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. 02, 1992
Filed:
Mar. 29, 1991
Eugene C Ngai, Northboro, MA (US);
Carlo J Mistretta, Maynard, MA (US);
Luther E Rhoades, Stow, MA (US);
Joseph B Sangiolo, Weston, MA (US);
Reuven Shavit, Acton, MA (US);
Electronic Space Systems Corporation, Concord, MA (US);
Abstract
A method and apparatus are provided performing near-field measurements on dish antenna, in particular large dish antenna, and for utilizing these measurements to realign dish panels. The antenna is tiltable about a pivot point on a mounting pedestal to any desired elevation angle. A substantially circular track is provided which is centered at and spaced a predetermined distance from the pivot point, the track preferably being adjustably mounted to a stiff circular arch. The antenna is rotatable in the azimuth direction, preferably by rotating the pedestal, and a scanning probe is provided which is mounted for control traversal on the circular track. The probe is utilized to perform near-field measurements on the antenna at selected azimuthal positions of the antenna and selected positions of the probe on the track. The probe may also be rotatable to at least two different polarizations. The movement are performed in small stepwise increments in a predetermined sequence and measurements are taken by utilizing an RF signal transmitted by the antenna or probe and received by the other. For panel realignment, the near-field measurements are transformed mathematically to far-field values which are in turn transformed mathematically to holographic pictures which provide an indication of panel misalignment. This indication is then used to realign appropriate panels and the process repeated until panel alignments are within acceptable limits.