The natural oscillations of an infinitely long cylinder coated with lossy material


  • W. M. Sun,

  • K. M. Chen,

  • D. P. Nyquist,

  • E. J. Rothwell


Investigations are reported of the effects of lossy coatings on the natural frequencies of a perfectly conducting cylinder with TE excitation. A general characteristic equation for extraction of the natural frequencies of a cylindrical structure is developed. It is found that the natural frequencies are substantially shifted only when the coating thickness is comparable to the radius of the cylinder. When the conductivity of the coating material is high enough, the behavior of the natural modes of a coated cylinder is essentially the same as that of a perfectly conducting cylinder.