Analysis of frequency selective surface with gridded square element using accurate integral equation technique is considered in this paper. An improved subsectional current approximation model is proposed. Two more terms of basis function, the downward half triangle (DHT) term and the upward half triangle (UHT) term, besides the commonly adopted rooftop function, are included to expand the induced current. The additional terms are used to account for the effect of the induced currents at the corners of the outer square of the unit cell. Green's functions are derived by using spectral domain immittance approach and the incident fields are derived by using the z-directed potential. The computed results are in good agreement with the measured results.
2. Vardaxoglou, J. C., Frequency Selective Surfaces: Analysis and Design, Wiley, New York, 1997.
3. Tsao, C. H., "Spectral-domain approach for analyzing scattering from frequency selective surface,", Ph.D. dissertation, University of Illinois at Urbana-Champaign, 1981.
4. Chan, C. H., "Investigation of iterative and spectral Galerkin techniques for solving electromagnetic boundary value problems,", Ph.D. dissertation, University of Illinois at Urbana-Champaign, 1987.
5. Lee, C. K., "Modeling and design of frequency selective surfaces for reflector antennas,", Ph.D. dissertation, Kent University, 1987.
6. Mittra, R., C. H. Chan, and T. Cwik, "Techniques for analyzing frequency selective surfaces-a review," Proc. IEEE, Vol. 76, No. 12, 1593-1615, 1988.
7. Chen, C. C., "Transmission through a conducting screen perforated periodically with apertures," IEEE Trans. Microwave Theory Tech., Vol. 18, No. 9, 627-632, 1970.
8. Lee, S. W., "Scattering by dielectric-loaded screen," IEEE Trans. Antennas Propagat., Vol. 19, No. 5, 656-665, 1971.
9. Luebbers, R. J. and B. A. Munk, "Some effects of dielectric loading on periodic slot arrays," IEEE Trans. Antennas Propagat., Vol. 26, No. 4, 536-542, 1978.
10. Rubin, B. J. and H. L. Bertoni, "Reflection from a periodically perforated plane using a subsectional current approximation," IEEE Trans. Antennas Propagat., Vol. 31, No. 6, 829-836, 1983.
11. Lee, C. K. and R. J. Langley, "Equivalent circuit models for frequency selective surfaces at oblique angle of incidence," IEE Proc. Microwaves, Antennas, Propagat., Vol. 132, No. 6, 395-398, 1985.
12. Cwik, T. A. and R. Mittra, "Scattering from a periodic array of free-standing arbitrarily shaped perfectly conducting or resistive patches," IEEE Trans. Antennas Propagat., Vol. 35, No. 11, 1226-1234, 1987.
13. Cwik, T. and R. Mittra, "The cascade connection of planar periodic surfaces and lossy dielectric layers to form an arbitrary periodic screen," IEEE Trans. Antennas Propagat., Vol. 35, No. 12, 1397-1405, 1987.
14. Chan, C. H. and R. Mittra, "On the analysis of frequencyselective surfaces using subdomain basis functions," IEEE Trans. Antennas Propagat., Vol. 38, No. 1, 40-50, 1990.
15. Styllanou, A., P. Debono, and J. C. Vardaxoglou, "Iterative computation of current and field distributions in multilayer frequency selective surfaces," IEE Proc. Microwaves, Antennas, Propagat., Vol. 139, No. 6, 535-541, 1992.
16. Prescott, D. T. and N. V. Shuley, "A technique for analyzing frequency selective surfaces using the finite-difference time-domain method," 1994 IEEE Int. Antennas Propagat. Symp. Dig., 2152-2155, 1994.
17. Roden, J. A., et al., "Time-domain analysis of periodic structures at oblique incidence: orthogonal and nonorthogonal FDTD implementations," IEEE Trans. Microwave Theory Tech., Vol. 46, No. 4, 420-427, 1998.
18. Glisson, A. W. and D. R. Wilton, "Simple and efficient numerical methods for problems of electromagnetic radiation and scattering from surfaces," IEEE Trans. Antennas Propagat., Vol. 28, No. 5, 593-603, 1980.
19. Harrington, R. F., Field Computation by Moment Methods, IEEE Press, New York, 1993.
20. Ishimaru, A., Electromagnetic Wave Propagation, Radiation, and Scattering, Prentice-Hall, Englewood Cliffs, NJ, 1991.
21. Itoh, T., "Spectral domain immittance approach for dispersion characteristics of generalized printed transmission lines," IEEE Trans. Microwave Theory Tech., Vol. 28, No. 7, 733-736, 1980.
22. Das, N. K. and D. M. Pozar, "A generalized spectral-domain Green’s function for multilayer dielectric substrate with application to multilayer transmission lines," IEEE Trans. Microwave Theory Tech., Vol. 35, No. 3, 326-335, 1987.
23. Cheng, D. K., Field and Wave Electromagnetics, Addison- Wesley, 1983.