Use of Time Domain Gating in Spherical Near-Field Measurements
Author: Jeffrey Fordham
Publication: ANTEM 2010
Copyright Owner: IEEE
Time domain gating has been widely used in antenna measurements for many years. The technique has proven useful in gating out extraneous signals from the range that can be uniquely separated from the primary desired signal. The well known process involves collecting data in the frequency domain and then transforming the data to the time domain for processing. In far-field antenna measurements the technique is limited in its applicability by factors such as antenna bandwidth and pattern shape vs. frequency, and internal time delays within the device under test. Spherical near-field presents additional challenges to the effective use of time domain gating.
These challenges of performing time domain gating in spherical near-field measurements are presented along with measured results from a small spherical near-field range. These results show the significant reduction in stray signals and the resulting increase in accuracy that can be achieved via time domain gating.
Finally, the paper concludes with measurements made on a large spherical near-field arch over a ground plane system. Additional challenges of such a system will be highlighted.
You have requested a Reprint of an IEEE Paper
Copyright 2010 IEEE. Reprinted from 2010 Antenna Measurement Conference, ANTEM 2010, July 5-9, 2010, Ottawa, Canada.
This material is posted here with permission of the IEEE. Such permission
of the IEEE does not in any way imply IEEE endorsement of any of NSI-MI Technologies' products or services. Internal or personal use of this
material is permitted. However, permission to reprint/republish this
material for advertising or promotional purposes or for creating new
collective works for resale or redistribution must be obtained from the
IEEE by writing to pubs-permissions@ieee.org.
By choosing to view this document, you agree to all provisions of the copyright laws protecting it.