Theoretical Methods for Determining the Interaction of Electromagnetic Waves with Structures.. Questo articolo non è disponibile.Theoretical Methods for Determining the Interaction of Electromagnetic Waves with Structures.

This volume contains almost complete proceedings of the NATO Advanced Study Institute (ASI) organised in 1979 to bring together principal innovators and numerous users of mathematical techniques for analysing the interaction of electromagnetic waves with engineering and biological structures. The mathematical disciplines which can be brought to bear on these problems necessitate examination of effectiveness, convergence and robustness of the derived analytic and num~rical algorithms. The aim of this ASI was to give a clear and up-to-date tutorial presentation of available techniques, and to bring together interested scientists, engineers and mathematiciaris, to discuss together their experience and to ensure wider familiarity with the subject. Our programme consists of three distinct yet related parts. The first two of these reflect two somewhat different methods applicable for different ranges of L/A, where L represents a characteristic dimension of a structure and A is a representative wavelength-of radiation. The third part deals with the specific problem of biological interaction. In the first part (Low and Intermediate Frequency Applications) we offer tutorial texts and user-oriented discussions on main techniques and problems concerning: radiation, scattering, aperture penetration, inverse scattering, using moment methods and their developments. The approach to the high frequency applications forms the subject of the second part of this volume, concentrating mainly on the geometrical theory of diffraction (GTD). There are three main variants of the GTD: uniform theory of diffraction (UTD), uniform asymptotic theory (liAT) , spectral theory of diffraction (STD).

I. Low and Intermediate Frequency Scattering Methods.- 1. Introduction to moment methods with simple applications.- 2. Wires and wire grid models for radiation and scattering including ground effects.- 3. Surface integral equations for conducting and dielectric bodies.- 4. Aperture problems.- 5. Natural mode methods in frequency and time domain analysis.- 6. Direct time-domain techniques for transient radiation and scattering — wires.- 7. Time domain solutions via integral equations — surfaces and composite bodies.- 8. Inverse scattering.- PANEL DISCUSSION, “Modelling of three dimensional bodies — solid patches and wire grids”.- 9. On using isoperimetric inequalities and isoperimetric quotients in electromagnetic theory and applied physics.- PANEL DISCUSSION, Comparison and evaluation of different formulations for scattering problems — integral equations, differential equation and combined methods..- PANEL DISCUSSION, Availability and limitations of general purpose computer programs.- II. High Frequency Scattering Methods and Applications.- 1. Introduction to geometrical optics.- 2. Foundations of the geometrical theory of diffraction.- 3. Canonical problems and diffraction coefficients.- 4. Uniform theories of diffraction by edges.- 5. A uniform GTD for the diffraction by edges, vertices and convex surfaces.- 6. Introduction to GTD applications.- 7. GTD applied to reflector antenna analysis.- 8. GTD applications at LCT.- 9. Transform approach to electromagnetic scattering.- 10. Some useful asymptotic and numerical techniques for solving high-frequency scattering problems.- 11. High-frequency fields excited by a line source located on a perfectly conducting concave cylindrical surface.- 12. Gaussian beams: paraxial theory.- 13. Evanescent waves.- III. Mechanisms of Biological Interaction and Microwave Bioeffects.- 1. History and state of the art on the quantitation of the interaction of electromagnetic fields with biological structures.- 2. Theoretical and numerical methods of quantitation of absorption patterns in man and animal bodies.- 3. Medical diagnosis and imaging using electromagnetic techniques.- PANEL DISCUSSION, Experimental methods of the quantitation of absorption patterns in biological tissues.- List of Lecturers and Delegates.