Radiation enhancement due to metamaterial substrates from an inverse source theory.

In this paper the formalism of the electromagnetic inverse source theory is used to investigate radiation enhancement due to antenna substrates. Particular attention is given to sources that are confined within a spherical volume and are embedded within two nested spheres of arbitrary materials. Emphasis is given to the special case when the two nested spheres are made up of materials with oppositely signed constitutive parameters.

Generalized power-spectrum Larmor formula for an extended charged particle embedded in a harmonic oscillator.

The nonrelativistic Larmor radiation formula, giving the power radiated by an accelerated charged point particle, is generalized for a spatially extended particle in the context of the classical charged harmonic oscillator. The particle is modeled as a spherically symmetric rigid charge distribution that possesses both translational and spinning degrees of freedom. The power spectrum obtained exhibits a structure that depends on the form factor of the particle, but reduces, in the limit of an infinitesimally small particle and for the charge distributions considered, to Larmor's familiar result.