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Search Publications by: John Ladbury (Fed)

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Displaying 76 - 100 of 154

Measurements of Metamaterial-Inspired, Electrically Small Antenna Systems

March 2, 2009
Author(s)
Christopher L. Holloway, John M. Ladbury, Richard Ziolkowski, Peng Jin, Chia-Ching Lin
The paper discusses the analysis and measurements of electrical small antennas. The antennas discussed here are based on antenna designed from metamaterial inspired concepts. An electromagnetic reverberation chamber is used for the test of the antennas. A

Using Reverberation Chambers to Determine the Shielding Effectiveness of Physically Small, Electrically Large Enclosures/Cavities

November 20, 2008
Author(s)
Christopher L. Holloway, David A. Hill, Marco Sandroni, John M. Ladbury, Jason B. Coder, Galen H. Koepke, Andrew C. Marvin
With the proliferation of small electric devices in recent years, along with various other applications, there is a growing need to test and determine the shielding properties or shielding effectiveness (SE) of physically small (but electrically large)

Source Stirring Technique for Reverberation Chambers; Experimental Investigation

September 8, 2008
Author(s)
Galen H. Koepke, Christopher L. Holloway, John M. Ladbury, David A. Hill, Valter Primiani, Paola Russo, Carlo Monteverde
The paper shows the source stirring technique from an experimental point of view. This technique exhibits good statistics for S21. The results illustrate that the field in the cavity has very similar characteristics to the field in a reverberation chamber

Use of Reverberation Chamber to Simulate the Power Delay Profile of a Wireless Environment

September 8, 2008
Author(s)
Christopher L. Holloway, E Genender, Catherine A. Remley, John M. Ladbury, Galen H. Koepke, H Garbe
Multipath propagation environment effects, such as frequency-selective fading, have a strong impact on the quality of the wireless channel. For example, multipath can impact bit error rate (BER) differently than Gaussian noise. For testing wireless devices

NIST Tests of the Wireless Environment in Automobile Manufacturing Facilities

September 1, 2008
Author(s)
Catherine A. Remley, Galen H. Koepke, Chriss A. Grosvenor, John M. Ladbury, Dennis G. Camell, Jason B. Coder, Robert Johnk
This report describes tests carried out by members of the NIST Electromagnetics Division to study the wireless environment in automotive manufacturing facilities. Testing was performed at three facilities during 2006 and 2007. We studied an assembly plant

Measurements to Support Modulated-Signal Radio Transmissions for the Public-Safety Sector

April 1, 2008
Author(s)
Catherine A. Remley, Galen H. Koepke, Christopher L. Holloway, Chriss A. Grosvenor, Dennis G. Camell, John M. Ladbury, Robert Johnk, David R. Novotny, William F. Young, George Hough, Michael McKinley, Yann Becquet, John Korsnes
We report on measurements of parameters utilized for characterization of broadband wireless technologies proposed for use by emergency responders (firefighters, police, and emergency medical personnel) and other public-safety personnel. We designed a

On the Use of Reverberation Chambers to Simulate a Controllable Rician Radio Environment for the Testing of Wireless Devices.

November 1, 2006
Author(s)
Christopher L. Holloway, David A. Hill, John M. Ladbury, Perry F. Wilson, Galen H. Koepke, Jason Coder
With the proliferation of wireless devices in recent years, there is a growing need to test the operation and functionality of these various devices in different multipath radio propagation environments, ranging from a direct line-of-sight environment to a

Requirements for an Effective Reverberation Chamber: Unloaded or Loaded

February 1, 2006
Author(s)
Christopher L. Holloway, David A. Hill, Galen H. Koepke, John M. Ladbury
In this paper we present two versions of a threshold metric for the purpose of accessing the effectiveness of a reverberation chamber. One metric is based on the chamber quality factor (Q), and the other is based on the volume of the loaded reverberation

Challenges in Using a Reverberation Chamber for Probe Calibration

February 13, 2005
Author(s)
John M. Ladbury, Dennis Lewis, Galen H. Koepke, Randy Direen
We discuss some of the challenges associated with attempts to calibrate electromagnetic field probes in a reverberation chamber. These include immunity issues, problems related to the transient nature of the fields in a reverberation chamber, and