Accession Number:

ADA459859

Title:

Delta-Sigma UHF Digital Waveform Generator

Descriptive Note:

Interim rept.

Corporate Author:

NAVAL RESEARCH LAB WASHINGTON DC RADAR DIV

Report Date:

2006-09-26

Pagination or Media Count:

19.0

Abstract:

The Naval Research Laboratory NRL has developed and built a prototype UHF Digital Waveform Generator DWG based on the Delta-Sigma algorithm, which allows arbitrary waveform generation. It provides predicted low phase and spurious noise. Much of the design uses field programmable gate arrays FPGAs for single-bit digital waveform generation. Four filter topologies were initially considered, including cascade, hybrid, parallel, and transposed. The cascade and parallel forms were eliminated because they imposed a heavy computational burden on the system. After analyzing the transposed topology, quantization error in higher-order filters led to the selection of the hybrid form of the digital filter because it performed well. A 12th order hybrid filter was selected and implemented using FPGAs. The NRL Development demonstrates that a simple-to-code single-bit Delta-Sigma DWG can cost-effectively provide the same resolution as a 16-bit or greater digital-to-analog converter DAC DWG. These results provide the promise of low-cost diverse waveform generation capability in future high-performance Navy radar systems.

Subject Categories:

  • Radiofrequency Wave Propagation
  • Active and Passive Radar Detection and Equipment

Distribution Statement:

APPROVED FOR PUBLIC RELEASE