Modelling of Emc Broadband Antennas With Complex Geometry Above 1 GHz

Abstract

Radiofrequency measurements of electromagnetic compatibility are negatively influenced by uncertainty of the measuring antenna. To make quantification of errors caused by the antenna faster, it is useful to create an antenna model and simulate the circumstance. A change in parameter values caused by a change of position of the antenna or a change of surroundings can be determined using a numerical electromagnetic simulation software. Modelling a precise copy of antenna, however, can cause unnecessarily high simulation requirements, therefore it is essential to know how model structure simplification affects the characteristics of the model. For this purpose, broadband antennas commonly used for measurements of electromagnetic compatibility above 1 GHz were taken into account: stacked logarithmic-periodic antenna and double-ridged horn antenna. Multiple models were created with various extent of simplification to achieve reduction in computational time and memory requirements. The level of correspondence of the model to the real antenna was inspected, using chosen electromagnetic simulation software, by obtaining characteristic parameters of the models, i.e. antenna factor, gain, and radiation pattern, and by comparison of results to measured values. Considering the results and computational effort of the simulation, the most suitable model was chosen for each antenna.