A hybrid equivalent source—particle swarm optimization model for accurate near-field to far-field conversion.

This paper proposes an improved equivalent source (ES) model based on particle swarm optimization (PSO) to predict the radiated emissions of a 2.4 GHz ISM band patch antenna. The proposed model uses near-field data to extract an equivalent set of infinitesimal electric dipoles representation. Characterized by their positions, orientations, and currents, these dipoles can reproduce the same field distribution as the target device under test (DUT). To build an accurate equivalent dipole model, a numerical experiment is performed and presented in this paper, where many variable selections of observation points and dipole numbers and locations of the dipole plane are examined, with the aspiration of determining a suitable conversion problem. Based on the proper combination of the two methods (ES-PSO), the complete modeling procedure consists of the application of the pseudo-inverse method to find the minimum norm solution to the least-square problem. Then, the obtained solution is provided to the PSO algorithm to initialize the search for the best-fit dipole parameters. The PSO method can further enhance the stability of the obtained dipole solution and improve the accuracy of the far field prediction. Promising and encouraging results in terms of field prediction at higher planes above the DUT are obtained. • Model the radiated emissions from a patch antenna using an equivalent source method. • Solving an inverse problem from field to source for near field-far field conversion. • Mitigating the effect of ill-conditioned system by preforming numerical experiment. • Improving the stability of the equivalent sources using particle swarm optimization. [ABSTRACT FROM AUTHOR]