Research/Patents/US 4794556
US 4794556

METHOD AND APPARATUS FOR SAMPLING IN-PHASE AND QUADRATURE COMPONENTS

Assignee

MASSACHUSETTS INSTITUTE OF TECHNOLOGY, A CORP. OF MA

Filed

Sep 19, 1984

Granted

Dec 27, 1988

Location

Cambridge MA (Draper Lab/MIT)

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° 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.

Source: Google Patents

35 USC §181 Secrecy Order

Imposed

Feb 22, 1985

Rescinded

Jun 17, 1985

Duration

3 months

Inventor

  • 1CHARLES M. RADER

Sensitive facility: Cambridge MA (Draper Lab/MIT)

Back to patent indexSource: USPTO 35 USC §181 secrecy order records