Rapid Far-Field Pattern Reconstruction from Phaseless Measurements Through the LM Algorithm

This study investigates the use of the Levenberg-Marquardt (LM) algorithm to accelerate spherical wave coefficient computation. Spherical wave expansion (SWE) using power correlation coefficients can reconstruct radiation patterns of antenna-under-test (AUT) within a reverberation chamber (RC), but the computation of SWE coefficients for large AUTs is computationally intensive. To mitigate this, the matrix decomposition was employed to break down high-dimensional matrices into smaller ones, and an analytical Jacobian solution within the LM framework was developed, achieving a computational speedup of over five times. The method's accuracy and effectiveness were validated through comprehensive numerical simulations.