Phaseless bi-polar planar near-field measurements and diagnostics of arrayantennas

Antenna near-field measurements typically require very accurate measurement of the near-field phase. There are applications where an accurate phase me asurement may not be practically achievable. Phaseless measurements are beg inning to emerge as an alternative microwave antenna measurements technique when phase cannot be directly measured, There are many important aspects f or successful implementation of a phaseless measurement algorithm. This pap er presents appropriate phaseless measurement requirements and a phase retr ieval algorithm tailored for the bi-polar planar near-field antenna measure ment technique. Two amplitude measurements and a squared amplitude optimal sampling interpolation method are integrated with an iterative Fourier proc edure to first retrieve the phase information and then construct both the f ar-field pattern and diagnostic characteristics of the antenna under test. In order to critically examine the methodologies developed in this paper, p haseless measurement results for two different array antennas are presented and compared to results obtained when the nearfield amplitude and phase ar e directly measured.