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Properties of Ultrawideband Arrays

  • Jodi Lisa Schwartz
  • Bernard D. Steinberg

Abstract

Highly thinning the elements required in a filled λ / 2-element spaced array can greatly reduce the quantity of electronics in the array and the data-handling requirements of an imaging system for a fixed number of array channels, greatly enlarge the aperture, and correspondingly improve its resolving power. The cost is a dramatic decrease in dynamic range. The resulting sparse array generally leaves the shapes of the main lobe and near-in sidelobes intact, but the loss in absolute gain implies that main lobe energy has been redistributed into the side radiation region. In conventional narrowband arrays, periodic thinning produces grating lobes of similar shape and strength to the main lobe. Aperiodic thinning destroys the coherent sidelobe buildup in the grating lobes but not the grating lobe energy, which becomes distributed throughout the visible region in a manner determined by the particular thinning procedure. It is common knowledge that sidelobe statistics are similar for a wide variety of thinning procedures, both deterministic and random, with a few notable exceptions1. Thus many proposed designs for high resolution two-dimensional arrays are based upon a random distribution of elements2.

Keywords

Periodic Array Main Lobe Dimensional Array Random Array Maximum Projection 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

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References

  1. 1.
    B.D. Steinberg Principles of Aperture and Array System Design: Including Random and Adaptive Arrays, John Wiley and Sons, Inc., New York, (1976).Google Scholar
  2. 2.
    D.H. Turnbull, P.K. Lum, A.T. Kerr, and F. S. Foster, “Simulation of B-Scan Images from Two-Dimensional Transducer Arrays: Part I: Methods and Quantitative Contrast Measurements, ” Ultrasonic Imaging, 14, pp. 323–343 (1992).Google Scholar
  3. 3.
    F. Anderson, Fullerton, L., Christensen, W., and B. Kortegaard, “Wideband Beam Patterns for Sparse Arrays,” Ultra-Wideband Radar: Proceedings of the First Los Alamos Symposium, (1991).Google Scholar

Copyright information

© Springer Science+Business Media New York 1997

Authors and Affiliations

  • Jodi Lisa Schwartz
    • 1
  • Bernard D. Steinberg
    • 1
  1. 1.University of PennsylvaniaPhiladelphiaUSA

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