently modulated at a low rate to produce a detectable change in reflected energy sensed by sub-Doppler processing circuitry and an on-line test circuit operative for the continuous supervision of system operation without affecting normal operation thereof.
Patent
Intrusion detection apparatus
TL;DR: In this article, the transmitter transducer establishes a relatively low frequency signal in the panel and a supervisory branch which couples from the receiver transducers monitors the presence of this supervisory signal.
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Microwave motion-detection apparatus employing a gunn oscillator in a self-detecting mode
TL;DR: In this article, the movement of a moving object was detected by detecting the variation in the bias current produced by a Gunn oscillator and a series-pass transistor connected to a source of DC potential and the operational amplifier and switchable between conducting and non-conducting states.
References
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Patent
Intrusion detection system
TL;DR: In this article, the authors present an alarm system for detecting the presence of a moving body in an area utilizing the Doppler effect, in which an alarm signal is initiated only when the amplitude of the selected signal exceeds a predetermined value.