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IEEE Transactions on Antennas and Propagation
Volume 47 Number 12, December 1999

Table of Contents for this issue

Complete paper in PDF format

Patch Antennas on Externally Perforated High Dielectric Constant Substrates

Joseph S. Colburn, Member, IEEE, and Yahya Rahmat-Samii, Fellow, IEEE

Page 1785.

Abstract:

Smaller physical size and wider bandwidth are two antenna engineering goals of great interest in the wireless world. To this end, the concept of external substrate perforation is applied to patch antennas in this paper. The goal was to overcome the undesirable features of thick and high dielectric constant substrates for patch antennas without sacrificing any of the desired features, namely, small element size and bandwidth. The idea is to use substrate perforation exterior to the patch to lower the effective dielectric constant of the substrate surrounding the patch. This change in the effective dielectric constant has been observed to help mitigate the unwanted interference pattern of edge diffraction/scattering and leaky waves. The numerical data presented in this paper were generated using the finite-difference time-domain (FDTD) technique. Using this numerical method, a patch antenna was simulated on finite-sized ground planes of two different substrate thicknesses, with and without external substrate perforation. The computations showed the directivity drop in the radiation pattern caused by substrate propagation was noticeably improved by introducing the substrate perforation external to the patch for the case of a patch antenna on a relatively thick substrate without any loss of bandwidth. Measurements of a few patch antennas fabricated on high dielectric constant substrates with and without substrate perforation are included for completness. Good correlation between the computed results and mesurements is observed.

References

  1. R. Coccioli, W. R. Deal, and T. Itoh, "Radiation characteristics of a patch antenna on a thin PBG substrate," in 1998 IEEE AP-S Dig., Atlanta, GA, June 1998, pp. 656-659.
  2. P. K. Kelly, M. Picket-May, I. Rumsey, and A. Bhobe, "Microstrip patch antenna performance on a photonic bandgap substrate," in 1998 USNC/URSI Nat. Radio Sci. Meet. Dig., Atlanta, GA, June 1998, p. 5.
  3. K. Agi, K. J. Malloy, E. Schamiloglu, and M. Mojahedi, "Compact microstrip patch on photonic crystal substrates," in 1998 USNC/URSI Nat. Radio Sci. Meet. Dig., Atlanta, GA, June 1998, p. 119.
  4. D. R. Jackson and J. T. Williams, and A. K. Bhattacharyya, "Microstrip patch designs that do not excite surface waves," IEEE Trans. Antennas Propagat., vol. 41, pp. 1026-1037, Aug. 1993.
  5. M. J. Vaughan, K. Y. Hur, and R. C. Compton, "Improvements of microstrip patch antenna radiation patterns," IEEE Trans. Antennas Propagat., vol. 42, pp. 882-885, June 1994.
  6. M. Stotz, G. Gottwald, and H. Haspeklo, "Planar millimeter wave antennas using SiNx-membranes on GaAs," IEEE Trans. Microwave Theory Tech., vol. 44, pp. 1593-1596, Sept. 1996.
  7. J. B. Muldavin, T. J. Ellis, and G. M. Rebeiz, "Taper slot antennas on thick dielectric substrates using micromachining techniques," in 1997 IEEE AP-S Dig., Montreal, Canada, July 1997, pp. 1110-1113.
  8. G. P. Gauthier, A. Courtay, and G. H. Rebeiz, "Microstrip antennas on synthesized low dielectric-constant substrate," IEEE Trans. Antennas Propagat., vol. 45, pp. 1310-1314, Aug. 1997.
  9. J. S. Colburn and Y. Rahmat-Samii, "Printed antenna pattern improvement through substrate perforation of high dielectric constant material: An FDTD evaluation," Microwave Opt. Technol. Lett., vol. 18, p. 1, May 1998.
  10. J. B. Birks and J. H. Schulman, Progress in Dielectrics.New York: Wiley, 1960, p. 2.
  11. M. A. Jensen and Y. Rahmat-Samii, "Performance analysis of antennas for hand-held transceivers using FDTD," IEEE Trans. Antennas Propagat., vol. 42, no. 8, pp. 1106-1113, Aug. 1994.
  12. R. F. Harrington, Time-Harmonic Electromagnetic Fields.New York: McGraw-Hill, 1961.
  13. J. Huang, "The finite ground plane effect on the microstrip antenna radiation patterns," IEEE Trans. Antennas Propagat., vol. AP-31, pp. 649-653, July 1983.
  14. S. Maci, L. Borselli, and L. Rossi, "Diffraction at the edge of a truncated grounded dielectric slab," IEEE Trans. Antennas Propagat., June 1996, vol. 44, pp. 863-873.
  15. D. H. Schaubert and K. S. Yngvesson, "Experimental study of a microstrip array on high permittivity substrate," IEEE Trans. Antennas Propagat., vol. AP-34, pp. 92-97, Jan. 1986.
  16. M. F. Otero and R.G. Rojas, "Analysis and treatment of edge effects on the radiation pattern of a microstrip patch antenna," in 1995 IEEE AP-S Dig., Newport Beach, CA, June 1995, p. 1050.