Low Cost and High Accuracy Alignment Methods for Cylindrical and Spherical Near-field Measurement Systems
Author: John Demas
Precise mechanical alignment of motion axes of both cylindrical and spherical near-field systems is critical to producing accurate data. Until recently the only way to align these types of systems was to employ traditional optical tooling (i.e. jig transits, theodolites). Alignment by these methods is difficult, time consuming, and requires specialized training. More recently, laser trackers have been used for this type of alignment. Unfortunately, these devices are expensive and demand an even higher level of operator training.
This paper describes the use of low cost alignment tools and techniques that have been developed by Nearfield Systems, Inc. (NSI) that greatly simplify the alignment process. Setup and alignment can be performed in a very short period of time by technicians that have been given minimal training. Suitable optical alignment procedures when followed by the use of electrical alignment techniques  yield sufficient alignment accuracy to permit testing up to Ku-band.