Resonant characteristics of a corrugated sphere

Abstract

The radiation from a radial electric dipole on t he surfacc of a corru gatcd sphcrc is treated . It is shown t hat t he power ra di ated in a given mode depends crit ically on t he surface reactance a nd t he circumference of t he sphere. In fac t, for certain values of t hese pa rameters, particular modes a re strongly excited and contain most of t he powcr . Such a structure can be regarded as a n extern al reso nator an d its resonan t characte ri stics are a function of the refractive index of th e surroundin g medium. This opcns t he possibility t hat a surface-wave spherical reso nator m ay have important appli cations to refmcto llwtry.