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IEEE Transactions on Antennas and Propagation
Volume 48 Number 6, June 2000

Table of Contents for this issue

Complete paper in PDF format

Design of a Vehicular Antenna for GPS/IRIDIUM Using a Genetic Algorithm

Edward E. Altshuler Life Fellow, IEEE

Page 968.

Abstract:

In this paper, we describe a vehicular wire antenna, designed using a genetic algorithm that may be used for both the GPS and IRIDIUM systems. It has right-hand circular polarization, near hemispherical coverage, and operates over the frequency band from 1225 to 1625 MHz. This antenna was simulated using the Numerical Electromagnetics Code (NEC) and then fabricated and tested. The antenna consists of five copper tubing segments connected in series, has an unusually odd shape, and is very inexpensive. It fits in a volume approximately 10 cm × 10 cm × 15 cm. The input voltage standing wave ratio (VSWR) and circular polarization radiation patterns were computed and measured. The VSWR was under 2.2 at the design frequencies of 1225, 1575, and 1625 MHz. The gain varied by less than 12 dB for a 170° sector; it generally fell off near the horizon so the variation was less for 150 ° and 160° sectors. This new design process, which uses a genetic algorithm in conjunction with an electromagnetics code, produces configurations that are unique and seem to outperform more conventional designs.

References

  1. N. Padros, J. I. Ortigosa, J. Baker, M. F. Iskander and B. Thornberg, "Comparative study of high-performance GPS receiving antenna designs", IEEE Trans. Antennas Propagat., vol. 45, pp.  698-705,  Apr.  1997.
  2. Y. Rahmat-Samii and E. Michielssen, Electromagnetic Optimization by Genetic Algorithms, New York: Wiley, 1999.
  3. D. S. Linden, "Using a real-valued chromosome in a genetic algorithm for wire antenna optimization", in 1997 IEEE AP-S Int. Symp., Montreal, Canada,July 1997.
  4. G. J. Burke and A. J. Poffio, "Numerical Electromagnetics Code (NEC)-Method of Moments", Lawrence Livermore Lab., CA, Rep. UCID18834, Jan. 1981.
  5. D. S. Linden and E. E. Altshuler, "Automating wire antenna design using genetic algorithms", Microwave J., vol. 39, pp.  74-86, Mar.  1996.
  6. E. E. Altshuler and D. S. Linden, "Process for the Design of Antennas Using Genetic Algorithms", U.S. Patent 5 719 794, Feb.  1998.
  7. D. S. Linden, "Automated design and optimization of wire antennas using genetic algorithms", Massachusetts Inst. Technol. Ph.D. dissertation, Cambridge, MA, Sept. 1997.