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. 04, 1992
Filed:
Mar. 08, 1991
Heyward S Williams, Derry, NH (US);
AM Sensor, Inc., Salem, NH (US);
Abstract
A microwave range detector system for determining the range of a moving object in a monitored area includes: a microwave antenna for focusing microwave energy in the area to be monitored; means for selectively generating microwave signals at a first microwave frequency and at a second microwave frequency for transmission by the antenna; microwave detector means, responsive to the microwave signal at the first microwave frequency and the return signal at the first microwave frequency from a target in the monitored area, for generating a pair of Doppler frequency signals with a fixed-phase relationshp, and responsive to the microwave signals at the first and second microwave frequencies and to the return signals at the first and second microwave frequencies, respectively, from a target in a monitored area, for generating a pair of Doppler frequency signals with a variable-phase relationship; direction decoder means, responsive to the Doppler frequency signals with the fixed-phase relationship, for determining which of the Doppler frequency signals with the fixed-phase relationship is leading and which is lagging to indicate the direction of motion of the object relative to the antenna; range decoder means responsive to the Doppler frequency signals with the variable-phase relationship, for determining the phase difference between the Doppler frequency signals with the variable-phase relationship; and means, responsive to the direction of motion indication from the direction decoder means and the phase difference from said range decoder means, for determining the range of the target from said antenna.