An Improved Source Reconstruction Method for Antenna Measurements in Complex Environments

This letter proposes a novel source reconstruction method for antenna measurements in complex environments where scatterers are located near the antenna. Independent equivalent sources are established for the antenna and scatterer, and their current distributions are expanded in the orthogonal eigenmode basis of each impedance matrix. By retaining only the dominant eigenmode currents, the number of unknown coefficients is drastically reduced, leading to lower computational costs and enhanced numerical stability. Based on prior knowledge of the antenna structural symmetry, symmetry constraints are imposed to ensure accurate source recovery even when the antenna and scatterer lie in very close proximity. Simulation results demonstrate that, on a combined antenna–scatterer system spanning approximately five wavelengths, the method reconstructs the far-field pattern within 0.5 dB error while using under 6% of the original coefficients and cutting computation time to just 10% of the original. These gains are expected to increase for larger electrical sizes or more complex antenna systems.