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Search Publications by: Ronald Wittmann (Assoc)

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Displaying 26 - 50 of 158

Configurable Robotic Millimeter-Wave Antenna Facility

April 13, 2015
Author(s)
Jeffrey R. Guerrieri, Joshua A. Gordon, David R. Novotny, Michael H. Francis, Ronald C. Wittmann, Miranda L. Butler
This paper introduces the Configurable Robotic Millimeter-Wave Antenna (CROMMA) facility by the Antenna Metrology Lab at the National Institute of Standards and Technology (NIST). NIST set out to develop an antenna measurement facility that would be

Evaluating and Verifying the Performance of the Ft. Huachuca Compact Range

July 6, 2014
Author(s)
Michael H. Francis, Ronald C. Wittmann
The National Institute of Standards and Technology (NIST) presents a plan for evaluating and verifying the performance of the refurbished Ft. Huachuca Antenna Test Facility outdoor compact range. This plan was drawn up based upon information supplied to

Evaluating the Performance of the Ft. Huachuca Compact Range

July 6, 2014
Author(s)
Michael H. Francis, Ronald C. Wittmann
The National Institute of Standards and Technology (NIST) presents a plan for evaluating and verifying the performance of the refurbished Ft. Huachuca Antenna Test Facility outdoor compact range. This plan was drawn up based upon information supplied to

Sensitivity of Probes in Near-Field Spherical-Scanning Antenna Measurements

July 7, 2013
Author(s)
Ronald C. Wittmann, Michael H. Francis
We define and calculate sensitivity for several actual and simulated probes. Probe sensitivity can have a significant impact on measurement uncertainty associated with probe deconvolution in near- field, spherical scanning, antenna measurements.

Using Truncated Data Sets in Spherical Scanning Antenna Measurements

February 8, 2012
Author(s)
Ronald C. Wittmann, Carl F. Stubenrauch, Michael H. Francis
We discuss the mitigation of truncation errors in spherical scanning measurements. The main emphasis is the spherical harmonic representation of probe transmitting and receiving functions; however, our method is applicable to near-field measurement of

Near-Field Spherical Scanning: Quiet-Zone Field Evaluation

June 1, 2009
Author(s)
Randy Direen, Michael H. Francis, Ronald C. Wittmann
Spherical near-field scanning measurements are used to determine the incident electromagnetic fields within a test volume. Results from two independent approaches are compared and found to agree within estimated uncertainties.

Near-Field Spherical Scanning: Uncertainties in Test-Zone Field Measurements

November 16, 2008
Author(s)
Randy Direen, Ronald C. Wittmann, Michael H. Francis
The electromagnetic field within a test volume can be measured using spherical scanning techniques. Characterization of the field within the sphere requires compensation for probe-pattern effects. We provide a simple uncertainty analysis to estimate

Chamber Imaging Using Spherical Near-Field Scanning

July 5, 2008
Author(s)
Ronald C. Wittmann, Michael H. Francis, Randy Direen
We discuss recent measurements performed at the National Institute of Standards and Technology (NIST) that were used to characterize the incident fields within a test volume and to produce images of the test chamber.

Near-field Scanning Measurements: Theory and practice

July 3, 2008
Author(s)
Michael H. Francis, Ronald C. Wittmann
This chapter summarizes theoretical and practical aspects of near-field scanning methods. These methods allow complete characterization of the transmitting or receiving properties using measurements made in close proximity to an antenna.

ANTENNA TEST RANGE IMAGING USING SPHERICAL NEAR-FIELD SCANNING

June 8, 2008
Author(s)
Michael H. Francis, Ronald C. Wittmann, Randy Direen
Although the theory is straightforward, practical implementation of spherical near-field scanning for evaluating test chambers presents some significant challenges. Among these are the selection of an appropriate probe and the difficulty in minimizing