Overview on Combination of Numerical Modelling and Near-Field Measurements for Complex Electromagnetic Systems

Full wave simulations and Near-field (NF) antenna measurements are two different but widely accepted engineering techniques to characterize the radiating properties of antennas placed in complex electromagnetic systems. Simulations are attractive as they scale to problem size by varying the numerical method or simply by applying more computational power. However, the simulation accuracy depends on the accurate knowledge of material characteristics and/or an accurate description of the radiating source. Such information is not always available. Measurements are generally provided with estimates of uncertainty and can be performed on any antenna regardless of the material properties. Unfortunately, measurements scale less well to problems size as very large measurements systems tends to be expensive. The logical solution to this problem is to measure only the pertinent antenna part and use the numerical techniques to model the external scattering in a combination of measurements and simulations. This can be obtained through the use of equivalent current (EQC) to accurately represent the measured antenna and as measured source in numerical simulation. This approach has been validated in applications such as automotive, aerospace, EMC etc. In this paper we give a brief introduction to method and a discussion on achievable accuracies. The method is illustrated by a new application example.