Phaseless Bi-spherical Near-field Measurement

To overcome the challenge of acquiring high-precision phase information in spherical near-field measurements, this paper treats the solution of the spherical mode coefficients (SMC) as a phase recovery problem. Targeting the two critical factors that determine the converting accuracy, that is, the phase recovery algorithm and the near-field sampling strategy, by comparing the error of the extrapolated far field, this paper identifies a phase recovery algorithm most appropriate for phaseless near-field measurement, and an adapted spherical sampling approach. The numerical results demonstrate that Reweighted Amplitude Flow integrated with the bi-spherical sampling strategy is capable of sufficiently retrieving the SMC and deriving the high-precision radiation characteristics of the antenna under test (AUT).