Title :
Uniform asymptotic formulas for the creeping wave field on or off a cylinder
Author_Institution :
Dept. of Electr. & Comput. Eng., Concordia Univ., Montreal, Que., Canada
fDate :
8/1/1993 12:00:00 AM
Abstract :
This work develops a uniform asymptotic formula for the creeping wave field in the shadow region of a conducting circular cylinder, excited by a magnetic line source or line dipole on the surface. Unlike previous developments in terms of Fock integrals, the uniform formula does not require switching between on and off surface formulas. Furthermore, the uniform formula is more accurate in the transition region near the surface, where neither the on nor off surface formulas work very well. Validation is by comparison with an exact numerical solution for the field due to a single surface ray. An empirical switchover criterion for the nonuniform formulas is suggested, and limitations of both the nonuniform and uniform formulas are discussed
Keywords :
antenna theory; electromagnetic field theory; electromagnetic wave scattering; antennas; conducting circular cylinder; creeping wave field; electromagnetic radiation; electromagnetic scattering; empirical switchover criterion; exact numerical solution; line dipole; magnetic line source; shadow region; single surface ray; surface formulas; uniform asymptotic formula; Councils; Engine cylinders; Helium; Physical theory of diffraction; Scattering; Surface waves; Switches;
Journal_Title :
Antennas and Propagation, IEEE Transactions on