Two-Dimensional Narrow-Waisted Gaussian Beam Analysis of Pulsed Propagation from Extended Planar One-Dimensional Aperture Field Distributions Through Planar Dielectric Layers
Propagation of electromagnetic (EM) wavefields in the presence of layered dielectric media is a problem of long-standing interest, with applications to antenna radome design, guided propagation, etc. For this class of problems, most available analytic (rigorous and approximate) approaches are in the frequency domain (FD).1,2 With a few exceptions,3, 4, 5, 6, 7 time domain (TD) analysis is typically pursued via inversion from the FD. However, advances in ultra-wideband technology and the consequent more frequent use of spacetime highly localized signals in communication and sensing systems motivate direct time domain (TD) analysis and processing, which is better matched to the short-pulse wave phenomenology and can therefore be expected to yield better numerical efficiency as well as deeper physical insight. These considerations have led to our investigation of a direct TD formulation of a previously developed FD Gabor-based narrow-waisted (NW) quasiray Gaussian beam (GB) algorithm for propagation of aperture-excited wave fields through planar dielectric layers. This approach is based on a NW-GB discretized decomposition of the aperture field distribution on the Gabor lattice and permits efficient quasi-real complex ray tracing (via the complex source point (CSP) method) of the thereby excited individual basis beams through the environment, with eventual recombination to synthesize the total field at the observer. In the FD, this approach has been applied successfully to propagation through arbitrarily shaped dielectric layers, for both two-dimensional (2-D) fields radiated by 1-D aperture distributions,8,9 and 3-D fields radiated by 2-D aperture distributions.10 Accurate predictions over calibrated parameter ranges have been obtained with modest computational effort. Basically, when dealing with electrically large domains, the NW-GB scheme preserves the favorable computational features of standard ray-optical techniques, without failing in typical rayfield transition regions.
KeywordsDielectric Layer Gaussian Beam Pulse Beam Aperture Distribution Short Pulse Radiation
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- 1.L.B. Felsen and N. Marcuvitz, Radiation and Scattering of Waves (Prentice Hall, Englewood Cliffs, 1973; Classic reissue, IEEE Press, Piscataway, 1994).Google Scholar
- 2.L.M. Brckhovskikh, Waves in Layered Media (Academic Press, New York, 1980).Google Scholar
- 10.J.J. Maciel and L.B. Felsen, Gabor-based narrow-waisted Gaussian beam algorithm for transmission of aperture-cxcitcd 3D vector fields through arbitrarily shaped 3D dielectric layers, to be published in Radio Sci., 38(2) (2002).Google Scholar
- 12.V. Galdi and L.B. Felsen, Two-dimensional pulsed propagation from extended aperture field distributions through planar dielectric layers via quasi-ray Gaussian beams, to be published in IEEE Trans. Antennas and Propagat., 51(6) (2003).Google Scholar
- 13.W.D. Wang and G.A. Deschamps, Application of complex ray tracing to scattering problems, Proc. IEEE 62(11), 7541–7551 (1974).Google Scholar