Charles P Rader

US Patent:

49723618, Nov 20, 1990

Filed:

May 13, 1988

Appl. No.:

7/193813

Inventors:

Charles M. Rader - Concord MA

Assignee:

Massachusetts Institute of Technology - Cambridge MA

International Classification:

G06F 1532

US Classification:

364736

Abstract:

Circuit for computing values of the elements of a triangular matrix, where ##EQU1## similar subcircuits provide CORDIC processing and memory, the subcircuits connected in a folded systolic array, the first subcircuit providing input capability to the array for receiving complex data containing N words, and the output of the last subcircuit coupled to its own input. The circuit may be used to process observation vector data taken from an antenna system of N elements to provide an output useful in determining weights for nulling out the observation data from a larger signal.

US Patent:

47945567, Dec 27, 1988

Filed:

Sep 19, 1984

Appl. No.:

6/652297

Inventors:

Charles M. Rader - Concord MA

Assignee:

Massachusetts Institute of Technology - Cambridge MA

International Classification:

G06F 738

US Classification:

36472417

Abstract:

In-phase and quadrature components of a waveform are generated by sampling the waveform at a rate of four times the center frequency of the frequency band for which components are generated. The samples are digitized and applied to a digital 90. degree. all-pass phase-splitting network. Each pair of output samples is generated as a function of input samples delayed by an even number of time instants through a first all-pass branch and delayed by an odd number of time instants through a second all-pass branch. A common network may form both branches by switching coefficients of a multiplier and alternating the output between in-phase and quadrature samples. The waveform may be shifted from a higher freqeuncy by a mixer and may be filtered prior to sampling.