Effect of dielectric anisotropy on the resonant frequency of rectangular resonators with several dielectric layers

INTEmUCTION A growing interest has been observed in the analysis of microstrip patch resonators on dielectric anisotropic layers Ell. This is due in part to some of the intrinsic properties of these materials, such as low loss and high reproducibility from batch to batch, and in part because many of the materials used as substrates for patch resonators exhibit dielectric anisotropy. For example, sapphire, alumina and a variety of teflon substrates are anisotropic [21.