Accession Number : AD0634150

Title :   SCATTERING OF A SURFACE WAVE FROM AN ABRUPT CHANGE IN THICKNESS ON A DIELECTRIC SLAB.

Descriptive Note : Interim scientific rept. (Technical),

Corporate Author : WASHINGTON UNIV SEATTLE DEPT OF ELECTRICAL ENGINEERING

Personal Author(s) : Cooley, William W. ; Ishimaru,Akira

Report Date : MAR 1966

Pagination or Media Count : 66

Abstract : Surface wave scattering is of interest in antenna design and radio propagation. This report obtains an approximate solution for the scattering of a TM surface wave from a step change in thickness on a ground dielectric slab, a problem which can not be solved exactly. The solution is developed from a new integral formula by a technique similar to the Born approximation. An integral formula is developed by applying the divergence theorem to two different problems which are related to the original, but because of their geometry are simpler to solve. This integral formula is then specialized to the two dimensional case for both TE and TM polarizations. The Scattering of a TM surface wave from a step change in thickness on a grounded dielectric slab is determined from an approximate solution of the integral formula. The approximation made is similar to the Born approximation, but different in that two known solutions are used rather than one. Radiation patterns and the total fraction of incident power scattered are calculated for both of the possible directions of incident wave. An equivalent circuit description of the discontinuity is also mentioned. Results of the analysis are compared favorably with previous workers in the special case of an abruptly terminated dielectric slab. Some experimental work is included to support the theoretical development. (Author)

Descriptors :   (*ELECTROMAGNETIC RADIATION, PROPAGATION), (*DIELECTRICS, SURFACE PROPERTIES), ANTENNA RADIATION PATTERNS, WAVEGUIDES

Subject Categories : Radiofrequency Wave Propagation

Distribution Statement : APPROVED FOR PUBLIC RELEASE