Spectral domain analysis of coupled microstrip resonators with tensor substrates and high-Tc superconductors

Various types of interacting resonant structures are used in microwave integrated circuits. In the case of antenna, there is a tendency for coupled microstrip resonators to be used as antenna array elements. One of the problems associated with designing such arrays is directly tired to mutual coupling between these elements. Mutual coupling must be considered when determining some of the array characteristics, because it can influence the value of some of its parameters, such as: the resonant frequency, losses and the radiation pattern. Only a few methods investigate anisotropic substrate and high-Tc superconductor patches. Both of these enhancement to the classical patch antenna can improve its performance if proper design procedures are followed. Therefore, this paper focuses on the analysis of coupled rectangular patch resonators with anisotropic substrates and high-Tc superconductor patches. The extended spectral-domain approach combined with the concept of imperfect conductors is used. A decoupling procedure for the electric and magnetic field is developed which makes it possible to arrive at closed form impedance dyadic Green´s functions in the spectral domain. The resonant frequencies in the even and odd resonance modes of coupled resonator are evaluated from the numerical solution of the characteristic equation. The radiation patterns are also calculated.