Optimum symmetrical number system phase sampled direction finding antenna architectures
By:  Thomas N. Hatziathanasiou
Publisher: Naval Postgraduate School; Available from National Technical Information Service
Published: 1998
Place of publication: Monterey, Calif; Springfield, Va
Language: eng
Number of pages: 194
Description: A new interferometer direction finding array architecture based on the optimum symmetrical number system      (OSNS) is presented. OSNS arrays are capable of unambiguous high-resolution direction finding with as few      as three elements, with multiple baseline options. The OSNS DF antenna architecture being investigated uses      the OSNS to decompose the analog spatial filtering operation into a number of parallel sub-operations      (moduli) that are of smaller complexity. One two-element interferometer is used for each sub-operation and      only requires a precision in accordance with its modulus. A much higher spatial resolution is achieved after the      sub-operations are recombined. By incorporating the OSNS concept, the dynamic range of a specific      configuration of antenna element spacings and comparator arrangements can be analyzed exactly. In this      thesis, the OSNS DF antenna concept was demonstrated experimentally, by designing, fabricating and      measuring the performance of a three-element array at 8.5 GHz. These three elements are grouped into two      pairs (channels) according to the set of relatively prime moduli (m1 = 6, m2 = 11). A mixer is used to      determine the phase difference between each pair of elements. The output voltage from the mixer in each      channel is a symmetrical folding waveform that is DC biased and amplified using a summing amplifier. The      output voltage of the amplifier is amplitude analyzed using a small comparator ladder. An EEPROM is used      to recombine the results of these low precision channels to yield the high resolution direction of arrival      (DOA). Simulated and experimental results are presented and compared.
Notes: "June 1998."

Thesis advisor(s): Phillip E. Pace, David D. Cleary.

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

Includes bibliographical references (p. 191-192).

Approved for public release; distribution unlimited.

Also available online.

Mode of access: World Wide Web.

System requirements: Adobe Acrobat reader.

Hellenic Air Force author.

dk/dk cc:9116 9/15/98.