Displacement errors in antenna nearfield measurements and their effect on the far field
Abstract
The effects of probe displacement errors in the nearfield measurement procedure on the farfield spectrum are studied. Expressions are derived for the displacement error functions that maximize the fractional error in the spectrum both for the onaxis and offaxis directions. Planar xy and zdisplacement errors are studied first and, consequently, the results are generalized to errors in spherical scanning. Some simple nearfield models are used to obtain order of magnitude estimates for the fractional error as a function of relevant scale lengths of the near field, defined as the lengths over which significant variations occur.
 Publication:

NASA STI/Recon Technical Report N
 Pub Date:
 October 1986
 Bibcode:
 1986STIN...8719602M
 Keywords:

 Antenna Radiation Patterns;
 Displacement;
 Errors;
 Mathematical Models;
 Far Fields;
 Measuring Instruments;
 Near Fields;
 Vectors (Mathematics);
 Communications and Radar