 
Summary: IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION 1
NearField Antenna Measurements Using Nonideal
Measurement Locations
Ronald C. Wittmann, Bradley K. Alpert, and Michael H. Francis
Abstract We introduce a near eld to far eld transfor
mationalgorithmthat relaxes the usual restrictionthat data
points be located on a planerectangular grid. Computa
tional complexity is ON logN, where N is the number of
data points. This algorithm allows e cient processing of
near eld data with known probe position errors. Also, the
algorithm is applicable to other measurement approaches,
such as planepolar scanning, where data are collected in
tentionally on a nonrectangular grid.
I. Introduction
WE introduce a near eld to far eld transformation
method that relaxes the usual restriction that data
points be located on a planerectangular grid.1 It is not
always practical or desirable to make uniformly spaced
measurements; for example, the maintenance of position
ing tolerances becomes more di cult as frequency is in
