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. 18, 1990
Filed:
Jun. 29, 1989
Roland Allezard, Verrieres le Buisson, FR;
U.S. Philips Corporation, New York, NY (US);
Abstract
The radar system of the FM/CW type transmits a wave which has a virtually linear frequency, between two frequencies f.sub.1 and f.sub.2 and supplies a first beat signal (Fb.sub.1) between transmitted and received waves; it is suitable for measuring the altitude h by measuring the overall phase rotation. According to the invention the radar supplies a second beat signal (Fb.sub.2) in quadrature with the first signal; the signals Fb.sub.1 and Fb.sub.2 are digitized (23 to 26) and comparing means (36) compare the consecutive samples of Fb.sub.1 and Fb.sub.2, then calculating means (37) derive therefrom by means of successive increments/decrements the number of zero crossings of the phase plane in a predetermined direction minus the number of zero crossings in the opposite direction (result m). The calculated altitude h is proportional to m.