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:
Nov. 25, 1997
Filed:
Mar. 25, 1996
Allan Charles Goetz, La Jolla, CA (US);
Robert Gene Riddle, II, San Diego, CA (US);
TRW Inc., Redondo Beach, CA (US);
Abstract
A technique for compensating for bias errors that are inevitably introduced in an N-port analog modeformer (14) of the Butler matrix type, used to transform antenna arm signals obtained from a cylindrically symmetrical or spiral antenna (10), to an equal number of more useful mode signals. Corrupted mode signals from the analog modeformer (14) are downshifted in frequency in a coherent receiver processor (18), converted to digital corrupted mode signals in an analog-to-digital converter (22), and then further processed in a bias error reduction processor (26) to produce output signals that are a close approximation of true, uncorrupted mode signals. The bias error reduction processor 26 uses a memory (28) to store matrix quantities obtained from measurements previously made of the analog modeformer (14), and performs an error reduction function by simple matrix manipulations of the digital corrupted mode signals and the matrix quantities stored in the memory (28). The processor (26) may perform the matrix manipulations by calculation or may make use of a look-up table for faster processing.