Patch Antenna Radiation Pattern Evaluation Based on Phaseless and Single-Plane Near-Field Scanning

Conventional near-field to far-field transformation based on phaseless planar near-field scanning usually requires field magnitude data over two parallel planes in front of the antenna under test (AUT). In this paper, an equivalent dipole array model is established for radiation pattern evaluation based on the phaseless and single-plane near-field scanning. The field magnitude is obtained by near-field scanner. Using an interpolation method, we can obtain a group of interpolated field magnitude under the assumption that field magnitude does not vary dramatically between two adjacent sampling points. Subsequently, an iterative algorithm together with singular value decomposition (SVD) method is performed between measured data and interpolated data for reconstructing the equivalent dipole array. Then, radiation pattern can be calculated by the equivalent sources. A measurement example is given to verify the effectiveness of the proposed method. Reducing a half of sampling points is the major advantage of this method, and it still can establish a valid equivalent source. This method can be regarded as a good compromise between efficiency and accuracy.