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:
May. 29, 2001
Filed:
Oct. 29, 1999
Kevin B. McDonald, Portland, OR (US);
Charles R. Barrows, Portland, OR (US);
Stephen K. Bigelow, Aloha, OR (US);
Steven J. McCoy, Clackamas, OR (US);
Interlogix, Inc., Tualatin, OR (US);
Abstract
A motion detector combines an FCC approved homodyne pulsed range-gated radar (“RGR”) detector (,) and a PIR detector (,). Narrow microwave pulses are transmitted at a predetermined pulse repetition frequency (“PRF”) and the pulses are reflected by a target. The RGR detector senses the presence of moving human sized objects within predetermined ranges. Moving objects beyond the ranges are not sensed. The RGR detector employs a pulsed microwave oscillator (,) that is triggered by a system clock (,) and immediately retriggered after a 3 to 100 nanosecond delay (,). The duration of each pulse is 3 to 20 nanoseconds with a half-sine envelope shape. The RGR employs a homodyne detector (,) and shares an antenna (,) with the transmitter. The receiver range is determined by the delay imposed between the transmitted pulses, the first being a transmitted pulse and the second being a local oscillator pulse. Each received 5.8 GHz pulse is mixed down to a baseband by the homodyne detector. The detected baseband signal is amplified, processed, and filted to frequencies below 100 Hz. If the output exceeds a predetermined threshold, an alarm condition is indicated. The threshold is adjustable as a function of range and may be set to discriminate object sizes. The PIR detector operates conventionally, but its output is logically combined with the RGR detector output to reduce false-alarm indications.