Advertisement

Fast Beamforming Processor

  • D. A. Gaubatz

Abstract

A beam former implementation is described which combines the computational efficiency of a Fast Fourier Transform algorithm with the speed and economy of analog signal processing hardware. The fast transform algorithm enables a single processor module to provide 32 simultaneous beams when used with a line array of 32 equidistantly-spaced transducers. The signal processing required to implement this function is the equivalent of performing, in real-time, a 32 point Fast Fourier Transform on 32 continuous 100 kilohertz input signals, 100 kilohertz being the isonifier frequency. The fast analog transform technique allows this amount of processing to be performed on a single circuit board, whereas a digital implementation would require a great number of high speed calculations. The operational amplifier circuit configurations which perform the multiplications and summations, and the algorithm characteristics which facilitate analog implementation, are described. The use of multiple Fast Beamforming Processor modules for the real-time generation of two-dimensional ime.és is also discussed.

Keywords

Fast Fourier Transform Algorithm Signal Flow Graph Line Array Transducer Output Analog Circuitry 
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.

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References

  1. 1.
    H. F. Harmuth, J. Kama1, S. S. R. Murthy, “Two-Dimensional Spatial Hardware Filters for Acoustic Imaging,” Applications of Walsh Functions and Sequency Theory, H. Schreiber and G. F. Sandy, ed., IEEE, New York, 1974, pp. 94–125.Google Scholar
  2. 2.
    G. Ramos, -“Analog Computation of the Fast Fourier Transform,” IEEE Proceedings Vol. 58, No. 11, Nov. 1970, pp. 1861–1863.Google Scholar
  3. 3.
    J. W. Cooley, J. W. Tukey, “An Algorithm for the Machine Calculation of Complex Fourier Series,” Mathematics of Computation, Vol. 19, No. 90, Apr. 1965, Pp- 297–301.Google Scholar
  4. 4.
    G. D. Bergland, “A Fast Fourier Transform Algorithm for R-,1Valued,Series,” Communications of the ACM, Vol. 11, No. 1.05 Oct. 1968, pp. 703–710.Google Scholar
  5. 5.
    R. G. Kostar - “Doubling Op Amr, Summint; Power,” Electronic’, Vol. 45, Nc. 4, Feb. 14, 1972, pp. 73Google Scholar
  6. 6.
    L. Wisseman, J J. Robertson, “High Fel-formance Integrated Operational Amplifiers,” Motorola Sem’_conductor Products, Inc. Application Note, AN-201t, Phoenix, 1968.Google Scholar
  7. 7.
    H. F. Harmuth, “Generation of Images by Means of Two-Dimensional Spatial Hardware Filters,” Advances in Electronics and Electron Physics, Vol. 40, Academic Press, New York, 1976, pp. 167–248.Google Scholar
  8. 8.
    D. A. Gaubatz, “FFT-Based Analog Beamforming Processor,” 1976 Ultrasonics Symposium rro L:ings, Annapolis, Maryland, Se/t. 29-Oct. 1, 1976.Google Scholar

Copyright information

© Springer Science+Business Media New York 1977

Authors and Affiliations

  • D. A. Gaubatz
    • 1
  1. 1.Electrical Engineering DepartmentThe Catholic University of AmericaUSA

Personalised recommendations