DocumentCode :
1040389
Title :
Creeping waves for objects of finite conductivity
Author :
Franz, W. ; Beckmann, P.
Author_Institution :
Munster Univ., Germany
Volume :
4
Issue :
3
fYear :
1956
fDate :
7/1/1956 12:00:00 AM
Firstpage :
203
Lastpage :
208
Abstract :
It is shown that it is not necessary to apply the van der Pol-Bremmer expansion in order to obtain the Watson residue series without remainder integral. There appear two kinds of residual waves. Those of the first kind do not enter the object and correspond to the usual creeping waves for objects of infinite conductivity. They arise from poles in the vicinity of the zeros of H\\upsilon (ka) . Residual waves of the second kind correspond to waves transversing the object and arise from poles in the vicinity of the zeros of J\\upsilon (nka) . They are of no importance in the case of strongly absorbing materials. Waves which are expected according to geometrical optics are obtained-as in the case of infinite conductivity-by splitting off an integral. Primary and reflected waves arise from two different saddle points of the same integrand which was thought of till now as only yielding the reflected waves. On the other hand the terms corresponding to the ingoing part of the primary wave give no contribution at all, but must be kept in order to assure the convergence of the integrals when shifting the path of integration.
Keywords :
Bessel series/transforms; Cylinders; Electromagnetic diffraction; Electromagnetic scattering by absorbing media; Green´s functions; Boundary conditions; Conducting materials; Conductivity; Convergence; Diffraction; Geometrical optics; H infinity control; Optical materials; Optical refraction; Poles and zeros;
fLanguage :
English
Journal_Title :
Antennas and Propagation, IRE Transactions on
Publisher :
ieee
ISSN :
0096-1973
Type :
jour
DOI :
10.1109/TAP.1956.1144413
Filename :
1144413
Link To Document :
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