Two Effective Approaches to Correct the Positioning Errors in a Spherical Near-Field–Far-Field Transformation

ABSTRACT Two techniques are developed to efficiently compensate known positioning errors affecting the near-field measurements in a non-redundant spherical near-field–far-field transformation for quasi-planar antennas, and they are fully assessed through numerical and experimental tests. They rely on a non-redundant sampling representation of the voltage measured by the probe, obtained by assuming that the antenna is enclosed in a surface formed by two circular bowls with the same aperture diameter. Both techniques use a two-step procedure. In the first step, the near-field data at the points fixed by the sampling representation are recovered from the irregularly spaced measured ones by properly applying an iterative technique or the singular value decomposition method. Then the near-field data needed by the standard spherical near-field–far-field transformation are effectively reconstructed by means of an optimal sampling interpolation algorithm.

[1]  Flaminio Ferrara,et al.  Effective Antenna Modellings for NF-FF Transformations with Spherical Scanning Using the Minimum Number of Data , 2011 .

[2]  Ovidio Mario Bucci,et al.  Interpolation of electromagnetic radiated fields over a plane by nonuniform samples , 1993 .

[3]  Michael H. Francis,et al.  IEEE Recommended Practice for Near-Field Antenna Measurements , 2012 .

[4]  J. Yen.  On Nonuniform Sampling of Bandwidth-Limited Signals , 1956 .

[5]  Bradley K. Alpert,et al.  Near-field antenna measurements using nonideal measurement locations , 1997 .

[6]  R.C. Wittmann,et al.  Near-field, spherical-scanning antenna measurements with nonideal probe locations , 2004, IEEE Transactions on Antennas and Propagation.

[7]  Flaminio Ferrara,et al.  Two Techniques for Compensating the Probe Positioning Errors in the Spherical NF–FF Transformation for Elongated Antennas , 2011 .

[8]  Flaminio Ferrara,et al.  Far-Field Reconstruction from Nonuniform Plane-Polar Data: A SVD-Based Approach , 2003 .

[9]  O. Bucci,et al.  Representation of electromagnetic fields over arbitrary surfaces by a finite and nonredundant number of samples , 1998 .

[10]  Flaminio Ferrara,et al.  On the Compensation of Probe Positioning Errors When Using a Nonredundant Cylindrical Nf-Ff Transformation , 2010 .

[11]  A.,et al.  FAST FOURIER TRANSFORMS FOR NONEQUISPACED DATA * , 2022 .

[12]  J. Thomas,et al.  On Some Stability and Interpolatory Properties of Nonuniform Sampling Expansions , 1967, IEEE Transactions on Circuit Theory.

[13]  Ovidio Mario Bucci,et al.  Electromagnetic fields interpolation from nonuniform samples over spherical and cylindrical surfaces , 1994 .

[14]  Ovidio Mario Bucci,et al.  Application of Nonredundant Sampling Representations of Electromagnetic Fields to NF-FF Transformation Techniques , 2012 .

[15]  Arthur D. Yaghjw.  An Overview of Near-Field Antenna Measurements , 2009 .

[16]  Flaminio Ferrara,et al.  Experimental validation of the NF–FF transformation with cylindrical scan from nonuniformly distributed data , 2011 .

[17]  F. Beutler.  Error-Free Recovery of Signals from Irregularly Spaced Samples , 1966 .

[18]  Flaminio Ferrara,et al.  Experimental Testing of Nonredundant Near-Field to Far-Field Transformations with Spherical Scanning Using Flexible Modellings for Nonvolumetric Antennas , 2013 .

[19]  J. Hansen.  Spherical near-field antenna measurements , 1988 .

[20]  H. Landau.  Sampling, data transmission, and the Nyquist rate , 1967 .

[21]  Flaminio Ferrara,et al.  Non-Redundant Spherical NF - FF Transformations Using Ellipsoidal Antenna Modeling: Experimental Assessments [Measurements Corner] , 2013, IEEE Antennas and Propagation Magazine.

[22]  H. Landau.  Necessary density conditions for sampling and interpolation of certain entire functions , 1967 .

[23]  Ovidio Mario Bucci,et al.  Data Reduction in the Nf-Ff Transformation Technique With Spherical Scanning , 2001 .

[24]  Clive Parini,et al.  Spherical near-field antenna measurements , 2014, Theory and Practice of Modern Antenna Range Measurements, 2nd Expanded Edition, Volume 2.