Analysis of low-profile antennas on isoimpedance metamaterial substrates using a novel robust spectral-domain integration methodology

We outline an efficient full-wave algorithm to compute the scattered field radiated by printed antennas on planar-stratified substrates where each layer may exhibit arbitrary material anisotropy and loss characteristics. The algorithm is based on the closed-form, well-conditioned spectral domain representation of the associated Green´s tensors and on a set of recently improved acceleration techniques to evaluate the resulting double Fourier integrals in the complex spectral plane. We illustrate the technique in the computation of the field radiated by a small loop antenna atop a thin isoimpedance metamaterial substrate. This type of substrate is designed to mimic the effects of a thicker substrate without exciting surface waves.