Spherical Near-Field Antenna Measurement Note: Disciplined Measurement Practices
Author: Brian B. Tian
Publication: MI Communicator, June 2008
Copyright Owner: NSI-MI Technologies
The number of users involved in spherical near-field (SNF) antenna measurement continues to grow rapidly due to the popularity of this technology. Pressured from competition in today’s commercial market, some must perform SNF antenna measurements and produce results before they have an opportunity to gain adequate understanding of the technology and the theory behind it. This note attempts to link some SNF measurement practices to theoretical requirements from a user’s perspective and to promote a disciplined approach in measurement practice. Topics covered include range setup, probe alignment, SNF data output and AUT mounting.
To achieve the above goal, we first lay out the coordinate system in which SNF transformation is formulated, and then illustrate in detail how this coordinate system is realized by practical SNF range and probe. We then discuss the interpretation of SNF output data and AUT mounting. We also address possible misunderstandings and misconceptions. To ensure consistency, this note follows a single set of conventions and definitions for symbols and formulations detailed in .