Accession Number : ADD017592
Title : Phase Shifter for Directly Sampled Bandpass Signals.
Descriptive Note : Patent, Filed 31 Mar 94, patented 25 Apr 95,
Corporate Author : DEPARTMENT OF THE NAVY WASHINGTON DC
Personal Author(s) : Waters, William M
Report Date : 25 Apr 1995
Pagination or Media Count : 10
Abstract : A phase shifter for shifting the phase of directly sampled bandpass signals without 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(n+1), r(n) and r(n-1) data samples. The r(n) sample is multiplied by cos phi to develop an r(n) cos signal, where phi is the desired phase shift angle. At the same time, the r(n+1) and r(n-1) data samples are subtracted from each other and the result is multiplied by w(1) sin phi to develop the value w(1)(r(n+1)-r(n-1))sin phi. This value is added to r(n) cos phi to produce an estimated sample value r(n)', which is approximately equivalent to data directly sampled from a signal phase shifted by phi.
Descriptors : *PATENTS, *PHASE SHIFT CIRCUITS, SIGNAL PROCESSING, ANGLES, SAMPLING, ANTENNA ARRAYS, BANDPASS FILTERS, PHASED ARRAYS, PHASE SHIFT
Subject Categories : Electrical and Electronic Equipment
Distribution Statement : APPROVED FOR PUBLIC RELEASE