Wide frequency band analysis of an antenna by finite elements

Abstract

PurposeThe aim of this paper is to calculate the impedance of a loop antenna, etched on a dielectric substrate, over a wide frequency band using finite element method (FEM).Design/methodology/approachThe electromagnetic analysis of the global structure is performed with a full wave finite element formulation. In this work, two methods for the calculation of the impedance of the antenna are presented: receiving and transmitting mode. The results obtained are compared with boundary element method (BEM).FindingsThe paper finds that from the FEM analysis an equivalent circuit of a rectenna was obtained over a wide frequency band. A good agreement was obtained with a BEM approach in the case of an air‐like substrate. A dielectric substrate was considered. Such a configuration is more difficult to deal with BEM and makes the FEM attractive.Practical implicationsThe equivalent circuit allows a global circuit simulation of the whole rectenna (antenna, rectifying diodes and load). This simulation can be achieved using spice simulator for example.Originality/valueThis paper shows the potentiality of the FEM to simulate an antenna over a broad band frequency. Two methods for the calculation of the impedance of the antenna are presented. It is addressed to R&D designers in the microwave area.