Digitally synthesized phased antenna for multibeam global positioning

US6828935B1 · kind B1 · utility

Assignee

• The United States of America as represented by the Administrator of the National Aeronautics and Space Administration · US

Inventors

• Charles Dunn · Boylston, US
• Lawrence E. Young · Tustin, US

Key dates

• Filing date: Jul 19, 2002
• Grant date: Dec 7, 2004
• Expiry date: Jun 6, 2023

Classification

• Technology area (CPC H): Electricity
• CPC primary: H01Q3/26
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

In a system according to the proposed technique (see figure), the signal received by each element of the array antenna would be subjected to downconversion, and spread-spectrum demodulation and correlation as necessary; this processing would be performed separately from, and simultaneously with, similar processing of signals received by the other antenna elements. For the GPS implementation, following downconversion to baseband, the signals would be digitized, and all subsequent processing would be digital. In the digital process, residual carriers would be removed and each signal would be correlated with a locally generated model pseudo random-noise code, all following normal GPS procedure. As part of this procedure, accumulated values would be added in software and the resulting signals would be phase-shifted in software by the amounts necessary to synthesize the desired antenna directional gain pattern of peaks and nulls. The principal advantage of this technique over the conventional radio-frequency-combining technique is that the parallel digital baseband processing of the signals from the various antenna elements would be a relatively inexpensive and flexible means for exploi…