Input impedance calculation of cylindrical rectangular microstrip antenna using GTLM theory

The cylindrical-rectanglar microstrip antennas have been recently studied by many authors. The feeding mechanisms of probe-fed and micro-stripline-fed cases have been considered, and different numerical techniques using the full-wave analysis, the cavity-model method, and the generalized transmission line model (GTLM) theory have been applied. Among these numerical methods, the full-wave analysis is rather complicated and computationally inefficient. On the other hand, both the cavity-model method and the GTLM theory are much simpler and requires less computational effort. The GTLM solution also shows good agreement with the measured data for the case of a probe feed excitation. In this paper, we further apply the GTLM theory to the analysis of cylindrical-rectangular microstrip antennas with a microstrip feedline or using slot coupling. For both feeding mechanisms, the equivalent circuits are described, and the calculated input impedance results are presented.