Degeneration of electromagnetic creeping waves in a vicinity of critical values of anisotropic impedance

作者：Andronov I V^*; Bouche D P

来源：IEEE Transactions on Antennas and Propagation, 2008, 56(7): 1984-1992.

DOI：10.1109/TAP.2008.924719

• boundary layer
• creeping waves
• degeneration
• electromagnetic propagation
• high frequency asymptotics
• impedance

Electromagnetic creeping waves on a 3-dimensional surface with an anisotropic impedance boundary condition are considered. The influence of the impedance is examined. The standard asymptotic formula for the creeping waves contains the factor 1/(tau - q(2)) where tau is the attenuation parameter and q is the Fock parameter which depends on the impedance matrix. Analysis of the equation for the attenuation parameter which describes its dependence on q shows that there exist such critical values of q when the factor 1/(tau - q(2)) diverges and the usual asymptotic formula gives infinite result. The equation for the critical values of the parameter q is derived and the 4 first critical values are found numerically. The new local asymptotics valid in domain of the size k(-2/9) (where k is the wave number) is derived in the supposition that the divergence takes place on a curve crossed by creeping waves. This new asymptotic decomposition is carried out by powers of the small parameter k(-1/9). The effect of creeping wave passing through the line where the usual asymptotics diverges is examined.

• 出版日期2008-7
• 单位中国地震局