Analysis of coaxial-fed electromagnetically coupled patch antenna using FDTD

Coaxial feed modeling has been a challenge in numerical simulation for a long time. Various modeling techniques, such as gap modeling, magnetic frill modeling and transmission line modeling have been applied successfully for specific applications. We challenge the same problem for an electromagnetically coupled patch antenna (EMCP). It has been shown that the mechanism of operation is the excitation of two modes which have almost the same resonance frequency (Zucher, J.-F., "Broadband Patch Antenna", Artech House, 1995; Hajiaboli, A. et al., ANTEM2004). Because of this complicated behavior, the general modeling may need modification or refinement. We present results of mesh refinement applied to our previous antenna model (Hajiaboli et al., 2004). Considering the increase in the simulation time, the changes obtained in the input impedance have been discussed.