The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Aug. 12, 1986
Filed:
Sep. 14, 1984
Daniel A Blattman, King County, WA (US);
Harold G Middleton, King County, WA (US);
Racon, Inc., Seattle, WA (US);
Abstract
An intrusion detector system with a transmitter having a clock operating at a selected frequency, a pseudorandom code sequence generator for generating one of a selected number of codes, a modulator for spread-spectrum modulating an electromagnetic signal with the generated pseudorandom code sequence signal, and an antenna for transmitting the modulated signal through a zone of protection; and a receiver having an antenna, a demodulator for detecting and demodulating the modulated signal to recover the transmitter pseudorandom code sequence signal, a clock operating at a frequency corresponding to the transmitter clock, a pseudorandom code sequence generator for generating one of a selected number of receiver code signals corresponding to the transmitter code signals, a detector for comparing the received code signal to the receiver code signal and generating a detection signal proportional to the signal amplitude of the received code signal when locked in phase with the receiver code signal, a phase detector for detecting the phase difference between the two code signals, a control for phase synchronizing the two code signals, and a monitor for detecting and signalling changes in the detection signal resulting from entry of movement of an intruder in the zone of protection.