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:
Jun. 06, 2000
Filed:
Aug. 12, 1997
Mark G Roos, Shawnee, KS (US);
AlliedSignal Inc., Morristown, NJ (US);
Abstract
In order to provide for dynamic calibration of a radio altimeter which utilizes frequency modulated continuous waves having a triangular wave form, a selected frequency output of the altimeter is compared, during a calibration interrupt of the output of the altimeter, to a predetermine value for that frequency and if it differs, the frequency is adjusted to the correct value. Each frequency in the triangular wave is individually calibrated during separate calibration mode interrupts. Specifically, each frequency is calibrated by coupling a portion of the altimeter signal to a prescaler circuit and using the prescaler circuit in combination with a modulation frequency counter to input a value representing the frequency to a control microprocessor. The microprocessor then compares this value to a desired frequency and adjusts a value in a memory that is used to control the frequency output of a voltage controlled oscillator that is used to generate the frequency modulated continuous wave.