On Phaseless Spherical Near-Field Antenna Measurements

In this article, the application of phaseless measurement in spherical near-field antenna measurements is discussed, where the amplitude is measured and used to estimate the Spherical Mode Coefficients (SMC) of the antenna. Implementing phaseless measurement in a spherical near-field setting is challenging, since the spherical near-field data and its SMC depend highly on the structure of the spherical harmonics or Wigner D-functions, which can be seen as the Fourier basis on the sphere and rotation group. Similar to the phaseless Fourier measurement, considering only an amplitude measurement in this setting creates ambiguity in the reconstruction of the SMC. This paper shows the numerical investigation of several phaseless algorithms applied to spherical near-field antenna measurements.