Accession Number:

ADA359358

Title:

Fiber Lattice Accumulator Design Considerations for Optical Sigma-Delta Digital Antennas

Descriptive Note:

Master's thesis

Corporate Author:

NAVAL POSTGRADUATE SCHOOL MONTEREY CA DEPT OF PHYSICS

Personal Author(s):

Report Date:

1998-12-01

Pagination or Media Count:

69.0

Abstract:

The ability to directly oversample and digitize microwave range signals at an antenna is not possible with current electronic technologies. The objective for this thesis was to design and computer model an optical sampling and digitization process using a mode-locked laser and fiber lattice accumulators. A novel fiber lattice accumulator design for integrated optical sigma-delta digital antenna technology is presented. The fiber lattice design uses phase modulation to produce the proper interference between input and recirculateddelayed optical pulses in order that they may coherently combine. In this manner, accumulation within the fiber lattice takes into account the sign of a sampled bipolar antenna signal. The fiber lattice performance is numerically evaluated within a first-order optical sigma-delta digital antenna phase coherent simulation. The initial computer simulations show promising results using lower frequency antenna signals to verify optical design feasibility and operation. Optical results closely matched all-electronic simulations. The error between the input antenna and output signals is quantified, and proves correct device performance. All results show the first-order optical sigma-delta does work and is ready for experimental construction. The significance of this device will be its usefulness in extending high resolution sigma-delta analog-to-digital conversion into the microwave signal bands.

Subject Categories:

  • Electrical and Electronic Equipment

Distribution Statement:

APPROVED FOR PUBLIC RELEASE