Comparative analysis of circuit and finite element models for a linear wire dipole antenna

Abstract

Antennas are a critical component of an internet of things device and are typically modelled using full-wave electromagnetic (EM) solvers for their optimal design. In this paper, we investigate and compare the impact, accuracy and limitations of three, four and five element equivalent circuit models from the literature to estimate the impedance characteristics of a center-fed linear wire dipole antenna at 2.45 GHz. All the circuit model results are compared against the finite element model. It was found that the three element model is inaccurate in estimating the input impedance of a dipole antenna at the resonant frequency. In comparison to the finite element model, the four element model estimates the input impedance with an error of 3.75 j2.54 Ohms at 2.45 GHz. For the five element model the error-in the input impedance was -6.21+j1.68 Ohms. The input impedance for the both, the four and five element models are in good agreement with the EM model. This approach is shown to enable efficient analysis of antenna impedance for wireless communication systems.