A Probe-Compensated Helicoidal NF-FF Transformation for Aperture Antennas Using a Prolate Spheroidal Expansion
Figure 13
Illustrating the need for probe compensation. When the probe rotates around the AUT from position 1 to 2 (a), approximately the same receiving features of the probe are involved. When the probe moves along the axis from position 1 to 2 (b), different receiving features of the probe become relevant.