Fiber lattice accumulator design considerations for opitcal [sigma-delta] digital antennas
By:  Scott A. Bewley
Publisher: Naval Postgraduate School; Available from National Technical Information Service
Published: 1998
Place of publication: Monterey, Calif; Springfield, Va
Language: eng
Number of pages: 59
Description: 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 recirculated/delayed 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.
Notes: "December 1998."

Thesis advisor(s): Phillip E. Pace, James H. Luscombe.

Thesis (M.S. in Applied Physics) Naval Postgraduate School, December 1998.

Includes bibliographical references (p. 57).

Approved for public release; distribution unlimited.

Also available online.

Mode of access: World Wide Web.

System requirements: Adobe Acrobat Reader.

US Navy (USN) author.

dk/dk cc:9116 02/18/99.