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Diffraction of Electromagnetic Waves by a Circular Aperture in an Infinitely Conducting Plane Screen.

AD600132

Publication Date	1964
Personal Author	Bazer, J.; Rubenfeld, L.
Page Count	0
Abstract	Attention is focused chiefly on the low frequency end of the spectrum where the product ka of the wave number k and the aperture radius a is small. Transverse electric and transverse magnetic modal excitation appropriate to the cylindrical geometry of the problem is assumed. New integral representa tions of the solution corresponding to incident fields of this kind are presented. These representations, which involve a pair of unknown functions, are designed so as to automatically satisfy Maxwell's equations, the boundary conditions, the radiation condition and all but one of the edge conditions. The unknown functions are shown to satisfy a pair of integrodifferential equations which follow directly from the representations by means of an elementary calculation. Convergent power series solutions of these integro-differential equations are readily obtained for small enough ka, when it is assumed merely that the excitation is sufficiently regular in the aperture. These results are employed to derive the first terms in the power series expansions of the far fields, the edge fields, the aperture fields and of the transmission coefficients. When the incident transverse electric and magnetic modes are specialized to those which occur in plane wave excitation these expressions are found to reduce to the well-known plane wave formulas obtained by other means. (Author)
Keywords	ELECTROMAGNETIC WAVES DIFFRACTION DIFFRACTION GRATINGS RINGS INTEGRAL EQUATIONS FUNCTIONS ELECTROMAGNETIC FIELDS PROPAGATION MATHEMATICAL ANALYSIS
NTIS Subject Category	57V - Radiobiology 46 - Physics
Corporate Authors	Courant Inst of Mathematical Sciences New York Univ N Y
Document Type	Technical Report
Title Note	Research rept.
NTIS Issue Number	196501
Contract Number	AF19 604 5238

Diffraction of Electromagnetic Waves by a Circular Aperture in an Infinitely Conducting Plane Screen.

Diffraction of Electromagnetic Waves by a Circular Aperture in an Infinitely Conducting Plane Screen.
AD600132

Publication Date	1964
Personal Author	Bazer, J.; Rubenfeld, L.
Page Count	0
Abstract	Attention is focused chiefly on the low frequency end of the spectrum where the product ka of the wave number k and the aperture radius a is small. Transverse electric and transverse magnetic modal excitation appropriate to the cylindrical geometry of the problem is assumed. New integral representa tions of the solution corresponding to incident fields of this kind are presented. These representations, which involve a pair of unknown functions, are designed so as to automatically satisfy Maxwell's equations, the boundary conditions, the radiation condition and all but one of the edge conditions. The unknown functions are shown to satisfy a pair of integrodifferential equations which follow directly from the representations by means of an elementary calculation. Convergent power series solutions of these integro-differential equations are readily obtained for small enough ka, when it is assumed merely that the excitation is sufficiently regular in the aperture. These results are employed to derive the first terms in the power series expansions of the far fields, the edge fields, the aperture fields and of the transmission coefficients. When the incident transverse electric and magnetic modes are specialized to those which occur in plane wave excitation these expressions are found to reduce to the well-known plane wave formulas obtained by other means. (Author)
Keywords	ELECTROMAGNETIC WAVES DIFFRACTION DIFFRACTION GRATINGS RINGS INTEGRAL EQUATIONS FUNCTIONS ELECTROMAGNETIC FIELDS PROPAGATION MATHEMATICAL ANALYSIS
NTIS Subject Category	57V - Radiobiology 46 - Physics
Corporate Authors	Courant Inst of Mathematical Sciences New York Univ N Y
Document Type	Technical Report
Title Note	Research rept.
NTIS Issue Number	196501
Contract Number	AF19 604 5238