Phase-only Beam Broadening in Large Transmit Arrays Using Complex-Weight Gradient Descent

Abstract

Day recently obtained phase-only element weights for a large transmit array of arbitrary geometry by optimizing complex weights using an objective function that penalized amplitude variation. He used gradient descent modified with a classic SVD technique to create point and sector nulls as desired. Here Day's approach is extended to allow for main-beam broadening as might be needed to illuminate multiple receive beams. This is done by adding a second objective term, one penalizing variation in array-factor amplitude across a grid of beamspace points covering the desired broad main-beam. The tension between the two objective terms turns out to be challenging to manage, and at this preliminary stage of algorithm development, parameter scheduling across a sequence of stages of the optimization is required to obtain good solutions.

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Document Details

Document Type
Technical Report
Publication Date
Apr 15, 2014
Accession Number
ADA603307

Entities

People

  • Jeffrey O. Coleman
  • W. Mark Dorsey

Organizations

  • United States Naval Research Laboratory

Tags

Communities of Interest

  • Air Platforms
  • Energy and Power Technologies

DTIC Thesaurus Topics

  • Abstracts
  • Algorithms
  • Amplitude
  • Arrays
  • Bessel Functions
  • Boresights
  • Convergence
  • Convex Programming
  • Department Of Defense
  • Geometry
  • Illumination
  • Iterations
  • Military Research
  • Optimization
  • Pencil Beams
  • Radar
  • Signal Processing

Fields of Study

  • Physics

Readers

  • Operations Research
  • Phased Array Antenna Design.