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. 04, 2001
Filed:
Jan. 28, 2000
Monty W. Bai, Scottsdale, AZ (US);
Keith A. Kingston, Mesa, AZ (US);
Hugh R. Malone, Phoenix, AZ (US);
John G. Doggett, Jr., Chandler, AZ (US);
Ronald P. Vidano, Scottsdale, AZ (US);
Earl R. Yingling, Chandler, AZ (US);
Motorola, Inc., Schaumburg, IL (US);
Abstract
The present invention provides two approaches for eliminating a keyhole problem associated with an azimuth-elevation gimbal antenna which is a problem that occurs when the antennae is tracking a satellite vehicle that is substantially directly overhead, i.e., the satellite vehicle is near the zenith position. At such a point, the azimuth motor of the gimbal antenna must turn very rapidly when the satellite passes through such near zenith position. A first approach involves tilting up one of the elevation axis joints when the antenna points at or near its zenith position such that the pointing angle may be altered by a predetermined angle, for example around 0.5° to 1°, from the zenith position. A second approach involves tilting the secondary reflector of the cassegrain antenna such that the pointing direction of the antenna may be altered by a predetermined angle.