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:
Apr. 25, 1995
Filed:
Mar. 31, 1994
William M Waters, Millersville, MD (US);
The United States of America as represented by the Secretary of the Navy, Washington, DC (US);
Abstract
A phase shifter for shifting the phase of directly sampled bandpass signals ithout having to convert to complex (I,Q) form is disclosed. An application requiring a plurality of appropriately phase shifted signals is a phased array antenna. In the operation of an exemplary phase shifter, a sequence of directly sampled data is passed into an exemplary three-stage storage unit to sequentially store r.sub.n+1, r.sub.n and r.sub.n-1 data samples. The r.sub.n sample is multiplied by cos .phi. to develop an r.sub.n cos .phi. signal, where .phi. is the desired phase shift angle. At the same time, the r.sub.n+1 and r.sub.n-1 data samples are subtracted from each other and the result is multiplied by w.sub.1 sin .phi. to develop the value w.sub.1 (r.sub.n+1 -r.sub.n-1)sin .phi.. This value is added to r.sub.n cos .phi. to produce an estimated sample value r.sub.n ', which is approximately equivalent to data directly sampled from a signal phase-shifted by .phi..