| The "classical" analysis techniques for single-layer, infinite, planar, periodic frequency selective surfaces (FSS) are thoroughly reviewed. Particular emphasis is placed on practical procedures for implementing the analysis for the case of subdomain basis functions. In this presentation, the focus is placed on concepts which will provide the engineer with the tools that will enable him to properly use a numerical implementation of the FSS analysis.; The single screen FSS analysis is extended to the case of multiple screen structures using a scattering matrix cascading technique. An investigation of the scattering matrix elements, along with a guide line for computing the appropriate size of this matrix, will provide the engineer with the necessary information for using the cascading techniques. Along with the scattering matrix approach, a method, known as the image screen technique, which can be used for the special case of symmetric, two-screen FSS systems, is discussed. In addition, a new procedure for handling multilayered FSS systems composed of screens of different periodicities is developed. Again, particular emphasis is placed on providing practical information about the numerical implementation procedures.; Finally, two "advanced" topics are briefly presented. The first involves using an interpolation technique for providing an efficient calculation of the zeroth-order scattering parameters for multiple angles of incidence. This technique gives a significant amount of savings in computer time over the standard method of computation. The second "advanced" topic provides a method for accelerating the computation of the currents on a finite FSS using a new hybrid basis function technique. In both instances, the "advanced" techniques discussed represent an initial proof of concept study of the topics and require a good deal of further research and development. |
