Phase retrieval techniques are key to phaseless near-field measurements and holographic diagnoses.Based on the probe correction

the weighed functional are constructed and the phaseless measurement condition is presented to avoid local extremes.For the purpose of iterative efficiency and practicality

Fletcher-Reeves conjugate gradient method is modified by the application of re-beginning technique

FFT algorithm and construction of initial guess.Numerical simulations show that the search variables should be selected as less as possible in virtue of a priori information on the antenna under test and near-field measurements.Experimental results prove this technique to be accurate and efficient.