Annular microstrip antenna in multilayered media containing uniaxial anisotropic dielectrics

In this work, Galerkin´s method in the Hankel transform domain is used for computing the resonant frequencies and bandwidths of the annular microstrip patch antenna. The metallic patch are assumed to be embedded in a multilayer substrate, which may contain uniaxial anisotropic dielectrics. The TM set of modes issued from the magnetic wall cavity model theory are used to expand the unknown currents on the patch. Convergence of the method is studied. The obtained results have been compared with the available data from other studies. Numerical results show that the bandwidth increases with increasing superstrate thickness. The influence of uniaxial anisotropy in the substrate on the complex resonant frequency and bandwidth of the annular microstrip antenna is also investigated using an integral equation formulation.