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IEICE Transactions. 01/2012; 95-C:16-26.
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IEICE Transactions. 01/2011; 94-C:10-17.
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IEICE Transactions. 01/2009; 92-C:25-32.
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IEICE Transactions. 01/2009; 92-C:46-54.
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ABSTRACT: In this paper it derived the asymptotic solution for the ground wave propagation over the land-to-sea mixed-path by applying the aperture field method and the high-frequency technique. The validity of the asymptotic solution has been confirmed by comparing with the reference solution calculated numerically, the conventional mixed-path theory, and the experimental results. Also confirmed both theoretically and experimentally is the recovery effect of the electromagnetic field appeared on the portion of the sea over the land-to-sea mixed-path propagation.
Antennas and Propagation Society International Symposium, 2008. AP-S 2008. IEEE; 08/2008
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ABSTRACT: In this paper, we have derived the new solution for the medium-frequency and the high-frequency ground wave propagation in a surface duct over mixed-paths. We have shown newly that the solution for the ground wave propagation in a standard atmosphere can be obtained directly from the solution for the surface duct problem by applying the analytic continuation from the negative equivalent radius of curvature of the earth to the positive one. Through the theoretical and experimental studies, it is confirmed that the radio wave propagating over the sea in the land-to-sea mixed-paths is enhanced by the recovery effect. It is clarified that the ground wave is also enhanced in the surface duct in a long range propagation. It is shown that the unexpected attenuation and the anomalous variation with distance are appeared in the propagation in the urban area due to the emergence of the slow-wave type trapped surface wave.
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ABSTRACT: When a cylindrically curved concave conducting surface is terminated abruptly at the edge, the whispering gallery (WG) mode propagating toward the edge direction is radiated into the free space from the aperture plane at the edge. In this paper, by applying the new analysis method, we shall derive a uniform geometrical theory of diffraction solution (UTD) for the electric-type WG mode radiation field applicable in the transition region near the geometrical boundaries produced by the incident modal ray on the edge of the curved surface. The UTD is represented by the summation of the solution for the geometrical ray converted from the modal ray of the WG mode and the solution for the uniform edge diffracted ray scattered at the cylindrically curved edge. By comparing with the reference solution obtained numerically from the integral representation of the radiation field, we will confirm the validity and the utility of the UTD proposed in this paper.
