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:
Sep. 06, 1994
Filed:
Aug. 04, 1993
Lawrence M Frazier, West Covina, CA (US);
Hughes Missile Systems Company, Los Angeles, CA (US);
Abstract
A motion detection radar system comprised of a low power frequency tunable continuous wave transmitter and antenna, a receiver, an FM transmitter and antenna, and a handheld remote FM receiver. The radar system may be adapted to operate at any frequency from 600 MHz to 1.2 GHz. The motion detecting radar system uses a technique for measuring the changes in phase difference and the rate of change of phase differences detected thereby. The receiver captures the total energy reflected from all reflective objects within the antenna field of view and compares that signal with the transmitted signal in a mixer. If all objects are stationary and the radar system is stationary, the total complex phase pattern of the return signal is constant, and a fixed DC output signal is provided from the mixer. Any motion within the field of view changes the fixed phase relationship and causes a phase rate of change at the receiver output. The phase rate of change is converted into a tone which allows an operator to recognize object motion. The tone is transmitted by the FM transmitter to the remote FM receiver used by the operator to monitor monitor object motion. The receiver output is almost inaudible when there are no moving objects, but an alarm tone is provided when object motion is present. The detection process used in the motion detecting radar is unique in that it captures minute changes in the complex signal from all reflectors and converts the moving object differences into the audible alarm.