On the Comparison Between the Spherical Wave Expansion and the Sources Reconstruction Method

A comparison between two well-known near field to far field (NF-FF) transformation methods is presented: the spherical wave expansion (SWE) and the sources reconstruction method (SRM). The goal of this paper is to show the methods performance for NF-FF transformation pointing out the advantages and limitations of each one. First, the computational cost is studied, showing its dependence with the antenna under test (AUT) electric size. Second, the NF-FF transformation accuracy of each method is compared for a fixed AUT electric size, analyzing also the influence of the main parameters that affect the SRM and SWE accuracy. Third, the SRM capabilities are presented, with focus on the NF-NF transformation inside the minimum sphere. Practical applications of the SWE and SRM are illustrated by means of an example of NF-FF transformation and antenna diagnostics problem using measured NF data.

[1]  A. Yaghjian.  An overview of near-field antenna measurements , 1986 .

[2]  T. Sarkar,et al.  Planar near-field to far-field transformation using an equivalent magnetic current approach , 1992 .

[3]  Tapan K. Sarkar,et al.  Near-field to near/far-field transformation for arbitrary near-field geometry, utilizing an equivalent magnetic current , 1996 .

[4]  Tapan K. Sarkar,et al.  Differences between modal expansion and integral equation methods for planar near-field to far-field transformation (Summary) , 1996 .

[5]  J.L. Besada,et al.  Equivalent source modelling and reconstruction for antenna measurement and synthesis , 1997, IEEE Antennas and Propagation Society International Symposium 1997. Digest.

[6]  Fernando Las-Heras,et al.  Far-field performance of linear antennas determined from near-field data , 2002 .

[7]  Y. Alvarez,et al.  Probe distortion correction in near field - far field transformations based on equivalent sources characterization , 2006, 2006 First European Conference on Antennas and Propagation.

[8]  Y. Alvarez,et al.  Integral equation algorithms for equivalent currents distribution retrieval over arbitrary three-dimensional surfaces , 2006, 2006 First European Conference on Antennas and Propagation.

[9]  Y. Alvarez,et al.  Evaluating near-field radiation patterns of commercial antennas , 2006, IEEE Transactions on Antennas and Propagation.

[10]  Manuel Arrebola,et al.  Design of a Reflectarray with Three Shaped Beams Using the Near-Field Radiated by the Feeds , 2006 .

[11]  Y. Alvarez,et al.  Improvement of the sources reconstruction techniques: analysis of the SVD algorithm and the RWG basis functions , 2007, 2007 IEEE Antennas and Propagation Society International Symposium.

[12]  F. Las-Heras,et al.  Reconstruction of Equivalent Currents Distribution Over Arbitrary Three-Dimensional Surfaces Based on Integral Equation Algorithms , 2007, IEEE Transactions on Antennas and Propagation.