An Efficient Electromagnetic Study of Circular Disc Microstrip Antenna with Two Parasitic Elements

In this paper, a rigorous analysis of three stacked circular microstrip patches is performed using a dyadic Green’s functions formulation. The circular discs are embedded in a multilayered substrate containing isotropic and/or uniaxial anisotropic materials. A very efficient technique to derive the dyadic Green’s functions of the stacked configuration in the vector Hankel transform domain is proposed. The complete orthogonal set of transverse magnetic (TM) and transverse electric (TE) modes of a cylindrical cavity with magnetic side walls and electric top and bottom walls is used in the approximation of the unknown current densities on the circular discs. Numerical results obtained for the resonant frequencies are found to be in good agreement with the experimental data available in the literature.