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:
Jul. 07, 1998
Filed:
Feb. 13, 1997
Allan C Goetz, La Jolla, CA (US);
Robert G Riddle, II, San Diego, CA (US);
TRW Inc., Redondo Beach, CA (US);
Abstract
An implementation of a Butler matrix transformation used to process antenna signals and, in particular, to transform signals obtained from an N-port antenna into mode signals used for direction finding and other purposes. A reverse transformation is used when the antenna is operating in a transmit mode. Instead of using a single Nth order transformation matrix, the circuit of the invention employs a decomposed form of the transformation matrix, thereby reducing the complexity of the transformation by using lower-order matrices. In an example of the invention for an 8.times.8 transformation, the circuit complexity is further reduced by using an additional level of decomposition, in which phase shifting is effected by a circuit implementation of a single 8.times.8 diagonal phase shift matrix requiring only three phase shift circuits. Reduction in circuit complexity, particularly in the number of phase shift circuits, reduces bias errors in the overall transformation and reduces fabrication cost.